基于IGCC的低水汽比变换过程的模拟优化

Simulation and optimization of low water/gas ratio CO shift process based on IGCC

为解决干煤粉气化变换系统CO反应负荷高,同时为避免甲烷化副反应、催化剂床层易飞温等问题,文中提出了一种适合干煤粉气化技术的低水汽比变换工艺,在Aspen Plus软件基础上开发了变换系统计算模型,根据计算模型考察了水汽比、变换炉入口温度及反应压力等关键参数对于变换反应的影响。模拟计算结果表明:采用水汽比0.2—0.3,变换炉入口温度180—200℃,三段低水汽比工艺,变换系统出口CO摩尔分数为1.63%,总变换率达到95.1%,可满足CO_2捕集率大于85%设计指标,捕集系统变换工段能耗为0.568 GJ/t。可以为基于IGCC的CO_2捕集及多联产变换系统工艺设计、技术改造及运行调优提供理论依据。

A low water/gas ratio CO shift process fit for dry pulverized-coal gasification technology was proposed, in order to solve dry pulverized-coal gasification system high CO shift reaction load, meanwhile, to avoid methanation side reaction and catalyst bed temperature runaway. A shift reaction calculation model was developed by Aspen Plus, according to calculation model, studied the effect such as water/gas ratio, shift converter inlet temperature and reaction pressure to CO shift reaction. The simulation results shows ： when water/gas ratio is 0.2-0.3, shift converter inlet temperature is 180-200 ℃, three-stage low water/gas ratio technology, shift system outlet CO mole fraction is 1.63%, total shift conversion is 95.1%, satisfied design target CO2 capture ratio more than 85%, shift system energy consumption is 0. 568 GJ/t CO2. The research can provide theoretical guide for IGCC CO2 capture and poly-generation shift unit process design, technology transformation and operation optimization.