Benzene purification process by treatment with sulfuric acid

Claim 1

A PROCESS FOR PURIFYING A CRUDE BENZENE CONTAINING 94-97 MOLE PERCENT BENZENE, 3-6 MOLE PERCENT ALKENE AND DIENE IMPURITIES AND BEING SUBSTANTIALLY FRE OF SATURATED HYDROCARBONS WHICH COMPRISES ACID-TREATING SAID CRUDE BENZENE WITH 20 TO 67 WT. PERCENT AQUEOUS SULFURIC ACID THAT CONTAINS 80 TO 90 WEIGHT H2SO4 TO CONVERT SAID IMPURITIES INTO SUBSTANCES READILY SEPARABLE FROM THE BENZENE, SAID IMPURITIES AND THE SULFURIC ACID BEING REACTED IN THE ABSENCE FO OTHER REACTIVE SUBSTANCES AT 60* TO 200*F., SEPARATING THE RESULTING ACIDTREATED BENZENE IN LIQUID PHASES AS AN UPPER LAYER FROM RESULTING USED AQUEOUS SULFURIC ACID CONTAINING THE REACTED OLEFINIC IMPURITIES REMOVED FROM THE BENZENE, TREATING THE SEPARATED ACID-TREATED BENZENE WITH ADMIXED AQUEOUS ALKALI TO REMOVE ACID IMPURITIES THEREFROM, SEPARATING THE RESULTING LIQUID BENZENE AS AN UPPER LAYER FROM THE AQUEOUS ALKALI CONTAINING ACIDIC IMPURITIES EXTRACTED FROM THE BENZENE, THEN DISTILLING THE ALKALI-TREATED BENZENE TO OBTAIN A DISTILLATE CONTAINING 99+MOLE PERCENT BENZENE.