Simulation of High Temperature Air – Steam Biomass Gasification in a Downdraft Gasifier Using ASPEN PLUS

2012 ◽  
Vol 267 ◽  
pp. 57-63
Author(s):  
Worapot Ngamchompoo ◽  
Kittichai Triratanasirichai

A comprehensive process model is developed for high temperature air – steam biomass gasification in a downdraft gasifier using the ASPEN PLUS simulator. The simulation results are compared with the experimental data obtained through pilot scale downdraft gasifier. In this study, the model is used to investigate the effects of gasifying agent preheating, equivalence ratio (ER), and steam/biomass (S/B) on producer gas composition, high heating value (HHV), and cold gas efficiency (CGE). Results indicate that H2 and CO contents have increased when gasifying agent preheating is used, while gasifying agent preheating has no effect with H2 and CO at high ER. At high level of S/B, the concentrations of H2 and CO are related with water-gas shift reaction in significant. HHV and CGE depend on the concentrations of H2 and CO in producer gas, which can increase by preheated gasifying agent. However, gasifying agent preheating should apply with waste heat from the process because there is no additional cost of energy price.

Author(s):  
Sahar Safarianbana ◽  
Runar Unnthorsson ◽  
Christiaan Richter

Abstract Wood and paper residues are usually processed as wastes, but they can also be used to produce electrical and thermal energy through processes of thermochemical conversion of gasification. This study proposes a new steady state simulation model for down draft waste biomass gasification developed using the commercial software Aspen Plus for optimization of the gasifier performance. The model was validated by comparison with experimental data obtained from six different operation conditions. This model is used for analysis of gasification performance of wood chips and mixed paper wastes. The operating parameters of temperature and moisture content (MC) have been varied over wide range and their effect on the high heating value (HHV) of syngas and cold gas efficiency (CGE) were investigated. The results show that increasing the temperature improves the gasifier performance and it increases the production of CO and H2 which leads to higher LHV and CGE. However, an increase in moisture content reduces gasifier performance and results in low CGE.


Author(s):  
Muhammad Kashif Shahzad ◽  
Yaqi Ding ◽  
Yongmei Xuan ◽  
Neng Gao ◽  
Guangming Chen

Open absorption heat pump (OAHP) system is more viable option to recover waste heat from moist gas as compared to the traditional condensation methods. This promising technology has great potential for latent heat recovery from moist gas, drying process in paper and other industrial heating applications. This study presents the process modelling and comparative analysis of OAHP system in Aspen Plus using two different solutions by adopting part regeneration technique. The promising potassium formate-water (HCOOK/H2O) which has lower causticity, lower costs and better crystallization characteristics is used as an alternative to the caustic lithium bromide-water (LiBr/H2O) solution in this study. Process model of the system is established in Aspen Plus and, the properties validity is confirmed with published experimental and Engineering Equation Solver (EES) library data. A detailed comparative parametric study is carried out to evaluate the effect of influencing parameters on coefficient of performance (COP), water recovery (φ) and heat recovery (ζ) efficiencies. The performance of OAHP system is found to be very similar using different concentrations as 2.13 COP value for 50% LiBr/H2O and 2.19 for 70% HCOOK/H2O solution over design conditions. Similarly, φ is found to be 0.701, 0.688 while ζ as 0.716 and 0.705 for both the absorbents. Moreover, the system’s operational concentration range is 45-61.3% for LiBr/H2O and 55-82.1% for HCOOK/H2O at 135 °C regeneration heat input. Potassium formate solution having quite similar properties to the aqueous lithium bromide is also confirmed to have similar performance trends using 50% and 70% concentrations.


Author(s):  
M. G. McKellar ◽  
G. L. Hawkes ◽  
J. E. O’Brien

A process model of syngas production using high temperature electrolysis and biomass gasification is presented. Process heat from the biomass gasifier is used to improve the hydrogen production efficiency of the steam electrolysis process. Hydrogen from electrolysis allows a high utilization of the biomass carbon for syngas production. Based on the gasifier temperature, 94% to 95% of the carbon in the biomass becomes carbon monoxide in the syngas (carbon dioxide and hydrogen). Assuming the thermal efficiency of the power cycle for electricity generation is 50%, (as expected from GEN IV nuclear reactors), the syngas production efficiency ranges from 70% to 73% as the gasifier temperature decreases from 1900 K to 1500 K.


Energy ◽  
2019 ◽  
Vol 167 ◽  
pp. 688-697 ◽  
Author(s):  
Yongqi Sun ◽  
Jingjing Chen ◽  
Zuotai Zhang

2014 ◽  
Author(s):  
Yunye Shi ◽  
Tejasvi Sharma ◽  
Guiyan Zang ◽  
Albert Ratner

A study of the gasification of corn kernels has been performed on an experimental, pilot-scale (50–100 lbs/hour) gasification unit. Analysis was made on the performance of the gasifier in terms of producer gas generation and composition, char production and process mass balance. In these experiments corn kernels was used so that the shapes and sized of the materials did not influence the results. Experiments were conducted with varying temperature of fuel bed. For each experimental condition, the permanent gas composition was measured continuously by gas chromatography (GC). Tar was collected according to CEN Standard. Bio-char were weighted for mass balance. The results from the study indicate that there were differences between various operational parameters in terms of producer gas concentration and char percentage.


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