Process for the preparationn of hydrocarbons from oxygenates
A process for the preparation of hydrocarbon products comprising the steps of a) providing a synthesis gas comprising hydrogen, carbon monoxide and carbon dioxide; (b) reacting at least part of the synthesis gas to an oxygenate mixture comprising methanol and dimethyl ether in presence of one or more catalysts which together catalyse a reaction of hydrogen and carbon monoxide to oxygenates at a pressure of at least 3 MPa; (c) withdrawing from step (b) a reaction mixture comprising amounts of methanol, dimethyl ether, carbon dioxide and water together with unreacted synthesis gas and cooling the reaction mixture to obtain a liquid phase with the amounts of methanol, dimethyl ether and water and simultaneously dissolving carbon dioxide in the liquid phase; (d) separating the carbon dioxide containing liquid phase from a remaining gaseous phase comprising hydrogen and carbon monoxide; (e) evaporating and reacting the liquid phase being withdrawn from step (d) in presence of a catalyst being active in the conversion of oxygenates to higher hydrocarbons and a tail gas comprising carbon dioxide; (f) separating tail gas from a liquid phase with the higher hydrocarbons; and wherein pressure employed in step (c) to step (f) is substantially the same as employed in step (b).
1. A process for the preparation of hydrocarbon products comprising the steps of
(a) providing a synthesis gas comprising hydrogen, carbon monoxide and carbon dioxide;
(b) reacting at least part of the synthesis gas to an oxygenate mixture comprising methanol and dimethyl ether in presence of one or more catalysts which together catalyse a reaction of hydrogen and carbon monoxide to oxygenates at a pressure of at least 3 MPa;
(c) withdrawing from step (b) a reaction mixture comprising amounts of methanol, dimethyl ether, carbon dioxide and water together with unreacted synthesis gas and cooling the reaction mixture to obtain a liquid phase with the amounts of methanol, dimethyl ether and water and simultaneously dissolving carbon dioxide in the liquid phase;
(d) separating the carbon dioxide containing liquid phase from a remaining gaseous phase comprising hydrogen and carbon monoxide;
(e) reacting the liquid phase being withdrawn from step (d) in presence of a catalyst being active in the conversion of oxygenates to higher hydrocarbons and a tail gas comprising carbon dioxide;
(f) separating tail gas from a liquid phase with the higher hydrocarbons;
wherein pressure employed in step (c) to step (f) is substantially the same as employed in step (b) and wherein at least part of the gaseous phase obtained in step (d) is recycled to step (b).
2. The process of claim 1 , wherein the gaseous phase obtained in step (f) is washed with heavy gasoline
3. The process of claim 1 , wherein the gaseous phase obtained in step (d) is washed with heavy gasoline
4. The process of claim 1 , wherein the gaseous phase obtained in step (d) is washed with dimethyl ether.
5. The process of claim 4 , wherein the gaseous phase after washing with dimethyl ether is further washed with heavy gasoline.
6. The process of claim 1 , wherein part of the gaseous phase obtained in step (d) is combined with the tail gas from step (f).
7. The process of claim 6 , wherein the combined tail gas is washed with heavy gasoline and wherein the heavy gasoline after having been used as washing agent is combined with the liquid phase from step (d).
8. The process of claim 1 , wherein part of the tail gas from step (f) is recycled to the liquid phase from step (d).
9. The process according to claim 1 , wherein at least part of the tail gas from step (f) is subjected to combustion.
10. The process according to claim 1 , wherein the tail gas from step (f) is sequestered.