Two-stage hydropyrolysis-cracking process for producing ethylene

Claim 1

A PROCESS FOR PRODUCING ETHYLENE FROM HIGHER HYDROCARBONS COMPRISING A. INTRODUCING A HYDROCARBON OIL AND HYDROGEN TO A FIRST STAGE HYDROPYROLYSIS ZONE, THE MOL RATIO OF HYDROGEN TO HYDROCARBON OIL BEING AT LEAST 1/1, B. HYDROPROLYZING THE HYDROCARBON OIL IN THE PRESENCE OF THE HYDROGEN IN SAID ZONE UNDER CONDITION OF TEMPERATURES IN THE RANGE OF ABOUT 600*C 600*C TO 900*C, PRESSURES OF AT LEAST ABOUT 5 ATMOSPHERES GAUGE AND RESIDENCE TIME IN THE RANGE OF ABOUT 0.1 TO 60 SECONDS, TO PROSUCE A HYDROPYROLYSIS EFFLUENT, C. INTRODUCING SUBSTANTIALLY ALL OF THE HYDROPYROLYSIS EFFUENT TO A SECOND-STAGE CRACKING ZONE AND SUBJECTING SAID EFFUENT TO CRACKING CONDITIONS OF TEMPERATURES IN THE RANGE OF ABOUT 750*C TO 900*C, PRESSURES NOT IN EXCESS OF ABOUT 2 ATMOSPHERES GAUGE AND RESIDENCE TIMES IN THE RANGE OF ABOUT 0.01 TO 10 SECONDS, TO PRODUCE A CRACKING ZONE EFFLUENT, D. SEPARATING SAID CRACKING ZONE EEFFLUENT INTO A HYDROGEN STREAM, A METHANE STREAM, AMN ETHYLENE STREAM, AN ETHANE STREAM, AND A HIGHER HYDROCARBON STREAM, E. RECYCLING THE HYDROGEN STREAM TO THE FIRST STAGE HYDROPROLYSIS ZNE AND RECYCLING THE ETHANE STREAM TO THE SECOND-STAGE CRACKING ZONE, F. AND RECOVERING THE METHANE STREAM AND ETHYLENE STREAM.