Pyrolyzing gasification system and method of use

Abstract

Pyrolyzing gasification system and method of use including primary combustion of non-uniform solid fuels such as biomass and solid wastes within a refractory lined gasifier, secondary combustion of primary combustion gas within a staged, cyclonic, refractory lined oxidizer, and heat energy recovery from the oxidized flue gas within an indirect air-to-air all-ceramic heat exchanger or external combustion engine. Primary combustion occurs at low substoichoimetric air percentages of 10-30 percent and at temperatures below 1000 degrees F. Secondary combustion is staged and controlled for low NOx formation and prevention of formation of CO, hydrocarbons, and VOCs. The gasifier includes a furnace bed segmented into individual cells, each cell is independently monitored using a ramp temperature probe, and provided with controlled air injection. Gasifier air injection includes tuyere arrays, lances, or both. The oxidizer includes three serially aligned stages separated by air injecting baffles, and ability to adjust the exit air temperature.

1 - 47 . (canceled) 
     
     
         48 . A tuyere assembly for injection of air into a furnace, the tuyere assembly comprising a refractory tuyere within the furnace wall, a pipe, and a manifold, the pipe having a first end, a second end opposed to the first end, and a body which extends between the first end and the second end, the first end of the pipe residing within the wall of the furnace, the second end of the pipe residing externally of the furnace, the refractory tuyere in fluid communication, with the first end of the pipe, the manifold in fluid communication with the body of the pipe, the manifold residing externally of the furnace, the second end of the pipe being provided with a selective closure means for selectively opening and closing the second end of the pipe, the selective closure means allowing access to the hollow interior of the pipe. 
     
     
         49 . The tuyere assembly of  claim 48  wherein the manifold is provided with selective detachment means for selectively detaching the manifold from the pipe, the selective detachment means allowing for cleaning, maintenance, and replacement of the manifold independently of the remaining components of the tuyere assembly. 
     
     
         50 . The tuyere assembly of  claim 49  wherein the tuyere assembly comprises an elongate bushing, the bushing being received within the hollow interior space of the pipe for purposes of modifying the air flow within the pipe, the bushing having an outer diameter which is sized to allow the outer surface of the bushing to confront and abut the inner surface of the pipe, the bushing capable of being inserted and removed from within the pipe via the second end of the pipe when the selective closure means is open. 
     
     
         51 - 59 . (canceled) 
     
     
         60 . A cyclonic, staged oxidizer, the oxidizer comprising an elongate, hollow, completely refractory-lined cylindrical body, the body having a first end, a second end opposed to the first end separated from it by a mid portion, and a longitudinal axis, the first end comprising a conical end wall, the conical end wall terminating in an apex, the apex comprising ignition and burning means, the second end comprising a generally flat end wall, the mid portion comprising a cylindrical sidewall, a first baffle and a second baffle, the first baffle and second baffle extending radially inward from the interior surface of the sidewall in a spaced relationship such that the first baffle and the second baffle segment the interior space into a first stage, a second stage, and a third stage, the first baffle and the second baffle each comprising a circular plate, the circular plate comprising a first area, the circular plate comprising a radius which is the same as the interior radius of the sidewall, the circular plate comprising a circular opening, the circular opening comprising a second area, the second area sized to be approximately one third of the first area, wherein a portion of the peripheral edge of the circular opening coincides with both a portion of the peripheral edge of the circular plate and the sidewall, the first baffle extending from the sidewall on a first side of the body, the second baffle extending from the sidewall on a side which is opposed to the first side such that fluid flow through the oxidizer is caused to travel a helical path about the longitudinal axis, the respective first, second and third stages being serially aligned along the longitudinal axis of the body such that the first stage resides between the first end and the first baffle, the second stage resides between the first baffle and the second baffle, and the third stage resides between the second baffle and the second end, the oxidizer comprising a fluid inlet duct for conveying un-oxidized fluids into the oxidizer is provided in the sidewall of the first stage, the fluid inlet duct comprising a first air injection means, the oxidizer comprising a fluid outlet duct for conveying oxidized fluids out of the oxidizer is provided in the sidewall of the third stage, the fluid outlet duct comprising a second air injection means, the oxidizer comprising an emergency relief duct is provided in the sidewall of the third stage for selective acute release of fluid from the oxidizer, the emergency relief duct comprising an emergency relief valve that, when activated, allows release of fluid to the atmosphere, the oxidizer comprising a first tuyere array and a second tuyere array, each of the first and second tuyere arrays comprising nozzles which are linearly-aligned and spaced-apart, wherein the first tuyere array is located along circular opening within the first baffle, and the second tuyere array is located along the circular opening in the second baffle. 
     
