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Ethanol Production from Lignocellulosic Waste

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Ethanol production from lignocellulosic waste refers to the biochemical conversion of plant biomass, primarily composed of cellulose, hemicellulose, and lignin, into ethanol. This process typically involves pretreatment, enzymatic hydrolysis, and fermentation, aiming to utilize agricultural and forestry residues as sustainable feedstocks for biofuel production.
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Recent Trends in Gasification Based Waste-to-Energy.pdf
by Dr. Abdul-Sattar Nizami and 
1 more
Mohammad Rehan
Addressing the contemporary waste management is seeing a shift towards energy production while managing waste sustainably. Consequently, waste treatment through gasification is slowly taking over the waste incineration with multiple... more
Table 1. Types and sources of waste [2]. As shown in Table 1, the diversity of materials in the waste and complexity of separation leads to a variety of waste treatment options. Since no single waste treatment option can address all types of waste, hence different waste types attract different treatments. Source segregation has made it possible to separate waste streams that can be destined for a waste treatment facility. For example, in an MRF or waste-based biorefinery, most of the readily separable waste streams are separated for reuse and recycling such as metals, plastics, glass, aggregates,
“Negative sign indicates an exothermic reaction, and the positive sign indicates an endothermic reaction. ®nr = Not reported. There is a significant rise in urbanization that is commensurate with waste generation, thus waste energy through gasification became an obvious trend. Waste is attractive for energy recovery due to huge volumes produced in urban areas. However, waste is not uniform in quality, and its moisture content varies from season to season and between geographic locations. Waste gasification can also be integrated with biomass blending to deliver low carbon energy and chemicals. Gasification processes are extensively studied where researc- hers have tried to optimize the gasification conditions using thermal and catalytic treatments in order to enhance the gas quality by reducing the tar content in the syngas [26, 27], along with increasing the hydrogen content and reducing the processing steps to name a few. Furthermore, various studies have focused on the effect of gasifier types [28], effect of proce- ssing temperatures [29-31], effect of feedstock types and their particle sizes [31], effect of gasifying (oxidant) agents [30, 31], effect of the bed materials [32, 33], and combining gasifi- cation with other processes to enhance the process economics and efficiency. During gasifi- cation, various complex homogeneous and heterogeneous reactions take place; some of these are shown in Table 2.
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Assessment of Bioenergy Production from Solid Waste.pdf
by Dr. Abdul-Sattar Nizami and 
1 more
Mohammad Rehan
Biogas potential was explored for animal manure, wheat straw, food waste and rice straw. Batch experiments were performed at a laboratory scale using potential biomethane assays (BMP) for a period of 50 days. The biogas yield was observed... more
Figure 1. Feedstocks used in the batch experiments of AD
Figure 2. BMP bottles stored in oven at 37.5 °C and accordingly the DS contents by the expression of DS (%) = 100 x Wpm / Ws. The VS contents were determined by burning the dried samples at 550 °C in a muffle furnace for 12 hours. After, the weight of ash (Wash) was measured and accordingly the final VS contents by using the expression of VS (%) = (100 * (Wp - Wash)/ Wom. At the start of the experiment, the VS content of the feedstocks (VSs) was determined, whereas, the VS of the digested mixture (VSm) and inoculum (VSi) were determined after 50 days of the experiment. For feedstock’s VS contents, the standard expression of VSs - (VSm - VSi) was used. The biogas yield was measured daily in initial 2 weeks, then in the 3" week measurement was decreased to 2 days using a syringe technique [11]. The frequency was further reduced to every 3" day in the 4"" week and afterward in the 5" week 2 times and once in the last weeks. The composition of biogas was measured using a Gas Chromatograph (GC). ion
Figure 3. Biogas production (m*/Kg VSydaea) from animal manure, wheat straw, food waste and rice straw
Table 1. Different feedstocks and their rations with inoculum 2.3 Analytical methods
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MANAGING AND EVALUATING THE IMPACTS OF LARGE RESEARCH PROGRAMMES
by Trevor Wren BSc MA MPhil PhD MBA

2009

This research was funded by, and implemented within, a UK national research organisation, while the author was the KE and Impact Evaluation Manager responsible for assessing impact on a £15m UK government-funded research programme. This... more
earlier and later stages, linking idea generation to the marketplace:
TABLE 3.1: Grounding methodology and methods in literature best practice
Table 3.2: Three proposed methods within the methodology
TABLE 3.3: Analysis summary for each proposed method
2D analysis matrix with possible assessment ‘grades’ is exemplified in the table below.
TABLE 8.1: Complimentary aspects of the different methods
TABLE 10.1: Method improvements suggested after trial
data matrix analysis, gives the table below gives some case examples. information needed, and enable easier communication of the programme as a whole.
impact research and assessment may differ by impact mechanism (to be developed).
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Agricultural Residues (Wastes) for Manufacture of Paper, Board, and Miscellaneous Products: Background Overview and Future Prospects
by Prof Dr Yehia Fahmy and 
3 more
Prof Dr Tamer Y A Fahmy
Fardous Mobarak
Mohamed El-Sakhawy

2017

An extensive background overview on the use of agricultural residues (wastes) for production of paper, board, binderless board, energy, different types of fuels by pyrolysis (solid, liquid and gaseous fuel), many petrochemicals... more
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Evaluation of Biogas Production from the Digestion and Co-Digestion of Animal Waste, Food Waste and Fruit Waste
by Temitope F . AJIBADE and 
2 more
Fidelis O . AJIBADE
Ojo, O.M.

2015, International Journal of Energy and Environmental Research (IJEER)

