利用吸附余压预冷的煤层气氮膨胀液化流程  

Integrated process of nitrogen expansion and liquefaction for precooling CBM by adsorbing residue pressure

作　　者：高婷[1] 林文胜[1] 顾安忠[1] 辜敏[2] 

机构地区：[1]上海交通大学制冷与低温工程研究所 [2]重庆大学采矿工程系

出　　处：《天然气工业》2009年第2期117-119,共3页Natural Gas Industry

基　　金：国家高技术研究发展计划(863计划)课题(编号:2006AA06Z234)内容

摘　　要：煤层气液化是对煤层气进行开发利用的一种有效方式。而由于受抽采技术的限制,煤层气中常含有较多的氮气。因此在预净化处理后,还须在液化前进行变压吸附或液化后进行低温精馏实现氮和甲烷的分离,从而提高甲烷浓度。为此,构建了一种新型的吸附—液化一体化的氮膨胀液化流程,将吸附后排出的带余压氮气直接膨胀对浓缩后的煤层气进行预冷。通过HYSYS模拟计算考察了不同含氮量和不同吸附余压下系统单位产品液化功的变化情况,并与不带预冷的普通氮膨胀液化流程及丙烷预冷氮膨胀液化流程进行比较。结果表明,高含氮量下,一体化的流程能够大大降低系统功耗。Liquefaction is a good way for recovery of coalbed methane(CBM).Generally,CBM contains a large amount of nitrogen,which is usually required to be separated by pressure swing absorption before liquefaction or by cryogenic rectification after liquefaction.This paper recommends a new integrated process of nitrogen expansion and liquefaction for precooling CBM by adsorbing residue pressure,in which the released nitrogen expanded directly to precool the enriched CBM.Taking the unit product liquefaction power consumption as the major index and nitrogen content of CBM feed gas together with residue pressure of waste nitrogen as variables,the system performance of the integrated process is studied and compared with that of the nitrogen expansion liquefaction process without precooling and the nitrogen expansion liquefaction process with propane precooling.By simulation and calculation with HYSYS,it is confirmed that system power consumption can be reduced in this integrated process,especially for the CBM with high content of nitrogen.

关 键 词：煤层气 液化流程 吸附分离 余压利用 功耗 

分 类 号：TD842[矿业工程—煤矿开采]