Non-circulating methanation process of coal-based synthetic natural gas and liquefied natural gas

• Main Authors: YI SHUPENG, HE YANG, ZHENG HENG, ZHANG XINBO, MA LEI, YANG KUANHUI, TAO PENGWAN
• Format: Patent
• Language: English
• Published: 18.02.2015
• Subjects: ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE ORUNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; CHEMISTRY; FIRELIGHTERS; FUELS; FUELS NOT OTHERWISE PROVIDED FOR; LIQUEFIED PETROLEUM GAS; LUBRICANTS; METALLURGY; NATURAL GAS; PEAT; PETROLEUM, GAS OR COKE INDUSTRIES; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BYSUBCLASSES C10G, C10K; TECHNICAL GASES CONTAINING CARBON MONOXIDE

The invention belongs to the field of chemical industry and in particular relates to a non-circulating methanation process of coal-based synthetic natural gas and liquefied natural gas. The process comprises the following concrete steps: introducing coal-based synthetic gas subjected to sulfur-tolerant shift and low-temperature methanol elution desulfurization and decarbonization into an ultra-precision purifier; enabling the total sulfur content to be less than 0.02 ppm, the chlorine content to be less than 0.01 ppm and the heavy metal content to be less than 0.01 ppm in the synthetic gas entering the methanation process; dividing the synthetic gas into three, four or five parts; enabling the synthetic gas parts to enter main methanation reactors respectively; enabling all gas at the outlet of the final main methanation reactor to enter auxiliary methanation reactors for continuous methanation reaction in sequence; cooling and dehydrating to obtain the synthetic natural gas (SNG) meeting the requirements, or adding a cryogenic separation liquefication process to obtain the liquefied natural gas (LNG). The process has the advantages of no circulating compressor, low investment, high energy utilization rate and low running expense.