초록 ▼

The present invention is generally directed to systems and methods for integrating gas-to-liquids (GTL) processing with biofuels production. In some embodiments of the present invention, carbon dioxide (CO2) generated by GTL processing is used to support grovel (via photosynthesis) of microalgae. In

The present invention is generally directed to systems and methods for integrating gas-to-liquids (GTL) processing with biofuels production. In some embodiments of the present invention, carbon dioxide (CO2) generated by GTL processing is used to support grovel (via photosynthesis) of microalgae. In some such embodiments, the microalgae can be further processed to yield a diesel fuel that can be used either by itself, or mixed with fuel produced by the GTL processing.

대표청구항 ▼

What is claimed: 1. A method comprising the steps of; a) generating CO2 in a gas-to-liquids plant; b) using at least some of the CO2 generated in the gas-to-liquids plant to grow microalgae by supporting photosynthesis in their growth cycle, wherein such growth yields harvestable microalgae; c) har

What is claimed: 1. A method comprising the steps of; a) generating CO2 in a gas-to-liquids plant; b) using at least some of the CO2 generated in the gas-to-liquids plant to grow microalgae by supporting photosynthesis in their growth cycle, wherein such growth yields harvestable microalgae; c) harvesting the microalgae and processing the harvested microalgae to yield a triglyceride-based biofuel precursor comprising triglycerides; d) hydroprocessing the triglyceride-based biofuel precursor to deoxygenate triglycerides contained therein and yield a paraffinic product; and e) isomerizing the paraffinic product to yield a transportation fuel. 2. The method of claim 1, wherein at least one of the hydroprocessing and isomerizing steps are integrated with processes carried out in the gas-to-liquids plant. 3. The method of claim 2, wherein the triglyceride-based precursor is hydroprocessed together with gas-to-liquid-derived hydrocarbons. 4. The method of claim 2, wherein the paraffinic product is isomerized together with gas-to-liquid-derived paraffins. 5. The method of claim 1, wherein the gas-to-liquids plant is operable for producing transportation fuels. 6. The method of claim 5, wherein using at least some of the CO2 generated in the gas-to-liquids plant to grow microalgae involves dissolving said CO2 in an aqueous solution. 7. The method of claim 6, wherein the aqueous solution comprises saline water. 8. The method of claim 6, wherein the microalgae are contained within the aqueous solution. 9. The method of claim 6, wherein the aqueous solution is delivered to the microalgae. 10. The method of claim 5, wherein using at least some of the CO2 generated in the gas-to-liquids plant to grow microalgae involves sequestering said CO2 through the use of gas separation membranes and subsequently delivering the sequestered CO2 to the microalgae. 11. The method of claim 5, wherein the step of harvesting comprises removal of at least some of the microalgae for subsequent processing. 12. The method of claim 11, wherein the subsequent processing serves to extract triglycerides from the microalgae. 13. The method of claim 11, wherein the subsequent processing comprises a process technique selected from the group consisting of dewatering, grinding, crushing, sonication, homogenization, solvent extraction, and combinations thereof. 14. The method of claim 5, wherein the triglyceride-based biofuel precursor comprises at least 75 weight percent triglycerides. 15. The method of claim 5, wherein the step of hydroprocessing comprising processing the triglyceride-based biofuel precursor in a hydrogen-containing environment in the presence of a catalyst. 16. The method of claim 5, wherein the paraffinic product comprises at least 75 weight percent paraffinic species. 17. The method of claim 16, wherein C5-C20 paraffins account for at least 75 weight percent of the paraffinic species. 18. The method of claim 5, wherein the step of isomerizing is carried using an isomerization catalyst. 19. The method of claim 5, further comprising a step of blending the transportation fuel with other transportation fuels. 20. The method of claim 5, wherein the transportation fuel is a low pour-point diesel. 21. The method of claim 1, wherein triglycerides obtained from sources other than microalgae are mixed with the triglyceride-based biofuel precursor prior to the latter being hydroprocessed. 22. The method of claim 21, wherein the triglycerides obtained from sources other than microalgae are derived from at least one source selected from the group consisting of vegetable oils and animal fats. 23. A system comprising: a) a conventional gas-to-liquids plant that produces a CO2 by-product; b) a repeatedly-harvestable population of microalgae; c) a means for directing the CO2 to the microalgae to support growth thereof; d) a means for harvesting the microalgae and extracting from it a triglyceride-based product comprising triglycerides; e) a means for hydroprocessing at least a portion of the triglyceride-based product to deoxygenate triglycerides contained therein and yield a paraffin-based product; and f) a means for isomerizing at least a portion of the paraffin-based product to yield a transportation fuel. 24. The system of claim 23, wherein at least one of the means for hydroprocessing and the means for isomerizing are integral with the gas-to-liquids plant. 25. The system of claim 23, wherein the conventional gas-to-liquids plant is operable for producing transportation fuels. 26. The system of claim 23, wherein the means for directing the CO2 to the microalgae comprises a subsystem means for sequestering the CO2 produced in the gas-to-liquids plant. 27. The system of claim 26, wherein the subsystem means for sequestering the CO2 produced in the gas-to-liquids plant involves filtration. 28. The system of claim 26, wherein the CO2 is sequestered in an aqueous solution. 29. The system of claim 28, wherein the aqueous solution comprises the repeatedly-harvestable population of microalgae. 30. The system of claim 28, wherein the aqueous solution is delivered to the repeatedly-harvestable population of microalgae. 31. The system of claim 26, wherein the means for harvesting involves removal of at least some of the repeatedly-harvestable population of microalgae for subsequent processing. 32. The system of claim 31, wherein the extracting comprises a subsystem means selected from the group consisting of dewatering, grinding, crushing, sonication, homogenization, solvent extraction, and combinations thereof. 33. The system of claim 26, wherein the means for hydroprocessing comprises a catalyst and a hydrogen-containing environment. 34. The system of claim 26, wherein the means for isomerizing comprises an isomerization catalyst. 35. The system of claim 26, further comprising a means for blending the transportation fuel with other species to impart to it desirable properties.