VAIBHAV NAIK

Mumbai, MECHANICAL, Faculty Member

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Address: Thane, Maharashtra, India

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Indian Institute of Technology Delhi

University of Idaho

Tezpur University

East West University

Czech Technical University in Prague

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Papers by VAIBHAV NAIK

Characterization of Canadian biomass for alternative renewable biofuel

Renewable Energy, 2010

Biomass represents the renewable energy source and their use reduces the consumption of fossil fu... more Biomass represents the renewable energy source and their use reduces the consumption of fossil fuels and limits the emission of CO 2 , SO x , NO x and heavy metals. They are used in pyrolysis, gasification, combustion and co-combustion. Present study aims to highlight the common biomass available in Canada such as wheat straw, barley straw, flax straw, timothy grass and pinewood. The biomass samples were collected form Saskatoon, Canada and examined for their physical and chemical characteristics using static bomb calorimeter, XRD, TGA, ICP-MS, CHNSO, FT-IR and FT-NIR. The biomass samples were subjected to three-step extraction process, i.e. hexane, alcohol and water extraction separately, after extraction the raffinate biomass was acid hydrolyzed. The acid soluble fractions, which mainly contained degraded sugars, were analysed by HPLC and the lignin content was determined using acid insoluble fraction. The hexane extract (i.e. waxes), alcohol extract and lignin were characterized by FT-IR spectroscopy. Among all the biomass samples pinewood shows lower ash and lignin content, while shows higher calorific value, cellulose and hemicellulose content. The appreciable amount of hexane soluble in pinewood was due to the presence of terpene hydrocarbons. However among the agricultural biomass samples barley straw shows higher ash, wax and lignin content compared to wheat and flax straw. All these properties combined together have shown that pinewood, wheat and flax can act as the potential candidates for bio-energy production.

$Fig. 6. FT-NIR spectra of biomass samples. The XRD analysis of various biomass samples are presented in Fig. 2. The intense X-ray diffraction peak was detected at 25°. The calculated areas of wheat straw: 325,881, barley straw: 541,938 flax straw: 525,051, timothy grass: 775,801 and pinewood: 581,217 in comparative square units. Among all these biomass samples the maximum crystallinity was obtained for timothy grass and minimum in case of wheat straw. The crystallinity of the surface is mainly related to the wax content (high molecular mass hydro- carbons and fatty components) in the biomass [14]. However, the overall crystallinity of biomass depends on wax, cellulose content and also depends on the complex nature of bonding [24] between cellulose, hemicellulose and lignin. Therefore, further study on nature of bonding between major chemical classes in the biomass is necessary to justify the XRD observation. During the hexane extraction, it was observed that, pinewood extract contained appreciable amount of hexane soluble materials because the pinewood contained high amount of terpeneoids, which are soluble in non-polar solvent (i.e. hexane). Therefore the pinewood hexane extract recovered terpenoids along with small fractions of waxy materials. As pinewood and flax straw shows less amount of waxy$

$Fig. 9. FT-IR spectra of pinewood and its extractives: a-biomass, b-wax, c-ethanol extract, d-lignin. In FT-NIR spectroscopy (Fig. 6), chemical species absorb throughout the spectrum region (4000-10,000 cm~!). The most informative range of NIR spectra was 5500-9000cm~!. The comparative NIR analysis of each biomass is presented in Fig. 6. The spectral range from 8700 to 8000 cm“! contained absorption bands corresponding to the second overtone of C-H stretching vibrations, where as the first overtone C-H stretching bands appeared in 5988-5813 cm7!. The peak at 6990 cm™' is due to first overtone of O-H (stretching) [30,31]. So the functional group identified by FT-IR was confirmed by FT-NIR spectra. However, a NIR spectrum is CHNSO analysis of biomass samples showed no marked difference as presented in Table 1. The pinewood contained high percentage of C (49.0%), H (6.4%) and low percentage of N (0.14%) and S (0.01%). Canadian encyclopedia reported that the hydrogen content of pinewood is 5.98% [10] and Nunez-Regueira et al. [27] reported that the pinewood of Spain origin contained C: 48.3-55.4%, H: 5.2-7.7%, N: 0.16-1.6% and S: 0.14-0.45% which agrees well with this study. The organic element composition of wheat, barley and flax straw was found to be almost similar, whereas timothy grass contained slightly high percentage of N and S. For example, high nitrogen and ash concentrations reduce hydrocarbon yields during thermochemical conversion [2]. A significant fraction of herbaceous biomass consists of inorganic constituents, commonly referred to ash, which cannot be con- verted into energy. The inorganic material commonly associated with oxygen, sulphur and nitrogen containing functional groups. These organic functional groups can provide suitable sites for inorganic species to be associated chemically in the forms of cations or chelates [28].$