Sisas Societa Italiana Serie Acetica E Sintetica Spa

La Chemical Spa

Roberto Ruggieri

Davino Gelosa

Franco Codignola

Aldo Bertola

Salvatore Cassarino

Massimo Morbidelli

Gianni Carvoli

Agostino Tricella

Sergio Conni

Giovanni Ranghino

Andrea Sliepcevich

Process for the esterification of organic acids with alcohols in a reactor of the chromatographic type in which the heterogeneous solid phase is capable of acting both as an esterification catalyst and as a means exhibiting preferential adsorption towards one of the reaction products (typically water). The process to which the present invention relates is particularly improved compared with conventional technology owing to the use, as the means for regenerating the catalyst, of a desorbent to which has been added a second compound, generally the anhydride of the acid used in the esterification reaction, which, by chemical reaction, completes the removal of the adsorbed water.

Process for esterification in a chromatographic reactor

An oligomer of an aspartic acid is provided having repeating monomeric units of aspartic acid of the formula: ##STR1## and by a first chain unit having formula: ##STR2## and a chain stopper unit A which is: ##STR3## wherein X is an alkali metal, R represents H or an alkyl containing from 1 to 4 carbon atoms and R.sub.1 is H or the group --COOX.

Polymers of aspartic acid with sequestering activity process for their

In producing maleic anhydride by catalytic oxidation of butane in vapor phase, the reaction mixture consists of butane and a recycle gaseous current made of compressed air and exhaust gas recovered from the absorption stage by a solvent of the maleic anhydride produced; oxygen and total butane concentration in the recycle stream are controlled.

Process to recycle exhaust gases from n-butane conversion into maleic

In the purification of maleic anhydride obtained with an oxidation process, by means of absorption with an organic solvent and fractionation of the resulting liquid phase and purification of the crude maleic anhydride thus separated, the above purification being accomplished through two serially placed fractionating columns, the accumulation of polymerisable acrylic acid overhead the first fractionating column of the purification section, and of water as well as of maleic acid overhead the second fractionating column of the purification section, is avoided by carrying the overhead vapours of said first fractionating column to an absorption tower, preferably operating with the same absorption organic solvent used to absorb the crude maleic anhydride from the reaction mixture, and by carrying the overhead vapours of said fractionating column of said purification section to two condensers placed in series, so that the gaseous fraction, coming out of the first condenser, is fed to said second condenser.

Process and plant for the purification of raw maleic anhydride recovered

Process for the recovery of maleic anhydride from a gaseous mixture thereof, in which the gaseous mixture containing maleic anhydride is contacted with an absorbant for the maleic anhydride to give an enriched absorbant. Water present in the enriched absorbant is then substantially removed by contacting the enriched absorbant with a water adsorbant or with a low humidity stripping gas to produce a dried enriched absorbant. The maleic anhydride is then recovered from the dried enriched absorbant.

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Milan, Italy

Roberto Ruggieri