煤层气液化技术研究进展

Research Progress of CBM Liquefaction Technologies

煤层气液化是对其回收利用的有效途径。由于需要进行甲烷提浓,低浓度煤层气的液化技术与常规天然气有较大差别。主要技术方案包括先液化再精馏提浓甲烷的液化-精馏方案,以及先吸附分离提浓甲烷再进行液化的吸附-液化方案。对于前者,主要介绍了适合于煤层气小型液化装置的液化流程、甲烷精馏提纯工艺、整体化液化-精馏方案等方面的研究进展。对于后者,主要介绍了甲烷/氮吸附分离、整体化吸附-液化方案等方面的研究进展。此外,还介绍了煤层气液化过程传热特性、超临界甲烷/氮冷却换热等研究情况。

Liquefaction provides an efficient approach for better recovery and utilization of CBM（coal bed methane）.For CBM with low methane content,methane enrichment has to be considered along with liquefaction,so the liquefaction technology is different from that for the ordinary natural gas.There are mainly two solutions for the liquefaction of CBM with low methane content： one is liquefaction at first and then concentrate methane via a distillation process;the other one is adopting an adsorption process firstly to concentrate methane and then liquefaction.For the former solution,researches for liquefaction processes suitable for small-scale CBM liquefaction plants,methane concentrate technologies by distillation,and integrated processes of liquefaction and distillation were introduced.For the latter one,researches for methane/nitrogen separation technologies by adsorption and integrated processes of adsorption and liquefaction were introduced.Furthermore,the heat transfer characteristics for CBM liquefaction processes as well as the cooling heat transfer characteristics for supercritical methane/nitrogen were also introduced.