System and method for purifying process water

• US 9,944,538 B2
• Filed: 12/21/2015
• Issued: 04/17/2018
• Est. Priority Date: 10/25/2013
• Status: Active Grant

• Current Assignee: Cool Planet Energy Systems, Inc.
• Original Assignee: Cool Planet Energy Systems, Inc.
• Inventors: Traxler, Vern S., Thompson, Timothy Alan, Faust, Paul, Hago, Wilson
• Primary Examiner(s): Barry, Chester T
• Application Number:
  US14/976,304
• Publication Number:
  US 20160101990A1
• Time in Patent Office: 848 Days
• Field of Search: None
• CPC Class Codes: B01J 20/20 comprising free carbon; comprising carbon obtained by carbonising processes
• CPC Class Codes: B01J 20/3078 Thermal treatment, e.g. calcining or pyrolizing
• CPC Class Codes: C02F 1/283 using coal, charred products, or inorganic mixtures containing them
• CPC Class Codes: C02F 2101/10 Inorganic compounds
• CPC Class Codes: C02F 2101/32 Hydrocarbons, e.g. oil
• CPC Class Codes: C02F 2103/365 from petrochemical industry (e.g. refineries)
• CPC Class Codes: C02F 2303/16 Regeneration of sorbents, filters
• CPC Class Codes: C10B 53/02 of cellulose-containing material production of pyroligneous acid C10C5/00
• CPC Class Codes: C10G 2/32 with the use of catalysts
• CPC Class Codes: C10J 2300/0903 Feed preparation
• CPC Class Codes: C10J 2300/0913 Carbonaceous raw material
• CPC Class Codes: C10J 2300/0916 Biomass
• CPC Class Codes: C10J 2300/1665 to alcohols, e.g. methanol or ethanol preparation of alcohols in general C07C29/00
• CPC Class Codes: C10J 2300/169 with water treatments treatment of water in general or water purification C02F
• CPC Class Codes: C10J 3/60 Processes
• CPC Class Codes: C10K 1/20 by treating with solids; Regenerating spent purifying masses separation by adsorption B01D53/02; separation by chemical reaction B01D53/34; refining of hydrocarbon oils with acids C10G17/02, C10G27/02, C10G29/12
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel
• CPC Class Codes: Y02E 50/30 Fuel from waste, e.g. synthetic alcohol or diesel
• CPC Class Codes: Y02P 20/129 Energy recovery, e.g. by cogeneration, H2recovery or pressure recovery turbines

Abstract

In accordance with one embodiment, a process is described for a water treatment process in which process water is treated with recycled biochar. In accordance with one aspect, process water is passed through activated carbon generated by the biomass pyrolysis and gasification. In accordance with another aspect, the process water is treated to expel gaseous compounds within the process water. In this manner both inorganics, light organics and heavy organics can be removed from the process water. No fermentation is involved.

Claims

1. A method for removing contaminants from process water comprising:

pyrolyzing biomass to produce gaseous compounds and biochar;

gasifying the biochar from the pyrolysis process to create an adsorptive medium; and

treating a process water comprising one or more of organic contaminants, inorganic contaminants or particulate contaminants by passing the process water through the adsorptive medium to remove one or more of organic contaminants, inorganic contaminants or particulate contaminants to produce treated process water.

2. The method of claim 1 further comprising gasifying organic contaminants adsorbed on the adsorptive medium.

3. The method of claim 2 wherein the gaseous compounds and biochar resulting from the pyrolyzing step are substantially uncontaminated.

4. The method of claim 2 wherein the minerals content of the biochar in the adsorptive medium increases after gasifying organic contaminants adsorbed on the adsorptive medium.

5. The method of claim 1 wherein the biomass is pyrolyzed in a pyrolysis reactor selected from the group consisting of fixed bed reactors, fluidized bed reactors, circulating bed reactors, bubbling fluid bed reactors, vacuum moving bed reactors, entrained flow reactors, cyclonic or vortex reactors, rotating cone reactors, auger reactors, ablative reactors, microwave or plasma assisted pyrolysis reactors, and vacuum moving bed reactors.

6. The method of claim 1 wherein the biomass is provided as thin sheets.

7. The method of claim 6 wherein the biomass is pyrolyzed by applying pressure shocks and temperature ramps to the thin sheets of biomass.

8. The method of claim 1 wherein the treated process water contains less than 1% hydrocarbons.

9. The method of claim 8 wherein the treated process water contains less than 1% aromatic hydrocarbons.

10. The method of claim 9 wherein the treated process water contains less than 100 ppm aromatic hydrocarbons.

11. The method of claim 10 wherein the treated process water contains less than 1 ppm aromatic hydrocarbons.

12. The method of claim 1 wherein the process water is contaminated with inorganic compounds.

13. The method of claim 1 wherein the adsorptive medium is activated in situ.

14. The method of claim 1 wherein the adsorptive medium comprises biochar having a surface area varying from 0.1 m²/g to 500 m²/g.

15. The method of claim 1 wherein waste heat from pyrolyzing the biomass is used in the step of treating the process water.

16. A biochar recycling system for treatment of water produced from biomass conversion to fuels comprising:

a pyrolyzer capable of pyrolyzing biomass to produce gaseous compounds and biochar;

a water treatment system for removing impurities from process water, wherein the water treatment system comprises an adsorptive medium comprising biochar; and

a gasification system for gasifying the removed impurities.

17. The system according to claim 16 wherein the water treatment system comprises a heating device capable of increasing the temperature of the process water to remove light organic impurities.

18. The system according to claim 16 wherein the gaseous compounds and biochar exit the pyrolyzer in substantially uncontaminated form.

19. The system according to claim 16 wherein the biochar produced by the system has a surface area varying from 0.1 m²/g to 500 m²/g.

20. The system according to claim 16 wherein the process water after treatment contains less than 1% hydrocarbons.

21. The system according to claim 20 wherein the process water after treatment contains less than 1% aromatic hydrocarbons.

22. The system according to claim 21 wherein the process water after treatment contains less than 100 ppm aromatic hydrocarbons.

23. The system according to claim 22 wherein the process water after treatment contains less than 1 ppm aromatic hydrocarbons.

24. The system according to claim 16 wherein the process water before treatment is contaminated with inorganic compounds.

25. The system according to claim 16 wherein the adsorptive medium is activated in situ.

26. The system according to claim 16 wherein the gasification system decomposes adsorbed contaminants in the process water.

27. The system according to claim 17 wherein the light organic impurities are directed to the gasifier.