Experiment on the continuous recovery of H-2 from hydrogenation plant off-gas via hydrate formation in tetra-n-butyl ammonium bromide solution

摘要

Here, an approach toward for continuous H-2 recovery from hydrogenation plant off-gas based on hydrate formation in the presence of tetra-n-butyl ammonium bromide (TBAB) is proposed. Firstly, we explored the conditions to form the CH4/H-2/TBAB hydrate through pressure search method in the single-stage equilibrium separation experiments toward CH4/H-2 mixture. The influence of initial pressure, temperature, and initial gas liquid volume ratio were systematically optimized in the context of 10 wt% TBAB solution. Then, we conducted the continuous separation experiments of CH4/H-2 binary mixture and hydrogenation plant off-gas using a set of laboratory-scale continuous stirred reactor according to the optimized conditions, in which the effects of pressure and liquid flow rate upon continuous separation were further studied. The experimental results that the H-2 concentration in the unhydrated gas (the recovered gas) is up to 89 mol% and the yield of H-2 recovery is more than 58.68% indicate the efficiency to recover H-2 using continuous hydrate separation, which lays the foundation for further industrial application. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.