Patent ID: 8586784
Filing Date: 2013-11-19
Classification: C07C,Y02P

Abstract:
1. A method for the continuous catalytic hydrogenation of at least one hydrogenatable compound using a hydrogenation gas in the presence of at least one solid catalyst disposed in a fixed bed, said method comprising: carrying out the hydrogenation in at least three series-connected hydrogenation units, and operating at least the first two hydrogenation units in loop operating mode, with, in the hydrogenation units, catalyst volumes being used which deviate by a maximum of 20% from the catalyst volumes which are obtained by a process which comprises a) determining the kinetics of the hydrogenation to be carried out, b) calculating the required catalyst volume for the reactor types used for preset reactor input and output concentrations, c) determining the required total catalyst volume by combining the calculated catalyst volumes, in each case only those combinations being performed which lead to the desired end concentration of the starting material to be hydrogenated used, d) preparing a curve from the total catalyst volumes determined in c) plotted against the conversion rate, e) determining the minimum of the curve prepared in d), and f) determining the catalyst volumes, of the individual hydrogenation units, to be assigned to the minimum, wherein the at least one hydrogenatable compound is selected from the group consisting of benzoic acid, an ester of benzoic acid, an anhydride of benzoic acid, 1-naphthoic acid, an ester of 1-naphthoic acid, an anhydride of 1-naphthoic acid, 2-naphthoic acid, an ester of 2-naphthoic acid, an anhydride of 2-naphthoic acid, a dicarboxylic acid of benzene, a mono-ester of a diarboxylic acid of benzene, a bis-ester of a dicarboxylic acid of benzene, an anhydride of a dicarboxylic acid of benzene, a polycarboxylic acid of benzene, a polycarboxylic acid of benzene that is partially esterified, a polycarboxylic acid of benzene that is fully esterified, an anhydride of a polycarboxylic acid of benzene, a polycarboxylic acid of diphenyl, a polycarboxylic acid of diphenyl that is partially esterified, a polycarboxylic acid of diphenyl that is fully esterified, an anhydride of a polycarboxylic acid of diphenyl, a polycarboxylic acid of naphthalene, a polycarboxylic acid of naphthalene that is partially esterified, a polycarboxylic acid of naphthalene that is fully esterified, an anhydride of a polycarboxylic acid of naphthalene, a polycarboxylic acid of diphenyl oxide, a polycarboxylic acid of diphenyl oxide that is partially esterified, a polycarboxylic acid of diphenyl oxide that is fully esterified, an anhydride of a polycarboxylic acid of diphenyl oxide, a polycarboxylic acid of anthracene, a polycarboxylic acid of anthracene that is partially esterified, a polycarboxylic acid of anthracene that is fully esterified, an anhydride of a polycarboxylic acid of anthracene, and combinations thereof.