Separation of isomeric c aromatic hydrocarbons by selective sulfonation

Claim 2

A PROCESS OF RECOVERING ORTHO XYLENE WHICH COMPRISES CONTACTING A MIXTURE OF ISOMERIC XYLENES COMPRISING ORTHO XYLENE WITH SULFURIC ACID OF 70 TO 7K% STRENGTH AT A TEMPERATURE VARYING INVERSELY WITH THE STRENGTH OF THE ACID IN A MANNER SUCH THAT WHEN THE ACID STRENGTH IS 70% THE TEMPERATURE IS ABOUT 135*C., AND WHEN THE ACID STRENGTH IS 75% THE TEMPERATURE IS ABOUT 125*C., SEPARATING A SOLUTION OF ORTHO XYLENE SULFONIC ACID IN SULFURIC ACID. HEATING THE SOLUTION TO A HYDROLYZING TEMPERATURE OF AT LEAST ABOUT 150*C., HYDROLYZING THE ORTHO XYLENE SULFONIC ACID, AND RECOVERING ORTHO XYLENE.

Claim 3

A PROCESS FOR RECOVERING PARA XYLENE WHICH COMPRISES CONTACTING A MIXTURE OF PARA XYLENE WITH AT LEAST ONE ISOMERIC XYLENE OTHER THAN ORTHO XYLENE WITH SULFURIC ACID OF 75 TO 80% STRENGTH AT A TEMPERATURE VARYING INVERSELY WITH THE STRENGTH OF THE ACID IN A MANNER SUCH THAT WHEN THE ACID STENGTH IS 80% THE TEMPERATURE IS ABOUT 130*C. AND WHEN THE ACID STRENGTH IS 75% THE TEMPERATURE IS ABOUT 140*C., SEPARATING A SOLUTION OF PARA XYLENE SULFONIC ACID IN SULFURIC ACID, HEATING THE SOLUTION TO A HYDROLYZING TEMPERATURE OF AT LEAST 150* C., HYDROLYZING THE PARA XYLENE SULFONIC ACID, AND RECOVERING PARA XYLENE.

Claim 4

A PROCESS FOR RECOVERING PARA XYLENE WHICH COMPRISES CONTACTING A MIXTURE OF PARA XYLENE WITH AT LEAST ONE ISOMERIC XYLENE OTHER THAN ORTHO XYLENE WITH SULFURIC ACID OF 75 TO 80% STRENGTH AT A TEMPERATURE VARYING INVERSELY WITH THE STRENGTH OF THE ACID IN A MANNER SUCH THAT WHEN THE ACID STENGTH IS 80% THE TEMPERATURE IS ABOUT 130*C. AND WHEN THE ACID STRENGTH IS 75% THE TEMPERATURE IS ABOUT 140*C., SEPARATING A SOLUTION OF PARA XYLENE SULFONIC ACID IN SULFURIC ACID, HEATING THE SOLUTION TO A HYDROLYZING TEMPERATURE OF AT LEAST 150* C., HYDROLYZING THE PARA XYLENE SULFONIC ACID, AND RECOVERING PARA XYLENE.

Claim 5

A CONTINUOUS PROCESS FOR SAEPARATING META XYLENE FROM ETHYL BENZENE WHICH COMPRISES CHARGING A FEEL STOCK CONSISTING ESSENTIALLY OF META XYLENE AND ETHYL BENZENE TO A SULFONATION TOWER, COUNTERCURRENTLY CONTACTIN THE FEED STOCK THEREIN WITH SULFURIC ACID OF 75 TO 80% STRENGTH IN A MOLAR RATIO OF ACID TO ETHYL BENZENE OF AT LEAST 6:1, AT A TEMPERATURE VARYING INVERSELY WITH THE STRENGTH OF THE ACID IN A MANNER SUCH THAT WHEN THE ACID STRENGTH IS 80% THE TEMPERATURE IS ABOUT 125*C. AND WHEN THE ACID STRENGTH IS 75% THE TEMPERATURE IS ABOUT 115*C., RECOVERING AN OVERHEAD PRODUCTS FROM THE SULFONATION TOWER ENRICHED IN META XYLENE, RECOVERING AS A BOTTOMS PRODUCT A SOULTION OF ETHYL BENZENE SULFONIC ACID IN SULFURIC ACID, HEATING THE SOLUTION TO A HYDROLYZING TEMPERATURE OF AT LEAST 140*C., HYDROLYZING THE SULFONIC ACID CONTENT OF THE SOLUTION, AND RECOVERING A PRODUCT ENRICHED IN ETHYL BENZENE FROM THE HYDROLYSIS PRODUTS.

Claim 6

A CONTINUOUS PROCESS FOR SAEPARATING META XYLENE FROM ETHYL BENZENE WHICH COMPRISES CHARGING A FEEL STOCK CONSISTING ESSENTIALLY OF META XYLENE AND ETHYL BENZENE TO A SULFONATION TOWER, COUNTERCURRENTLY CONTACTIN THE FEED STOCK THEREIN WITH SULFURIC ACID OF 75 TO 80% STRENGTH IN A MOLAR RATIO OF ACID TO ETHYL BENZENE OF AT LEAST 6:1, AT A TEMPERATURE VARYING INVERSELY WITH THE STRENGTH OF THE ACID IN A MANNER SUCH THAT WHEN THE ACID STRENGTH IS 80% THE TEMPERATURE IS ABOUT 125*C. AND WHEN THE ACID STRENGTH IS 75% THE TEMPERATURE IS ABOUT 115*C., RECOVERING AN OVERHEAD PRODUCTS FROM THE SULFONATION TOWER ENRICHED IN META XYLENE, RECOVERING AS A BOTTOMS PRODUCT A SOULTION OF ETHYL BENZENE SULFONIC ACID IN SULFURIC ACID, HEATING THE SOLUTION TO A HYDROLYZING TEMPERATURE OF AT LEAST 140*C., HYDROLYZING THE SULFONIC ACID CONTENT OF THE SOLUTION, AND RECOVERING A PRODUCT ENRICHED IN ETHYL BENZENE FROM THE HYDROLYSIS PRODUTS.