Sorption-enhanced dimethyl ether synthesis-Multiscale reactor modeling

作者：Iliuta Ion; Iliuta Maria C^*; Larachi Faical

来源：Chemical Engineering Science, 2011, 66(10): 2241-2251.

DOI：10.1016/j.ces.2011.02.047

• CO(2) conversion
• DME synthesis
• Fixed bed
• Sorption-enhanced reaction process
• In-situ H(2)O removal
• Modeling

As an opportunity for the attenuation of atmospheric CO(2) emissions, conversion of carbon dioxide into valuable oxygenates as fuel additives or fuel surrogates was explored conceptually in terms of a potentially feasible dimethyl ether (DME) conversion process. Incentives for application of conventional CO(2)-DME conversion process are insufficient due to low CO(2) conversion, and DME yield and selectivity. In-situ H(2)O removal by adsorption (sorption-enhanced reaction process) can lead to the displacement of the water gas shift equilibrium and therefore, the enhancement of CO(2) conversion into methanol and the improvement of DME productivity. A two-scale, isothermal, unsteady-state model has been developed to evaluate the performance of a sorption-enhanced DME synthesis reactor. Modeling results show that under H(2)O removal conditions, methanol and DME yields and DME selectivity are favoured and the methanol selectivity decreases. The increase of methanol and DME yields and DME selectivity becomes more important at higher CO(2) feed concentration because a relatively large amount of water is produced followed by a large quantity of water removed from the system. Also, the drop in the fraction of unconverted methanol becomes more important when CO(2) feed concentration is higher and the dehydration reaction is favoured. Therefore, application of the sorption-enhanced reaction concept allows the use of CO(2) as a constituent of the synthesis gas as the in-situ H(2)O removal accelerates the reverse water gas shift reaction.

• 出版日期2011-5-15