     
         61 . The oxidizer of  claim 60  wherein the first air injection means comprises an all-refractory first member, the first member comprising an elongate hollow tube having a first end, a second end opposed to the first end, and a mid portion between the first end and the second end, the first end of the first member residing externally of the fluid inlet duct, the second end and mid portion of the first member residing within the fluid inlet duct such that the elongate tube lies generally centered within and aligned with the inlet duct, the second end of the first member comprising an end nozzle which is in fluid communication with the hollow interior of the tube so that when air is propelled within the hollow interior of the tube from the first end to the second end, air is injected into the fluid inlet duct via the end nozzle. 
     
     
         62 . The oxidizer of  claim 61  wherein the fluid inlet duct is formed of ceramic, the fluid inlet duct comprising a constricted portion, the constricted portion having an inlet side and an outlet side, the fluid inlet duct comprising a diverging portion, the diverging portion abutting the outlet side of the constricted portion, the end nozzle of the first member positioned adjacent the inlet side of the constricted portion, the position of the first member within the fluid inlet duct being adjustable such that the end nozzle is movable toward and away from the constricted portion. 
     
     
         63 . The oxidizer of  claim 62  wherein the second air injection means comprises an all-refractory second member, the second member comprising a ring about the interior surface of the fluid outlet duct, the ring comprising a hollow interior, an outer peripheral edge which confronts the interior surface of the fluid outlet duct and an inner peripheral edge which is opposed to the outer peripheral edge and faces the centerline of the fluid outlet duct, the inner peripheral edge comprising a plurality of ring nozzles in fluid communication with the hollow interior of the ring such that when air is propelled within the hollow interior of the ring, air is injected into the fluid outlet duct via the plurality of ring nozzles, each ring nozzle of the plurality of ring nozzles comprising an angled orientation within the ring such that air flowing through the ring nozzle is directed downstream and away from the oxidizer. 
     
     
         64 . The oxidizer of  claim 63  wherein the longitudinal axis of the oxidizer is oriented generally horizontally, the oxidizer comprising an upper side and a lower side, the fluid inlet duct intersects the sidewall between the upper side and the lower side such that the fluid inlet duct is oriented generally horizontally and generally transverse to the longitudinal axis of the oxidizer, the fluid outlet duct intersects the sidewall at the lower side such that the fluid outlet duct is oriented generally vertically and generally transverse to the longitudinal axis of the oxidizer, the emergency relief duct intersects the sidewall at the upper side such that the emergency relief duct is oriented generally vertically and generally transverse to the longitudinal axis of the oxidizer, the first baffle and second baffle are each provided with small vent holes, the vent holes extending through the circular plate of the respective baffle such that the vent holes lie adjacent the upper side of the oxidizer so as to prevent pocketing of gas during oxidizer start up and shut down. 
     
     
         65 . A system for recycling biomass waste into useful ash and recoverable heat energy without formation of toxic by-product gases, the system comprising a pyrolyzing gasifier with all-refractory internals, a staged, cyclonic oxidizer with all refractory internals, and at least one heat exchanger, the biomass waste being gasified within the gasifier to form useable ash and a primary combustion gas, the primary combustion gas then being directed to the oxidizer, the primary combustion gas undergoing secondary combustion in a staged manner within the oxidizer to form a generally clean flue gas, the generally clean flue gas then being directed to the at least one heat exchanger, heat energy being recovered from the generally clean flue gas as it is passed through the at least one heat exchanger. 
     
     
         66 . The system of  claim 65  wherein the at least one heat exchanger comprises an all ceramic indirect air-to-air heat exchanger. 
     
     
         67 . The system of  claim 65  wherein the at least one heat exchanger comprises an all ceramic indirect air-to-air heat exchanger and a metal indirect air-to-air heat exchanger, the metal indirect air-to-air heat exchanger having internal surfaces coated with a thermal barrier. 
     
     
         68 . The system of  claim 66  wherein the biomass waste is gasified within the gasifier at a maximum temperature of 1000 degrees F. 
     
     
         69 . The system of  claim 68  wherein the biomass waste is gasified in starved air conditions in the range of 20 to 40 percent stoichiometric. 
     
     
         70 . The system of  claim 69  wherein the primary combustion gas produced within the gasifier is mixed with air using an all-ceramic high temperature ejector means as it enters the oxidizer, the high temperature ejector means being adjustable. 
     
     
         71 . The system of  claim 69  wherein a negative draft is maintained within the gasifier using an all ceramic high temperature ejector means, the all-ceramic high temperature ejector means positioned in the system between the pyrolyzing gasifier and the staged, cyclonic oxidizer. 
     
     
         72 . The system of  claim 70  wherein the oxidizer comprises a means for adjusting the temperature of the generally clean flue gas as it exits the oxidizer so that temperature of the generally clean flue gas can be controlled without reducing mass flow from the oxidizer, the means for adjusting the temperature of the generally clean flue gas comprising an annular arrangement of air injection nozzles which encircles the stream of generally clean flue gas as it exits the oxidizer. 
     
