US Patent 7253304 Carbonylation process

Disclosed is a carbonylation process wherein a mixture of a dialkyl carbonate and halide compound is contacted with carbon monoxide in the presence of a metal selected from Group VIII of the Periodic Table to co-produce carbon dioxide and a carbonyl compound selected from a carboxylic acid, an alkyl carboxylate ester, a carboxylic acid anhydride or a mixture of any two or more thereof. The carbon dioxide co-product of the process may be recovered, and sold or further reacted with a suitable substrate to produce useful chemicals such as urea or cyclic carbonates.