Process for integrating conversion of hydrocarbonaceous assets and photobiofuels production using an absorption tower

• US 8,076,122 B2
• Filed: 07/25/2007
• Issued: 12/13/2011
• Est. Priority Date: 07/25/2007
• Status: Expired due to Fees

• Current Assignee: Chevron USA Incorporated (Chevron Corp.)
• Original Assignee: Chevron USA Incorporated (Chevron Corp.)
• Inventors: O'Rear, Dennis J.
• Primary Examiner(s): Tate, Chris R
• Assistant Examiner(s): KOSAR, AARON J
• Application Number:
  US11/828,071
• Publication Number:
  US 20090028775A1
• Time in Patent Office: 1,602 Days
• Field of Search: None
• US Class Current: 435/262.5
• 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 7/649 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 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;

c) collecting at least a portion of the CO₂-containing absorption liquid obtained in step (b) and, in a photobiofuels process, providing said collected CO₂-containing absorption liquid to support photosynthesis;

d) forming an algal and/or diatomaceous biomass in the collected CO₂-containing absorption liquid;

e) removing the formed biomass from the absorption liquid, thereby forming a regenerated absorption liquid;

f) recycling at least a portion of the regenerated absorption liquid to the absorption tower;

g) producing O₂ in the photobiofuels process; and

h) providing at least a portion of said O₂ as (i) a gaseous oxidant for producing synthesis gas, (ii) an oxidant of synthesis gas for producing power therefrom, or (iii) combinations thereof;

wherein the photobiofuels process is a closed photobiofuels process.

2. The process of claim 1, wherein the absorption liquid is selected from the group consisting of water and caustic water.

3. The process of claim 2, further comprising forming water in the step of converting hydrocarbonaceous assets, and blending at least a portion of the water with the absorption liquid.

4. The process of claim 3, 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 said 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.

5. The process of claim 4, wherein the target pH is greater than 6.

6. The process of claim 4, wherein the target pH is between 8 and 10.

7. The process of claim 3, further comprising setting a target salinity for the absorption liquid used in the photobiofuels process, and controlling the salinity to this target by controlled blending of water from the converting of said hydrocarbonaceous assets.

8. The process of claim 7, wherein the salinity is measured in terms of conductivity, and wherein the conductivity is less than 70 mmho·

cm<sup>−

1</sup>.

9. The process of claim 8, wherein the conductivity is between 10 mmho·

cm<sup>−

1</sup> and 30 mmho·

cm<sup>−

1</sup>.

10. The process of claim 3, wherein the converting of the hydrocarbonaceous assets comprises converting via a Fischer-Tropsch process.

11. The process of claim 1, further comprising setting a target temperature for the photobiofuels process, and controlling temperature to this target by providing 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.

12. The process of claim 11, wherein the target temperature is between 10°

C. and 40°

C.

13. The process of claim 11, wherein the target temperature is between 20°

C. and 35°

C.

14. The process of claim 1, wherein the biomass is microalgae and wherein the photobiofuels process comprises (i) regulating the metabolism of said microalgae by modulating a temperature, salinity, and/or pH thereof and (ii) harvesting said microalgae.

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

16. The process of claim 1, wherein in step (g) the producing O₂ further comprising:

(i) storing during daylight hours at least a portion of said produced O₂ in a container selected from the group consisting of an above ground gas tank, an underground salt dome, and combinations thereof; and

(ii) recovering from the container during the night at least a portion of the stored O₂.

17. 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.

18. The process of claim 1, wherein in step (a) said converting the hydrocarbonaceous assets comprises forming a synthesis gas and converting the synthesis gas to methanol by a methanol synthesis reaction, a Fisher-Tropsch reaction, or a combination thereof;

wherein the photobiofuels process is a triglyceride-producing process; and

wherein the produced triglyceride is capable of being recovered from the photobiofuels process, transesterified with said methanol, and then purified to produce a methylester biodiesel.

19. The process of claim 18, wherein the synthesis gas converting process is a Fisher-Tropsch reaction.

20. The process of claim 1, wherein in step (a) said converting the hydrocarbonaceous assets further comprises removing from the CO₂-containing gas a reduced nitrogen species, and wherein the reduced nitrogen species is consumed in said photobiofuels process.

21. The process of claim 1, 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.

22. 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.

23. The process of claim 22, further comprising hydrogenating the unsaturated polyester to form a saturated polyester.

24. The process of claim 22, 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.

25. The process of claim 22, further comprising a step of blending the polyester with a lubricant base oil made from a Fischer-Tropsch process.

26. The process of claim 21, wherein the Fisher-Tropsch process is used to convert the synthesis gas formed in the step of converting the hydrocarbonaceous assets.