Process for preparing olefinic hydrocarbons and recycle acid catalyst for absorptionprior to alkylation

Claim 1

A PROCESS OF ALKYLATING ISOPARAFFINIC HYDROCARBONS AND OLEFINS WITH A CATALYST OF THE SULFURIC ACID TYPE COMPRISING THE STEPS OF CONTACTING THE ISOPARAFFINS AND OLEFINS IN THE PRESENCE OF SAID CATALYST IN A REACTION STEP, SEPARATING THE REACTION MIXTURE IN A SEPARATING STEP MAINTAINED AT PRESSURES SUFFICIENT TO KEEP THE HYDROCARBONS IN LIQUID PHASE, INTO A LIQUID CATALYST PHASE AND A HYDROCARBON PHASE, SIMULTANEOUSLY COOLING THE ACID CATALYST AND VAPORIZING HYDROCARBONS FROM THE CATALYST PHASE IN A STRIPPING STEP OPERATED AT PRESSURES BELOW THOSE OF THE SEPARATNG STEP, FURTHER COOLING THE STRIPPED CATALYST AND PASSING SAID CATALYST TO AN ABSORPTION STEP AND THERE CONTACTING IT WITH AN OLEFIN-BEARING FEED STOCK, AND RECYCLING THE ACID CATALYST WITH THE ABSORBED OLEFINS TO THE REACTION STEP.