Abstract: A process the dehydration of methanol to dimethyl ether in the presence of a solid Brønsted acid catalyst selected from aluminosilicate zeolites which have a maximum free sphere diameter of greater than 3.67 Angstroms and heteropolyacids and a promoter selected from methyl formate, dimethyl oxalate and dimethyl malonate and the molar ratio of promoter to methanol is maintained at less than 1.

Abstract: A process for the preparation of ethylene by the dehydration of ethanol in the presence of a zeolite catalyst having the MOR framework code, wherein the process is operated at a temperature in the range of from 100° C. to 300° C., for example from 140° C. to 270° C., such as from 150° C. to 250° C., and wherein the zeolite catalyst having the MOR framework code has been modified by the adsorption of an optionally substituted pyridine compound.

Abstract: A process for dehydrating C2+ alcohols to ether products in the presence of a catalyst and promoter, wherein the catalyst is at least one aluminosilicate zeolite catalyst which is a medium pore zeolite having a 3-dimensional framework structure, and the promoter is one or more organic carbonyl compounds or derivatives thereof, and wherein and the molar ratio of promoter to C2+ alcohols is maintained at less than 1.

Abstract: A process for dehydrating methanol to dimethyl ether product in the presence of a solid Brønsted acid catalyst which is an aluminosilicate zeolite or a heteropolyacid and a promoter which is (i) a ketone of formula R1COR2 (Formula I) in which R1 and R2 are identical or different and are each a C1-C11 alkyl group and furthermore R1 and R2 together with the carbonyl carbon atom to which they are bonded may form a cyclic ketone; or (ii) a ketal derivative of a ketone of Formula I; and the molar ratio of promoter to methanol is maintained at 0.5 or less.

Abstract: A process for dehydrating methanol to dimethyl ether product in the presence of a catalyst and a promoter, wherein the catalyst is at least one aluminosilicate zeolite, wherein:—the aluminosilicate zeolite is selected from: (i) a zeolite having a 2-dimensional framework structure comprising at least one channel having a 10-membered ring, and having a maximum free sphere diameter of at least 4.

Abstract: A process for dehydrating C2+ alcohols to ether products in the presence of a catalyst and promoter, wherein the catalyst is at least one aluminosilicate zeolite catalyst which is a medium pore zeolite having a 3-dimensional framework structure, and the promoter is one or more organic carbonyl compounds or derivatives thereof, and wherein and the molar ratio of promoter to C2+ alcohols is maintained at less than 1.

Abstract: A process for dehydrating methanol to dimethyl ether product in the presence of a catalyst and a promoter, wherein the catalyst is at least one aluminosilicate zeolite, and the promoter is selected from one or more compounds of Formula I: (I) wherein each of X and any or all of the Y's may independently be selected from hydrogen, halide, a substituted or unsubstituted hydrocarbyl substituent, or a compound of the formula —CHO, —CO2R, —COR, or —OR, where R is hydrogen or a substituted or unsubstituted hydrocarbyl substituent, and wherein the molar ratio of promoter to methanol is maintained at less than 1.

Abstract: A process for dehydrating methanol to dimethyl ether using a Brønsted acid catalyst which is a 1-dimensional or a 3-dimensional aluminosilicate zeolite or a heteropolyacid, and a promoter of Formula I CnH(2n+1)CO2CH3 wherein n=1 to 11 or Formula II CmH2m(CO2CH3)2 wherein m=2 to 7 and the molar ratio of promoter to methanol is maintained at less than 1.

Abstract: A process for dehydrating methanol to dimethyl ether product in the presence of an aluminosilicate zeolite catalyst and a promoter selected from (i) aldehyde of formula R1CHO (Formula I) in which R1 is hydrogen, a C1-C11 alkyl group or a C3-C11 alkyl group in which 3 or more carbon atoms are joined to form a ring; or (ii) acetal derivative of an aldehyde of Formula I; and the molar ratio of promoter to methanol is maintained at 0.1 or less.

Abstract: A process for dehydrating methanol to dimethyl ether product in the presence of a solid Brønsted acid catalyst which is an aluminosilicate zeolite or a heteropolyacid and a promoter which is (i) a ketone of formula R1COR2 (Formula I) in which R1 and R2 are identical or different and are each a C1-C11 alkyl group and furthermore R1 and R2 together with the carbonyl carbon atom to which they are bonded may form a cyclic ketone; or (ii) a ketal derivative of a ketone of Formula I; and the molar ratio of promoter to methanol is maintained at 0.5 or less.

Abstract: A process for dehydrating methanol to dimethyl ether using a Brønsted acid catalyst which is a 1-dimensional or a 3-dimensional aluminosilicate zeolite or a heteropolyacid, and a promoter of Formula I CnH(2n+1)CO2CH3 wherein n=1 to 11 or Formula II CmH2m(CO2CH3)2 wherein m=2 to 7 and the molar ratio of promoter to methanol is maintained at less than 1.

Abstract: A process for dehydrating methanol to dimethyl ether product in the presence of an aluminosilicate zeolite catalyst and a promoter selected from (i) aldehyde of formula R1CHO (Formula I) in which R1 is hydrogen, a C1-C11 alkyl group or a C3-C11 alkyl group in which 3 or more carbon atoms are joined to form a ring; or (ii) acetal derivative of an aldehyde of Formula I; and the molar ratio of promoter to methanol is maintained at 0.1 or less.

Abstract: A process the dehydration of methanol to dimethyl ether in the presence of a solid Br?nsted acid catalyst selected from aluminosilicate zeolites which have a maximum free sphere diameter of greater than 3.67 Angstroms and heteropolyacids and a promoter selected from methyl formate, dimethyl oxalate and dimethyl malonate and the molar ratio of promoter to methanol is maintained at less than 1.