Method and apparatus for recovering energy from fossil resources

Information

  • Patent Application
  • 20070175096
  • Publication Number
    20070175096
  • Date Filed
    February 01, 2006
    18 years ago
  • Date Published
    August 02, 2007
    17 years ago
Abstract
A method and apparatus for recovering energy from a fossil resource that contains organic matter together with mineral material such as oil shale, coal. oil sand, etc., wherein a hydroretort and a gasifier are interconnected and are utilized in such a way as to have the hydroretort serve as the vessel for pyrolizing the resource by direct contact with hot syngas produced in said gasifier in order to extract oil from the resource while co-producing a residual mineral laden with carbon and some hydrocarbons. This residual mineral is fed from said hydroretort to said gasifier via a lockhopper and by means of oxygen and steam injected into the gasifier, the carbon and the hydrocarbons are converted to a hot syngas and the mineral matter converted to a molten slag which is cooled to a non-leaching substance.
Description
INTRODUCTION

This invention relates to recovering energy from fossil resources that contain mineral material combined with organic material that are found in nature in the form of various coals, oil shales, oil sands, etc. These fossil resources may be processed individually or in combination to optimize the recovery of the energy contained in them. By way of example, the present invention will be described in detail as it relates to the recovery of oil and gas from oil shale per se, since it contains large amounts of mineral material (around 80%) and by reference to the application ofthis invention to coal per se since the mineral material in coal generally does not exceed 15%. The invention will also be described in detail by using oil shale and coal in combination, with the aid of a process flow diagram.


BACKGROUND

In 1983 a U.S. patent was issued to the applicant bearing U.S. Pat. No. 4,376,033 which covers the recovery of shale oil from shale. This patent discloses the pyrolysis of oil shale by making use of electrical power in a plurality of cells within which the shale is contained and insulating the outer walls of the cells from one another. By means of induction, said walls are heated to cause thermal energy from the walls of the cells to effect the pyrolysis of the shale and result in the release of the oil from the shale in vapor form that leaves from the top of the cells.


The raw shale, after being pyrolized, takes the form of spent shale which is discharged from the bottom of the cells. This spent shale is further processed by compression into blocks to reduce the volume of the spent shale in order to facilitate its disposal within the mine whence the raw shale was excavated. Prior to the delivery of the blocks to the mine, a sealer is applied to the blocks to make them impervious to water in order to prevent the contamination of the surroundings where the blocks are stored.


In 2005, a U. S. patent was issued to the applicant bearing U.S. Pat. No. 6,911,058 B2 relating to the processing of coal. It covers the feeding of coal into a chamber which is equipped with a mechanical pusher which advances the coal within the chamber while an oxidant is injected from the discharge end of said chamber to combust a portion of the coal to generate thermal energy that devolatilizes the coal, producing a hydrogen-rich gas and a hot char which is subsequently gasified. The disadvantage of this reference is the massive pusher required to maintain the movement of the coal within said chamber.


Objectives


In the recovery of oil from oil shale, the biggest impediment towards exploitation of this vast resource is the solid spent shale that is generated after pyrolysis. Since the volume of the spent shale is quite large, very voluminous, and produces a serious negative impact to the environment, the main object of this invention is to overcome this serious and objectionable factor by providing a method and apparatus that converts the spent shale into a dense, non-leaching slag by melting it and then re-solidifying it into a vitreous material which may have useful applications.


Another object of this invention is to convert the residue in the spent shale which is in the form of carbon and certain residual hydrocarbons to a valuable, hot synthesis gas via gasification, the synthesis gas being hereafter referred to as “syngas.”


Still another object of this invention is to improve the transfer of heat into the raw shale during its pyrolysis by making use of the hot syngas to hydroretort the raw shale by directly contacting the hot syngas at the optimum temperature and residence time with the shale to result in increasing the overall efficiency of oil recovery from the shale.


Therefore, another object of the present invention is to provide a pressurized system to effect the movement of the gases through the various steps of the method.


Further, another object of the invention is to provide an integrated method and apparatus to conduct same comprising hydroretorting, gasification, and product distillation.


Further still, another object of the present invention is to substitute coal for oil shale to produce gas(es), liquids(s) or a combination of both.


Yet another object of the present invention is to supplement the raw shale with a carbonaceous material such as coal in order to increase the oil yield and also provide sufficient carbon as fuel to be adequate to melt the relatively large quantities of spent shale into a hot liquidus material hereinafter referred to as molten “slag.”


It is another object of the present invention to recover thermal energy from the molten slag.


It is still another object of the present invention to quench the molten slag in order to re-solidify it and thus obtain a non-leaching, vitreous frit.


It is therefore another object of the present invention to produce a shale oil vapor product via hydroretorting which is fractionated yielding various liquid fractions and a non-condensable gas.


It is further another object of the present invention to produce a hydrogen-rich gas as a by-product which is useful in the upgrading of the recovered oil and/or in the manufacture of synthetic natural gas hereinafter referred to as SNG.


It is yet another object of the present invention to produce a hydrogen-rich gas as a by-product which is converted to a liquid product to supplement the liquid product extracted from the shale.


