低浓度含氧煤层气深冷精馏流程模拟研究

Simulation Study on Cryogenic Rectification Process of Low- concentration Oxygen- contained Coal- bed Methane

利用深冷技术对含氧煤层气进行液化处理，可回收其中的甲烷，减少污染排放。应用HYSYS软件对低浓度含氧煤层气液化精馏工艺流程进行了模拟，并考察精馏塔回流比、塔板数量、精馏压力对甲烷回收率、LNG产品纯度和LNG单位产品生产能耗的影响。综合考虑可取回流比为1．1～1．2，精馏塔板为25～30块，精馏绝对压力为300～400kPa。模拟结果可为工艺设计和实际操作提供参考。

To liguefy and recover methane from the low-concentration oxygen-contained coal-bed methane by cryogenic liquefaction technology can reduce pollution emission. Simulation was made on the cryogenic rectification process of the low- concentration oxygen-contained coal-bed methane by using HYSYS software, and study was carried out on the influence of the reflux ratio of the rectifying tower, the number of trays and the rectification pressure upon the methane recovery rate, the purity of LNG products and the energy consumption of unit LNG product. Through the comprehensive consideration, it came to the conclusion that the desirable reflux ratio was 1.1 ～1.2, the number of trays was 25 ～30 and the absolute rectification pressure was 300 ～400 kPa. The simulated results can provide a reference for the process design and actual ooeration.