Production of aromatic hydrocarbons

Claim 1

A PROCESS FOR THE PRODUCTION OF DURENE AND RECOVERY OF PARA-XYLENE FROM MIXED XYLENES WHICH COMPRISES CONTACTING IN A CONDENSATION ZONE A MIXTURE OF C3 AROMATICS CONTAINING AT LEAST META- AND PARA-XYLENE AND A C9 AROMATICE STREAM CONSISTING ESSENTIALLY OF PSEUDOCUMENE, OBTAINED FROM SOURCES DESCRIBE HEREINAFTER, WITH FORMALDEHYDE IN THE PRESENCE OF AN ACIDIC CATALYST SELECTED FROM THE GROUP CONSISSTING OF LIQUID ACID CATALYSTS CONTAINING SULFURIC ACID AS ACTIVE INGREDIENT AND SOLID ACIDIC CATALYSTS SELECTED FROM THE GROUP CONSISTING OF SILICA GEL CONTAINING FROM 0.1 TO 15% BY WEIGHT OF AN ABSORBED MINERAL ACID AND CALCINED SILICA ALUMINA COMPOSITE CONTAINING FROM 0.1 TO 13% ALUMINA TO PRODUCE A CONDENSATION PRODUCT CONTAINING AT LEASR THE CORRESPONDING DIARYLMETHANES OF ONLY A PORTION OF THE C3 AROMATICS AND OF PSEUDOMENE, SEPARATING THE EFFLUENT FROM SAID CONDENSATION ZONE BY FRACTIONAL DISTILLATION INTO A FIRST C3 AROMATICS STREAM, FIRST C9 AROMATICS STREAM CONSISTING ESSENTIALLY OF PSEUDOCUMEME AND A STREAM CONTAINING AT LEAST A PORTION OF SAID CONDENSATION PRODUCT, HYDROCRACKING AT LEAST A PORTION OF SAID CONDENSATION PRODUCT AT AN ELEVATED TEMPERATURE UNDER HYDROCRACKING CONDITIONS IN THE PRESENCE OF HYDROGEN AND OF A HIGH MELTING ESSENTIALLY NUETRAL INORGANIC SUBSTANCE HAVING HYDROGENATING ACTIVITY, SELECTED FROM THE GROUP CONSISTING OF OXIDES, SULFIDES, AND COMPOSITES THEREOF OF GROUP VI TO GROUP VIII METALS HAVING ATOMIC NUMBERS OF AT LEAST 24 AND OF ACTIVATED CARBON, AS CATALYST, SUBJECTING THE HYDROCRACKED PRODUCT TO FRACTIONAL DISTILLATION TO RECOVER THEREFROM A SECOND C3 AROMATICS STREAM, A SECOND C9 AROMATICS STREAM AND A C10 AROMATICS STREAM CONTAINING AT LEAST ABOUT 90% DURENE, SEPARATING SAID SECOND C9 AROMATICS STREAM TO RECOVER THEREFROM A THIRD C9 AROMATICS STREAM CONSISTING ESSENTIALLY OF PSEUDOCUMENE, RETURNING TO SAID CONDENSATION ZONE AT LEAST SAID SECOND C8 STREAM AND SAID FIRST AND THIRD C9 STREAM, AND RECOVERING PARA-XYLENE AND DURENE IN HIGH PURITY FROM SAID FIRST C8 STREAM AND SAID C10 STREAM, RESPECTIVELY.