     
         73 . The system of  claim 66  wherein the system further comprises at least one external combustion engine, wherein the heat energy recovered from the generally clean flue gas as it passes through the all-ceramic indirect air-to-air heat exchanger heats air, the air then is used as input heat source for the at least one external combustion engine, the at least one external combustion engine producing electrical power. 
     
     
         74 - 81 . (canceled) 
     
     
         82 . A method of pyrolyzing solid wastes to produce a useable ash and generate power using a gasification system, the system comprising a gasifier and at least one external combustion engine, the method comprising the following method steps:
 step 1. solid wastes are gasified within the gasifier producing ash and combustion flue gases,   step 2. the combustion flue gases discharged from the gasifier are directed to the at least one external combustion engine and used therein to fire the at least one external combustion engine, the external combustion engine generating power.   
     
     
         83 . The method of pyrolyzing solid wastes to produce a useable ash and generate power of  claim 82  wherein the system further comprises a staged cyclonic oxidizer, and wherein the following method steps 3, 4, and 5 replace step 2:
 step 3. combustion flue gases discharged from the gasifier are directed to the staged cyclonic oxidizer, 
 step 4. the combustion flue gases are oxidized within the staged cyclonic oxidizer and discharged as clean flue gas from the staged cyclonic oxidizer, 
 step 5. the clean flue gas is directed to the at least one external combustion engine and used therein to fire the at least one external combustion engine, the external combustion engine generating power and discharging flue gas. 
 
     
     
         84 . The method of pyrolyzing solid wastes to produce a useable ash and generate power of  claim 83  wherein the system further comprises an alloy metal heat exchanger, and wherein the following method step follows step 5:
 step 6. the flue gas discharge from the at least one external combustion engine is directed to the alloy metal heat exchanger, the alloy metal heat exchanger recovering heat energy from the flue gas discharge. 
 
     
     
         85 . The method of pyrolyzing solid wastes to produce a useable ash and generate power of  claim 82  wherein the system further comprises a staged cyclonic oxidizer and an all-ceramic air-to-air indirect heat exchanger, and wherein the following method steps 3-8 replace step 2:
 step 3. combustion flue gases discharged from the gasifier are directed to the staged cyclonic oxidizer, 
 step 4. the combustion flue gases are oxidized within the staged cyclonic oxidizer and discharged as clean flue gas from the staged cyclonic oxidizer, 
 step 5. the clean flue gas is directed to the to the air-side of the all-ceramic heat exchanger, 
 step 6. the clean flue gases heat clean air within the tube-side of the all-ceramic heat exchanger to produce hot clean air, 
 step 7. the hot clean air is discharged from the tube-side of the all-ceramic heat exchanger and is directed to the at least one external combustion engine, 
 step 8. the hot clean air is used to fire the at least one external combustion engine, the external combustion engine generating power. 
 
     
     
         86 . The method of pyrolyzing solid wastes to produce a useable ash and generate power of  claim 85  wherein the system further comprises an alloy metal heat exchanger, and wherein the following method step follows step 8: step 9. the flue gas discharge from the at least one external combustion engine is directed to the alloy metal heat exchanger, the alloy metal heat exchanger recovering heat energy from the flue gas discharge. 
     
     
         87 . The method of pyrolyzing solid wastes to produce a useable ash and generate power of  claim 85  wherein the following method step follows step 8:
 step 9. the flue gas discharge from the at least one external combustion engine is directed to the staged cyclonic oxidizer, the staged cyclonic oxidizer using the flue gas discharge from the at least one external combustion engine as a source of preheated air. 
 
     
     
         88 . An apparatus for high temperature draft control, the apparatus comprising an all-ceramic duct for directing high temperature combustion flue gases, the apparatus comprising an elongate hollow ceramic tube for injecting a fluid into the duct, the duct comprising a first end, a second end, and a mid portion, the mid portion of the duct comprising a constricted portion adjacent the first end such that the inner diameter of the duct within the constricted portion is less than the inner diameter of the duct within both the first end and the second end, the mid portion of the duct comprising a conical portion extending between the constricted portion and the second end such that the inner diameter of the duct is enlarges from the constricted portion to the second end, the tube comprising a first end and a second end, the first end of the tube residing outside the duct, the second end of the tube residing within the duct, the second end of the tube terminating in a tapered nozzle, the second end of the tube positioned within the first end of the duct adjacent the constricted portion, the tube adjustably positionable within the duct such that the second end of the tube can be moved relative to the constricted portion. 
     
     
         89 . The apparatus for high temperature draft control of  claim 88  wherein the apparatus comprises an all-ceramic guide pipe, the guide pipe being fixed within the first end of the duct, having an insulated core and a hollow interior, wherein the second end of the tube resides within the hollow interior of the guide pipe such that the tube is supported within the duct by the guide pipe and such that the tube is selectively moveable relative to the guide pipe.