METHOD AND APPARATUS FOR PRODUCING PURE METHANOL Russian patent published in 2022 - IPC C07C27/00 C07C29/151 C07C31/04 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing pure methanol from synthesis gas containing hydrogen and carbon oxides as components of synthesis gas, involving the following steps: (a) at least partial conversion of synthesis gas containing hydrogen and carbon oxides under methanol synthesis conditions in a methanol synthesis unit comprising at least one methanol synthesis reactor, (b) tapping a liquid stream of crude methanol containing methanol, water, dissolved constituents of synthesis gas and low-boiling by-products from a methanol synthesis unit, (c) introducing a liquid stream of crude methanol into a decompression vessel, discharging the liquid decompression stream of crude methanol depleted in terms of components of synthesis gas in the form of still products and a stream of gaseous overhead products containing components of synthesis gas from the decompression vessel, (d) introducing a liquid decompression crude methanol stream, depleted in terms of components of synthesis gas, into a pretreatment column, distillation separation of said stream, tapping a liquid stabilized stream of methanol, depleted in low-boiling by-products, in the form of a stream of bottoms and a stream of gaseous overhead products containing low-boiling by-products and methanol vapours, from the pretreatment column, (e) introducing a stream of bottoms from the pretreatment column into the single- or multi-stage methanol purification device, discharging the pure methanol product stream from the methanol purification device, (f) sending a stream of overhead products from the column for pretreatment to an off-gas removal device. Method is characterized by the fact that (g) prior to being sent to the off-gas removal device, the stream of upper products from the pretreatment column is subjected to a scrubbing step using a methanol-selective scrubbing medium in a scrubbing device and methanol-depleted overhead products stream is sent to off-gas removal device, wherein water is used as scrubbing medium and the methanol-laden water is discharged from the scrubber and recycled to the pre-treatment column or methanol purifier.

EFFECT: use of the disclosed method enables to maximize output of methanol.

4 cl, 3 dwg, 1 ex