Process for separating acrylonitrile and ammonia from gaseous mixtures

Claim 1

A PROCESS FOR SEPARATING ACRYLONITRILE AND AMMONIA FROM GASEOUS MIXTURES WHICH COMPRISES CONDUCTING A GASEOUS MIXTURE INTO A FIRST STAGE WHERE IT IS SCRUBBED COUNTERCURRENTLY WITH A WASHING LIQUID THEREBY OBTAINING AN AMMONIA CONTAINING RESIDUAL GAS AND ACRYLONITRILE AND RESIDUAL AMMONIA CONTAINING WASHING LIQUID, WITHDRAWING THE AMMONIA-CONTAINING RESIDUAL GAS AT THE HEAD OF SAID STAGE, DISCHARGING THE ACRYLONITRILE AND RESIDUAL AMMONIACONTAINING WASHING LIQUID AT THE BOTTOM OF SAID STAGE, CONDUCTING IT INTO A SECOND STAGE APPROXIMATELY AT ITS CENTER WHERE RESIDUAL AMMONIA IS DESORBED BY MEANS OF AN EXPELLING GAS INTRODUCED NEAR THE BOTTOM OF SAID SECOND STAGE, REMOVING THE DESORPTION GAS AT THE HEAD OF THE SECOND STAGE, SUPPLYING ADDITIONAL WASHING LIQUID AT THE HEAD OF THE SECOND STAGE, WITHDRAWING THE TOTAL AMOUNT OF WASHING LIQUID CONTAINING THE ACRYLONITRILE AT THE BOTTOM OF SAID SECOND STAGE, INTRODUCING SAID WASHING LIQUID CONTAINING THE ACRYLONTRILE APPROXIMATELY AT THE CENTER INTO A THIRD AND HEATED STAGE, DISTILLING SAID LIQUID TO SEPARATE THE ACRYLONTRILE, DISCHARGING SAID ACRYLONTRILE AT THE HEAD OF SAID THIRD STAGE, WITHDRAWING THE WASHING LIQUID FROM THE SUMP OF THE THIRD STAGE, RECYCLING IT INTO THE FIRST AND SECOND STAGE AT THE HEAD THEREOF, THE WASHING LIQUID ABSORBING THE ACRYLONITRILE BEING A MEMBER SELECTED FROM THE GROUP CONSISTING OF TRIMETHYLBENZENES, XYLENES, TOLUENE, CUMENE, P-CYMENE, DIPHENYL, TETRALINE, DECALINE, A-METHYLNAPHTHALENES, A-ETHYL-NAPHTHLENES, ANISOL, DIPHENYL OXIDE, AND MIXTURES THEREOF.