METHOD FOR PURIFYING PARAXYLENE

• Main Authors: MONSON JOHN JOSEPH, DAVID LEE JOHNSON, MARK PAUL HAGEMEISTER
• Format: Patent
• Language: English
• Published: 17.07.2014
• Subjects: ACYCLIC OR CARBOCYCLIC COMPOUNDS; APPARATUS THEREFOR; CHEMISTRY; CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION ORPROCESSING OF GOODS; GENERAL METHODS OF ORGANIC CHEMISTRY; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; METALLURGY; ORGANIC CHEMISTRY; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINSTCLIMATE CHANGE

PROBLEM TO BE SOLVED: To provide an efficient method for producing paraxylene.SOLUTION: The method for producing paraxylene includes: (i) a step of reacting toluene with methanol under an alkylation condition in the presence of a catalyst suitable for producing products comprising paraxylene and oxygenates, (ii) a step of recovering the products comprising paraxylene and oxygenates from the step (i), (iii) a step of subjecting the recovered products from the step (ii) to purification, and (iv) a step of recovering a paraxylene fraction from the step (iii), wherein the fraction has a BI (bromine index) of 30 or less, and contains the oxygenate impurities in an amount smaller than that in the products recovered from the step (ii), and the catalyst includes a porous crystalline material having a diffusion parameter for 2,2-dimethylbutane of 0.1-15 secwhen measured at a temperature of 120°C and a 2,2 dimethylbutane pressure of 60 torr (8 kPa) wherein the porous crystalline material has undergone prior treatment with steam at a temperature of at least 950°C to adjust the diffusion parameter of the material to 0.1-15 sec.