Generalized Analysis of Gasifier Performance using Equilibrium Modeling

Abstract

Thermodynamic modeling of gasification process provides a quick estimate of performance of the gasifier. Most of the earlier work on thermodynamic modeling is restricted to a particular feedstockÀgasification agent combination and hence the results cannot be generalized. In the present work, the equilibrium modeling based on Gibb's free energy minimization approach is used to analyze the performance of gasification of any fuel using oxygen or steam. The performance is analyzed at the carbon boundary point at which the cold gas efficiency is maximum. The gasification temperature, amount of gasification agent required, composition of syngas, and cold gas efficiency are predicted using Aspen Plus. The results are presented as contour plots on Van Krevelen coordinates (H/C vs O/C) and interpreted based on simplified gasification reactions. The performance for different feedstocks represented in Van Krevelen diagram is also analyzed. Finally, advantage of cogasification of feedstocks is highlighted.

Simulation of Syngas Production from Lignin Using Guaiacol as a Model Compound

“…These results are consistent with the literature that establishes that at about 550 °C the steam reforming process yields the maximum CO2 production [10,12]; for this analysis, the maximum production is obtained at 500-600 °C and with w/g ratios of 16 to 20. The proposed Reactions (2), (3) and (9) produce CO2, but Reaction (9) is present when carbon is in the system as graphite, and as Figure 4b has shown, this is possible for w/g ratios lower than 5 and in this case the w/g ratio is 20. Figure 5d shows that at low temperatures the production of methane is high so Reactions (4) and (5) are present.…”

“…Process simulation has been used to determine the best options and operating conditions for producing biofuels [5,6,[18][19][20][21][22][23][24][25][26], particularly the software ASPEN PLUS ® (Aspen Technology, Inc., Bedford, MA, USA) has been widely used. However, the models used for lignin have oversimplified the process.…”

“…is necessary to use the lignin chemical structure or a model compound. Therefore, in this work there is proposed to use the molecule of guaiacol, which has a H/C and O/C ratio in the range reported in other studies [20], as a lignin model during the simulation of the gasification process of softwood. This will serve as a starting point that will surely culminate in the use of models very close to the actual chemical structure of lignin, so that research can be performed by process simulators for processing into intermediate products with high added value and production chain initiators, all under the concept of biorefineries.…”

ASPEN Plus simulation of coal integrated gasification combined blast furnace slag waste heat recovery system

“…The vast majority of energy in the coal was occupied by them. When only these three elements were considered, the obtained results and conclusions would not deviate much with the original coal sample [33,34]. The simulation was calculated by the method of Gibbs free energy minimization.…”

An Experimental and Theoretical Study of the Gasification of Miscanthus Briquettes in a Double-Stage Downdraft Gasifier: Syngas, Tar, and Biochar Characterization

“…Produced gases, with high concentrations of CO and H 2 from the gasifier, can be fed into internal combustion engines for power production [4,5]. The syngas from the gasifier could be used for different purposes, such as producing chemical products, especially when it contains a high percentage of CO 2 and CH 4 [6]. The calorific value of the gas is dependent on the gasifying agent.…”