STUDY ON THERMODYNAMIC EQUILIBRIUM MODEL OF DOWNDRAFT BIOMASS GASIFIER

Yang Hui; Chen Wenyu; Sun Jiao; Chen Wenyi

doi:10.19912/j.0254-0096.tynxb.2021-0156

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Acta Energiae Solaris Sinica ›› 2022, Vol. 43 ›› Issue (10) : 335-342. DOI: 10.19912/j.0254-0096.tynxb.2021-0156

STUDY ON THERMODYNAMIC EQUILIBRIUM MODEL OF DOWNDRAFT BIOMASS GASIFIER

Yang Hui^1,2, Chen Wenyu^1,2, Sun Jiao^1,2, Chen Wenyi^1,2

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Abstract

The thermodynamic equilibrium model of downdraft biomass gasifier was established, which includes coke, tar and gas. The model was verified with published experimental data, and its root mean square（RMS） was between 1.304 and 3.814. The results show that the predicted value of the model is in good agreement with the experimental data, and the model could be considered reliable. Then, the effects of different operating parameters （equivalent ratio, preheating temperature and reaction temperature of gasifier） on gas composition, calorific value and yield of cotton stalk gasification in two gasification atmospheres of cotton stalk downdraft biomass gasifier with air and oxygen-rich gas were simulated. The simulation results show that when the oxygen-enriched gas is used as the gasification agent, with the equivalent ratio from 0.20 to 0.35, the N₂ content in the gas is significantly lower than that in the air, decreasing more than 10%. While it was found that the content of H₂ and CO and the calorific value in the gas can be increased, and the calorific value is about 20% higher than that with air. The preheating temperature had a limited effect on the change of gasification composition. As the preheating temperature changed from 30 ℃ to 130 ℃, the average calorific value of the gas increased from 5.2 MJ/m³ of air to 7.0 MJ/m³ of oxygen-enriched gas. As the reaction temperature of the gasifier increased from 750 ℃ to 1250 ℃, H₂ and CO under the two gasification agents of air and oxygen-enriched gas decreased from 20.94%、26.84% and 21.77%、28.67% to 4.06%、9.12% and 10.49%、21.60%,leading to a decrease in the calorific value of the gas.

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biomass / downdraft gasifier / thermodynamic model / rich oxygen gasification

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Yang Hui, Chen Wenyu, Sun Jiao, Chen Wenyi. STUDY ON THERMODYNAMIC EQUILIBRIUM MODEL OF DOWNDRAFT BIOMASS GASIFIER[J]. Acta Energiae Solaris Sinica. 2022, 43(10): 335-342 https://doi.org/10.19912/j.0254-0096.tynxb.2021-0156

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