The invention discloses a process method for preparing
methanol from
blast furnace gas and converter gas. The process method comprises the following steps: S1, introducing the
blast furnace gas and the converter gas into a
gas mixing cabinet for mixing; s2, performing pressure and cooling after mixing; s3, enabling the pressurized and cooled
mixed gas to pass through a PSA (
Pressure Swing Adsorption)
denitrification device, and separating out
nitrogen; s4, the denitrified
mixed gas enters a
decarburization and desulfurization device, and
carbon dioxide and inorganic
sulfur are separated out; s5, injecting steam into the decarburized and desulfurized
mixed gas, heating, and introducing into a CO conversion device for reaction; and S6, further removing
carbon dioxide and
hydrogen sulfide from the reacted gas through a medium-temperature
pressure swing adsorption device to obtain a mixed gas with a synthesis gas component, and introducing the mixed gas into a
methanol synthesis device to synthesize
methanol. Through pressurized cooling, adsorption
denitrification and
ammonia liquid
decarburization, the CO concentration in the mixed gas is increased,
carbon dioxide emission is reduced, the gas temperature is maintained through medium-temperature
pressure swing adsorption, consumption is reduced, methanol is synthesized after low-steam-gas-ratio CO conversion, and high-value utilization of
coal gas and emission reduction of steel plants are achieved.