Process for pyrolytic heat recovery enhanced with gasification of organic material

• US 20060112639A1
• Filed: 11/23/2004
• Published: 06/01/2006
• Est. Priority Date: 11/29/2003
• Status: Active Grant

• Current Assignee: Eric A. Anderson, Geoffrey E. Dolbear, Hugh Hunnicutt, Peter A. Nick, Robert Roy Peters
• Original Assignee: Eric A. Anderson, Geoffrey E. Dolbear, Hugh Hunnicutt, Peter A. Nick, Robert Roy Peters
• Inventors: Dolbear, Geoffrey E., Anderson, Eric A., Nick, Peter A., Hunnicutt, Hugh, Peters, Robert Roy
• Granted Patent: US 7,452,392 B2
• Time in Patent Office: Days
• US Class Current: 48/198.100
• CPC Class Codes: C10J 2200/156 Sluices, e.g. mechanical sluices for preventing escape of gas through the feed inlet
• CPC Class Codes: C10J 2300/0903 Feed preparation
• CPC Class Codes: C10J 2300/0916 Biomass
• CPC Class Codes: C10J 2300/093 Coal
• CPC Class Codes: C10J 2300/0946 Waste, e.g. MSW, tires, glass, tar sand, peat, paper, lignite, oil shale
• CPC Class Codes: C10J 2300/0969 Carbon dioxide
• CPC Class Codes: C10J 2300/0973 Water
• CPC Class Codes: C10J 2300/0989 Hydrocarbons as additives to gasifying agents to improve caloric properties
• CPC Class Codes: C10J 2300/1253 by injecting hot gas
• CPC Class Codes: C10J 2300/1634 Ash vitrification
• CPC Class Codes: C10J 2300/1659 to liquid hydrocarbons
• CPC Class Codes: C10J 2300/1807 Recycle loops, e.g. gas, solids, heating medium, water
• CPC Class Codes: C10J 3/08 with ash-removal in liquid state
• CPC Class Codes: C10J 3/14 using gaseous heat-carriers
• CPC Class Codes: C10J 3/723 Controlling or regulating the gasification process
• CPC Class Codes: C10K 1/003 of acid contaminants, e.g. acid gas removal
• CPC Class Codes: C10K 1/004 Sulfur containing contaminants, e.g. hydrogen sulfide
• CPC Class Codes: C10K 1/005 Carbon dioxide
• CPC Class Codes: C10K 1/026 by centrifugal forces cyclones B04C
• CPC Class Codes: C10K 1/101 with water only
• CPC Class Codes: C10K 1/12 : alkaline-reacting including the revival of the used wash liquors
• CPC Class Codes: Y02E 50/30 : Fuel from waste, e.g. synthetic alcohol or diesel
• CPC Class Codes: Y02P 20/145 : the feedstock being materials of biological origin

Abstract

This invention is a reactor and a process for the conversion of organic waste material such as municipal trash, sewage, post-consumer refuse, and biomass to commercially salable materials. The invention produces the following: 1. Maximum energy conversion from the organic material 2. High volume consumption of the organic feed material 3. Less pollution of gaseous products than prior art systems 4. Solid residuals for disposal are minimal and non-hazardous.

The conversion is accomplished by combining anaerobic gasification and pyrolysis of the feed organic material and making it into synthetic gas. The synthetic gas is a mixture of hydrocarbons (C_xH_y), hydrogen, and carbon monoxide with small amounts of carbon dioxide and nitrogen. An essential feature of the invention is a hot driver gas, devoid of free oxygen and rich in water, which supplies the entire thermal and chemical energy needed for the reactions. This hot driver gas is produced by complete sub-stoichiometric combustion of the fuel (C_xH_y) before it enters the reactor . . .

Claims

1. A process for the production of gaseous effluent rich in hydrogen, carbon monoxide, and other fuel gases of composition C_xH_y from a feed of heterogeneous organic material comprised of municipal trash, refuse, garbage, or other post-consumer wastes, which is completed in a reactor by means of anaerobic gasification and pyrolysis that is caused by a hot driver gas devoid of free oxygen and of sufficient heat and water content to effect the conversion reactions and produced externally to the reactor chamber.

2. The process of claim 1, further defined in that depending upon the organic composition of the feed the temperature of the driver gas at the reactor inlet is 2000-3600 F;

the temperature at pyrolytic conversion is 500-1200 F;

the temperature at gasification is 1200-2500 F; and

the produced gas exiting from the reactor has a temperature of 200-250 F.

3. The process of claim 1 further defined that the driver gas has a water content of 1.1-3.5 times the molar amount of carbon formed from the pyrolysis of the solid feed materials.

4. The process of claim 1 is further defined that the solid feed material can contain up to 30% by individual volume or 75% by total accumulated volume of tires, wood, plastics, paper, petroleum resid, coke, charcoal, wood, forest by-products, agricultural waste, medical waste, asphalt, metals, asbestos, and batteries or other material defined as supplemental feeds.