The increased use of fossil fuels for energy consumption has causes environmental problems both locally and globally. The study investigates the anaerobic digestion in the production of biogas a renewable energy from the digestion and... more
Figure 1. Volume of Biogas of Waste against Number of Days
Figure 3. Temperature of Slurry for Waste against Number of Days Figure 3 shows the temperature of cow dung, fruit waste and food waste within the 30 days retention period. The temperature varies from 25.1°C - 28.4°C for cow dung, 24.4°C — 27.4°C for fruit waste and 25°C — 27.7°C for food waste. These temperature ranges signifies a mesophilic thermal stage of biogas production (25°C - 45°C). In this stage, the reaction of rate are slow because of the effect of the environmental temperature. The maximum biogas produced for each waste (cow dung, fruit waste and food waste) was attained at day 22, day 24 and day 30 in which the temperature for these days was 27.7°C, 26.9°C and 27.1°C respectively
_ Published by European Centre for Research Training and Development UK (www.eajournals.org) Figure 2. Volume of Biogas of C o-digestion Waste against Number of Days
Figure 4 indicates the temperature of the co-digestion of cow dung fruit waste, cow dung food waste and cow dung food and fruit waste. The temperature varies from 25.1°C - 27.4°C for cow dung and fruit waste, 25.2°C — 27.8°C and remained stable on day 15 to day 17 witha temperature of 26.3°C for cow dung and food waste and 25.4°C — 27.8°C for cow dung fruit and food waste. These temperature ranges also signifies a mesophilic thermal stage of biogas production (25°C - 45°C). The maximum biogas produced for each co-digestion (cow dung fruit waste, cow dung food waste and cow dung food and fruit waste) was attained at day 24, day 14 and day 19 in which the temperature for these days was 27.1°C, 26.4°C and 26.9°C respectively. Temperature has been observed by most biogas researchers to be quite critical for anaerobic digestion, since methane — producing bacteria operate most efficiently at temperatures 30.0 — 40.0°C or 50.0 — 60.0°C (Ilori et al., 2007). For this study, the six digesters operated under a mesophilic which is similar to the temperature of the work of Ukpai, and Nnabuchi, 2012. The temperature of below 30°C in which this experiment was operated, could have contributed to the slow development of methanogens and consequently low methane production. This is similar to the report of (Ilori et al., 2007) that the recovery time for biogas production as well as the quality and quantity of biogas produced from agricultural materials are a function of the nature, and composition of the digester feedstock. Figure 4. Temperature of Slurry for C o-digestion W aste against Number of Days pH of Slurry for each Waste and Co-digestion Waste
Figure 5. pH of Slurry for Waste against Number of Day and from this day, the pH reduced gradually for the whole retention period. The pH wa: within the range of 4.9 and 3.1 throughout the retention period. The pH range for food waste varies between 4.6 and 2.7, in which the decrease in pH also begins on the tenth day till the completion of the retention day. It was reported by Suyog 2011 that kitchen waste (fooc waste) pH decreases highly means reaction is fast, means hydrolysis and acidogenesis reaction is fast as organism utilize the waste more speedily than dung (Suyog, 2011).
Figure 7. Cumulative Volume of Biogas of Waste against Number of Days Figure 7 shows the cumulative of biogas produced from cow dung, fruit waste and food waste within the retention period 30 days. At the end of 30 days retention period the cumulative of 7975 ml, 7670 ml and 7742.5 ml biogas was produced from cow dung, fruit waste and food waste respectively with cow dung producing the highest biogas.
Figure 6. pH of Slurry for C o-digestion Waste against Number of Days _ Published by European Centre for Research Training and Development UK (www.eajournals.org)
Figure 8. Cumulative V olume of Biogas of C o-digestion W aste against Number of Days cow dung food and fruit waste respectively with co- digestion of cow dung and food waste producing the highest biogas.
Published by European Centre for Research Training and Development UK (www.eajoumals.org) Figure 9. Percentage of Biogas Produced
Table 1. Ratio of Waste and Water Used
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Trends and Sustainability Criteria for Liquid Biofuels.pdf
by Dr. Abdul-Sattar Nizami
Anthropogenic greenhouse gas (GHG) emissions are changing our Earth’s climate very rapidly and causing global warming phenomenon. There is a scientific, social, and political consensus that 20% of global GHG emissions are due to the... more
second-, and third-generation biofuels (Ragauskas et al. 2006). The classification of liquid biofuels and the potential production routes for bioethanol and biodiesel are shown in Figure 4.1. Raw materials used in biofuel production may come from forest, agriculture, and municipal or industrial organic wastes (Larson 2008; Nizami et al. 2015a,b,c; Ouda et al. 2016).
Figure 4.2 An example study showing that the production of both corn grain ethanol and soybean biodiesel results in positive net energy balance (NEB). Energy inputs and outputs are expressed per unit energy of a biofuel. All nine input categories are consistently ordered in each set of inputs, as in the legend, but some are so small as to be nearly imperceptible. Individual inputs and outputs of 20.05 are labeled. The NEB (energy output — energy input) and NEB ratio (energy output/energy input) of each biofuel are presented for both the entire production process (a) and the biofuel only (i-e., after excluding coproduct energy credits and energy allocated to coproduct production) (b) (From Hill, J. et al., Proc. Natl. Acad. Sci. USA, 103, 11206, 2006.)
Photosynthesis is a key component for survival of autotrophic algae, where they convert solar radiation and CO, into oxygen and adenosine triphosphate that are usable energy currency at the cellular level (Brennan and Owende 2010). This energy is converted to biomass and lipid material in microalgae. Lipid accumulation means an increased concentration of lipids within the cells of microalgae (Brennan and Owende 2010). An integrated system for biofuel production from microalgae includes the cultivation step with separation of the biomass from the growth medium along with succeeding lipid extraction for biodiesel production using a thermochemical process of transesterification. Following oil extraction, enzymatic hydrolysis leads to formation of fermentable sugars that can be converted into bioethanol through fermentation and distillation using the conventional ethanol distillation technology Dragone et al. 2010).
Figure 4.4 Schematic of a green biorefinery that also represents the biorefinery concept for first-generation biofuels. (Adapted from Naik, S. et al., Renew. Energy, 35(8), 1624, 2010.)
Figure 4.5 Schematic of a lignocellulose-based biorefinery that also represents the bio- refinery concept for second-generation biofuels. (Redrawn based on Naik, S. et al., Renew. Energy, 35(8), 1624, 2010.) Igure 4.5 Schematic of a lignocellulose-based biorefinery that also represents the bio-
Figure 4.6 Schematic presentation of the microalgae-based biorefinery concept for third- generation biofuels. (Reused from Venkata Mohan, S. et al., Algal biorefinery, in Biomass and Biofuels: Advanced Biorefineries for Sustainable Production and Distribution, 2015a, pp. 199-216; Venkata Mohan, S. etal., Bioresour. Technol., 102(2), 1109, 2015b. With permission.) AULOA), IVLALLY dled© species dloO PLOUUCE PIICTLYL GCLIVALIVES SUCTIL ds CdLOLCLIOINS, LOL~ penes, tocopherols, quinones, and phenylated pyrroles (Venkata Mohan et al. 2011). Algae can grow under diverse and varying environmental conditions that allow them to be used for wastewater treatment (Figure 4.6). Since algae have high CO, tapping and fixation ability, it can be utilized to reduce CO, emissions from power plants and other industries (Brown and Zeiler 1993). The algae biomass can be used for extracting oil and producing biodiesel. Algae synthesize different fatty acids such as medium-chain, long-chain, and very-long-chain species of fatty acids. Algae oil from the stagnant water bodies that were receiving domestic sewage showed 33 dif- ferent types of saturated and unsaturated fatty acids along with food and fuel features (Venkata Mohan et al. 2011). Oil content of some algae species is found to be 80% of
Figure 4.7 Venn diagram representing the three main components of criteria for sustain- ability of liquid biofuels. (Adapted from Remmen, A. et al., Life cycle management: A busi- ness guide to sustainability, UNEP and Danish Standards, 2007.)
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A simple rapid GC-FID method for the determination of ethanol from fermentation processes
by Yoram Gerchman
In the recent years, we have been facing an exponential increase in energy demand. To date, fossil fuels are the fuel of choice, but rise in costs, depletion of reservoirs and growing awareness to the environmental effects, have elevated... more
Figure 2. Calibration curve for n-BuOH in EtOAc. nBuOH, n-Butanol; EtOAc, ethyl acetate. Figure 1. Typical GC chromatogram exhibiting full resolution between EtOH (1.75 min), EtOAc (3.9 min) and n-BuOH (5.0 min). GC, Gas-chromatography; EtOH, ethanol; nBUOH, n-butanol; EtOAc, ethyl acetate.
Figure 3. Calibration curves for ethanol using with 1% v/v n-BuOH as an internal standard. nBUOH, n-Butanol.
Figure 4. Fermentation by ale yeast - % v/v EtOH vs. time. EtOH, Ethanol. REFERENCES
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Fruit Waste to Energy through Open Fermentation.pdf
by Dr. Abdul-Sattar Nizami and 
1 more
Mohammad Rehan
District heating networks are commonly addressed in the literature as one of the most effective solutions for decreasing the greenhouse gas emissions from the building sector. These systems require high investments which are returned... more
Figure 1. (a) Effect of different fruit waste on pectinase and lipase production from Penicillium expansum CM 39671 in SSF. (b) Effect of different nitrogen sources on pectinase and lipase production from P. expansum CMI 39671 in orange peel SSF. Coproduction of pectinase and lipase from mutant strain Penicillium expansum CMI 39671 were performed using various process conditions including different fruit waste feedstocks, nitrogen sources, pH, temperature, time and moisture conditions. Fruit wastes substrates such as orange peel, lemon waste, banana peel, papaya peel, and apple pomace, were used as energy source. The substrate provided pectin as an inducer of pectinase enzyme. The overall results on coproduction of pectinase and lipase from fruit waste are shown in figurel (a). The highest activities of pectinase (2817 U/g) and lipase (1870 U/g) enzymes were found with orange peel feedstock, whereas the lowest activities of 1662 U/g and 1266 U/g were found with banana peel and papaya peel feedstocks respectively. Figure 1(b) shows the effect of different nitrogen sources on enzymes production from the fungal strain. High concentration of nitrogen sources in fermentation and growth medium enhanced the microbial growth and enzyme production [10]. Peptone, yeast extract, corn steep liquor, beef extract, casein, ammonium sulfate, sodium nitrate and potassium nitrate were examined as nitrogen sources. Organic nitrogen sources enhanced pectinase and lipase production as compared to inorganic nitrogen sources. Highest pectinase and lipase concentrations of 2817 and 1870 U/g dry substrate respectively were achieved in peptone medium. Although, fruit waste contain proteins but supplemented nitrogen further improved the enzyme production.
Figure 2. The effect of (a) initial pH (4-9) with fermentation conditions of 72 h, 30 °C, 50% moisture, (b) fermentation temperature (25-60 °C with fermentation conditions of 72 h, initial pH of 7, 50% moisture, (c) fermentation time (1-7 days) with fermentation conditions of initial pH o 7, 50% moisture, and (d) effect of moisture contents (30 to 90%) with fermentation conditions of 5 days, initial pH of 7, on coproduction oi pectinase and lipase from P. expansum in solid state fermentation using orange peel and peptone as carbon and nitrogen source. The time course of pectinase and lipase production from Penicillium expansum using orange peel as a substrate | given in figure 2(c). Pectinase and lipase concentrations increased with fermentation period from | day up to 5 day and then started to decrease. The highest pectinase and lipase titers were 11657 U/g dry substrate and 7367 U/g dr substrate found on day 5, respectively. Both enzymes activities highest on 5th day suggest that enzyme production | growth dependent. The reason for the decrease in activity after Sth day could be due to decrease in pH (due t organic acids production), denaturation of pectinase and lipase and a decrease of available nutrients in th fermentation medium. Moisture concentration also plays a vital role in SSF, as can be seen in results (Figure 2d). T test the effect of moisture contents on pectinase and lipase activity during SSF, orange peel was moistened wit varying concentration of moistening agent (30, 40, 50, 60, 70, 80 and 90%) before fermentation. The results showe that 70% of moisture was optimal that gave maximum pectinase and lipase production rate of 13791 and 8114 U/ of the substrate, respectively. Increase or decrease of moisture content negatively affected the enzyme productio because of change in physical properties of the solid substrate. The porosity of solid substrates decreases wit increasing moisture content and consequently decreasing the gas exchange. Microbial growth and enzym production significantly decrease due to the reduction of moisture content J121].
Figure 3. (a) Comparison of sterile and nonsterile solid-state fermentations for coproduction of pectinase and lipase (b) Comparison of citrus pectin hydrolysis using crude extract and fermented solids At the end of SSF, fermented solid were collected from different rounds of fermentation and homogenized, and then air dried. Air dried fermented solids were directly applied in the saccharification of citrus pectin. In the routine, crude pectinase from submerged fermentation or crude extract or purified pectinase is applied in the hydrolysis of pectin. In this study, 2 set of experiments, including (1) using fermented solids, and (2) crude extract obtained from the fermented solids were tested and compared (Figure 3a,b). Results showed that reducing sugar content increased with the time in both experiments and there was no difference in the hydrolysis of pectin when fermented solids or crude extract was used in hydrolysis. Utilization of fermented solids saves enzyme recovery and purification cost.
Table 1. Chemical composition of substrates 3. Results and Discussion
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Wastewater Biorefinery Based on the Microbial Electrolysis Cell: Opportunities and Challenges.pdf
by Dr. Abdul-Sattar Nizami and 
1 more
Mohammad Rehan
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Waste-based biorefineries in developing countries: an imperative need of time.pdf
by Dr. Abdul-Sattar Nizami
The current world population of 7.2 billion is projected to reach up to 8.2 billion in 2025 with current annual growth rate of 1%. The Asia, Middle East, Africa and Latin America are the places, where most of this growth will occur due to... more
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Membangun Bangsa dan Negara Lewat Singkong/Ubi Kayu
by Arief Poyuono
Ini yang tidak mau dilakukan oleh pemerintaha .padahal tumbuhan ini sangat cocok di Indonesia ..menghasilkan energi dan pangan
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Environmental and Economic Benefits of Recovered Paper: A Case Study of Saudi Arabia.pdf
by Dr. Abdul-Sattar Nizami and 
1 more
Mohammad Rehan
District heating networks are commonly addressed in the literature as one of the most effective solutions for decreasing the greenhouse gas emissions from the building sector. These systems require high investments which are returned... more
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Energy, Economic and Environmental Savings by Waste Recycling: A Case Study of Madinah City.pdf
by Dr. Abdul-Sattar Nizami and 
1 more
Mohammad Rehan
District heating networks are commonly addressed in the literature as one of the most effective solutions for decreasing the greenhouse gas emissions from the building sector. These systems require high investments which are returned... more
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Comparative Analysis of Some Animal Wastes in Biogas Production Using Locally Constructed Mini-Digesters
by Fidelis O . AJIBADE and 
1 more
Kayode H . Lasisi

2017, African Journal of Renewable and Alternative Energy

This research compared biogas generated from three different wastes namely poultry waste, cow dung and rabbit waste. Three mini-digesters were locally fabricated to contain each of this waste. The parameters studied are the individual... more
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Lignocellulosic agriculture wastes as biomass feedstocks for second-generation bioethanol production: concepts and recent developments
by Jitendra Saini
Production of liquid biofuels, such as bioethanol, has been advocated as a sustainable option to tackle the problems associated with rising crude oil prices, global warming and diminishing petroleum reserves. Secondgeneration bioethanol... more
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Soil Quality Analysis for Dumpsite Environment in a University Community in Nigeria
by Fidelis O . AJIBADE

2016, Journal of Engineering and Engineering Technology (FUTAJEET)

