Separation of mixtures with modified zeolites

Claim 2

A process according to claim 2 wherein the modified zeolite is maintained in a column maintained at an elevated temperature, and said mixture and a carrier is passed therethrough for separation and recovery of the products.

Claim 3

A process according to claim 3 wherein said carrier is selected from the group consisting of steam, water, nitrogen, air, helium, hydrogen, hydrocarbons and mixtures thereof.

Claim 4

A process according to claim 4 wherein the temperature maintained in the column ranges from about 100* to about 250* C.

Claim 5

A process according to claim 5 wherein the C8 aromatics feed mixture contains ethylbenzene, para-xylene, meta-xylene and ortho-xylene and wherein a mixture of the meta-xylene and ortho-xylene is initially removed from the column followed by the para-xylene and then the ethylbenzene.

Claim 6

A process according to claim 5 wherein the C8 aromatics feed mixture contains para-xylene, meta-xylene, and ortho-xylene and wherein a mixture of meta-xylene and ortho-xylene is initially removed from the column followed by the para-xylene.

Claim 7

A process according to claim 2 wherein, in preparation of the modified zeolite, the zeolite and silane are reacted in weight ratios of about 5:1 to 1:5, respectively, in the presence of an organic solvent.

Claim 8

A process according to claim 8 wherein the organic solvent is pyridine and the reaction is carried out at a temperature of about 75* to 200* C.

Claim 9

A process according to claim 9 wherein the silane compound is of the formula: wherein R is an alkyl group of 1 to about 40 carbon atoms, an alkyl or aryl acyl group where the organic portion of said alkyl group contains about one to 30 carbon atoms, and of said aryl group contains about six to 24 carbon atoms, aryl groups of about six to 24 carbon atoms, alkaryl and aralkyl groups containing about seven up to about 30 carbon atoms and each R1 is the same as R, hydrOgen, or a halogen atom, providing that no more than one R1 is the same as R and at least one R1 is halogen.

Claim 10

A process according to claim 10 wherein said zeolite and said silane are reacted in the presence of a binder for said zeolite by refluxing in a 3:1 to 1:3 weight ratio in n-heptane solvent.

Claim 11

A process according to claim 11 wherein said zeolite is selected from the group consisting of ZSM-5 type zeolites having the X-ray diffraction pattern of Table 1, ZSM-8 type zeolites having the X-ray diffraction pattern of Table 4 and mixtures thereof.

Claim 12

A process for the separation of a C8 aromatic mixture feedstock into its component parts which comprises contacting said mixture with a modified zeolite which is the reaction product of a crystalline zeolite with an organic radical-substituted silane of the formula: wherein R is an organic radical and R1 is an organic radical, hydrogen or halogen, provided that at least one R1 is halogen, by passing said C8 aromatic mixture in contact with said modified zeolite whereby any mixture of meta-xylene and ortho-xylene passes through the modified zeolite rather uninhibited while any ethylbenzene and para-xylene are sorbed at different respective rates by the modified zeolite, removing a mixture of meta-xylene and ortho-xylene, recovering para-xylene followed by recovery of ethylbenzene, if the latter is present in the C8 aromatic mixture, passing the mixture of meta-xylene and ortho-xylene into contact with a partitioning liquid whereby said meta-xylene and ortho-xylene are separated by sorption at different rates and recovering the meta-xylene followed by the ortho-xylene.

Claim 13

A process according to claim 13 wherein the zeolite is a ZSM-5 type zeolite having the X-ray diffraction pattern of Table 1, a ZSM-8 type zeolite having the X-ray diffraction pattern of Table 4 or mixtures thereof.

Claim 14

A process according to claim 14 wherein the C8 aromatic feed mixture contains about 0 to 15 weight percent ethylbenzene, about 20 to 30 weight percent para-xylene, about 40 to 50 weight percent meta-xylene and about 15 to 25 weight percent ortho-xylene.

Claim 15

A process according to claim 15 wherein, in preparation of the modified zeolite, the zeolite and silane are reacted in weight ratios of about 5:1 to 1:5 in the presence of an organic solvent.

Claim 16

A process according to claim 16 wherein the organic solvent is pyridine and the reaction is carried out at a temperature of about 75* to 200* C.

Claim 17

A process according to claim 17 wherein the silane compound is a compound of the formula: wherein R is an alkyl group of one to about 40 carbon atoms, an alkyl or aryl acyl group where the organic portion of said alkyl group contains about one to 30 carbon atoms, and of said aryl group contains about six to 24 carbon atoms, aryl groups of about six to 24 carbon atoms, alkaryl and aralkyl groups containing about seven up to about 30 carbon atoms, and each R1 is the same as R, hydrogen or halogen atoms, providing that no more than one R1 is the same as R and at least one R1 is halogen.

Claim 18

A process according to claim 18 wherein said zeolite and said silane are reacted in the presence of a binder for said zeolite by heating in a 1:2 to 1:1 weight ratio in an organic solvent.

Claim 19

A process according to claim 19 wherein said partitioning liquid is selected from the group consisting of Terigtol NPX (nonyl phenol ether of polyethylene glycol), m-bis (m-phenoxy-phenoxy) benzene and 2 percent squalane, UCON 1840, UCON LB-550X, di-n-propyl tetrachlorophthalate, squalane, 40 percent 1,2,3 tris (2-cyanoethoxy) propane and 70 percent oxybis (2-ethylbenzoate) and di-n-decylphthalate.

Claim 20

A process according to claim 20 wherein the zeolite and partitioning liquid are maintained in columns through which the mixture is passed at a temperature of about 100* to 250* C.

Claim 21

A process according to claim 21 wherein the column containing the liquid has a volume about twenty times greater than the zeolite column.

Claim 22

A process according to claim 22 wherein a carrier is admixed with the mixture prior to passage through the columns and wherein the carrier is selected from the group consisting of steams, water, nitrogen, air, helium, hydrogen, hydrocarbons and mixtures thereof.

Claim 23

A process according to claim 23 wherein the zeolite is selected from the group consisting of ZSM-5 and ZSM-8 and the partitioning liquid is Tergitol NPX.