| 摘要 |
PURPOSE:To efficiently suppress production of nitric acid as a by-product and continuously obtain dimethyl carbonate useful for solvent, etc., in high yield by treating carbon monoxide and methyl nitrite under specific conditions and then, purging a part of an uncondensing gas and feeding the purged gas to a methyl nitrite recovering tower. CONSTITUTION:Vapor phase catalytic reaction of carbon monoxide with methyl nitrite is carried out in a reactor 1 in the presence of a solid catalyst to produce dimethyl carbonate and dimethyl carbonate is absorbed in dimethyl oxalate which is an absorbing solvent in a dimethyl carbonate absorption tower 2. Nitrogen monoxide in an uncondensing gas is brought into contact with molecular oxygen and methanol in a methyl nitrite regeneration tower 3 to produce methyl nitrite, and dimethyl carbonate in the absorbing liquid is separated by distillation. A purge gas from a gas circulation system and oxidizing gas of ammonia are fed to a methyl nitrite recovering tower 4 and nitrogen oxide in the gas is brought into contact with methanol so as to produce methyl nitrite. Further, a part of the uncondensing gas is purged and fed to the methyl nitrite recovering tower 4 to continuously provide the objective dimethyl carbonate. |
