Method for coal co-production of natural gas and hydrogen

The invention discloses a method for coal co-production of natural gas and hydrogen. The method comprises the following steps that (1) coal gas and vapor are subjected to a CO conversion reaction to prepare conversion gas with the CO mole content lower than 3%; (2) after the conversion gas is subjected to heat exchange and cooled, low-temperature methanol washing is conducted to obtain purified CO2 and purified hydrogen-rich technology gas; (3) a partial amount of hydrogen-rich technology gas is subjected to pressure-change adsorption to obtain hydrogen; (4) the residual hydrogen-rich technology gas and CO2 obtained in the second step are subjected to a CO2 methanation reaction to obtain natural gas. According to the method, the technology process is adjusted and integrated, and the doubleproducts of natural gas and high-purity hydrogen are produced in a natural gas production project through coal. According to the method, high-purity CO2 which is originally discharged is subjected toresource utilization, CO2