Physicochemical analyses were carried out on soil samples from four different waste dumpsites in the Federal University of Technology Akure (FUTA), Nigeria to ascertain the effects of the refuse dumpsites on soil and groundwater... more
Figure la :Sampling location near the PG students’ hostel (Source: Google Earth, 2014)
Figure lc: Sampling location three close to 2 in 1 walkway, SEMS Extension (Source: Google Earth, 2014)
Figure 1b: Sampling location two near the senior staff quarters (Source: Google Earth, 2014)
Figure 1d: Sampling location four near the university health center (Source: Google Earth, 2014)
Table 1: Physical properties of soils from the four different locations Mean in a given row with the same letter were not significantly different at P< 0.05. Note: All units in % except where otherwise stated; bulk density (BD) in g/em’; WHC — Water Holding Capacity; MC - Moisture Content
Mean in a given row with the same letter were not significantly different at P< 0.05. Note: All units in mg/kg except where otherwise stated; ND — Not detected; pH is dimensionless, organic carbon (OC), organic matter (OM) and Nitrogen are in %; Electrical conductivity (EC) is in s/em. Table 2: Chemical properties of soils from four different locations
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Lignocellulosic Biomass: As Future Alternative for Bioethanol Production
by Manoj Kumar
Biofuels provide a potential and promising green alternative to avoid the global political instability and environmental crises that arise from dependence on petroleum. It has an important role to mitigate global warming and to conserve... more
Fig. 8.1 Mechanism of cellulase action (Lynd et al. 2002)
$6 Conclusion and Future Perspective
Table 8.1 Comparison between the two main fermentation techniques microorganisms that possess the ability to ferment both pentose as well as hexose sugars (Talebnia et al. 2010). To commercialize the lignocellulosic biofuel tech- nology, an ideal microorganism must fulfill the following criteria. These include: (1) wide substrate utilization (2) high ethanol yield (3) capable to bear high titre of ethanol and temperature (4) ability to withstand inhibitors or toxic by-products present in hydrolysate and have cellulolytic activity. Currently, C, sugars (hexoses) are readily fermented into bioethanol but bioconversion of C; (pentoses) sugars into bioethanol is a recent approach. Fermentation of pentoses along with hexoses is not common among microorganisms (Toivolla et al. 1984). The well-known microor- ganism S. cereviseaepossesses the ability to ferment only hexose sugar into bioethanol. Recently, novel microorganisms such as Pichiastipitis, Candida shehatae, and Pachysolantannophilus have been screened and characterized that possess the ability to ferment both C; as well as C, sugars into bioethanol. Thermophilic microorganisms are the ideal candidates for bioethanol production at the industrial level because they possess the ability to tolerate high temperature and toxic by-products formed during fermentation process. Currently, the main techniques that are usually involved in the fermentation of biomass hydrolysates are separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF). SSF is considered as a superior, cost-effective, and effi- cient technique for the production of bioethanol than SHF because it prevents the formation of inhibitory by-products and does not involve the use of separate reac- tors. However, any fluctuation in optimum temperature conditions of enzymes for hydrolysis and fermentation diminishes its efficiency (Neves et al. 2007). Buaban et al. (2010) reported that ethanol yield coefficient is higher under SSF than SHF because of more conversion of pentose sugar (xylose) into xylitol. Comparative study among these two techniques (SHF and SSF) is presented in Table 8.1. Apart from SSF or SHF, there are other alternative techniques which include consolidated
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Pretreatment of lignocellulose: Formation of inhibitory by-products and strategies for minimizing their effects
by Carlos Orestes Martín Medina
Biochemical conversion of lignocellulosic feedstocks to advanced biofuels and other commodities through a sugar-platform process involves a pretreatment step enhancing the susceptibility of the cellulose to enzymatic hydrolysis. A side... more
Fig. 1. Degradation products from lignocellulose as a result of pretreatment under acidic conditions. Numbers indicate fractions of constituents of wood of Norway spruce Red arrows indicate tentative formation pathways. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article Acid hydrolysis is one of the most promising pretreatment methods with respect to industrial implementation. It is usually performed with mineral acids, but organic acids and sulfur dioxide are other options. Dilute sulfuric acid pretreatment has been stud- ied for a wide range of lignocellulosic biomass (Yang and Wyman, 2008; Hu and Ragauskas, 2012). It results in high recovery of the hemicellulosic sugars in the pretreatment liquid, and in a solid cellulose fraction with enhanced enzymatic convertibility. Acid pretreatment has also some drawbacks, such as high cost of the materials used for construction of the reactors, gypsum formation
Fig. 2. Comparison of reactions effected by treatment of inhibitors with sulfur oxyanions (sulfite, dithionite) and sodium borohydride. While treatments of lignocellulosic hydrolysate with sulfur oxyanions or sodium borohydride were beneficial with regard to alleviating the inhibition of yeast, only the treatment with sulfur oxyanions was beneficial for alleviating inhibition of cellulolytic enzymes. This indicates that the hydrophilization of aromatic substances caused by sulfonation was essential for the positive effect on enzymatic hydrolysis.
Overview of pretreatment methods for lignocellulosic feedstocks prior to enzymatic hydrolysis of cellulose.
Overview of strategies to circumvent problems with soluble lignocellulose-derived inhibitors formed during pretreatment under acidic conditions. Table 2
This work was supported by a grant from the Swedish Research Council (621-2011-4388) and through the strategic research envi- ronment Bio4Energy (www.bio4energy.se).
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A polymorphic approach to policy analysis: a case study of Ontario's Ethanol in Gasoline Regulation
by Dragos Simandan

2015

This article develops a " polymorphic " approach to policy analysis, that is, an approach that draws on multiple forms of spatial reasoning. Specifically, the proposed framework deploys scale and network not merely as epistemological... more
Figure 1. An illustration of Canada’s corn-based balance of trade: trade in corn and corn goods dur- ing the period in focus in this article. Source: data from Agriculture and A gri-Foods Canada. Canadian Trade of Corn and Corn Goods
NB reasons for lack of participation for those who responded shown in italics. Table 1. Summary of response and participation rates.
Table 2. Describing the context within which the EGR was conceived and implemented.
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Bioconversion of food waste to energy: A review
by Antoine Trzcinski

2014, Fuel

ABSTRACT According to Food and Agricultural Organization (FAO), one third of food produced globally for human consumption is lost along the food supply chain. In many countries food waste are currently landfilled or incinerated together... more
Table 1. Typical wasted foods in several Asia-Pacific countries and around the globe. FW: Food Waste, T: ton, KT: Kilotons, MT: million tonnes, NR: not reported, a: Gustafsson, Wills [5]; b: Melikoglu, Lin [3]; c: Seng, Kaneko [6]; d: OECD [7]; e: Noor, Y usuf [8].
Total Solid, Total sugar, Starch, Cellulose, Lipid, Protein and Ash Contents were given in wt% on the basis of dry weight. Volatile solid contents were given as the %VS ratio or total solid basis. NR: not reported.
Table 3. Ethanol production from food wastes.
NR: not reported, FW: food waste, LAB: Lactic acid bacteria, RS: reducing sugar, Y : yield, P: productivity, Simultaneous: Simultaneous saccharification fermentation, Separate: Separate saccharification fermentation, fb: fed-batch.
FW: food waste, Y : yield, P: productivity, ASBR: anaerobic sequencing batch reactor, SBR: sequencing batch reactor, SS: seed sludge, HSSS: heat shocked seed sludge, US: Ultrasonication, d: day, min: minute; NR: not reported, NA: not applicable.
FW: food waste, SS: seed sludge, UASB: Upflow anaerobic sludge blanket reactor, SsF: simultaneous saccharification fermentation, MBR: Membrane bioreactor, LAB: lactic acid bacteria, NR: Not reported, NA: Not applicable.
FW: food waste, Y: yield, P: productivity, SmF: submerged fermentation, 11: specific growth rate, A.: Aspergillus, NR: Not reported.
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Biogasoline: An out-of-the-box solution to the food-for-fuel and land-use competitions
by Yahaya Sani

