Dimerization method

Claim 1

METHOD FOR THE PREPARATION OF CYCLIC DI-P-XYLYLENE WHICH COMPRISES: (A) COOLING A STREAM CONTAINING STEAM AND P-XYLYLENE RADICALS TO A TEMPERATURE BETWEEN ABOUT 450*C. AND ABOUT 800*C.; (B) THERMALLY AND PHYSICALLY ISOLATING SAID STREAM FROM NON-WETTED SURFACES MAINTAINED AT TEMPERATURES BELOW ABOUT 350*C, (C) ABSORBING A SUBSTANTIAL PORTION OF THE P-XYLYLENE DIRADICALS FROM SAID STREAM BY CONTACTING SAID STREAM IN A FIRST SPRAY ZONE WITH A SPRAY OF A QUENCH LIQUOR CONTAINING A SOLVENT FOR THE P-XYLYLENE DIRADIICALS WHEREIN SAID DIRADICALS CAN DIMERIZE TO THE CYCLIC DIMER, DI-P-XYLYLENE, SAID QUENCH LIQUOR MAINTAINED AT A TEMPERATURE ABOVE THE CONDENSATION TEMPERATURE OF THE STREAM IN SAID STREAM (D) DESUPERHEATING SAID STREAM IN SAID FIRST SPRAY ZONE BY CONTACTING SAID STREAM WITHIN SAIS SPRAY OF QUENCH LIQUOR AND VAPORIZING A PORTION OF SAID QUENCH LIQUOR SPRAY WITHOUT EXCESSIVE REDUCTION OF SPRAY VOLUME; (E) FURTHER CONTACTING THE EFFLUENT FROM SAID FIRST SPRAY ZONE WITH A FINE SPRAY OF SAID QUENCH LIQUOR IN A SECOND SPRAY ZONE, SAID QUENCH LIQUOR MAINTAINED AT A TEMPERATURE ABOVE THE CONDENSATION TEMPERATURE OF THE STEAM IN SAID STREAM UNDER CONDITIONS SUFFICIENT TO REMOVE SUBSTANTIALLY ALL OF THE RESIDUAL P-XYLENE DIRADICALS FROM SAID STREAM; (F) MAINTAINING ALL SURFACES IN SAID FIRST AND SECOND SPRAY ZONES WET WITHIN SAID QUENCH LIQUOR; (G) SEPARATING THE QUENCH LIQUOR FROM THE EFFLUENT FROM SAID SECOND SPRAY ZONE AND RECOVERING THE CYCLIC DI-PXYLYLENE FROM SAID QUENCH LIQUOR.