Catalytic cracking of pretreated hydrocarbon oils

Claim 1

A PROCESS FOR THE CATALYTIC CRACKING OF GAS OILS WHICH CONTAIN ORGANIC NITROGEN COMPOUNDS IN AMOUNTS DELETERIOUS TO THE CATALYTIC CRACKING STEP, WHICH PROCESS COMPRISES SIMULTANEOUSLY CONTACTING AT LEAST ONE PETROLEUM GAS OIL BOILING BELOW ABOUT 800* F. SELECTED FROM THE GROUP CONSISTING OF VIRGIN GAS OIL AND THERMALLY CRACKED GAS OIL, WITH (A) A LIQUID SELECTIVE SOLVENT SELECTED FROM THE GROUP CONSISTING OF SULFUR DIOXIDE, PHENOL, CRESOL, B,B'' DICHLORODIETHYL ETHER, METHYL CELLOSOLVE, METHYL CARBITOL, DIMETHYLFORMAMIDE, DIMETHYLSULFOLANE, THIOSULFONIC ACID ESTERS, TETRAHYDROFURFURYL ALCOHOL, DIACETONE ALCHOL AND ACETONYL ACETONE, AND (B) AN ACID SELECTED FROM THE GROUP CONSISTING OF HYDROCHLORIC, CONCENTRATED SULFURIC, SULFUROUS, SULFONIC, AMIDO-SULFONIC, TRICHLOROACETIC, TRIFLUORACETIC AND FORMIC, SIAD ACID BEING USED IN AN AMOUNT BETWEEN ABOUT 0.005 AND 0.5 PERCENT BY WEIGHT OF SAID GAS OIL AND SAID SOLVENT BEING USED IN AN AMOUNT SLIGHTLY IN EXCESS OF THAT NECESSARY TO PRODUCE A SEPERATE EXTRACT PHASE, WHEREBY SEPARATE EXTRACT AND RAFFINATE PHASES ARE PRODUCED, SAID EXTRA PHASE COMPRISING PRECIPITATED OF SAID ORGANIC NITROGEN COMPOUNDS AND A MAJOR PORTION OF SAID SOLVENT AND SAID RAFFUNATE PHASE COMPRISING OIL OF REDUCED NITROGEN CONTENT DISSOLVED AND OCCLUDED SOLVENT, SEPERATING SAID RAFFINATE PHASE FROM SAID EXTRA PHASE, RECOVERING GAS OIL TO REDUCED NITROGEN CONTENT FROM SAID RAFFINATE PPHASE AND CONTACTING SAID RECOVERED GAS OIL WITH A SOLID CATALYTIC CRACKING CATALYST UNDER CONDITIONS TO EFFECT CATALYTIC CRACKING THEREOF.