Manufacture of acrylonitrile from

Claim 1

THE PROCESS FOR PRODUCTION OF ACRYLONITRILE WHICH COMPRISES CONTINUOUSLY REACTING ACETYLENE AND HYDROCYANIC ACID IN THE PRESENCE OF AN ACRYLONITRILE-FORMING AQUEOUS CATALUYST SOLUTION AT 75-90* C., COOLING THE GASEOUS PRODUCTS OBTAINED TO A TEMPERATURE OF 20* TO 30* C. AND RETURNING THE CONDENSATE TO THE CATALYST SOLUTION; ABSORBING PART OF THE UNCONDENSED GASES AND SUBSTANTIALLY ALL OF THE ACRYLONITRILE PRESENT INTO WATER, RECYCLING AT LEAST A PORTION OF THE UNABSORBED GASES TO TEH CATALYST SOLUTION AFTER TREATING THEM AT -30* TO 15* C. WITH A SOLVENT FOR THE PREFERENTIAL ABSORPTION OF VINYL ACETYLENE, SAID SOLVENT BEING SELECTED FROM THE GROUP CONSISTING OF ACETONE, METHANOL AND ETHYL BENZENE, STRIPPING THE ACRYLONITRILE-CONTAINING AQUEOUS SOLUTION WITH ACETYLENE TO REMOVE IMPURITIES CONSISTING SUBSTANTIALLY ENTIRELY OF CYANOBUTADIENE AND RECYCLING AT LEAST A PART OF THE CYANOBUTADINE-CONTAINING ACETYLENE SO PRODUCED FOR USE AS REACTANT MATERIAL; DISTILLING THE AQUEOUS ACRYLONITRILE SOLUTION, FEED FROM CYANOBUTADINE, TO PRODUCE ACRYLONITRILE AND WATER AS DISTILLATE ALONG WITH BY-PRODUCT IMPURITIES AND UNREACTED FEED MATERIALS, LEAVING WATER FREE FROM ACRYLONITRILE AS STILL BOTTOMS, AND RETURNING THESE STILL BOTTOMS TO THE PROCESS FOR USE IN ABORBING SUBSEQUENTLY PRODUCED ACRYLONITRILE; REMOVING BY-PRODUCT IMPURITIES AND UNREACTED FEED MATERIALS FROM THE ACRYLONITRILE-WATER DISTILLATE BY DISTILLATION, SEPARATING THE ACETYLENE FROM IMPURITIES BY SCRUBBING WITH WATER, AND REUTILIZING THE ACETYLENE SO SEPARATED AS REACTANT MATERIAL; COOLING THE WATER-ACRYLONITRILE MIXTURE AFTER REMOVAL OF THE VOLATILE IMPURITIES AND PERMITING LAYERS OF THE MIXTURE, SEPARATING THE TWO LAYER THUS FORMED AND RETURNING THE LOWER OR AQUEOUS LAYER TO THE PROCESS TO BE ADMIXED WITH AQUEOUS ACRYLONITRAILE SOLUTION SUBSEQUENTLY PRODUCED, DISTILLING THE UPPER OR ORGANIC LAYER TO PRODUCE PURE ACRYLCONITRILE DISTILCATE CONTAINING A SMALL AMOUNT OF WATER AND A STILL BOTTOMS CONTAINING SOME ACRYLONI TRILE ALONG WITH NON-VOLATILE IMPURITUES, RECOVERING THE ACRYLONITRILE FROM THE BOTTOM BY DISTILLATION, AND RETURNING THE ACRYLONITRILE SO RECOVERED TO THE PROCESS TO BE ADMIXED WITH SUBSEQUENTLY PRODUCED IMPURE ACRYLONITRILE.