2015, Energy Conversion and Management

Societal developments are hinged on the energy supplied by fossil fuels. However, the supply of these fuels is finite in the foreseeable future. This is aside the associated environmental degradation and economic sustainability of these... more
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By-products resulting from lignocellulose pretreatment and their inhibitory effect on fermentations for (bio)chemicals and fuels
by Edwin van der Pol
Lignocellulose might become an important feedstock for the future development of the biobased economy.
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Developments in a sulphite pulping process for the valorisation of its carbohydrate resources within the biorefinery concept
by Dra. Tamara Llano Astuy
Dissolving cellulose is a low-yield chemical pulp (30-35 %) with a high alpha-cellulose content (91-93 %) and relatively low hemicellulose (1-10 %) and lignin (<0.05 %) content.Sugar-rich residual streams generated during sulphite pulping... more
‘ig. 1.7 Dissolving pulp end use segments, demand by end product and region (Flickinger et al., 2011). calculated by Flickinger et al. (2011) considering the total market. in large changes in dissolving pulp demand. The International Cotton Advisory Committee (ICAC) foresees the cotton acreage to be reduced from a historical trend of 33 million hectares to 32 million hectares by 2020 (Floe, 2011). The supply constraints of cotton are serious and the supply forecast for 2020 by ICAC would allow cotton to capture only a small portion of core demand growth leaving viscose fibres a significant market opportunity in substitution (Floe, 2011). Figure 1.7 shows the global demand of dissolving pulp distributed by region, common end uses and substituting products. Percentages of end-product and region graphs were calculated by Flickinger et al. (2011) considering the total market.
Following the steps of Figure 1.3, the first step is the pretreatment of the LCB, breaking down the structure of the lignocellulosic matrix, rendering cellulose and hemicellulose accessible for subsequent steps. Biomass pretreatment (BP) which overcomes the biomass recalcitrance, is a process to ameliorate the accessibility for carbohydrates prior to the hydrolysis reactions. An easy way to see the effect of the BP on the complex LCB structure is shown in Figure 1.4.
Throughout the steps described above (from section 1.3.1 pretreatment to section 1.3. ermentation) different hemicellulose and cellulose-derived products can b senerated together with lignin-derived byproducts. A summary of by-products i shown in Figure 1.5. The main applications of byproducts derived from the thre .CB macrocomponen ts are: (i) production of advanced materials, polymers an aromatic aldehydes in the case of lignin (Santos et al., 2011; Sanchez et al., 2008 uels, oxygen barrier films, food additives, thickeners, emulsifiers and even medica ises in the case of hemicelluloses (Canilha et al., 2013); binders, glues, explosives acquers, cellophane films, sponge products, paper or textile fibres in the case o rellulose (Coz, 2014).
Fig. 2.5 Laboratory digesters used to make the cooking trials. Some digestion trials at laboratory scale were done with the purpose of studying the operational variables affecting the final quality of pulp and composition. Cooking tests were carried out in two 1-L stainless s temperature and pressure control (see Figure 2.5). The contro aboratory digesters reproduces the industrial process ramps from to degasification and cooling stages. The end point is crucial to ob iquor fractions to control the change of the colour to determine the teel fain pulp. For this reason, digesters are also equipped with a liquid samp the point. This behaviour is due to the presence of furfural to predic hydrolysate vessels with system of the acid pre-heating high quality er to extract end cooking t the end of delignification (Sixta, 2006). After each experiment the hydrolysate and the cellulose pulp were analysed in terms of sugars, LS, furfurals, acids and kappa index, viscosity and alpha-cellulose content respectively.
Fig. 3.1 Acid sulphite pulping process.
temperature, pressure and time data are not displayed since they are confidential.
Final standards and sample chromatograms are represented in Figure 3.5. Peaks 1 to 13 correspond to: (1) cellobiose, (2) glucose, (3) xylose, (4) galactose, (5) fucose, (6) arabinose, (7) mannose, (8) formic acid, (9) acetic acid, (10) levulinic acid, (11) methanol, (12) HMF, (13) furfural. Biorad HPX-87P and Transgenomic CHO-782Pb columns were adequated to separate sugars. Major C6 sugars like glucose, galactose and mannose and major C5 sugars like xylose and arabinose could be integrated and separated in mixed standards and liquor samples. Biorad HPX-87H and Shodex SH- 1011 columns are not adequate for sugar quantification since peaks of galactose, mannose, and xylose co-eluted and overlapped and it was only possible to assume that peak belonged to xylose, the major sugar of the SSL samples. Nevertheless, HPX-87H and SH-1011 separate furfurals and carboxylic acids. Furfural and HMF are separated mainly by SH1011 column because it has lower detection limits.
Regarding lead-based columns, either CHO-782Pb or HPX-87P columns are adequate for measuring monosaccharides. However, CHO-782Pb operates at < wider pH range in comparison to HPX-87P. Taking into account that liquor samples in sulphite pulping are acidic (pH=1-3), using the HPX-87P column would make it necessary to neutralise the samples. 1011 has been chosen for this app regression coefficients and the wider the pH range and a correct separa furfurals is possible with this column Regarding the hydrogen-based columns, SH. ication because of the detection limits, the pH interval. This column can be used in all o: tion of organic aliphatic acids, alcohols anc . For all of these reasons both CHO-782Pb anc SH-1011 columns are recommend ed as a solution for the separation ot
Fig. 3.6 Characterisation of the weak spent liquor WSSL (results expressed in % w/w dry basis).
Fig. 3.7 Characterisation of the thick spent liquor (results expressed in % w/w dry basis).
i aANMS TERE GELLER LULA PERU EIUD GARR LIAL IME D UTIREE ALE BPI EUVELIICLELD VV ALLE TE OPEL LY the reference acid sulphite cook (26.7 g/L of total monosaccharides) in trials C2, C5 and C8 giving concentrations of 27.7 g/L, 33.9 g/L and 27.2 ¢/L respectively. There was a considerably jump from Cl (12.33 g/L) to C2 (27.7 g/L) caused by the increase of maximum temperature in 4 °C, demonstrating that the effect of maximum temperature affects the monosaccharides which are hydrolysed and dissolved in the spent liquors. Another cooking parameter that also affects the amount of monosaccharides is the cooking ramp. Making the comparison between C2 and C5 which have the same maximum temperature (1.03T) but different heating rates (R and 0.501R) it is also demonstrated that lowering heating rates promotes major release of sugars. C8 (1.072T, 0.285R) is the only trial from the three selected (C2, C5 and C8) that fulfills the dissolving pulp quality properties. Making the comparison with the reference sulphite cook, total sugars increased from 52.4 g/L to 59.7 g/L, reducing sugars from 29.6 g/L to 32.9 g/L and monosaccharides from 26.7 g/L to 27.2 g/L. Considering total monosaccharides as the best sugar determining method, it can be concluded that increasing the maximum temperature 8 °C and 0.074 °C/min the cooking ramp, total monomers dissolved in the spent liquors rises by only 1.87 % which is not cost effective for the P&P mill.
Fig. 3.12 Results of the major compounds of the spent liquors under different cooking conditions.
The kappa number is related to the delignification degree and it is correlated with the lignin content. A high kappa number implies a low degree of delignification which gives a low LS content in the liquor. This is due to the fact that LS have not been dissolved in the liquor and therefore they remain in the pulp. The intrinsic viscosity is related to the polymerisation degree and high viscosity involves a lower hydrolysis grade which gives a low presence of monosaccharides in SSL. All of these conclusions are corroborated in Figure 3.13; however, no correlation has been obtained in the two cases.
Figure 3.14 contemplates total monosaccharides (Figure 3.14-A) calculated as the sum of glucose, xylose and arabinose; total inhibitors (Figure 3.14-B) calculated as the sum of acetic acid and furfural; and glucose (Figure 3.14-C). Glucose was considered since concentrated hydrolysis is oriented to cel Concentrated hydrolysis attacks high recalcitrant and comparison with diluted acid hydrolysis that mostly attac ulose depolymerisation. crystalline polymers in ks hemicellulosic sugars. Glucose concentrations increase in the majority of cases. However, xylose and arabinose (C5 sugars) decrease and they contribute to a fal in monosaccharides.
Looking at Figure 3.15, experiments performed at 80 °C obtained increases in total monosaccharide (Figure 3.15-A) and xylose (Figure 3.15-C) contents. The best results increasing the total monosaccharides from 154.5 g/L to 166.7 g/L producing extra xylose (from 131.7 to 140.8 g/L) and glucose (from 14.2 g/L to 17.1 g/L) contents were obtained at 80 °C, acid-to-TSSL ratio of 10 v/v, 0.5 % w/w H2SOu, for 60 minutes.
from 7.85 to 7.80 g/L, and furfurals, from 0.27 to 0.20 g/L, was obtained.
Fig. 3.17 (A) Effect of pH over LS and sugar; (D) Effect of pH over furfural concentration. regarding sugar concentration and LS precipitation. increases the fermentability of the hydrolysates. Maximum LS precipitation occurs at pH 10 where the LS decrease from 421.9 to 260.4 g/L, phenolics from 12.60 to 8.0 g/L and furfurals from 0.27 to 0.076 g/L. However, acetic acid maintained its concentration at 7.80 g/L. The effect of pH is not as drastic as the effect of temperature. The treatment at 25 °C and pH 10 resulted in a better fermentability regarding sugar concentration and LS precipitation.
Cruz et al. (1999) concluded that phenolics derived from Eucalyptus globulus present high antioxidant and antimicrobial activities. Faustino et al. (2010) determined the radical scavenging capacity of kraft and sulphite liquors extracted with ethyl acetate at 1:3 v/v sample-to-solvent ratio giving AAI of 3.29 + 0.35 at pH 2 for sulphite liquors and 3.41 + 0.33 at pH 6 for black liquors. Looking at Figure 3.14-B, the best liquors and 3.41 + 0.33 at pH 6 for black liquors. Looking at Figure 3.14-B, the best
measuring the TPC in the extracts (see Table 3.10). The results of TPC and AAI demonstrate that chloroform and diethyl ether are the most efficient solvents among those that were tested. As Figure 3.21 indicates, there is a liner regression between the TPC and AAT as well as TPC and IPC expressed as the sum of individual phenolics obtained by HPLC/DAD. According to this, the effect of settling time, initial pH and sample-to-solvent ratio have been studied measuring the TPC in the extracts (see Table 3.10).
Fig. 3.22 Sequential L-L extraction and effects of the stage number on the TPC. The comprehension and discussion of the HPLC-DAD results have a special interest considering that phenolic hydroxyl groups vary significantly among hardwood species (Lai and Guo, 1991). Similar phenolics from litera presence of low molecular weight phenolic compounds and ellagic), aldehydes (syringaldehyde and sinapa ture were found with the like acids (gallic, vanillic dehyde) and flavonols (naringenin and quercetin) as well as ferulic acid, homovanillyl alcohol and syringic acid recently detected in Eucalyptus globulus species (Marq ués et al., 2009; Gonzalez et al., 2004). These kind of phenolic compounds are reported to have higher anti- oxidant and anti-microbial activity than others (Cruz et al., 2005). In addition, the major contribution of gallic acid and syringic acid in sulph by Marqués et al. (2009). ite liquors was confirmed
Phenolic compounds comprise an aromatic ring, bearing one or more hydroxyl substituents and range from simple molecules to highly polymerised compounds. Among the phenolic classifications appearing in literature, the Vermerris and Nicholson (2008) criteria used is based on the number of carbons in the molecu Phenolics derived from Eucalyptus globulus hydrolysates and dissolved into the SSL can be divided into: (i) simple phenolics like 1,2-dihydroxybenzene; (ii) phenoli acids such as gallic acid, p-hydroxybenzoic acid or vanillic acid and pheno e. ic ic aldehydes with the presence of an aldehyde group substituted on a phenol like 4- hydroxybenzaldehyde and syringaldehyde; (iii) cinnamic acids like caffeic acid and ferulic acid; (iv) hydrolysed tannins like ellagic acid; (v) flavonoids with two benzene rings linked by a group of three carbons like quercetin, luteolin, naringenin, rutin or isoharmnetin. substituents and range from simple molecules to highly polymerised compounds.
Fig. 3.24 (A) HPLC chromatogram of initial and detoxified SSL; (B) FTIR spectrum of initial and detoxified SSL. The results of the HPLC in Figure 3.24-B also show the difference between the detoxification of SSL with resin in series and the concentrated SSL. This chromatogram belongs to the sugar and LS analysis at the CHO-782 column. The first peak at 13.5-16 min corresponds to LS whereas peaks at 25.8, 28.5, 31.4, 35.6 and 38.1 min belong to glucose, xylose, galactose, arabinose and mannose. It can be seen how either LS or sugars give lower signals in the detoxified-SSL than in the original- SSL, caused by the simultaneous removal of LS and sugars. The most suitable detoxification treatment would be one that maximizes TIR while minimizing TSL.
Fig. 3.25 Detoxification pathways of lignocellulosic hydrolysates within the most common LCH fermentation scenarios. The first group of inhibitors corresponds to furfurals which inhibit the growth of yeast and decrease ethanol yield and productivity (JGnsson et al., 2013). This group is not problematic working with concentrated SSL since concentration of F and HMF correspond to 0.20 and 0.07 g/L respectively. More concentration of these inhibitors in necessary according to literature. There are studies demonstrating that furfural concentrations above 2 g/L stopped the cell growth of Pichia stipitis almost completely (Sainio et al., 2011), a concentration of 1.5 g/L gives a reduction of the 90 % of ethanol yield and 85 % of the productivity, whereas only 9.9 % of reduction is obtained in the case of using a concentration of furfural of 0.27 g/L (Nigam et al.,
Fig. 3.26 Block diagram with main steps of the sulphite P&P mill. The stages studied in this dissertation regarding industrial sulphite wood processing are represented in Figure 3.26. Currently, the enterprise Lignotech Ibérica reuses the LS from the SSL which constitutes 65 % (w/w on dry weight) of the spent liquors (Coz et al., 2015). Nevertheless, hemicellulosic sugars and other woody constituents are not being valorised.
purification of the sugar-substrate should be implemented. A diagram about the improvements and modifications of the sulphite pulping mill has been developed. Different models can be assayed and simulated, working with detoxification stages in series producing different qualities of sugar substrates able to adapt to market value-added product fluctuations. The complexity of such models depends not only on the substrate quality but also on the variety of wood compounds separated from the indutrial waste stream. In order to simplify the models, a diluted acid hydrolysis stage to improve hemicellulosic sugar depolymerisation and pH adjustment with a moderated neutralisation stage up to pH of 5.5 before sugars fermentation are recommended. In addition to the valorisation of the sugar substrate and depending on the main by-products (phenolics, acetic acid and lignosulphonates), different detoxification steps can be used: liquid-liquid extraction in the case of phenolics, overliming and/or anionic exchange resin when lignosulphonates are valorised and the use of adsorption with activated charcoal or anionic exchange resin in the case of acetic acid.
Table 1.1 Composition of lignocellulosic biomass feedstocks on % w/w dry weight.
Pretreatment of LCB is one of the main challenges in biorefinery and regarded as the most expensive step where the cell wall complex structure should be broken down for the availability of free cellulose. Theoretically, less than 20 % cellulose hydrolysis is done in the absence of pretreatment while it is about 90 % when pretreatment is game, & 7 7 = ee
Table 1.3 Summary of hydrolysis conditions, advantages and disadvantages (Verardi et Fernandes et al., 2015-a; Silva-Fernandes et al., 2015-b).
Table 1.4 Strategies for lignocellulosic hydrolysates detoxification.
2010; Mussatto and Teixeira, 2010; Olsson and Hahn-Hdgerdal, 1996). Nhi ITO 9e considered. For example, acetic acid inhibits the growth of yeasts in the ITO e decisions about the most adequate pretreatment and hydrolysis step depend yn the f uct uc eedstock, detoxification and fermentation of LCH change as a function of the of interest; therefore, different detoxification-fermentation scenarios should tion of either xylitol or ethanol (Parajé et al., 1998; Takahashi et al., 2013 whereas phenolics are problentafie for growth, of bacteria which produce succinic 01 oe a | ae ee ae: 1 i le a
