IMPROVED SOLVENT FOR EXTRACTION OF MALEIC ANHYDRIDE FROM GAS STREAM Russian patent published in 2017 - IPC C08F222/02 C07D307/60 C08F22/06 C08F222/08 

FIELD: chemistry.

SUBSTANCE: invention relates to methods of producing raw maleic anhydride. In particular, method includes steps where: reactor output stream, containing maleic anhydride, is fed into bottom part of absorption column, where it comes into contact with a non-cyclic solvent, that is fed close to its upper part and is a diester, having a boiling point under normal conditions between 250 °C and 350 °C, solubility of fumaric acid at least 0.06 wt% at temperature of 60 °C, solubility of maleic anhydride at least 10 wt% at temperature of 60 °C, water solubility not higher than 100 mg/l, density, different from water density at least to 0.020 g/ml, and a water-soluble hydrolysis product with molecular weight not higher than that of pentanol, with transfer of maleic anhydride of outlet stream of reactor into a solvent, wherein gas stream to be extracted is blown off from absorption column, and enriched solvent, containing maleic anhydride, is removed from absorption column near bottom of absorber and directed into flash tower near its middle part, untreated maleic anhydride is removed from stripping column near its middle or upper part.

EFFECT: methods make it possible to use cheaper solvent than phthalates.

11 cl, 1 dwg, 1 tbl