提高再生气中H2S浓度的方案研究

对以生物质热解气为原料的低温甲醇洗工艺进行模拟和研究，热解气主要成分为CO₂、H₂、CO、H₂S、COS和水等。采用Aspen plus对低温甲醇洗工艺进行全流程模拟，通过对比分析可知，模拟结果与实际值基本吻合。针对原工艺H₂S浓度低的问题，提出两个改进方案以提高H₂S的浓度：①提高气提塔的N₂流量；②在气提塔后添加一个闪蒸罐，气提塔塔底的甲醇溶液经过加热和闪蒸后再进入甲醇再生塔。结果表明改进方案可以大大提高再生气中H₂S的浓度。

Solution method for increasing the concentration of H2S in regeneration gas

Production of biomass pyrolysis gas as a raw material in a plant has been simulated and studied and the main components found to be CO₂, H₂, CO, H₂S, COS and water. Aspen plus was utilized to simulate the rectisol process. Comparative analysis shows that the simulation results are consistent with actual values. In consideration of the low concentration of H₂S in conventional processes, two methods are proposed to increase the concentration of H₂S:(1) Improving the N₂ flow of the gas tower; (2) Adding a heat exchanger and flash tank to the stripper, so that the methanol solution at the bottom of the stripper tower is heated and flashed before entering the methanol regeneration tower. The results show that the concentration of H₂S can be significantly increased by using these two steps.