Papers by David Chiaramonti
Biomass and Bioenergy, Jun 20, 2014
Timber-concrete-composite (TCC) systems, commonly with timber at the bottom and concrete at the t... more Timber-concrete-composite (TCC) systems, commonly with timber at the bottom and concrete at the top, are efficient solutions for floors because of their advantages compared to pure timber or pure concrete slabs, one of the advantages being better fire resistance. This paper presents experimental and numerical investigations on the fire resistance of a novel TCC setup with timber beams at the top and a concrete layer at the bottom. This setup has several advantages in facilitating the connection to the surrounding structure and mechanical installations. The results from fire tests on a subsection of the system are reported. The concrete side of one test specimen was subjected to a fire according to the standard temperature-time curve and proofed to achieve a 60-min fire rating. Subsequently the temperature behavior was numerically modeled by performing a transient thermal analysis with temperature dependent material properties. The temperature profiles for the TCC system was accurately modeled allowing for the validated model to be used for future optimizations and predicting the fire resistance ratings of optimized systems.
Biomass Conversion and Biorefinery, 2013
A survey on available MGT suitable for the Bioliquids-CHP project purpose has been carried out, c... more A survey on available MGT suitable for the Bioliquids-CHP project purpose has been carried out, comparing technical characteristics towards needed modifications. The MGT architecture was carefully examined, as the possibility to implement minor modifications largely depends on the type of MGT: issues such as combustion – chamber type, injector characteristics, fuel line, and control system, were the driving factor for comparing the various options. The criteria which drove the selection of the MGT for the project were therefore summarised. Main fuel physical and chemical characteristics were reported and compared towards standard fossil fuels as diesel oil or kerosene. A preliminary correlative study of droplet evaporation and combustion has been carried out, in order to better understand the peculiarity of each bio-fuel, and data compared to experimental data by Istituto Motori-CNR in Naples, Italy. The only purpose of this activity is to derive preliminary indications about conver...
Micro gas turbines units are reliable and versatile units for distributed combined heat and power... more Micro gas turbines units are reliable and versatile units for distributed combined heat and power production (CHP). Compared to internal combustion engines, CHP units based on micro gas turbines offer several advantages, among which the compactness, the high powertoweight ratio, lower pollutant emissions and lower maintenance costs. Depending on the specific type of gas turbine, also fuel flexibility could be higher than engines. This study report on the preliminary results obtained with a small size (25 kWe) Garrett GTP 3067, liquid fuel micro gas turbine, which was adapted to run on alternative first generation biofuels, such as vegetable oil and biodiesel and pyrolysis oil. An inhouse test bench for biofuel testing, capable of accommodating the micro gas turbine, was designed, engineered and built. In this paper, results from experimental measurement on the micro gas turbine are presented. Micro gas turbine performance (e.g specific fuel consumption, heat rate) were monitored...
Alternative fuels are expected to play a major role in EU aviation in the coming years due to the... more Alternative fuels are expected to play a major role in EU aviation in the coming years due to the European Directives on the promotion of Renewable Energies and the target set by the EU Advanced Biofuels Flightpath Initiative for the aviation sector, which requires that synthetic or biologically-derived fuels are produced from biomasses. Given a target of 2 Mt aviation alternative fuel by 2020, i.e. 4% of annual fuel consumption, new processes towards bio-hydrocarbons must be developed, demonstrated and industrialized in a very short period. To date, the alternative fuels adopted mainly originate from the hydro-processing of non-edible vegetable oil or Fisher Tropsch synthesis to obtain hydrocarbon based drop-in fuels, which are fully compatible with the existing infrastructure but with a negative impact on the global costs. In this framework, catalytic pyrolysis could be considered as an alternative process to obtain a jet-fuel, since its capital and operating cost are lower compar...
Airborne transportation accounts for around 2% of world's anthropogenic CO 2 emissions and 10... more Airborne transportation accounts for around 2% of world's anthropogenic CO 2 emissions and 10% of fuel use and aviation traffic is expected to double within 15 years from 2012, while fuel consumption and CO 2 emissions should double in 25 years. Alternative fuels are expected to play a major role in EU in the coming years thanks to the European Directives on the promotion of Renewable Energies and the target set by the EU Advanced Biofuels Flightpath Iniative for the aviation sector, which requires that synthetic or biologically-derived paraffinic fuels are produced from biomasses; given a target of 2 Mt aviation alternative fuel by 2020, i.e. 4% of annual fuel consumption, new processes towards bio-hydrocarbons must be developed, demonstrated and industrialized in a very short period. In this context, biofuels represent a viable opportunity for greening the sector, since only paraffinic fuels can be used as drop-in fuels, and thermochemical processes for BtL, lipid/sugar extrac...
Lignin is an aromatic polymer, consisting in randomly linked phenolics, found in lignocellulosic ... more Lignin is an aromatic polymer, consisting in randomly linked phenolics, found in lignocellulosic biomasses. Thanks to its structure, it is the main renewable source of aromatic chemicals and it is regarded by the scientific community as a promising feedstock to improve the economics of lignocellulosic biorefinery for the production of high added-value chemicals and energy. Lignin-rich residue from 2nd-generation bioethanol process was analysed to settle a preliminary characterization of this compound and its properties compared toward conventional organic feedstocks. The sample was characterized in its chemical and physical properties (proximate and ultimate analysis, calorific value, etc) and thermogravimetric behavior. The latter was investigated through non-isothermal thermogravimetric analysis in nitrogen atmosphere under slow to moderate heating rate and final temperature up to approx. 800 °C. Solid residues produced at 300 °C and 800 °C from TGA were also analysed to determine...
Microalgae are considered a promising feedstock to produce biofuels. Open ponds are identified as... more Microalgae are considered a promising feedstock to produce biofuels. Open ponds are identified as low cost production systems in terms of energy consumptions. In order to design large scale raceway ponds, a Computational Fluid Dynamics (CFD) tool has been used. The flow pattern has been modeled to study the turbulence and mixing in the cultivation medium. Simulations have been carried out by means of OpenFOAM software. A post-processing tool has been developed to estimate the mixing efficiency of the ponds, focusing the interest on the microalgae trajectories. Then, a statistical analysis of algae deviation (respect to undisturbed trajectories) has been proposed to evaluate the real mixing. An experimental campaign performed on a small scale RWP has been exploited for the validation of the CFD approach. The model developed has been applied to large scale systems.
Biomass obtained from olive pruning has been torrified at different conditions, namely at 180 - 2... more Biomass obtained from olive pruning has been torrified at different conditions, namely at 180 - 280°C for 60 -120 min. , grinded with mill having sieve of 50 mesh (0.32 mm), and used as substrate in SHF experiments. The bioconversion has been carried out at flask scale using a mix of cellulosolytic, hemicellulosolitic and ßglucosidase enzymes, and a commercial strain of Saccharomyces cerevisiae. The comparison between the bioconversion yields achieved using grinded biomass or torrified + grinded biomass highlighted that: 1) Mild torrefaction conditions limit sugar degradation within 5-10 percent; 2) Torrified biomass do not lead to enzymatic and fermentation inhibition. How a torrefaction step could be integrated in an ethanol production process has been preliminary estimated, above all as regard the energy integration. The new developed concept has been patented.
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Papers by David Chiaramonti