Microchannel reactive distillation for the conversion of aqueous ethanol to ethylene  

作　　者：Johnny Saavedra-Lopez Stephen D.Davidson Paul H.Humble Dan R.Bottenus Vanessa Lebarbier Dagle Yuan Jiang Charles J.Freeman Ward E.Te Grotenhuis Robert A.Dagle 

机构地区：[1]Pacific Northwest National Laboratory,902 Battelle Blvd.,Richland,WA 99354,USA

出　　处：《Journal of Energy Chemistry》2024年第11期481-493,共13页能源化学（英文版）

基　　金：financially U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Bioenergy Technologies Office, and the Office of Technology Transitions Technology Commercialization Fund;Financial support also was provided by Lanza Tech through a Cooperative Research and Development Agreement。

摘　　要：Here we demonstrate the proof-of-concept for microchannel reactive distillation for alcohol-to-jet application:combining ethanol/water separation and ethanol dehydration in one unit operation.Ethanol is first distilled into the vapor phase,converted to ethylene and water,and then the water co-product is condensed to shift the reaction equilibrium.Process intensification is achieved through rapid mass transfer-ethanol stripping from thin wicks using novel microchannel architectures-leading to lower residence time and improved separation efficiency.Energy savings are realized with integration of unit operations.For example,heat of condensing water can offset vaporizing ethanol.Furthermore,the dehydration reaction equilibrium shifts towards completion by immediate removal of the water byproduct upon formation while maintaining aqueous feedstock in the condensed phase.For aqueous ethanol feedstock(40%_w),71% ethanol conversion with 91% selectivity to ethylene was demonstrated at 220℃,600psig,and 0.28 h^(-1) wt hour space velocity.2.7 stages of separation were also demonstrated,under these conditions,using a device length of 8.3 cm.This provides a height equivalent of a theoretical plate(HETP),a measure of separation efficiency,of ^(3).3 cm.By comparison,conventional distillation packing provides an HETP of ^(3)0 cm.Thus,9,1 × reduction in HETP was demonstrated over conventional technology,providing a means for significant energy savings and an example of process intensification.Finally,preliminary process economic analysis indicates that by using microchannel reactive distillation technology,the operating and capital costs for the ethanol separation and dehydration portion of an envisioned alcoholto-jet process could be reduced by at least 35% and 55%,respectively,relative to the incumbent technology,provided future improvements to microchannel reactive distillation design and operability are made.

关 键 词：Catalytic distillation Ethanol dehydration Process intensification MICROCHANNEL Alcohol-to-jet process 

分 类 号：TQ221.211[化学工程—有机化工]