Process for Integrating Conversion of Hydrocarbonaceous Assets and Photobiofuels Production Using an Absorption Tower

• US 20090028775A1
• Filed: 07/25/2007
• Published: 01/29/2009
• Est. Priority Date: 07/25/2007
• Status: Active Grant

• Current Assignee: Chevron USA Incorporated (Chevron Corp.)
• Original Assignee: Chevron USA Incorporated (Chevron Corp.)
• Inventors: O'Rear, Dennis J.
• Granted Patent: US 8,076,122 B2
• Time in Patent Office: Days
• US Class Current: 423/437.100
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 53/77 Liquid phase processes
• CPC Class Codes: C10G 2/00 Production of liquid hydrocarbon mixtures of undefined composition from oxides of carbon
• CPC Class Codes: C12P 7/00 Preparation of oxygen-containing organic compounds
• CPC Class Codes: C12P 7/6458 by transesterification, e.g. interesterification, ester interchange, alcoholysis or acidolysis
• CPC Class Codes: C12P 7/649 Biodiesel, i.e. fatty acid alkyl esters
• CPC Class Codes: Y02C 20/40 of CO2
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel
• CPC Class Codes: Y02P 20/151 Reduction of greenhouse gas [GHG] emissions, e.g. CO2
• CPC Class Codes: Y02P 20/59 Biological synthesis; Biological purification

Abstract

The present invention is generally directed to processes that integrate CO₂-producing conversions of hydrocarbonaceous assets with biofuels processes that utilize CO₂ photosynthesis. In some embodiments such processes involve the absorption of CO₂ in an absorption liquid. In some such embodiments such absorption is carried out in an absorption tower. In some other such embodiments, there is a subsequent desorption of the CO₂. Generally, at least some of the CO₂ captured by the absorption liquid is used to grow microbes or diatom species.

Claims

1. An integrated process for conversion of hydrocarbonaceous assets, the process comprising the steps of:

a) converting at least one hydrocarbonaceous asset to produce a CO₂-containing gas;

b) absorbing at least a portion of the CO₂ of the CO₂-containing gas into an absorption liquid in an absorption tower, wherein the absorption liquid flows downward, and wherein the CO₂-containing gas flows upward; and

c) using at least a portion of the CO₂ in the absorption liquid to support photosynthesis in a photobiofuels process.

2. The process of claim 1, further comprising the steps of:

a) forming biomass in the absorption liquid used in the photobiofuels process;

b) removing the biomass to form a regenerated absorption liquid; and

c) recycling at least a portion of the regenerated absorption liquid to the absorption tower.

3. The process of claim 2, wherein the absorption liquid is selected from the group consisting, of water and caustic water.

4. The process of claim 3, further comprising forming water in the step of converting hydrocarbonaceous assets, and blending at least a portion of the water with the absorption liquid.

5. The process of claim 4, further comprising setting a target pH for the absorption liquid used in the photobiofuels process, and controlling the pH to this target pH by methods selected from the group consisting of (a) controlling blending of water from the converting of hydrocarbonaceous assets;

(b) controlling temperature of the absorption liquid in the absorption tower;

(c) controlling absorption liquid to gas ratio in the absorption tower;

(d) controlling residence time of the absorption liquid in the absorption tower; and

(e) combinations thereof.

6. The process of claim 5, wherein the pH target is greater than 6.

7. The process of claim 5 wherein the pH is between 8 and 10.

8. The process of claim 4, further comprising setting a target salinity for the absorption liquid used in the photobiofuels reactor, and controlling the salinity to this target by controlled blending of water from the converting of hydrocarbonaceous assets.

9. The process of claim 8, wherein the salinity is measured in terms of conductivity, and wherein the conductivity is less than 70 mmho·

cm<sup>−

1</sup>.

10. The process of claim 9, wherein the conductivity is between 10 mmho·

cm<sup>−

1</sup> and 30 mmho·

cm<sup>−

1</sup>.

11. The process of claim 4, further comprising use of a Fischer-Tropsch process in converting the hydrocarbonaceous assets.

12. The process of claim 1, further comprising setting a target temperature for the photobiofuels process, and controlling temperature to this target by use of gases and liquids from the converting of hydrocarbonaceous assets, said gases and liquids being selected from the group consisting of steam, condensate from steam, cold nitrogen gas, chilled water, and combinations thereof.

13. The process of claim 12, wherein the target temperature is between 10°

C. and 40°

C.

14. The process of claim 12, wherein the target temperature is between 20°

C. and 35°

C.

15. The process of claim 1, wherein the photobiofuels process involves harvesting of microalgae, wherein the process further comprises a step of regulating microalgae metabolism at night, and wherein said regulation comprises a method selected from the group consisting of (a) temperature modulation;

(b) salinity modulation;

(c) pH modulation;

modulation of O₂ concentration, and combinations thereof.

