Abstract: A process for continuously preparing the tert-butyl ester of an ethylenically unsaturated carboxylic acid, by a) reacting an ethylenically unsaturated carboxylic acid with isobutene in the presence of an acidic catalyst to give an esterification mixture; b) removing the acidic catalyst; c) removing low-boiling components; and d) supplying a tert-butyl ester-comprising liquid to a distillation apparatus and subjecting it to purifying distillation in the distillation apparatus, where d1) in the distillation apparatus the tert-butyl ester-comprising liquid is separated into a tert-butyl ester-comprising gaseous top product and a carboxylic acid-comprising liquid bottom product; d2) the tert-butyl ester-comprising gaseous top product is at least partly condensed and the condensate is recycled partly as reflux to the distillation apparatus; d3) the carboxylic acid-comprising liquid bottom product is recycled at least partly to step a); d4) carboxylic acid-comprising liquid bottom product is drawn off and passed to

Abstract: A process for continuously preparing the tert-butyl ester of an ethylenically unsaturated carboxylic acid, by a) reacting an ethylenically unsaturated carboxylic acid with isobutene in the presence of an acidic catalyst to give an esterification mixture; b) removing the acidic catalyst; c) removing low-boiling components; and d) supplying a tert-butyl ester-comprising liquid to a distillation apparatus and subjecting it to purifying distillation in the distillation apparatus, where d1) in the distillation apparatus the tert-butyl ester-comprising liquid is separated into a tert-butyl ester-comprising gaseous top product and a carboxylic acid-comprising liquid bottom product; d2) the tert-butyl ester-comprising gaseous top product is at least partly condensed and the condensate is recycled partly as reflux to the distillation apparatus; d3) the carboxylic acid-comprising liquid bottom product is recycled at least partly to step a); d4) carboxylic acid-comprising liquid bottom product is drawn off and passed to

Abstract: A process for continuously preparing the tert-butyl ester of an aliphatic C1-C4 carboxylic acid comprises: a) the reaction of an aliphatic C1-C4 carboxylic acid with isobutene in the presence of an acidic catalyst to give an esterification mixture (G1); b) the partial evaporation of the esterification mixture (G1), giving a liquid first high boiler phase (SPh1) comprising the acidic catalyst, and a first vapor (B1) comprising tert-butyl ester; c) the fractional condensation of the first vapor (B1) by partially condensing the first vapor (B1) at a first pressure and a first temperature and obtaining a first condensate (K1), partially condensing the uncondensed second vapor (B2) at a second pressure and a second temperature and obtaining a second condensate (K2), the first temperature being 0 to 45° C. below the condensation temperature of the tert-butyl ester at the first pressure and the second temperature being 45 to 80° C.

Abstract: A process for continuously preparing the tert-butyl ester of an aliphatic C1-C4 carboxylic acid comprises: a) the reaction of an aliphatic C1-C4 carboxylic acid with isobutene in the presence of an acidic catalyst to give an esterification mixture (G1); b) the partial evaporation of the esterification mixture (G1), giving a liquid first high boiler phase (SPh1) comprising the acidic catalyst, and a first vapor (B1) comprising tert-butyl ester; c) the fractional condensation of the first vapor (B1) by partially condensing the first vapor (B1) at a first pressure and a first temperature and obtaining a first condensate (K1), partially condensing the uncondensed second vapor (B2) at a second pressure and a second temperature and obtaining a second condensate (K2), the first temperature being 0 to 45° C. below the condensation temperature of the tert-butyl ester at the first pressure and the second temperature being 45 to 80° C.

Abstract: A compression device for compression of an oxidant for a fuel cell stack includes an oxidant compressor for compressing the oxidant, and an oxidant cooler for cooling the compressed oxidant. The oxidant compressor and the oxidant cooling device are connected to a common coolant circuit.