Process for the purification of benzene

Claim 1

AN IMPROVEMENT IN A PROCESS FOR THE PURIFICATION OF CRUDE BENZENE CONTAINING UNSATURATED HYDROCARBON AND SULFUR IMPURITIES BY POLYMERIZING THE IMPURITIES WHICH WILL POLYMERIZE TO POLYMERS WHEN SAID CRUDE BENZENE IS MAINTAINED AT AN ELEVATED TEMPERATURE AND PRESSURE FOR A SUSTAINED PERIOD OF TIME, REMOVING THE BENZENE AND LOW BOILING IMPURITIES AS VAPORS FROM SAID POLYMERS WHILE LEAVING SAID POLYMERS TO REMAIN AS LIQUID RESIDUE, HYDROGENATING SAID VAPORS, AND REMOVING THE BENZENE FROM THE PRODUCTS OF SAID HYDROGENATION, SAID IMPROVEMENT COMPRISING TREATING SAID CRUDE BENZENE PRIOR TO SAID POLYMERIZ ING STEP BY CONTACTING A HYDROGEN-CONTAINING COKE OVEN GAS WITH SAID CRUDE BENZENE WHILE SAID CRUDE BENZENE IS A HOT LIQUID WHOSE TEMPERATURE IS HIGHER THAN THAT OF THE GAS AND WHILE ANY INDIRECT TRANSFER OF HEAT TO SAID GAS IS AVOIDED SO THAT SAID GAS IS HEATED BY DIRECT TRANSFER OF HEAT FROM THE LIQUID TO THE GAS AND IS WASHED WITH THE LIQUID, SEPARATING THE SAID GAS FROM SAID LIQUID WITHOUT SUBSTANTIAL VAPORIZATION OF SAID LIQUID, AND THEREAFTER USING SAID LIQUID AS THE CRUDE BENZOL FRO SAID POLYMERIZING AND SAID GAS FOR HYDROGENATING SAID VAPORS.