In this work, the steam gasification of mixed food waste was carried out with torrefaction as pretreatment. Torrefaction was carried out at various temperatures; 230 °C, 260 °C, and 290 °C and for one-hour residence time. Improvement in physico-chemical properties of food waste by torrefaction was studied using proximate, elemental, and compositional analysis. Additionally, the effect of torrefaction on mass yield, energy yield, mass density and energy density was presented. Gasification was then carried out using torrefied food waste as biomass with steam as a gasification agent at 700 °C. The steam flow rate was kept at 0.625 mL/min with a steam to biomass ratio of 1.25. The resulting syngas was characterized for syngas yield, syngas composition, H2yield, and high heating value (HHV). It was found that syngas yield and H2field varied from 0.95 to 3.49 m3/Kg and 0.6 to 2.15 m3/Kg respectively from gasification of food waste torrefied at different temperatures. The highest HHV of syngas was found to be 12.19 MJ/Nm3. Cold gas efficiency and carbon conversion efficiency were also determined to evaluate the performance of proposed pretreatment on steam gasification. © 2020 Georg Thieme Verlag. All rights reserved.

Sanjeev Yadav

Chemical Engineering

(SoE) School of Engineering

Singh D.

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Shiv Nadar University

Journal of Environmental Chemical Engineering

Large amount of food waste is generated from Indian kitchens and disposing off such a large amount possesses a great challenge in terms of environmental degradation and viable food waste processing technology. In this work, steam gasification was tested as an alternative viable technology to process the kitchen food waste. Preliminary study was carried out at low temperature on steam gasification in a fixed bed reactor to study the influence of steam flow rate (SFR) and temperature on the syngas yield, syngas composition, hydrogen yield. Performance parameters such as carbon conversion efficiency (CCE), and apparent thermal efficiency (ATE) are also calculated. Steam flow rates are varied from 0.125 mL/min to 0.75 mL/min and the temperatures are varied from 700 °C to 800 °C. The highest hydrogen yield is obtained at 0.5 mL/min SFR and 800 °C temperature and its highest value is 1.2 m3/kg. The highest value of performance parameters, CCE and ATE are found to be 63\% and 1.8. © 2020 Hydrogen Energy Publications LLC

International Journal of Hydrogen Energy

Low temperature steam gasification to produce hydrogen rich gas from kitchen food waste: Influence of steam flow rate and temperature

This study evaluated the change in physical and chemical properties of sun-dried food waste, during torrefaction in a fixed bed reactor. Torrefaction was carried out at different temperatures 230 °C, 260 °C, and 290 °C, for different residence times of 15, 30, 45, 60, 75, and 90 min in a fixed bed reactor. The solid torrefied products were analyzed by elemental analysis, proximate analysis, compositional analysis, and thermogravimetric analysis (TGA), and it was found that most suitable residence time for torrefaction was 60 min as torrefaction beyond 60 min did not yield much improvement in changing the properties of kitchen food waste. Carbon content increased from 46.0 to 58.5\%, consecutively increasing higher heating value (HHV) from 16.1 to 21.9\%. Compositional analysis demonstrated that there was not much hemicellulose left in the raw food waste after cooking; however, it had cellulose in significant proportion which went through decomposition during torrefaction. Lignin was not affected much. Various process parameters such as mass yield, energy yield, and energy density were also studied, and it was found the mass and energy yield decreased by 65.0\% and 47.5\%, respectively, and energy density increased by 35\%. Van Krevelen indicated clearly that torrefied char had achieved coal characteristics. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature.

Biomass Conversion and Biorefinery

Evaluation of the physico-chemical development of kitchen food wastes through torrefaction - a biodiversity case study

Journal of the Energy Institute

Gasification of torrefied oil palm biomass in a fixed-bed reactor: Effects of gasifying agents on product characteristics

Fuel

Effect of torrefaction on steam gasification of starchy food waste

Renewable and Sustainable Energy Reviews

Wet torrefaction of biomass for high quality solid fuel production: A review

Steam gasification with torrefaction as pretreatment to enhance syngas production from mixed food waste