5. The process of claim 1 is further defined that the sum of solid feed material can replaced by up to 25% by total weight of heavy oils, lube oils, waste hydrocarbons, black liquor, organic solvents, chlorinated solvents, paint, and carcinogenic organics.

6. A process for the production of hydrocarbon gases from a feed of heterogeneous organic material where the heat source comprises a hot driver gas that performs the following functions:

(a) gasifying the carbon in the pyrolytic residual char/slag to less than 0.1 wt % of the final solid effluent via the reaction C+H2O->

CO+H₂, making a syngas product that adds to the total driver gas stream.

(b) liquefying the pyrolytic slag material to allow for its ultimate removal from the reactor.

(c) providing complete or nearly complete pyrolytic decomposition of the organic feed material.

(d) providing all the sensible heat necessary to raise the feed material to the appropriate decomposition temperatures.

(e) drying and removing water entrained by surface adsorption or other physico-chemical attraction to the feed material charged into the reactor.

7. The process of claim 6 is further defined that the chemical potential of the driver gas is a reducing atmosphere in which incidental heteroatoms, X, such as chlorine, fluorine, bromine, and sulfur contained in the solid feed material, are liberated by pyrolysis to form acid gases of the form H_X and in which nitrogen atoms released by pyrolysis form ammonia.

8. The process of claim 6 is further defined that the oxidant source of the driver gas before entering the reactor is comprised of air of natural content, oxygen, oxygen-enriched air, or ozone.

9. The process of claim 6 is further defined that the fuel source for the driver gas is comprised of natural gas;

diesel oil;

residual oil;

combustibles such as wood, biomass, coal, petroleum coke, or charcoal;

recycled syngas;

recycled white oils;

or other carbonaceous material.

10. The process of claim 6 is further defined that supplemental driver gas sources are comprised of steam;

exhaust from combustion turbines and fired heaters; and

recycled effluents from exited syngas.

11. The process of claim 6 is further defined that the driver gas is comprised of oxygen-depleted products from any combustion process that is both external to the reactor and comprised of a solid, liquid, or gaseous fuel and an oxidant.

12. The process of claim 6 is further defined that the exiting driver gas is a stream of hot gases comprised of the following gaseous/vapor species:

H2, CO, CO2, C_xH_y, H2O, C_xH_yO_z, N₂, Ar, and He but with a free molecular oxygen and/or ozone content of less than 1000 parts per million by weight.

13. A process for the production of hydrocarbon gases from a feed of heterogeneous organic material where the reactor for the process has:

(a) sequential anaerobic pyrolysis and gasification of organic feed material via direct countercurrent contact of a wet, oxygen-devoid thermal driver gas flowing upward opposite a downward moving bed of solid feed material;

(b) use of segregated feed types of known organic heat content such as plastic, paper, and sludge;

(c) statistical analysis and correlation of feed types with easily measured bulk properties such as density;

(d) exact real time feed calorific and component determination of C/H, C/O, and O/H ratios via fast neutron analysis or equivalent scanning methodology;

(e) exact real time determination of reactor off-gas calorimetric content via on-line spectrophotmetric or GC-analysis and component analysis via GCMS analysis or appropriately calibrated spectrophotometric analyses.

14. The process of claim 13 is further defined that control of the reactor temperature and reaction profile can be accomplished by calculated manipulation of oxidant flow, fuel flow, supplemental gas flow, total feed, and organic feed material content.

15. The process of claim 13 is further defined that the reactor solid bed porosity and permeability are maintained by the irregularly sized and shaped post-consumer waste material being used as received, the sizing of any comminuted materials in the feed, the overburdening weight of feed supply above the reaction zones, the variance of the driver gas inlet pressure to move the solid bed incrementally in order to break bridging, and the injection of small amounts of new or recycled liquid feeds at different locations in the reactor.

16. The process of claim 13 is further defined that slag product flow at the bottom of the reactor is enhanced by the adding silica, alumino-silicates, alkaline earth oxides, clays, sandy sludge, or specialty papers to the feed material.

17. The process of claim 13 is further defined that the molten reactor slag is removed by collection in a reservoir at the bottom of the reactor and removed with use of a hot tap with mud gun control as in a standard blast furnace or dropped into a reservoir of water in which the melted material is cooled and results in a course granulated form.

18. The process of claim 13 is further defined that the reactor is constructed of a steel or other metal shell that is lined with a sufficient amount of standard refractory material to resist the high temperature, acids, and abrasions.

19. The process of claim 13 is further defined that the reactor is constructed in several flanged and bolted segments of 2-6 feet in height such that fabrication, transport, installation and maintenance of each segment can be easily and readily accomplished with standard construction and maintenance equipment.