Process and apparatus for producing liquid hydrocarbon
The invention relates to continuous process for converting carbonaceous material contained in one or more feedstocks into a liquid hydrocarbon product, said feedstocks including the carbonaceous material being in a feed mixture including one or more fluids, said fluids including water and further liquid organic compounds at least partly produced by the process in a concentration of at least 1% by weight, where the process comprises converting at least part of the carbonaceous material by pressurizing the feed mixture to a pressure in the range 50-400 bar; heating the feed mixture to a temperature in the range 250-500° C., maintaining said pressurized and heated feed mixture in the desired pressure and temperature ranges in a reaction zone for a predefined time; cooling the feed mixture to a temperature in the range 25-200° C. and expanding the feed mixture to a pressure in the range of 1-70 bar, thereby causing the carbonaceous material to be converted to a liquid hydrocarbon product; at least partly expanding said converted feed mixture in a flash separation step, wherein the converted feed mixture is separated into a gas phase and a liquid phase, and wherein liquid CO2 is recovered from said gas phase, and separating from the liquid phase a fraction comprising liquid hydrocarbon product.
1. A continuous process for converting one or more carbonaceous feedstocks into a liquid hydrocarbon product, the process comprising:
providing a feed mixture comprising said one or more carbonaceous feedstocks and water,
adding liquid organic compounds to the feed mixture, wherein the liquid organic compounds comprise at least 5% by weight of the feed mixture,
passing said feed mixture to a reaction zone,
converting at least part of the one or more carbonaceous feedstocks in the feed mixture into a liquid hydrocarbon product by:
pressurizing the feed mixture to a pressure in the range of 75-400 bar,
heating the feed mixture to a temperature in the range of 250-500° C., and
maintaining said pressurized and heated feed mixture in said pressure and temperature ranges in the reaction zone for a predefined time, thereby producing a converted feed mixture,
cooling the converted feed mixture to a temperature in the range of 100-200° C.,
expanding said cooled converted feed mixture to a pressure in the range of 50-70 bar in a flash separation step, wherein the cooled converted feed mixture is separated into a gas phase and a liquid phase, wherein the liquid phase comprises the liquid hydrocarbon product;
cooling said gas phase as pressurized in the range of 50-70 bar to a temperature in the range of 35 to 80° C. to produce a cooled gas phase and a first condensate comprising water, and subsequently cooling said cooled gas phase as pressurized in the range of 50-70 bar to a temperature in the range of 12 to 30° C., thereby producing a second condensate comprising liquid CO 2 , and
recycling a portion of the liquid phase to the feed mixture as part of the liquid organic compounds.
2. The process according to claim 1 , wherein said step of cooling the converted feed mixture comprises cooling said converted feed mixture at the pressure used for pressurizing the feed mixture to a temperature in the range of 100-200° C. by heat exchange with the feed mixture passed to said reaction zone.
3. The process according to claim 1 , wherein the concentration of said liquid organic compounds contained in the feed mixture is at least 10% by weight of the feed mixture.
4. The process according to claim 1 , where the feed mixture further contains at least one homogeneous catalyst comprising a compound of potassium and/or sodium in an amount of at least 0.5% by weight based on the dry weight of the one or more carbonaceous feedstocks in the feed mixture.
5. The process according to claim 1 , wherein the weight ratio of said liquid organic compounds to the dry weight of the one or more carbonaceous feedstocks in said feed mixture is in the range of 0.1 to 2.0.
6. The process according to claim 1 , wherein the pressure during said pressurizing step is in the range of 275 to 350 bar.
7. The process according to claim 1 , wherein the temperature during said conversion step is in the range of 380 to 430° C.
8. The process according to claim 1 , wherein said pressurizing the feed mixture occurs prior to said heating the feed mixture.
9. The process according to claim 1 , further comprising measuring a pH during and/or after the conversion, and adding a base to the feed mixture when the measured pH is below 8.
10. The process according to claim 1 , wherein the heating of the feed mixture to 250-500° C. comprises heating the feed mixture at a rate of at least 50° C./min while the feed mixture is still in the temperature range of 140-250° C.