A Thermodynamic Study of Rice Husk (Oryza Sativa) Pyrolysis

Abstract

Rice (Oryza sativa) is one of the major agricultural products of tropical West Africa in general and Nigeria in particular. In this study ASPEN plus V8.8 was used to develop a thermodynamic model for the pyrolysis of rice husk. The model was validated and found to be accurate especially on the domain of oil and gas yields. It was used to study the effect of temperature on the product yield and oil composition. The fluid products increase with temperature and an optimum of 60% can be obtained from rice husk. The optimum oil yield was 44.2% obtained at 400°C. The synthesis gas was composed basically of hydrogen gas, methane and traces of higher hydrocarbons, the char consisted of carbon and silicon oxide ash while the oil was madeup of acidic organic compounds, aldehydes, pyrolytic water and others. At 600°C, the predictions revealed an oil composition of 84.7% acids, 7.9% pyrolytic water, 7.42% aldehyde and traces of alcohol and other compounds. The results from the thermodynamic predictions showed that rice husk is an excellent feedstock for the biofuels production via the thermo-chemical energy conversion route. The study has provided a useful framework for proper comparisons of the energy potential between different biomass feedstock.

Modeling the valorization of poultry litter via thermochemical processing

“…It can be observed that there is a significant increase in the gas yield with increasing temperature while the oil and char yields reduce with temperature. The increase in gas yield with temperature is due to the more intense thermal breakdown of the biomass to lighter chemical species existing in the gas phase in ambient conditions . At an optimal temperature of 450 °C, the product yield is 43.74 wt% bio‐oil, 6.71 wt% gas and 49.55 wt% char.…”

“…Following the approach taken by Peters et al ., hemicellulose and cellulose were represented in the simulation by their monomers, C 5 H 8 O 4 (xylan) and C 6 H 10 O 5 (xylose‐like cellulose monomer), lignin was represented by a phenyl propane monomer. Further details of the pyrolysis methodology (component selection, flow diagram and process description) used in this study have been discussed elsewhere . The temperature range of the pyrolysis study was 450 °C to 650 °C.…”

“…Further details of the pyrolysis methodology (component selection, flow diagram and process description) used in this study have been discussed elsewhere. 26 The temperature range of the pyrolysis study was 450 °C to 650 °C.…”

“…The increase in gas yield with temperature is due to the more intense thermal breakdown of the biomass to lighter chemical species existing in the gas phase in ambient conditions. 26 At an optimal temperature of 450 °C, the product yield is 43.74 wt% bio-oil, 6.71 wt% gas and 49.55 wt% char. As the temperature rises to 650 °C, oil and char yields drop to 17.67 and 32.58 wt%, respectively while the gas yield rises to 49.74 wt%.…”

“…This was not necessarily the point of interest in previous gasification modeling studies. We previously utilized in silico platforms to investigate biofuel development via the thermochemical processing of waste lubricating oil, sugarcane bagasse, banana residues, rice husks, acetic acid, glycerol, and waste plastics . In this study, the thermochemical processing of poultry litter was studied via a thermodynamic model.…”