高含硫天然气净化装置分析

Exergy analysis of highly sour natural gas purification plant

针对高含硫天然气净化装置运行能耗高的问题,本文建立了高含硫天然气净化过程中各类值计算方法,并对离子溶液体系的值计算方法进行了修正,使其适用于酸气吸收过程中醇胺溶液的值计算。在天然气净化过程模拟软件Pro Max建立的净化过程全流程模型的基础上,采用分析方法对高含硫净化装置的全流程进行用能分析。分析结果表明,净化装置全流程的效率为54.2%,其中硫黄回收单元和尾气处理单元效率最高,分别为66.8%和66.1%;脱酸气单元的损失最高,占全流程总损失的43.5%,这是由于净化装置处理的原料气中H2S含量很高,需要更大溶剂循环量才能使净化气达到商品气标准,这导致吸收溶剂再生过程的能耗大大增加。本文研究成果可指导高含硫天然气净化装置的用能评价及节能改造。

To address the problem of high energy consumption of highly sour natural gas purification plant,exergy analysis was used to study the energy process of highly sour gas purification plant. The exergy calculation methods of natural gas purification process were established,and exergy calculation method of ionic solution system was corrected to calculate exergy of methylamine solution. On the basis of the whole process model built with simulation software of gas purification process ProMax, energy consumption process of the whole process of highly-sour natural gas purification plant was analyzed by exergy analysis. The exergy efficiency of the whole process of purification plant was 54.2%,with the highest exergy efficiency values of sulfur recovery unit and tail gas treatment unit 66.8%and 66.1%respectively. And the exergy loss of acid gas sweetening unit was the highest. The raw gas of purification plant was high H2S concentration and needed a greater amount of circulating solvent to remove acid gas to reach commodity gas standards. So the energy consumption of absorbing solvent regeneration process was greatly increased. Research conclusions could be used to guide energy evaluation and energy saving retrofit for highly sour natural gas purification plant.