Table 1.6 Review of pulping processs, qualities and operational conditions (INERIS, 2015; Salmenoja, 2012; Flickinger et al., 2011; Floe, 2011; Sixta et al., 2011; Teschke et al., 2011; OTA, 1989).
Table 2.1 Analytical procedures used in this thesis for wood, pulp and hydrolysate characterisation. * Total phenolic content was determined over the liquid extracts
Table 2.2 Preparation of the metal standards calibration curves. Dilution of the hydrolysate depends on the stage of the process where it is collected. Different samples were collected from the pulp mill at the end of digestion stage or after passing through the evaporation plant. Such samples are named respectively weak spent sulphite liquor (WSSL) and thick spent sulphite liquor (TSSL). Synthetic liquors obtained in the laboratory were also measured. Dilutions also vary as a function of the metal which is of interest: (i) WSSL is 50 times diluted for Ca and Fe analysis, 100 times diluted for Na and K and 2000 times diluted for Mg analysis; (ii) TSSL is 200 times diluted for Ca and Fe, 500 times for Na and K and 10000for Mg. Sample solutions were prepared using 25 yL of releasing agent per 25 mL of sample and ultrapure water. As the pH was acid, addition of hydrochloric acid was not required. Dilution of detoxified samples is quite different. It depends on the experimental assay varying from 1:50 to 1:5 for Ca and from 1:25 to 1:1000 for Mg.
Table 2.3 Stoichiometric factors used to calculate the percentage of theoretical homopolymer. 2.4.3 Weak phenolics in the Spent Sulphite Liquor by HPLC/DAD mass balance of the sample were calculated considering the stoichiometric factors of Table 2.3.
Table 2.4 Factorial design of concentrated acid hydrolysis. Table 2.5 Factorial design of diluted acid hydrolysis.
Table 2.6 Testing conditions and purpose of detoxification techniques assayed at laboratory 2.7.1 Evaporation The industrial multiple effect evaporation plant (MEEP) was reproduced a laboratory scale in a rotary evaporator (Heid olph, LR-4000), a vacuum pumg (Vacuubrand, MZ 2C NT) controlled by the vacuum controller CVC 3000. Pressure and temperature conditions, which are confiden tial data, were taken from the plant Ten samples corresponding to five concentrates (bottom phase) and _ five condensates (light phase) of each effect were co in triplicate. Solid concentrations at the bottom lected. Every sample was analysec phase were fixed according to the industrial plant; such concentrations were in every effect 10.0, 11.7, 14.4, 18.5, 27.¢ and 55.3 % w/w respectively.
Table 2.7 Physico-chemical properties of the selected solvents. After the determination of the two most efficient solvents, the effect of the initial pH values of the hydrolysate was studied. The pH values under investigation were: 1.5, 2, non-adjusted at 3.6, 4.5 and 6.5. In order to study the settling time on phenolics extraction, the resulting mixtures were left to separate at 10, 30, 150 and 390 minutes. The effect of hydrolysate-to-solvent ratio, for the two best solvents previously selected, was evaluated at four different ratios, i.e. 1:1, 1:2, 1:3 and 1:5 (v/v). The number of consecutive extraction stages was also studied.
Table 2.8 Studied parameters for liquid-liquid extraction.
Table 3.2 Operating column guidelines, standards and method conditions.
Table 3.3 Sugars and decomposition products of the spent liquors obtained by HPLC/RID. 4 Method : 0.5mL/min 0.05M H2SOsz (isocratic flow), 60°C, 20ul, 198psi
*Lignin data in SSL is the lignosulphonate content, derived from lignin sulphonation. Table 3.4 Total weight content of the industrial samples.
Table 3.5 Total carbohydrate content and biofuel potentials of the woody hydrolysates. « EtOH (L/Kg.dry sample) calculated from the homopolymers using hydrolysis and fermentation factors
Cooking time is standardised according to the equivalent energy employed tc obtain a final kappa index of 6 and taking into account loads of wood in the reacto1 of 173.14 g. The equivalent energy concept refers to the energy employed during cooking step and an approximation can be calculated as the area under the curve ot temperature versus time at constant temperature, excluding impregnation anc cooking ramps. In addition, it is necessary to consider that kappa index decreases one unit every ten minutes according to the industrial data. Therefore, there are three possible situations depending on the final kappa index: (i) kappa equal to 6. (ii) kappa lower than 6; or (iii) kappa higher than 6. The following equations (22 tc 25) were used for these situations:
Table 3.7 Pulp and SSL results under conditions tested.
Table 3.8 Removals and concentrations of SSL within five evaporation effects. Analysis of furfurals, formic and levulinic acids was undertaken but instead o removals, such woody constituents were concentrated throughout the evaporation effects giving increases of concentration of 37.2 % (furfurals), 26.0 % (formic acid and 53.1 % (levulinic acid) at the outlet of the fifth effect. Consequently, evaporation gets to remove some critical inhibitors but there are other woody constituents tha still remain in the spent liquor and have to be removed before fermentation.
Table 3.9 Detoxification by means of adsorption: influence of temperature, adsorbent and furfurals, 14-28 % of acetic acid or 88 % of total phenolics.
Table 3.10 Ion exchange resin experiments at laboratory scale. One of the advantages of ion exchange resins is their ability to be regenerated, recovering the LS and phenolics. Because of the conclusions of the results, the ability of the AR to be reused after cleaning and regenerating was determined. Figures 3.19- A and 3.19-B show the obtained results by subjecting the AR to 16 successive cycles. Regarding recovery efficiency of LS, acetic acid and furfurals (Figure 3.19-A), 16 cycles do not affect the selectivity of the AR towards LS, acetic acid and furfurals. However, low molecular phenolic efficiency decreases after seven cycles (Figure 3.19-B). Due to the fact that these compounds can be recovered from the regenerated solution for valorisation purposes because of their strong antioxidant capacities (Alexandri et al.. 2014). six evcles of rezeneration are recommended in this work.
Table 3.11 Effect of L-L solvent extraction variables in the two best solvents on the TPC
1 Concentrations < DL means below the detection limit Table 3.12 Individual phenolic compounds found in the extracts. Result comparison of the detoxification alternatives The complete list of individual phenolics detected by HPLC/DAD within five SSL extracts studied in the Agriculture University of Athens (AUA) is presented in Table 3.12.
Table 3.13 Summary of the best detoxification techniques. Ethanol potentials after detoxification at optimal conditions under equilibrium are displayed in Table 3.13. Such potentials were calculated considering the sugar losses resulted from each detoxification technique. From the mass balances of the whole process, untreated liquors resulted in 0.215 L.EtOH/Kg.dry.SSL calculated from the monomers (see Table 3.5). Looking at Table 3.13, ethanol potentials after detoxification were considerably ameliorated. The best results were 1.231, 1.818 and 1.799 L.EtOH/Kg.dry.SSL after detoxification with OV and L-L extraction with chloroform and diethyl ether. Such values are significantly higher than values of the
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The Potential for Grass Biomethane as a Biofuel, Compressed Biomethane Generated from Grass, Utilised as a Transport Biofuel.pdf
by Dr. Abdul-Sattar Nizami and 
1 more
Beatrice Smyth
Grass is an excellent energy crop due to long persistence of high yields accompanied by low energy inputs. Approximately 91% of Irish agricultural land is under grass. The national herd has decreased and will continue to do so. Cross... more
Table 4.6. Greenhouse gas emissions from digesters (Korres et al., 2010). yotent GHG than carbon dioxide. Methane losses where h/is heat loss (J /s), U is the overall coefficient of heat transfer (W/m2/°C), A is the cross-sectional area
Figure 1.1. Comparison of gross and net energy output of selected energy crop biofuel systems (Smyth et al., 2009; Korres et al., 2010). Gross energy is the energy produced in the form of transport fuel. Net energy is the gross energy less all the energy inputs to the system including for all the steps in the production of the crop and all parasitic energy demands in the production system. WDGS, wet distiller’s grains with solubles. ‘Grass biomethane, base case’ excludes the use of digestate as a fertiliser and uses gas to satisfy thermal parasitic demand. ‘Grass biomethane, digestate fertilizer’ allows for the use of digestate as a substitute for mineral fertiliser. ‘Grass biomethane, wood chips’ allows for woodchips to satisfy thermal parasitic demand.
Figure 2.1. Distribution of (a) perennial ryegrass, (b) Italian ryegrass, and (c) white clover in Irish grassland. Maps constructed based on data provided from the National Biodiversity Network Gateway (http://data.nbn.org.uk).
Figure 2.2. Effects of nitrogen fertilisation on the concentration of structural carbohydrates (cellulose and hemicellulose). Based on data from Keady et al. (2000).
Figure 4.1. Grass-to-biomethane system (Smyth et al., 2009).
Digestate yield: (t/year) Figure 4.2. Daily mass balance of anaerobic digester (Smyth et al., 2009). DS, dry solids; VDS, volatile dry solids; CSTR, continuous stirred tank reactor.
‘he government has set a target for 12% renewable 1eat by 2020 and has also stated that the public sector vill lead the way with the deployment of bioenergy eating (DCMNR, 2007). The residential sector is esponsible for the largest share of natural gas final nergy consumption, at 40.7% (SEI, 2009c). Twenty- ight per cent of houses have gas central heating O’Leary et al., 2008), with the highest proportion in Jublin, where there are almost 375,000 natural gas ‘ustomers or about 60% of national customers. \verage residential natural gas demand (weather orrected) in 2008 was 14.4 MWh (51.8 GJ) per \ousehold. The grass biomethane plant in this analysis ould fuel about 320 houses solely on biomethane or 665 houses on bioNG containing 12% renewable Figure 5.1. Comparison of heating costs for various systems (Smyth et al., 2010b). calculated using a heat cost comparison spreadsheet could fuel about 320 houses solely on biomethane or
OFMSW, organic fraction of municipal solid waste. Table 1.1. Strategy for meeting the target of 10% renewable energy in transport by 2020 (adapted from Singh and Murphy, 2009).
8D MI (dry matter indigestible): dietary fibre (sometimes called roughage) is the indigestible portion of plant food. >DMD (dry matter digestible): the percentage of the feed dry matter actually digested by animals; high-quality feeds have a DMD of over 65%, whilst feeds below 55% DMD are of poor quality. SADF (acid detergent fibre): estimation of cellulose and lignin content in a feed; the lower the ADF the higher the DMD (and metabolisable energy).
Yields of early, intermediate and late perennial ryegrass were reported equal to 16.7, 15.3 and 15 t DM/ha/ye respectively (Lockhart and Wiseman, 1988). Based on 0.18-0.34 m? CHa/kg dry matter (Pettigrew, 2000; Chynoweth et al., 2001; Samson, 2006). ‘Litres of methane (CH,4) per gram of volatile solids (Wilkie, 2008). PS, photosynthetic; DM, dry matter.
PRG, perennial ryegrass; CF, cocksfoot; MF, meadow foxtail; MIX, mixture; FM, fresh matter. Table 2.3. Comparison of fresh and ensiled grass characteristics in batch and continuously stirred tank reactor (CSTR) digesters (Nizami et al., 2009).
Table 2.4. Effects of pasture type on methane production (Prochnow et al., 2005). @Harvesting mid-May (before anthesis), end of May (anthesis), mid-J une (after anthesis), respectively. VDS, volatile dry solids.
Table 3.2. Comparison of process weaknesses and benefits of various digester types (Nizami and Murphy, 2010).
Table 3.3. Comparison of the optimal anaerobic digesters for grass silage (adapted from Nizami and Murphy, 2010). HRT, hydraulic retention time; OLR, organic loading rate; VDS, volatile dry solids; CSTR, continuously stirred tank reactor; DRANCO, DRy ANaerobic COnversion; UASB, upflow anaerobic sludge blanket.
Table 4.2. Size of the digester tanks and biomethane yield (Korres et al., 2010).
“Vata on energy consumption tor rolling and ensiling trom smyth etal. (2ZUU9). DF ertiliser is applied four times during the first year of the crop cycle and twice every subsequent year after each harvesting. Lime is applied at two intervals during the crop cycle, the first and fifth year after establishment dH erbicides are applied before ploughing and after sowing to favour crop-against-weed competition. Application is in the first year and twice during the rest of the crop cycle in the third and sixth year (corresponding values for energy consumption and related emissions are shown in parentheses). Transport and spreading were estimated based on the assumption that each load carries 16 t digestate; hence, 418 loads needed per year of which 250 were assumed, excluding empty return. The energy consumption for transport is assumed as 1 and 1.6 MJ /t/km, excluding and including empty return, respectively (Salter and Banks, 2009). Energy required for loading and spreading of digestate is assumed as 2.5 and 17 MJ /t, respectively (Power and Murphy, 2009). ‘Harvesting includes operations such as cutting, mowing and turning the grass. 9Ensiling comprises operations such as silage collection, unloading and inlaying. NT he firct number in the narentheses renresents values for the 3rd and 6th vear and the second number for the 5th vear. Table 4.3. Direct energy consumption and related carbon dioxide emissions during the 8-year crop cycle (emissions from diesel production are included) (Korres et al., 2010).
Table 4.4. Direct and indirect nitrous oxide emissions (Korres et al., 2010), Nitrogen and potassium have the highest percentages
Table 4.5. Indirect energy consumption and related carbon dioxide emissions during the 8-year crop cycle (Korres et al., 2010).
GHG, greenhouse gas. Table 4.7. Emissions in maceration, mixing and pumping activity during biogas production (Korres et al. 2010). The electrical demand for biogas scrubbing and compression ranges between 0.3 and 0.6 kWh/m? and 0.35 and 0.63 kWh/m? upgraded biomethane, respectively (Persson, 2003; EC, 2006; Murphy and Power, 2009a). A value of 0.35 kWh/m? is assumed for each operation, which equates to 317.7 MWh/year (8,318 MJ /ha/year) electricity demand. Approximately 172.4 t CO>e are emitted during the production of the
Table 4.8. Energy demand and greenhouse gas (GHG) emissions for biomethane production from grass silage under base-case scenario (adapted from Korres et al., 2010).
RES-T, Renewable Energy Supply in Transport; OF MSW, organic fraction of municipal solid waste. Table 5.1. Biomethane potential in Ireland in 2020 (adapted from Singh et al., 2010b).
AD, anaerobic digestion; CHP, combined heat and power. E+H, the sale of heat and electricity with no capital grant; G+E, the sale of electricity only with capital grant; G+E-+H, the sale o electricity and heat with capital grant. Table 5.3. Scenario 1: Grass to biogas to combined heat and power base-case economic analysis (Smyth et al., 2010b).
Table 5.4. Scenario 2: Biogas to biomethane to grid; tariff required for break-even (Smyth et al., 2010b)
There is a government target to achieve at least 800 MW, from CHP by 2020, with emphasis on biomass- fuelled CHP (DCMNR, 2007). The use of grass biogas in an on-site CHP plant struggles economically, due largely to the current tariff structure and the lack of heat markets in Ireland. However, there is potential for existing natural-gas-fuelled CHP plants to purchase renewable gas from the grid, with the advantages that the capital investment has already been made and there is generally a market for heat at existing plants.
Table 5.7. Break-even of compressed biomethane from grass silage as a vehicle fuel (Smyth et al., 2010b). The break-even price of compressed biomethane from grass varies between €0.078 and €0.132/kWh (Table 5.7). Excise duty is not charged on gas used as a propellant, but VAT at 21% has to be added (EC, 2010), giving a minimum selling price (i.e. break-even price) of between €0.096 and €0.163/kWh. The sale price of petrol and diesel lies within this range (Table 5.8). The price of CNG is significantly lower than that of petrol and diesel, meaning that The obvious stumbling block for the sale of biomethane as a transport fuel in Ireland is the absence of a market; there are currently only two natural gas vehicles in the country (NGV, 2009). The development of biomethane for transport in other
“Price of petrol and diesel is the price at the pumps (AA Ireland, 2010). >Price of compressed biomethane is the minimum selling price of grass biomethane. The highest and lowest prices from Table 5.8 are used. ‘In the absence of Irish compressed natural gas (CNG) prices, the prices in Austria, Germany and the UK (NGV, 2009) are shown for comparison. 4Bio-CNG price calculated using UK CNG prices and a blend of 10% biomethane/90% CNG. Table 5.8. Comparison of vehicle fuel costs (Smyth et al., 2010b).
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Conversion of residues from agro-food industry into bioethanol in Iran: An under-valued biofuel additive to phase out MTBE in gasoline
by Hamed Kazemi Shariat Panahi and 
1 more
Mona Dehhaghi

