Catalyst composition comprising modified crystalline aluminosilicate for dehydration of alcohols

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;
• wherein air comprises air or 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 provided crystalline aluminosilicate of step (i) has Si/AI 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 comprising the modified crystalline aluminosilicate 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.