16. The process of claim 1, further comprising the steps of:

a) storing at least a portion of the absorption liquid from the absorption tower during nighttime operations in a tank;

b) recovering, during daylight hours, at least a portion the stored absorption liquid; and

c) utilizing at least a portion of the CO₂ in the recovered absorption liquid to support photosynthesis in the photobiofuels process.

17. The process of claim 1, further comprising the production of O₂ in the photobiofuels process and using at least a portion of the O₂ to convert the hydrocarbonaceous assets, wherein the O₂ is used in a manner selected from the group consisting of (a) a gaseous oxidant for synthesis gas production, (b) an oxidant of synthesis gas to produce power, and (c) combinations thereof;

and wherein the photobiofuels process is a closed photobiofuels process.

18. The process of claim 17, further comprising the steps of:

a) storing at least a portion of O₂ produced in the photobiofuels process during daylight hours in containers selected from the group consisting of above ground gas tows, underground salt domes, and combinations thereof;

b) recovering, during the night, at least a portion the stored O₂; and

c) using at least a portion of the recovered O₂ in the converting of hydrocarbonaceous assets from, wherein the O₂ is used in a manner selected from the group consisting of (a) as a gaseous oxidant for synthesis gas production, (b) as an oxidant of synthesis gas to produce power, and (c) combinations thereof.

19. The process of claim 1, wherein energy is created during the converting of hydrocarbonaceous assets, wherein said energy manifests itself in a form selected from the group consisting of electrical power, stream, hot gases, super-atmospheric pressure gases, and combinations thereof, and wherein at least a portion of this energy is utilized in the photobiofuels process in a manner selected from the group consisting of (a) stirring and pumping the liquid in the photobiofuels process, (b) sonicating the liquid, (c) processing the liquid in a high shear mixer, (d) separating microbes contained therein from the liquid, (e) drying microbes contained therein, (f) grinding microbes contained therein to free lipids and other components, (g) separating the components, and (h) combinations thereof.

20. The process of claim 1, further comprising producing a methylester for use as a biodiesel, the producing comprising the substeps of:

a) recovering trigylcerides from the photobiofuels process;

b) transesterifying the trigylcerides from the photobiofuels process with an alcohol to form an ester and glycerin; and

c) purifying the ester;

wherein at least a portion of the alcohol used in the transesterification is manufactured, in the process for converting hydrocarbonaceous assets, by synthesis gas conversion processes selected from the group consisting of methanol synthesis, Fisher-Tropsch, and combinations thereof.

21. The process of claim 20, wherein the alcohol is methanol.

22. The process of claim 20, wherein a liquid hydrocarbonaceous product is manufactured from the step of converting the hydrocarbonaceous assets;

wherein this liquid is blended with at least a portion of the ester and/or triglyceride; and

wherein the synthesis gas conversion process is a Fischer-Tropsch process.

23. The process of claim 1, further comprising the steps of:

a) removing a reduced nitrogen species from the CO₂-containing gas derived from the converting of hydrocarbonaceous assets; and

b) consuming the reduced nitrogen species in the photobiofuels process.

24. The process of claim 17 wherein the step of converting the hydrocarbonaceous assets involves a Fischer-Tropsch process, and wherein said process further comprises the steps of:

a) recovering triglycerides from the photobiofuels process;

b) recovering a product from the Fischer-Tropsch process;

c) processing at least a portion of both the triglyceride and the Fisher-Tropsch product in a hydroprocessing process to form paraffinic liquid hydrocarbonaceous products; and

d) recovering at least a portion of the paraffinic liquid hydrocarbonaceous products.

25. The process of claim 1, further comprising the steps of:

a) recovering triglycerides from the photobiofuels process;

b) converting the triglycerides to fatty acids, at least a portion of which are unsaturated;

c) oligomerizing the unsaturated fatty acids to form polyacids; and

d) esterifying the polyacids with an alcohol to form an unsaturated polyester operable for use as a synthetic lubricant.

26. The process of claim 25, further comprising hydrogenating the unsaturated polyester to form a saturated polyester.

27. The process of claim 25, wherein at least a portion of the alcohol used in the esterification is manufactured in the step of converting the hydrocarbonaceous assets by a synthesis gas conversion processes selected from the group consisting of methanol synthesis, Fisher-Tropsch, and combinations thereof.

28. The process of any of claim 25, further comprising a step of blending the polyester with a lubricant base oil made from a Fischer-Tropsch process.

29. The process of claim 24, wherein the Fisher-Tropsch process is used to convert the synthesis gas formed in the step of converting the hydrocarbonaceous assets.