PROCESS MAKES FORMIC ACID FROM SYN GAS.

A description is given of a process that achieves formic acid synthesis with a net consumption of carbon monoxide and water. It has only minor requirements for makeup methanol and catalyst. In this process, methanol is carbonylated to methyl formate at moderate to high pressure. The ester is subsequently autocatalytically hydrolyzed to produce formic acid and methanol, with methanol being recycled to the carbonylation step. Synthesis gas of the selected quality is compressed from the battery limits delivery pressure and fed to the reactor system, in a typical plant, where the available syn gas contains more than 90 mol% CO, a single back-mixed reactor is used. For CO concentrations in the syn feed below this, and as low as 50 mol; mol backmixed reactor system is preferred. Economics are also presented. 4 refs.