2020, Renewable Energy

It is obvious that Iran agricultural industry, unlike Brazil and USA, cannot afford to provide conventional biomass, i.e. sugary or starchy biomass for bioethanol production, mainly due to climatic and geographic conditions. With some... more
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Review on Pretreatment Methods and Ethanol Production from Cellulosic Water Hyacinth
by Shahabaldin Rezania
Lignocellulosic biomass resources are renewable materials that can be converted to fermentable sugars and subsequently into ethanol. Water hyacinth (Eichhornia crassipes) is a cellulosic aquatic plant that has high carbohydrates, low... more
Table 1. Composition of Different Lignocellulosic Biomass (Untreated Form)
Table 2. Composition of Water Hyacinth (Carbohydrates and Lignin) Different studies obtained different amounts of carbohydrates and lignin from WH biomass. Biotic and abiotic factors such as differences in species, growth state, and time of harvesting have also influenced carbohydrate and lignin content. As Table 2 shows, the cellulose content ranged from 18% to 35%, hemicellulose content ranged from 17% to 45%, and lignin content from 3% to 20%. Although the lignin content of WH shows some variation, the average is lower than other lignocellulosic materials, 17% to 40%, which makes it more suitable for ethanol production.
Table 3. Advantages and Disadvantages of Selected Pretreatment Methods
Table 4. Characterization of Different Types of Sugars in WH
Table 5. Recent Studies of Ethanol Production from WH
in com were N As shown in as been no pu pretreatment, moval. ts during fermentation, which n to wheat straw ( as reported by de Assis Castro et al. ot very favorable for pretrea and lignin re pariso of irradiation structu on the WH struc re that may reduce the amou isre (20 tment ture. Fo nt of ated to the higher 0%) as reported by Li et 16). Similarly, r instance, irradi reducing sugars i of WH. The reason cou ation can disrupt the cell moistu al. (201 microwav he evaluatio tion of water molecules wi re content of WH (25%) Table 5, although most studies used combined pretreatment met blished study regarding ethanol production from IL pretreated researchers mostly have focused on tl The reason might be due to the reac 6) and rice straw ( n WH bi omass. hods, WH. n of reducing sugars ith IL 0%) e-assisted pretreatments d be the negative effect wall
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Various pretreatments of lignocellulosics
by Harifara Rabemanolontsoa
Biomass pretreatment for depolymerizing lignocellulosics to fermentable sugars has been studied for nearly 200 years. Researches have aimed at high sugar production with minimal degradation to inhibitory compounds. Chemical,... more
Fig. 1. Changes in phase of pure water according to temperature and pressure.
Fig. 2. Proposed pathway of cellulose decomposition as treated by a flow-type supercritical water. Hot-compressed water, also known as liquid hot water, has been explored as a milder condition compared to sub- and super- critical water. With temperatures above 200 °C at various pressure conditions below the critical point, hot-compressed water presents The decomposition pathway of cellulose as treated by flow-type supercritical water at 380 °C/40 MPa/0.12-0.48 s is shown in Fig. 2 (Ehara et al., 2002). At first, cellulose is hydrolyzed to polysaccha- rides which degree of polymerization (DP) is in a range between 13 and 100. The obtained polysaccharides are further hydrolyzed to oligosaccharides with DP between 2 and 12. The reducing ends of the resulting oligosaccharides are then dehydrated to levoglu- cosan and fragmented to erythrose/glycolaldehyde as revealed by analyses with Matrix-Assisted Laser Desorption/lIonization-Time- of-Flight Mass Spectrometry (MALDI-TOFMS) analysis (Ehara et al., 2002). The non-reducing ends of the oligosaccharides are hydrolyzed to glucose, which, to some extent, can be isomerized to fructose. If the treatment is prolonged, the resultant hexoses may be decomposed to levoglucosan, 5-HMF, erythrose, glyco- laldehyde, methylglyoxal, and dihydroxyacetone by way of dehy- dration or fragmentation. The dehydrated and fragmented products can further be oxidized to low-molecular-weight organic acids such as pyruvic, lactic, formic and acetic acids. Under high supercritical temperature and pressure around 400-650 °C/28- 34.5 MPa, the biomass is gasified and the main products are Hp, CO, and CH, (Antal et al., 2000).
Culture conditions and performances of various cellulolytic, hemicellulolytic and/or ligninolytic microorganisms. C: cellulase, H: hemicellulase, L: ligninase. Table 1
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Renewable and non-renewable exergy costs and CO2 emissions in the production of fuels for Brazilian transportation sector
by Julio Da Silva and 
2 more
Daniel Flórez-Orrego
Julio A. M. da Silva
An exergy and environmental comparison between the fuel production routes for Brazilian transportation sector, including fossil fuels (natural gas, oil-derived products and hydrogen), biofuels (ethanol and biodiesel) and electricity is... more
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Grape Winery Waste as Feedstock For Bioconversions: Applying the Biorefinery Concept
by Myrto-Panagiota Zacharof
Grape wine is among the most important alcoholic beverages in the globe, with a continuously rising world demand, currently sizing at 25 billion litres. Such a large and heavily industrialised market calls for the maintenance of a steady... more
Table 2: Typical composition of winery waste wastewater [17,60,71,72]
Table 3: Indicative elemental composition of white and red grape marc(pomace) based on Romanian wine [59]
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Process design and sustainability in the production of bioethanol from lignocellulosic materials
by Felipe Scott and 
1 more
German Aroca
Background: Bioethanol is produced mainly from sugar cane and corn. In the last years it has been subject of debate due to the effects in food prices and land use change. The use of lignocellulosic materials for bioethanol production,... more
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Phytochemical Analysis of Alfalfa (Medicago sativa) Seed Extract by Soxhlet Extraction Using Different Solvents
by American Journal of Advanced Drug Delivery (AJADD)

2014, American Journal of Advanced Drug Delivery

According to a recent report nearly 42 per cent Indian kids are malnourished and stunted. The aim of our project was to develop nutraceutical products using alfalfa as one of the components to overcome undernourishment particularly... more
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DESIGN OF A 10 MILLION Litres /YR BIO-ETHANOL PRODUCTION PROCESS USING HYACINTH (EICHHORNIA CRASSIPES MARTIUS) AS FEEDSTOCK
by TINOTENDA KURWARA
Rising world fuel prices, the growing demand for energy, and concerns about global warming are the key factors driving the increasing interest in renewable energy sources, and in biofuels in particular. But some policymakers and analysts... more
DESIGN OF A 10 MILLION/YR BIO-ETHANOL PRODUCTION PLANT USING HYACINTH (EICHHORNIA CRASSIPES MARTIUS) AS FEEDSTOCK DESIGN OF A 10 MILLION/YR BIO-ETHANOL PRODUCTION PLANT
1.2: Problem statement
Figure 3: Hyacinth faming and harvesting (adopted from Burton, J., (2005) has seen these countries making use of a plant that had been considered to be a threat to their 1.4: Innovation
Table 1: Percentage composition of hyacinth. (Adopted from: Mosier et all, (2004)) 1.3.3: Hyacinth farming
Table 2: Budget for project 1.11.: Grant chart
Table 3: Gantt Chart
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COMPOSITE ACTIVATED CARBON FROM PLASTIC WASTE AND LIGNOCELLULOSIC WASTE MATERIALS
by AARF Publications Journals and 
1 more
Abdoul Ntieche Rahman
Composite activated carbons were prepared by physical activation methods from both synthetic polymer and lignocellulosic waste materials. The precursors were first carbonized at 600 °C in N2 atmosphere and then activated with steam at 850... more
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EXERGETIC ANALYSIS OF THE ETHANOL PRODUCTION BY ENZYMATIC HYDROLYSIS PROCESS FROM SUGARCANE BIOMASS
by Silvia Nebra
The aim of this study is to make an exergetic analysis of the ethanol production process, by enzymatic hydrolysis of sugarcane bagasse, integrated to the conventional process of ethanol production. Three cases were evaluated, which... more
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The imaginaries and governance of ‘biofueled futures’
by Kean Birch and 
1 more
Stefano Ponte
Since the 1990s governments in both the Global North and the Global South have been heavily promoting liquid biofuels and enacting policies as a result of concerns related to climate change mitigation, energy security, and rural... more
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Bioethanol production from woody biomass by recombinant Saccharomyces cerevisiae expressing thermostable enzyme
by Masjuki Haji Hassan

