Chen, Shuangtao 1;Niu, Lu 1;Zeng, Qiang 2;Li, Xiaojiang 2;Lou, Fang 2;Chen, Liang 1;Hou, Yu 1 1 State Key Laboratory of Multiphase Flow in Power Engineering, Xi'An Jiaotong University, 710049, China firstname.lastname@example.org 2 Xinjiang Coal Research Institute, 830091, China
Coal-bed methane (CBM) reserves are rich in Sinkiang of China, and liquefaction is a critical step for the CBM exploration and utilization. Different from other CBM gas fields in China, CBM distribution in Sinkiang is widespread but scattered, and the pressure, flow-rate and nitrogen content of CBM feed vary significantly. The skid-mounted liquefaction device is suggested as an efficient and economical way to recover methane. Turbo-expander is one of the most important parts which generates the cooling capacity for the cryogenic liquefaction system. Using turbo-expander, more cooling capacity and higher liquefied fraction can be achieved. In this study, skid-mounted CBM liquefaction processes based on Claude cycle are established. Cryogenic turbo-expander with high expansion ratio is employed to improve the efficiency of CBM liquefaction process. The unit power consumption per liquefaction mole flow-rate for CBM feed gas is used as the object function for process optimization, compressor discharge pressure, flow ratio of feed gas to turbo-expander and nitrogen friction are analyzed, and optimum operation range of the liquefaction processes are obtained.
Coal liquefaction (major);Coal bed methane;Coal deposits;Cooling;Cryogenics;Gas compressors;Gas industry;Liquefaction;Methane;Natural gas fields;Nitrogen;Optimization;Proven reserves;Thermoanalysis;Turboexpanders