Other objects of the invention will appear from the following description and appended claims.




BRIEF DESCRIPTION OF DRAWINGS


FIG. 1 is an overall representation of the apparatus to carry out the method. It comprises, in succession from the top down: a raw material delivery system, an upper lockhopper, a hydroretort, a hot lockhopper, a slagging gasifier, a heat recovery steam generator, a molten slag quencher, a lower lockhopper, a slag collection tank, and a fractionator.



FIG. 2 is an enlarged representation of the hydroretort, shown in section.



FIG. 3 is an enlarged representation of the slagging gasifier, the heat recovery steam generator, and the molten slag quencher, illustrated in section.



FIG. 4 is a representation in greater detail showing various piping systems with respect to the heat recovery steam generator with its manifolds, steam drum, and syngas heat exchanger, bottom lockhopper, and collection tank for the quenched, re-solidified, vitreous slag.



FIG. 5 is the hot lockhopper shown in section, with the upper and lower valves being in the closed position, illustrating the condition under which pressurization of the hot lockhopper by means of steam takes place.



FIG. 6 is the hot lockhopper shown in section, with the upper valve being opened and the lower valve closed, illustrating the step of receiving spent shale from the hydroretort.



FIG. 7 is the hot lockhopper shown in section, with the upper valve being closed and the lower valve opened, illustrating the step of delivering spent shale from the hot lockhopper to the top of the gasifier.



FIG. 8 is a process flow diagram illustrating the various reactors and streams when the method is applied to the co-production of liquids and gases by co-feeding oil shale together with coal as the feedstock.




Before explaining in detail the present invention, it is to be understood that this invention is not limited to the details of construction and the arrangement of the parts illustrated in the accompanying drawings, since the invention may possess other embodiments. Also it is to be understood that the phraseology or terminology herein contained is for the purpose of description and not limitation. Reference is now made to the accompanying drawings forming a part of this specification wherein like reference numerals designate corresponding parts in the various figures.


DETAILED DESCRIPTION OF DRAWINGS

In FIG. 1, numeral 10 represents the hydroretort, numeral 11 the gasifier, numeral 12 the heat recovery steam generator, numeral 13 the slag quencher, and numeral 14 the fractionator. Above hydroretort 10, lockhopper 15 is situated which is supplied with raw oil shale by conveyor 16. Below hydroretort 10 and above gasifier 11, hot lockhopper 17 is mounted; it interconnects hydroretort 10 to gasifier 11. At the bottom of gasifier 11, common port 18 is provided, through which: (i) hot syngas leaves gasifier 11 via a first gas conduit which is denoted by numeral 19; and (ii) molten slag is discharged into quencher 13 by way of heat recovery steam generator 12 (hereinafter called “HRSG”). Conduit 19 delivers hot syngas to the top of hydroretort 10. A second gas conduit, denoted by numeral 20, leaves the bottom of hydroretort 10 and delivers a combination of syngas and shale oil in vapor form to the bottom of fractionator 14. The miscellaneous liquid fractions leave fractionator 14 through a group of pipes, such as conduits 21, 22, 23, and 24, and the non-condensable gas via conduit 25. Steam from HRSG 12 feeds a steam drum, denoted by numeral 26, via conduit 27 and from steam drum 26 to the top of conveyor 16 via conduit 28 to preheat the raw shale as it is conveyed. A conduit denoted by numeral 29, situated at the bottom of conveyor 16, returns the condensate to HRSG 12. Water for quenching the molten slag is stored in tank 30. Beneath slag quencher 13, lockhopper 31 is provided to deliver the quenched slag to the atmosphere. A slag collection tank equipped with a drag chain (not shown, but known in the art) and marked by numeral 32, is situated beneath lockhopper 31.


Referring to FIG. 2 which illustrates (in section) hydroretort 10 in a magnified representation, comprises the following: an upper part denoted by numeral 33 and a lower part denoted by numeral 34. Part 33 is a vertically disposed cylindrical steel shell 35, with refractory/insulation denoted by numeral 36 being installed against the inner wall of shell 35 in such a way as to preferably diverge downwardly. Part 34 which is sloped, is also constructed from a steel shell marked by numeral 37, with refractory/insulation marked by numeral 38 being installed against the inner wall of shell 37 in such a way as to preferable diverge downwardly. Preferably, part 34 is larger in its inner diameter than the inner diameter of part 33 in order to cause the feedstock to feed by gravity while continuously providing a physical relief in the downward direction by providing a downward diverging taper of refractory/insulation 36; this configuration facilitates the downward free movement of the feedstock to prevent bridging. A feeder marked by numeral 39 is equipped with actuator 40. Hydroretort 10 is provided with 4 ports: port 42 for the inlet of the feedstock, port 43 for the inlet of the hot syngas from gasifier 11, port 44 for the exit of the shale oil together with the injected syngas in the form of a vapor product, and port 45 for the discharge of the spent shale into gasifier 11 via hot lockhopper 17 (partially shown) which is connected to the bottom of hydroretort 10 by means of flange connection 46.


