METHOD FOR PRODUCING METHANOL FROM SYNTHESIS GAS WITH ZERO EMISSION OF CARBON DIOXIDE Russian patent published in 2023 - IPC C07C29/151 C07C29/78 C07C29/80 C07C31/04 C01B3/34 C01B3/36 

FIELD: methanol production method.

SUBSTANCE: proposed method includes the following stages: (a) in the installation for production of synthesis gas (A) from carbon-containing raw materials (I) synthesis gas is received (II) containing carbon monoxide, carbon dioxide and hydrogen, (b) synthesis gas (II) from stage (a) is sent to the methanol synthesis unit (B) and at a temperature of 150 to 300°C and pressure from 5 to 10 MPa abs. in presence of a methanol synthesis catalyst, it is converted into a reaction mixture containing methanol, water, carbon monoxide, carbon dioxide, hydrogen, dimethyl ether and methane, from which a stream of crude methanol (III) enriched in methanol and water is condensed, and a crude methanol stream (III) alongside a gaseous stream (IV) containing carbon monoxide, carbon dioxide, hydrogen and methane are removed from the methanol synthesis unit (B), (c) a crude methanol stream (III) from step (b) is subjected to a reduced pressure ranging from 0.1 to 2 MPa abs. in a reduced pressure unit (C) and a degassed crude methanol stream (VI) enriched with methanol and water is obtained, (d) in the distillation device (D) low-boiling components (VII), containing carbon dioxide and a simple dimethyl ether, are separated from a degassed crude methanol stream (VI) with stage (c) by distillation stream and the bottom stream (VIII), enriched in methanol and water is received, and (e) water-containing stream of high-boiling components (IX) is separated and methanol is recovered by distillation as stream (X) from the bottom stream (VIII) from step (d) in an additional distillation device (E). Further, in stage (f), the valuable components of streams - carbon monoxide, carbon dioxide, dimethyl ether and methane (IV), as well as at least one of the two streams (V) and (VII), are fed into the combustion unit (F) and are burned by supplying an oxygen-containing gas (XI) which has an oxygen content of 30 to 100% by volume, and a carbon dioxide-containing flue gas (XII) is obtained in step (g) from a carbon dioxide-containing flue gas (XII) from step (f) the carbon dioxide recovery unit (G) to separate the carbon dioxide-rich stream (XIV) and form an off-gas stream (XIII), and in step (h) the carbon dioxide-rich stream (XIV ) from step (g) separated in the carbon dioxide recovery unit (G) is returned to the synthesis gas plant (A) of step (a) and/or to the methanol synthesis plant (B) of step (b).

EFFECT: method has been developed in which carbon monoxide and carbon dioxide with hydrogen contained in synthesis gas are almost completely converted into methanol and, thus, in terms of synthesis gas, it operates with zero carbon dioxide emissions.

17 cl, 6 dwg, 7 tbl, 7 ex