Recovery of alkylation acid

Claim 1

A PROCESS FOR PURIFYING SPENT ACID CATALYST IN THE ALKYLATION OF ISOPARAFFINS WITH OLEFINS WHICH INCLUDES THE STEPS OF INTRODUCING SAID SPENT ACID INTO THE LOWER SECTION OF A PURIFICATION ZONE IN THE FORM OF AT LEAST ONE DOWNWARDLY DIRECTED JET, WITHDRAWING LIQUID FROM THE TOP OF THE PURIFICATIONS ZONE AND REINTRODUCING A PORTION OF THE WITHDRAW LIQUID INTO THE LOWER SECTION OF SAID PURIFICATION ZONE, ABOVE THE POINT OF INTRODUCTION OF SAID SPENT ACID, IN THE FORM OF AT LEAST ONE UPWARDLY DIRECTED JET, INTRODUCING A LIQUEFIED NORMALLY GASEOUS HYDROCARBON INTO SAID PURIFICATION ZONE ABOVE THE POINT OF RE-INTRODUCTION OF SAID WITHDRAW LIQUID, VAPORIZING THE LIQUEFIED HYDROCARBON WITHIN SAID PURIFICATION ZONE AND THEREBY EFFECTING REFRIGERATION OF SAID ZONE, AND WITHDRAWING PURIFIED ACID FROM SAID PURIFICATION ZONE BELOW THE POINT OF INTRODUCTION OF SAID SPENT ACID.