Process for continuously producing dimethyl carbonate

A process for continuously producing dimethyl carbonate comprising:

• a first step of introducing a feed gas containing carbon monoxide and methyl nitrite into a reactor and catalytically reacting carbon monoxide with methyl nitrite in a gas phase in the presence of a solid catalyst in the reactor, to prepare a reaction product gas comprising dimethyl carbonate mixed with a by-product containing nitrogen monoxide;
• a second step of bringing the reaction gas into contact with an absorption medium comprising dimethyl oxalate in a dimethyl carbonate-absorbing column, to provide a liquid fraction containing dimethyl carbonate absorbed by the absorbing medium and a non-condensed gas fraction containing nitrogen monoxide and non-reacted carbon monoxide and methyl nitrite;
• a third step of bringing the non-condensed gas fraction of the second step into contact with molecular oxygen and methyl alcohol in a methyl nitrite-regenerating column, to regenerate methyl nitrite from the nitrogen monoxide and provide a regenerated gas fraction containing the regenerated methyl nitrite;
• and
• a fourth step of collecting dimethyl carbonate from the liquid fraction of the second step, wherein before the fourth step, the second step liquid fraction is brought into contact with carbon monoxide, to recover methyl nitrite accompanying with the second step liquid fraction and allow the recovered methyl nitrite and the carbon monoxide to be incorporated into the non-condensed gas fraction of the second step in the absorbing column;
• and after the third step, at least a major portion of the resultant regenerated gas fraction of the third step containing carbon monoxide and methyl nitrite is recycled as a feed gas to the reactor of the first step.