2008, 4th Kuala Lumpur International Conference on Biomedical Engineering 2008, Biomed 2008

Biomass is one of the major natural resources and biomass has always been a major source of energy for mankind and it is presently estimated to contribute of the order 10-14% of the world energy supply. The more efficient use of biomass... more
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Pretreatment of Macadamia Nut Shells with Ionic Liquids Facilitates Both Mechanical Cracking and Enzymatic Hydrolysis
by Leigh Aldous
The effect of ionic liquids upon the mechanical and (bio)chemical integrity of macadamia nut shells (from Macadamia integrifolia) has been investigated. Whole macadamia nuts-in-shell are notoriously difficult to crack, and the Australian... more
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Analysis of by-product formation and sugar monomerization in sugarcane bagasse pretreated at pilot plant scale: differences between autohydrolysis, alkaline and acid pretreatment
by Edwin van der Pol
Sugarcane bagasse is an interesting feedstock for the biobased economy since a large fraction is polymerized sugars. Autohydrolysis, alkaline and acid pretreatment conditions combined with enzyme hydrolysis were used on lignocellulose... more
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Direct Alcohol Alkaline Fuel Cell as Future Prospectus
by Advanced Energy: An International Journal (AEIJ)
Fuel cells are called the fourth electricity power generation after water, nuclear power generation devices.Fuel cells are widely recognized as very attractive devices to obtain directly electric energy from the electrochemical combustion... more
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Production of ethanol from Parthenium hysterophorus L. through dilute acid hydrolysis with varying environmental condition and fermentation using Pichia stipitis
by Shubhaneel Neogi
Production of Bio-ethanol as fossil fuel supplement from biomass of the waste land weed Parthenium hysterophorus L. which causes reduction of biodiversity and crop production drastically because of its high regeneration capacity, high... more
Fig. 1: Xylose yield from Parthenium biomass in three different concentration of sulphuric acic at 190 °C, 210 °C & 230 °C for 10 min treatment; (a) 0.35 mm, (b) 0.95 mm & (c) 1.78 mm particle size respectively. Various environmental conditions of pretreatment on different particle size of Parthenium hysterophorus L using dilute concentrations of sulphuric acid for the extraction of xylose and other pentoses as well as hexoses from lignocellulosic biomass has been studied successfully.
treatment of 0.95 mm particles of Parthenium biomass, the use of 5% H2zSO, has increased xylose yield to 61.7 mg/g with similar increase of total reducing sugar to 115.5 mg/g at 121 °C for 15 minutes as pointed up in Fig. 3 which is more than that of the farnace treatment time as in Fig. 1. Fig. 2: Xylose yield and total reducing sugar from 0.35 mm particle size of Parthenium biomass in different concentration of sulphuric acid at 121°C and 15 Ib. pressure.
Fig. 3: Xylose yield and total reducing sugar from 0.95 mm particle size of Parthenium biomass in different concentration of sulphuric acid at 121°C and 15 lb. pressure.
Fig. 4: Xylose yield and total reducing sugar from 1.78 mm particle size of Parthenium biomass in different concentration of sulphuric acid at 121°C and 15 lb. pressure.
Successful Fermentation was achieved wielding the optimum particle size of Partheniun: biomass, pre-treated with efficient moist heat environment of Fig. 3. Pichia stipitis is able tc exploit both hexose & pentose sugars. Growth pattern of Pichia stipitis in hydrolisate depict: the consumtion of hexose before assimilation of pentose sugar, xylose. Consumable hexos« was initially exploited within 9 hours to achieve the stationary phase. Fig. 5 demonstrates tha after completion of 12 hours, Pichia stipitis started utilization of xylose in order to survive and rendered further growth via pentose phosphate pathway to attend maximum growth at 1 hours.
Fig 6: Ethanol yield with the reduction percentase of sugars.
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Ethanol fermentation in an immobilized cell reactor using Saccharomyces cerevisiae
by Najafpour Prof. Ghasem and 
1 more
Habibollah Younesi
Fermentation of sugar by Saccharomyces cerevisiae, for production of ethanol in an immobilized cell reactor (ICR) was successfully carried out to improve the performance of the fermentation process. The fermentation set-up was comprised... more
Fig. 1. Schematic diagram of ICR experimental setup.
Fig. 2. Electronic photomicroscope of the outer surface of immobilized S. cerevisiae beads: (a) outer surface of the fresh beads with magnification of 300 pum; (b) outer surface of the fresh beads with magnification of 2000 tm; (c) outer surface of the used beads after 72 h with magnification of 300 um; (d) outer surface of the used beads after 72 h with magnification of 2000 um.
Fig. 3. Electronic photomicroscope of the inner surface of immobilized S. cerevisiae beads: (a) inner surface of the fresh beads with magnification of 300 tm; (b) inner surface of the fresh beads with magnification of 2000 tm; (c) inner surface of the used beads after 72 h with magnification of 300 pum; (d) inner surface of the used beads after 72 h with magnification of 2000 um.
Fig. 4. Glucose concentration, cell density and production of ethanol in batch fermentation with initial concentration of 50 g/l glucose versus time.
Fig. 5. Kinetic model for batch fermentation, Langmuir—Hanes plot.
Fig. 6. Relative activities of S. cerevisiae in batch fermentation.
Fig. 7. Percentage, growth of immobilized cell with various initial beads loading.
Fig. 9. Conversion versus retention time in immobilized cell column. Fig. 8. Consumption of glucose in immobilization cell column. tively. At high concentration of sugar, conversion was highly influenced by dilution rate. The conversion de- creased to less than 10% once the dilution rate ap- proached wash out. The sugar conversion at low sugar concentration appeared to be much less sensitive to feed dilution rate. The conversion for 25 g/l glucose was constant at 74% for a retention time of greater than 3 h (Fig. 9). The trend of the data with 50 g/l sugar showed that conversion increased with respect to retention time. At a higher sugar concentration, it required a longer retention time to achieve higher conversion.
Fig. 11. Glucose concentration and ethanol production versus reten- tion time in ICR with initial substrate concentration of 150 g/l glucose. Fig. 10. Ethanol production versus retention time in immobilized cell column. ality factor may have increased while the substrate concentration was increased. As the sugar concentration was doubled, the slope of the line for ethanol produc- tivity with 50 g/l sugar was increased 5-fold. These re- sults indicated that the ICR column has high capacity to produce very high concentrations of ethanol. The final ethanol concentrations with 25 and 50 g/l of glucose were 7.6% and 16.73% v/v, respectively.
Physical properties and appearance of S. cerevisiae beads Table 1 such as overgrowth and expansion of beads diameter when grown in sugar solution. The high alginate beads (6%) were very hard and almost unbreakable by pressing manually. It was very rigid therefore diffusion was the most probable cause since ethanol production declined. The 2% alginate was used since the beads were strong enough to hold the weight of packing in the ICR col- umn. The packed beads were used in ICR column for the duration of 10 days. The prepared beads were refrigerated for two weeks and activated in sugar solu- tion. The storage condition and ICR column were non- sterile; therefore, there were chances of contamination in the packing of ICR and in activation process. sole carbon source for S. cerevisiae. The purpose of batch experiment was to compare the amount of glucose concentration and ethanol production in batch fermen- tation and immobilized cells reactor (ICR). The con- centration of glucose was gradually decreased while the cell density and ethanol production were increased for a duration of 27 h, shown in Fig. 4. There was a lag phase of 4-6 h; the glucose consumption was low at this stage. Subsequently the concentration profile markably de- creased during batch fermentation after 8-16 h. Since the cell density was initially low the trend of sugar consumption was also low. The resulting cell growth curve from batch experiment was a typical sigmoidal shape (S-shape). The maximum cell density of S. cere- visiae in batch fermentation was 13.7 g/l with 50 g/l glucose concentration. The average yield of biomass and product on substrates (Yx s and Yp/s) were 33% and 32% respectively. The rate of ethanol productivity for 24 h was 1.4 g/lh.
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Impact of cellulase production on environmental and financial metrics for lignocellulosic ethanol.pdf
by Dr. Abdul-Sattar Nizami and 
2 more
Heather Maclean
B. Saville
The cost of cellulases remains a key issue in the production of cellulosic ethanol, and the impact of enzymes on greenhouse gas (GHG) emissions of cellulosic ethanol has received little attention. This study evaluates life cycle emissions... more
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Comparative study on chemical composition of various biomass species
by Harifara Rabemanolontsoa

