Catalyst Composition Comprising Modified Crystalline Aluminosilicate for Dehydration

A process for preparing a catalyst composition containing a modified crystalline aluminosilicate and a binder, wherein the catalyst composition comprises from 5 to 95% by weight of crystalline aluminosilicate as based on the total weight of the catalyst composition, the process being characterized in that it comprises the following steps:

• a) providing a crystalline aluminosilicate having a Si/Al framework molar ratio greater than 10;
• b) optionally calcining said crystalline aluminosilicate;
• c) steaming said crystalline aluminosilicate:
• at a temperature ranging from 100° C. to 380° C.;
• and
• under a gas phase atmosphere, without liquid, containing from 5 wt % to 100 wt % of steam, the rest being one or more gas selected from N2, CO2, Ar, He, CH4, air, or any mixture of thereof;
• with preference air is selected from air and depleted air containing below 10 wt % of oxygen as based on the total weight of the depleted air;
• and
• at a pressure ranging from 2 to 200 bars;
• at a partial pressure of H2O ranging from 2 to 200 bars;
• and
• said steaming being performed during at least 30 min and up to 144 h;
• and in that the process comprises a step of shaping, or of extruding, the crystalline aluminosilicate with a binder, wherein the binder is selected to comprise:
• at least 85 wt % of silica as based on the total weight of the binder, and
• less than 1000 ppm by weight as based on the total weight of the binder of aluminium, gallium, boron, iron and/or chromium.

A process for dehydration of a mono-alcohol, or of a mixture of at least two mono-alcohols, having at least 2 carbon atoms and at most 7 carbon atoms into olefins having the same number of carbons;

• the process being conducted in a dehydration reactor or in a dehydration and skeletal isomerization reactor, and being characterized in that it comprises the following steps:
• i. providing a catalyst composition comprising a crystalline aluminosilicate shaped with, or extruded with, a binder;
• wherein the catalyst composition comprises from 5 to 95% by weight of crystalline aluminosilicate as based on the total weight of the catalyst composition, and steaming said catalyst composition in situ in the dehydration reactor or in the dehydration and skeletal isomerization reactor:
• at a temperature ranging from 100° C. to 380° C.;
• under a gas phase atmosphere, without liquid, containing from 5 wt % to 100 wt % of steam, the rest being one or more gas selected from N2, CO2, Ar, He, CH4, air, or any mixture of thereof;
• with preference air is selected from air and depleted air containing below 10 wt % of oxygen as based on the total weight of the depleted air;
• at a pressure ranging from 2 to 200 bars;
• at a partial pressure of H2O ranging from 2 to 200 bars;
• and
• said steaming being performed during at least 30 min and up to 144 h;
• wherein the crystalline aluminosilicate having a Si/Al framework molar ratio greater than 10;
• wherein the binder is selected to comprise at least 85 wt % of silica as based on the total weight of the binder, and less than 1000 ppm by weight as based on the total weight of the binder of aluminium, gallium, boron, iron and/or chromium;
• and
• wherein the step of steaming the catalyst composition comprising a crystalline aluminosilicate results in a catalyst composition comprising a modified crystalline aluminosilicate;
• ii. providing a feed (A) comprising said mono-alcohols, optionally water, optionally an inert component;
• iii. contacting said feed (A) with said catalyst composition at conditions effective to dehydrate at least a portion of said mono-alcohol;
• iv. recovering an effluent (B) and removing water, the inert component if any and unconverted alcohols if any to get said olefins having the same number of carbons as said mono-alcohol.