FLUID BED DIRECT CONTACT STEAM GENERATOR SYSTEM AND PROCESS

• US 20100050517A1
• Filed: 08/28/2009
• Published: 03/04/2010
• Est. Priority Date: 08/28/2008
• Status: Active Grant

• Current Assignee: Ex-Tar Technologies Inc.
• Original Assignee: Ex-Tar Technologies Inc.
• Inventors: TSILEVICH, Maoz BETZER
• Granted Patent: US 8,551,200 B2
• Time in Patent Office: Days
• US Class Current: 48/127.100
• CPC Class Codes: F22B 1/1853 coming in direct contact with water in bulk or in sprays
• CPC Class Codes: F22B 31/0007 with combustion in a fluidized bed fluidized bed apparatus per se B01J8/00; fluidized bed combustors F23C10/00
• CPC Class Codes: F23G 2202/30 in a pressurised chamber
• CPC Class Codes: F23G 7/008 for liquid waste waste oil F23G7/05, waste liquors F23G7/04, sludges F23G7/001
• CPC Class Codes: F23L 7/002 Supplying water
• CPC Class Codes: Y02E 20/34 Indirect CO2mitigation, i.e. by acting on non CO2directly related matters of the process, e.g. pre-heating or heat recovery

Abstract

The present invention is a method and system for vertically producing a steam and combustion gas mixture, typically used in enhanced oil recovery processes. The system is a fluid bed up-flow combustor system, including a vertical vessel with fours sections. In a first section, fuel, oxidizer, and possibly water are supplied to the high pressure combustor at a combustion section of a vertical vessel. The combustion gas from the first section flows to a second section for steam generation, where low quality water is injected and turned into steam. Next, the third section is a homogenizer vessel, where any remaining water drops are converted to steam and solid particles and discharged from the vessel. The fourth section located at the bottom of the vessel is a fluid bed, receiving and processing the falling solids from the combustion and the steam generation sections.

Claims

1. A method for vertically producing a steam and combustion gas mixture, the method comprising the following steps:

mixing a carbon or hydrocarbon fuel and an oxidation gas containing oxygen;

combusting the mixture under high pressure and temperature so as to convert the fuel to a gas and solid byproducts such as slag, fly ash and char, said solid byproducts being in solid or liquid form;

injecting and mixing liquid water to the flowing combustion gas, said liquid water having suspended and dissolved solids and organics and being injected in an amount such that all the liquid water is converted into steam, remaining solid particles being mixed with the gas flow;

converting all liquids to gas and solids so as to generate steam and solid waste;

injecting and flowing cold gas through a fluid bed section at a bottom of the vessel so as to increase the heat exchange duration and to cool combustion solid particles where said injected cold gas is recycled produced steam and gas at a temperature close to the discharge temperature; and

discharging the produced steam, gas and solid mixture.

2. The method for vertically producing a steam and combustion gas mixture, according to claim 1, wherein said carbon or hydrocarbon fuel is selected from a group consisting of coal, pet-coke, asphaltin, vacuum residuals (VR) or untreated crude oil in a slurry form;

wherein said liquid water is selected from a group consisting of tailing pond water with levels of TSS, TDS and organics, brackish water, and sewage effluent water;

wherein said oxidation gas is selected from a group consisting of oxygen, oxygen-enriched air and air in stoichiometric ratio; and

wherein said cold gas fluid bed injected through the fluid bed is at a temperature range of 150°

C. and 500°

C.

3. The method for vertically producing a steam and combustion gas mixture, according to claim 1, further comprising:

incorporating a heat exchanger to use up to 45% of the generated combustion heat to generate super-heated steam and gas mixture from saturated steam and gas mixture.

4. The method for vertically producing a steam and carbon dioxide mixture, according to claim 1, wherein temperature of the produced steam, combustion gas and dry solids in the step of converting all liquids to gas and solids are between 150°

C. and 500°

C., the pressure being between 103 kpa and 10,000 kpa.

5. The method of claim 1, wherein the up-flow velocity of the up-flow gas injected through the fluid bed to carry-on solid particles in the pressurized vertical vessel is in a range of 0.2 m/s and 6 m/s.

6. The method for vertically producing a steam and combustion gas mixture, according to claim 1, further comprising:

flowing the discharge solids-rich gas to a first cyclone solid separation, recycling solid lean gas flow, and directing the solid lean gas flow back to the fluid bed.

7. The method for vertically producing a steam and carbon dioxide mixture, according to claim 1, wherein the solids rich flow is processed by a dry solids separation unit, the method further comprising the step of:

removing solids from the gas flow for disposal.

8. The method for vertically producing a steam and combustion gas mixture, according to claim 1, for integrating to produce gas mixtures ready for EOR, the method further comprising:

washing the gas by mixing the gas and steam with saturated water of saturated temperature at the particular pressure, so as to produce a saturated wet steam and combustion gas mixture, scrubbing any remaining solids from the gas, separating the liquid phase from the gas phase, and recycling the water with the scrubbed solids back to the fluid bed steam generation vertical chamber.

