| 摘要 |
PURPOSE:To advantageously obtain lactones by circulating hydrogen-containing gas used in hydrogenation reaction to reaction zone and making carbon monoxide concentration in gas phase of reaction zone to a specific value in hydrogenation of dicarboxylic acids in liquid phase in the presence of ruthenium catalyst. CONSTITUTION:In production of lactones by liquid phase hydrogenation 1 of dicarboxylic acid, dicarboxylic acid anhydride and/or dicarboxylic acid ester 4 in the presence of a ruthenium catalyst, at least a part of hydrogen-containing gas used in the hydrogenation reaction 1 is circulated into the reaction zone 1 and simultaneously CO concentration is kept below 400ppm (vol%) in the reaction zone 1 by, e.g. a method of purging a part of the circulating gas, or CO in the gas is made to harmless in converting to methane with providing reactor 7 converting to methane in the circulating path of the gas, etc., to inhibit decrease of activity of ruthenium catalyst and to stably continue the hydrogenation reaction for a long period of time to industrially advantageously obtain the aimed compound. |
