基于动力学模型的合成气完全甲烷化回路系统模拟分析

doi:10.16085/j.issn.1000-6613.2017.01.019

摘要/Abstract

摘要： 为了研究工艺条件对某甲烷化工业装置回路系统的影响，利用Aspen Plus软件建立了多级绝热甲烷化反应器回路系统动力学模型，动力学方程由Fortran编程嵌入模型中，模拟结果与实际运行值吻合较好。本文进而考察了不同工艺参数对甲烷化回路系统的影响，结果表明：循环比对各级反应器的出口温度、热点位置、出口气中CO₂及CH₄含量影响显著，但对产品气中CH₄含量影响较小；增大原料气流量，仅使各级反应器的热点位置后移，对各反应器出口温度、气体组成和产品气质量的影响可以忽略；提高进料温度，各级反应器的出口温度随之升高、出口气中CO₂含量增加、CH₄含量下降，产品气中CH₄含量略微降低；氢碳比的变化，对各级反应器出口气组成及产品气中CH₄含量影响显著，对第四反应器的出口温度影响也很大，但对第一至第三反应器的温度分布影响不大，氢碳比由2.8增至3.2，产品气CH₄含量呈先增大后减小的趋势，验证了氢碳比为3是甲烷化反应系统的最优值。

关键词: 甲烷化, 固定床反应器, Aspen Plus, 动力学, 模拟分析

Abstract: In order to study the effect of process conditions on the loop system of methanation equipment,the kinetics model of multi-stage adiabatic methanation reactor loop system was established using the Aspen Plus,in which the kinetics equations were embedded using Fortran. The simulation results had been verified with actual operating data. The results showed that the recycle ratio significantly affected the exit temperature,hotspot locations,and the exit CO₂ and CH₄ contents in all reactors,but it had little impact on CH₄ purity in the final product gas. Hotspot location moved backward as feed flowrate increased,while exit temperature,exit gas components and CH₄ purity were hardly affected by the feed flowrate. As feed temperature increased,both exit temperature and exit CO₂ content increased,while exit CH₄ content decreased and CH₄ purity decreased slightly. The H/C ratio significantly influenced the exit gas composition and CH₄ purity. It also affected the exit temperature of the 4th reactor,but not for 1st,2nd and 3rd reactors. The CH₄ content in the final product gas increased first,then decreased as the H/C ratio increased from 2.8 to 3.2. The H/C ratio of 3 was concluded as the optimum value for methanation system.

Key words: methanation, fixed bed reactor, Aspen Plus, kinetics, simulation analysis

中图分类号:

TQ546

李春启. 基于动力学模型的合成气完全甲烷化回路系统模拟分析[J]. 化工进展, 2017, 36(01): 146-155.

LI Chunqi. Simulation analysis of the loop system of syngas methanation based on kinetics model[J]. Chemical Industry and Engineering Progree, 2017, 36(01): 146-155.

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