9. The method for vertically producing a steam and combustion gas mixture, according to claim 7, further comprising:

adding limestone slurry to the solid scrubbing, saturated liquid water in a vessel where the lime reacts with the sulfur while generating gypsum solid, when the gas contains sulfur and where there is a need to reduce the amount of sulfur.

10. The method for vertically producing a steam and combustion gas mixture, according to claim 9, further comprising:

heating the saturated steam and gas mixture in a heat exchanger with the gas phase leaving the combustion chamber, the heated gas product being a solid free, super-heated dry steam and gas mixture, preventing condensation on the pipes of the apparatus.

13. The method of claim 10, further comprising:

transferring the combustion gases to a counter flow direct contact vessel;

mixing the combustion gas mixture in with process water;

recovering the heat from the combustion gas and condensing the steam to water while heating the process water to a temperature in the range of 70°

C.-90°

C. for oil sand extraction facility for oil recovery.

11. A method for producing a high-pressure steam mixture for enhanced oil recovery comprising the steps of:

mixing fuel with oxidation gases in a high pressure reactor to form a mixture;

combusting the mixture under high pressures and temperatures in a vertical pressurized vessel reactor to generate combustion gases;

mixing the combustion gases with water in the high pressure reactor having a high level of solids therein to form a combustion gas mixture;

evaporating the water in the combustion gas mixture to leave the solids in a dry form;

recycling a portion of the generated steam and combustion gas mixture to the bottom of the vertical pressurized vessel reactor to generate fluid bed up-flow gas;

transferring the combustion gases to a dry-solid separator unit; and

removing the dry form solids from the dry-solid separator unit.

12. The method of claim 11, further comprising:

transferring the combustion gases to a steam generation and wash vessel;

washing the combustion gas mixture in the steam generation and wash vessel with water at a saturated temperature and pressure;

scrubbing any remaining solids from the combustion gas mixture to form a clean steam and gas mixture for injection into an underground formation for the enhanced oil recovery.

14. A system for vertically producing a steam and combustion gas mixture, the system comprising:

a first section being comprised of a burner means for mixing carbon or hydrocarbon fuel and oxidation gas containing oxygen in stoichiometric ratio, and combusting the mixture under high pressure and temperature, wherein said fuel being is selected from a group consisting of coal, pet-coke, asphaltin, vacuum residuals (VR), untreated liquid crude oil and gas carbon fuel, said oxidation gas being selected from a group consisting of oxygen, oxygen-enriched air, and air;

a second section being adjustably engaged to said first section and being comprised of a means for injecting low quality liquid water to flowing combustion gas, said low quality water containing levels of suspended and dissolved solids and organics and having an amount, such that all water converts into steam, said low quality water being selected from a group consisting of tailing pond water with levels of TSS, TDS and organics, brackish water, and sewage effluent water;

a third section being adjustable engaged to said second section being comprised of produced steam, gas and solid mixture discharge means in a vertical vessel with flow deflectors, ensuring flow mixture and preventing liquid remains and heavy solid particles from flowing with produced steam, gas and solid mixture and depositing; and

a fourth section being a fluid bed section at a bottom of the vessel of the first section, said fluid bed section having a gas injector and dispenser and containing solids generated from the fuel and from the water turning into steam, the fluid bed solids being maintained at relatively cold temperature by the cold gas up-flow and being eventually removed from the system by the solid discharge from said bottom of the vessel for heavy solid particles that fall through the fluid bed up-flow.

15. The system for vertically producing a steam and combustion gas mixture, according to claim 14, further comprising:

grinding means for solid carbon fuel, mixing the ground fuel with water, when said low quality fuel is a solid carbon fuel.

16. The system for vertically producing a steam and carbon dioxide mixture, according to claim 14, further comprising:

a heat exchanger means to use up to 45% of the generated combustion heat to generate super-heated steam and gas mixture from saturated steam and gas mixture.

17. The system for vertically producing a steam and combustion gas mixture, according to claim 14, wherein said fourth section has a cold gas temperature and a temperature of the fluid bed section close to the discharge steam temperature, in the range of 150°

C. and 500°

C.

18. The system for vertically producing a steam and combustion gas mixture, according to claim 14, further comprising:

means for generating recycle gas flow for the fluidized bed, the means for generating being comprised of means for flowing solids-rich gas to a cyclone solid separation, means for recycling solid lean gas flow, and means for directing the solid lean gas flow back to the fluid bed wherein the up-flow velocity of the up-flow gas injected through the fluid bed to carry-on solid particles in the pressurized vertical vessel is in a range of 0.2 m/s and 6 m/s.

19. The system for vertically producing a steam and carbon dioxide mixture, according to claim 18, further comprising:

means for removing solids from the gas flow for disposal;

means for scrubbing sulfur dioxide and solids by adding lime and saturated liquid water in a vessel, when the combustion gas contains sulfur and where there is a need to reduce the amount of sulfur;

means for using the produced steam and combustion gas for bitumen recovery.