Simulation of Synthesis Gas Production from Steam Oxygen Gasification of Colombian Coal Using Aspen Plus®

Jorge Preciado,Gerardo Gordillo,Juan Gonzalez-Rivera,Rocio Sierra-Ramirez,John Ortiz-Martinez

doi:10.3390/en5124924

Abstract

A steady state simulation of syngas production from a Steam Oxygen Gasification process using commercial technologies was performed using Aspen Plus®. For the simulation, the average proximate and ultimate compositions of bituminous coal obtained from the Colombian Andean region were employed. The simulation was applied to conduct sensitivity analyses in the O2 to coal mass ratio, coal slurry concentration, WGS operating temperature and WGS steam to dry gas molar ratio (SDG) over the key parameters: syngas molar composition, overall CO conversion in the WGS reactors, H2 rich-syngas lower heating value (LHV) and thermal efficiency. The achieved information allows the selection of critical operating conditions leading to improve system efficiency and environmental performance. The results indicate that the oxygen to carbon ratio is a key variable as it affects significantly both the LHV and thermal efficiency. Nevertheless, the process becomes almost insensitive to SDG values higher than 2. Finally, a thermal efficiency of 62.6% can be reached. This result corresponds to a slurry solid concentration of 0.65, a WGS process SDG of 0.59, and a LTS reactor operating temperature of 473 K. With these fixed variables, a syngas with H2 molar composition of 92.2% and LHV of 12 MJ Nm−3 was attained.

Highlights

In a world of high and growing energy demands and increasing oil prices, alternative and sustainable raw material resources are being sought
Syngas is considered a clean fuel with environmental advantages compared to other fossil fuels because the sulfur oxides (SOx), nitrous oxides (NOx) and CO2 emissions are considerably lower [1,2]
The variable effect was evaluated over the key process parameters: (1) syngas molar composition upstream and downstream the water-gas shift (WGS) process; (2) overall carbon monoxide (CO)

Summary

Introduction

In a world of high and growing energy demands and increasing oil prices, alternative and sustainable raw material resources are being sought. These sources would be used for either energy generation or as valuable chemical feedstocks for variety of chemical processes and synthesis. Syngas is an important building block in the chemical, oil and energy industries due to its applications: (1) as a feedstock for the production of several chemicals such as hydrogen, ammonia, methanol, and Fischer-Tropsch products [3]; (2) as a fuel in a gas turbine to produce electricity [4];. Hydrogen could help to satisfy the world energy demand as recent reports show that global energy consumption grew 5.6% in 2010, the largest yearly increase since

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Conclusion