Continuous process for the synthesis of dimethyl carbonate over a cerium-based catalyst formulation
AssigneeCouncil of Scientific and Industrial Research
InventorsDarbha Srinivas, Vijay Vasant Bokade, Prashant Suresh Niphadkar, Unnikrishnan Pulikkeel, Snehalkumar Parmar, Vinay Amte, Surajit Sengupta, Asit Kumar Das
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Abstract
The present invention discloses a continuous process for the synthesis of dimethyl carbonate from methanol and carbon dioxide over a ceria-based mixed metal oxide-silica catalyst formulation in the presence of a dehydrating or water trapping compound (2-Cyanopyridine).
Claims14
A continuous process for synthesis of dimethyl carbonate (DMC), said process comprising contacting methanol with CO2 over a catalyst formulation;
- at a reaction temperature in a range of 120 to 160° C.;
- for a reaction time period in a range of 2 to 10 hours;
- reaction pressure in a range of 30 to 100 bar in the presence of an organic nitrile dehydrating or water trapping compound, wherein the catalyst formulation has at least 30 hours of catalytic stability;
- and wherein said catalyst formulation comprises:
- (a) mixed oxides of cerium (Ce) with other elements selected from the group consisting of zirconium (Zr), lanthanum (La), gallium (Ga) and combinations thereof and the metal oxides have an elongated hexagonal, spindle-shaped, rod-like or spherical morphology;
- and
- (b) a form of silica (SiO2) selected from the group consisting of colloidal silica, silicate, orthosilicate, Si/Al combinations and silica source material wherein the silica content in the catalyst formulation is in the range of 2 to 25 weight percent, and content of Ce-oxide in the mixed oxide portion is in the range of 50 to 95 mole percent;
- (c) wherein the hydrophobicity, represented by water adsorption capacity, is less than 10 weight percent of the catalyst, the crush strength of the catalyst is 2 to 7 Newton, and acidity/basicity molar ratio of the bi-functional catalyst is in the range of 0.5 to 2.5.
A catalyst formulation for a continuous process for synthesis of dimethyl carbonate, wherein said catalyst formulation comprises:
- (a) mixed oxides of cerium (Ce) with other elements selected from the group consisting of zirconium (Zr), lanthanum (La), gallium (Ga) and combinations thereof and the metal oxides have an elongated hexagonal, spindle-shaped, rod-like or spherical morphology respectively, and
- (b) a form of silica (SiO2) selected from the group consisting of colloidal silica, silicate, orthosilicate, Si/Al combinations and silica source material wherein the silica content in the catalyst formulation is in the range of 2 to 25 weight percent, and content of Ce-oxide in the mixed oxide portion is in the range of 50 to 95 mole percent;
- (c) wherein the hydrophobicity, represented by water adsorption capacity, is less than 10 weight percent of the catalyst, the crush strength of the catalyst is 2 to 7 Newton, and acidity/basicity molar ratio of the bi-functional catalyst is in the range of 0.5 to 2.5.
Dependencies are inferred from the claim text.