2013, RSC Advances

In this study, the chemical composition of 32 samples coming from 29 different biomass species including a gymnosperm, 2 dicotyledonous angiosperms, 17 monocotyledonous angiosperms and 9 algae species was successfully determined using an... more
Fig. 1 Simplified evolution and diversity of various biomass species. '7 Woody biomass was analyzed according to wood analytical procedures,” ‘* whereas agricultural residues, grass species”
Fig. 2 Analytical method applied to various biomass samples to quantify their chemical composition.'®
Fig. 4 PCA score plot for the 32 biomass samples characterized by their contents in cellulose, hemicellulose, lignin, protein, extractives, starch and ash.
Fig. 3 FT-IR spectra of crude Klason lignins from algae species as compared to the one from Japanese beech (Fagus crenata). Fig. 4 shows the resulting scatter plot using the scores of the first 2 principal components, preserving 44.6 and 23.6% of the total variance, respectively. Woody biomass represented by Japanese cedar (No. 1) and Japanese beech (No.2) were relatively close in the clustering but appeared to be respectively quite apart from the other samples. The monocotyledonous terrestrial plants including Gramineae (No.4-No.15) and palm species (No.16-No.18) built a relatively compact cluster, while the other samples were rather diverse. The monocotyledonous aquatic plants (No.20-No.23) formed an intermediate cluster between the higher plants and the lower ones. The algae species represented by Cryptogamae (No.24-No.31) and Eubacteria (No.32) samples formed a different cluster on the
Fig. 5 Chemical composition of various biomass species in relation with their taxonomic classification. From Fig. 5, it became more obvious that chemical composition of the lower plants is very different from the higher ones. In the lower plants including Heterokontophyta, Chlorophyta, Rhodophyta and Cyanophyta, the carbohydrates are characterized by the inexistence or low range of cellulose but high hemicellulose content with acid sugars. Such a
* Cellulose = a-Cellulose. ? Hemicellulose = Holocellulose - a-Cellulose (Holocellulose was ash, lignin and protein-corrected). Table 2 Chemical composition and calorific value of the various biomass samples studied
“ Gle : Glucose, Man : Mannose, Gal : Galactose, Rum : Rhamnose, Fru : Fructose, Xyl : Xylose, Ara : Arabinose Table 3 Monosaccharides composition of the biomass samples studied (g kg~! of the original oven-dried biomass basis)?
Table 4 Molar ratio of syringaldehyde and p-hydroxybenzaldehyde to vanillin in the biomass samples studied as determined by alkaline nitrobenzene oxidation
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From lignocellulosic metagenomes to lignocellulolytic genes: trends, challenges and future prospects
by Jorge Folch-mallol and 
1 more
Paola Talia
Lignocellulose is the most abundant biomass on Earth with immense potential to act as a primary resource for the production of a range of compounds currently obtained from fossil fuel sources. However, lignocellulosic feedstocks remain... more
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Low Cost Fermenter for Ethanol Production from Rice Straw in Egypt
by Assem A . A . Mohamed
In Egypt, significant emissions arise caused by rice straw burning on the field. The total amount produced yearly about three million Mg, essential nutrients and organic matter are lost. The combined energy and material utilizations of... more
HCE MICHIUCH [VWEAMULACUULE LS A fermenter or bioreactors is a container designated to provide an optimum environment in which mi- cro-organisms or enzymes can in- eract with a substrate and perform the desired products. Batch fer- menter design was carried out using fermenter design software version 4.0, and solid state fermentation bio- reactor fundamentals of design; also hand- book operation, fermentation monitoring, design, operation and biochemical engineering II course notes. Two fermenters were built as ollow: First fermenter 20 litres ca- pacity, with the following features: capacity 20 litres double cool and heat jacket, control panel, electric voltage and temperature indica- or. The fermenter has five props to measure solution PH, temperature, dissolved oxygen, pressure outlet and material inlet hole, also, fer- menter equipped with three sample valves and drain valve from bottom side. Second fermenter specifica- tions are: capacity 300 litres, double cool and heat jacket to control opti- Based on this composition and
Table 1 Rice straw: chemical composition
Table 2 Chopper and milling machine costs per hour Source: Central Laboratory for Agricultural Climate (CLAC), CEMUWA project 3145, ARC, Egypt, 2013.
Table 3 Material energy consumption and costs
Table 4 Total investment costs for small scale fermenter mum temperature required by two electric sensors, electric control panel, electric voltage, overload control, fermenter has five props to measure fermenter temperature, materials PH, stirrer and gas out-let, as shown in (Fig. 1).
Table 5 Cost analysis of ethanol production from rice straw first scenario (300 litres capacity)
Table 7 Cost analysis of ethanol production from rice straw second scenario (600 litres capacities)
Table 6 Total return for first scenario (300 litres capacity)
Table 8 Total return for second scenario (600 litres capacity)
Table 9 Cost analysis of ethanol production from rice straw third scenario (900 litres capacities)
Table 12 Operational costs (USD)
Table 11 Investment and replacement costs (USD)
Table 10 Total return for third scenario (900 litres capacity)
Table 13 Total project cost (USD)
Table 14 Total project return (USD)
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Lignocellulosic Biomass: As Future Alternative for Bioethanol Production
by Manoj Kumar and 
1 more
Tanveer Bilal
Abstract Biofuels provide a potential and promising green alternative to avoid the global political instability and environmental crises that arise from dependence on petroleum. It has an important role to mitigate global warming and to... more
Fig. 8.1 Mechanism of cellulase action (Lynd et al. 2002)
$6 Conclusion and Future Perspective
Table 8.1 Comparison between the two main fermentation techniques microorganisms that possess the ability to ferment both pentose as well as hexose sugars (Talebnia et al. 2010). To commercialize the lignocellulosic biofuel tech- nology, an ideal microorganism must fulfill the following criteria. These include: (1) wide substrate utilization (2) high ethanol yield (3) capable to bear high titre of ethanol and temperature (4) ability to withstand inhibitors or toxic by-products present in hydrolysate and have cellulolytic activity. Currently, C, sugars (hexoses) are readily fermented into bioethanol but bioconversion of C; (pentoses) sugars into bioethanol is a recent approach. Fermentation of pentoses along with hexoses is not common among microorganisms (Toivolla et al. 1984). The well-known microor- ganism S. cereviseaepossesses the ability to ferment only hexose sugar into bioethanol. Recently, novel microorganisms such as Pichiastipitis, Candida shehatae, and Pachysolantannophilus have been screened and characterized that possess the ability to ferment both C; as well as C, sugars into bioethanol. Thermophilic microorganisms are the ideal candidates for bioethanol production at the industrial level because they possess the ability to tolerate high temperature and toxic by-products formed during fermentation process. Currently, the main techniques that are usually involved in the fermentation of biomass hydrolysates are separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF). SSF is considered as a superior, cost-effective, and effi- cient technique for the production of bioethanol than SHF because it prevents the formation of inhibitory by-products and does not involve the use of separate reac- tors. However, any fluctuation in optimum temperature conditions of enzymes for hydrolysis and fermentation diminishes its efficiency (Neves et al. 2007). Buaban et al. (2010) reported that ethanol yield coefficient is higher under SSF than SHF because of more conversion of pentose sugar (xylose) into xylitol. Comparative study among these two techniques (SHF and SSF) is presented in Table 8.1. Apart from SSF or SHF, there are other alternative techniques which include consolidated
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Ethanol fermentation in an immobilized cell reactor using Saccharomyces cerevisiae
by Habibollah Younesi

2004, Bioresource Technology

Fermentation of sugar by Saccharomyces cerevisiae, for production of ethanol in an immobilized cell reactor (ICR) was successfully carried out to improve the performance of the fermentation process. The fermentation set-up was comprised... more
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Assessment of Pre-Treatment Methods for Bio-ethanol Production from Sugarcane Bagasse
by Michael Short and 
2 more
Adeniyi Isafiade
Joanne Crimes
Lignocellulosic biomass such as sugarcane bagasse is non-food biomass that can be used to produce ethanol. Lignocellulose is a complex network of cellulose, hemicellulose and lignin, which requires pre-treatment to improve access to... more
Various bioproducts can be obtained from biotransformation of pre-treated lignocellulosic materials. Garcia et al. (2013) used Aspen Plus to evaluate some of these biotransformations. The authors also simulated the separation and product recovery stages. Chiaramonti at al. (2014) presented a review of biofuel producing plants in the United States of America and the European Union. The authors found that most of these plants use lignocellulosic biomass as their feedstock. They also found that biochemical based processes were dominant, however thermo-chemical biofuel processes were also coming on stream. Bio- ethanol production from lignocellulosic biomass can be divided into a few process steps: pre-treatment, hydrolysis, fermentation and separation. Figure 1 below shows a block flow diagram of a bio-ethanol plant.
The following pre-treatment methods were selected for modelling in this study: steam explosion (un: catalysed and acid-catalysed) and acid pre-hydrolysis. The pre-treatment was followed by an optiona delignification unit which uses NaOH to remove lignin. Hydrolysis could use either acid or enzymes. Figure 2 below shows the superstructure used in this paper. In order to perform a true simultaneous optimisation of the pre-treatment flowsheet the superstructure shown in Figure 2 above needs to be programmed using optimisation software, such as GAMS (GAMS, 2013), so that all possible options can be compared simultaneously in terms of both economic and environmental objectives. For a network involving many choices of unit operations, and thus many binary variables, a sophisticated optimisation procedure is needed. To use this approach, GAMS models with fixed topologies would be solved individually as mixed integer non-linear programs (MINLPs) and used to initialise the overall superstructure MINLP which would then be solved using MipSyn (Kravanja, 2010). However, solving the initial fixed flowsheets was time consuming and the overall superstructure in MipSyn could not be completed. As a result, a more sequential approach was used for the flowsheet optimisation, and is presented in this paper. The sequential method involved decomposing the superstructure (Figure 2) into eight separate flowsheets 2. Methodology
can be seen on Figure 3 as the points that contain ‘H2’. Figure 3 below shows how much larger the environmental impact of models using enzymatic hydrolysis for models using scenario H1 is, even though on-site enzyme production was considered. By using scenario H2, the El of enzymes decreased significantly and enabled the enzymatic hydrolysis models to be competitive with the acid hydrolysis models from an environmental perspective. Often the two optimum points for enzymatic models are close together because the enzyme flowrate cannot be reduced significantly and the profit and El cannot change significantly. Figure 3: Solution space for pre-treatment flowsheets considering two enzyme production methods
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CMTC-150673-PP Analysis of Biofuel Policy and Efficiency Towards Greenhouse Gas Reduction
by Marc Petrequin
The use of fossil fuels for transportation represents one of the largest anthropogenic contributions to greenhouse gases (GHGs), and the need for clean, renewable, alternative fuel sources has become a global priority. It is no wonder... more
However, as with any renewable energy source, bio uel technology brings ancillary costs to any country promoting its use, and numerous studies have questioned the overall efficiency of biofuel in regards to GHG reductions. In addition to the sheer amounts of land and wa inflate global food prices), biofuel production requires fossil f studies point out that many biofuel crops rely on nitrogen fer er required to grow biofuel crops (which can further uels for nearly every step of the process. Other case ilizers that emit significant amounts of nitrous oxide (N20), a GHG many times more potent than COs, potentially undermining if not altogether eliminating any environmental benefit conferred (Keyzer et al., 2008). Addressing these concerns will require analysis of the policies behind biofuel production trends, the production me displacement therein. hods of different regions, and the relative GHG
Figure 3: Historic and Required Ethanol Use under the 2005 Energy Policy Act (Wang et al, 2007) amended standards acknowledged the heterogeneity in biofuels and provided incentives for cost reductions, the suffered the same inefficiency of most policies based on upper-bound standards: they offered no incentive for tl development of advanced biofuel technologies beyond those needed to meet the threshold requirements. Consequently, while biofuel production continues to rise with federally inflated demand, the efficiency of such fuels remains at a relatively stagnant margin (Hochman et al., 2010).
DIVIUG! VPIVUQUCLION Call US UIVIUCU L into four phases: 1) biomass production (cultivation), 2) pretreatment, storage, and transport of crops to a conversion plant, 3) conversion into biofuels, and 4) transport and distribution to gas stations (Hoefnagels et al., 2010). Each phase of the process requires energy and consequenily contributes to GHG emissions, with the largest contributions occurring during production and conversion. Total energy use in production must also account for the production and application of fertilizers and agro-chemicals (see Figure 4) (Hoefnagels et al., 92010).
Figure 5: GHG Emissions of Various Biofuel Crop Production (Hoefnagels et al., 2010) emission from rapeseed methyl ester (RME) production can be almost twice as high as fossil diesel, 140 g CO>- per megajoule RME, if cultivated in East Europe, but only 17 g COz-e per megajoule RME if cultivated in Wester Europe. Their results showed that Brazilian eucalyptus had the lowest energy requirement for producing biodiesel due to high crop yields and limited fertilizer inputs. All second-generation biofuels (from lignocellulosic crops) had higher efficiency yields than oil, sugar, and starch crops (see Figure 5) (Hoefnagels et al., 2010).
Table 1: Comparison of Fossil Energy and GHG Improvement of Various 1* Generation Biofuels (M enichetti, 2009)
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A Multiobjective Optimization Framework for Design of Integrated Biorefineries Under Uncertainty
by Aryan Geraili
A systematic approach for development of a reliable optimization framework to address the optimal design of integrated biorefineries in the face of uncertainty is presented. In the current formulation, a distributed strategy which is... more
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