Referring to FIG. 3, gasifier 11 is illustrated in section and comprises the following: an upper part marked by numeral 47 and a lower part marked by numeral 48. Part 47 is cylindrical in shape and is constructed in the form of a vertical steel shell marked by numeral 49, with refractory/insulation marked by numeral 50 that is installed against the inner wall of shell 49 in such a way as to preferably diverge downwardly. Part 48 is sloped and constructed from a steel shell marked by numeral 51, with refractory/insulation marked by numeral 52 that is installed against the inner wall of shell 51 in such a way as to preferably diverge downwardly. Preferably, part 48 is larger in its inner diameter than the inner diameter of part 47 in order to cause the spent shale to move by gravity without impediment while continuously providing a downward physical relief to facilitate the movement of the solid spent shale together with the semi-molten spent shale without bridging, toward common port 18 as the spent shale transitions from a solid state to a molten slag.


To initiate the start-up of the method, a burner marked by numeral 53 is provided and mounted at the top of gasifier 11. An array of injectors marked by numeral 54 is provided at various locations in gasifier 11 for the introduction of an oxidant which may be air or oxygen, but preferably oxygen which is moderated with steam to produce a hot syngas in gasifier 11; this syngas serves as a medium for directly heating the raw shale by introducing it at the top of hydroretort 10, as shown in FIGS. 1 and 2. In addition, an oxidant injection means which takes the form of a water-cooled lance that is adapted to move vertically and marked by numeral 55, is provided to insure that common port 18 remains open and un-plugged by preferably injecting oxygen and combusting some of the syngas produced in the gasifier as it flows toward common port 18 in order to furnish adequate thermal energy at port 18 to prevent premature solidification of the slag.


Gasifier 11 possesses two main ports: port 56 for the entry of the hot spent shale from hot lockhopper 17, and common port 18 for the flow of the spent shale in the form of a molten, vitreous slag together with the syngas, both being produced in gasifier 11. As secondary ports, port 57 is for the introduction of the flue gas from burner 53, ports 58 for the introduction of the gasification oxidant and steam from injectors 54, and port 59 for the introduction of the oxidant from lance 55.


Referring to FIG. 4 for a more detailed description of the preferred embodiment in the lower half of gasifier 11, the equipment comprises five components, namely: the syngas exhaust denoted by numeral 60; the HRSG marked by numeral 12; the slag quench denoted by numeral 13; the slag lockhopper marked by numeral 31, and the slag tank/drag conveyor denoted by numeral 32.


With respect to syngas exhaust 60, it includes gas conduit 61 and temperature control heat exchanger 62 which moderates the temperature of the syngas and generates high-pressure steam. Exhaust conduit 19 is provided for directing the moderated syngas to the top of hydroretort 10 shown in FIG. 1.


With respect to HRSG 12, it comprises a bottom manifold 63 for feed water, with inlet 64 for water delivery into manifold 63, a top manifold 65 for steam collection, and an array of vertical pipes configured as a cage and marked by numeral 66 which interconnects manifold 63 to manifold 65. The delivery of high-pressure steam out of manifold 65 and into steam drum 26 is effected via conduit 67; high pressure steam out of steam drum 26 is effected via conduit 68.


With respect to slag quench 13, it comprises conical quench section 69 which is integrated to the bottom of HRSG 12, and water tank 30 to maintain a designated level of water within quench section 69. Conduit 70 communicates bottom of tank 30 to section 69. An exit port denoted by numeral 71 is provided at the top of HRSG 12 for the exhaust of the low-pressure steam generated when the molten slag is quenched in the pool of water contained in conical quench section 69. This low-pressure steam (via conduit 72) is delivered to conveyor 16 (shown in FIG. 1) for oil shale preheat while it is being conveyed.


With respect to lockhopper 31 and slag tank/drag conveyor 32, upper valve 73 and lower valve 74 are provided, with valve 73 controlling the quenched slag into lockhopper 31 from quench section 69, and valve 74 controlling the quenched slag out of lockhopper 31 and into slag tank/drag conveyor 32. Slag tank/drag conveyor 32 is known in the art and is briefly herein described. It consists of a tank within which a drag-chain conveyor is installed. The conveyor is configured to drag particulate matter from the bottom of the tank and elevate it on a slope prior to discharging it at the end of the slope. The slag containing tank is denoted by numeral 75, and its discharge chute is denoted by numeral 76.


Referring to FIGS. 5, 6, and 7 for disclosure of hot lockhopper 17, it is mounted between the bottom of hydroretort 10 and the top of gasifier 11 by making use of flange mountings 77 and 78, respectively. Beneath mounting 77 a pancake valve denoted by numeral 79 is disposed. Above mounting 78, a similar pancake valve denoted by numeral 80 is disposed. Each pancake valve includes a swing linkage arrangement 82 to enable the opening and the closing of either valve 79 or valve 80, by utilizing actuator 81 which causes closure disk 83 to swing towards the seat of valve 79 or valve 80. A material storage magazine denoted by numeral 84 is disposed between valve 79 and valve 80 by making use of flange connections 85 and 86.


Referring now to FIG. 8 which illustrates a process flow diagram of the invention as it relates to the co-production of liquids and a syngas which is converted to synthetic natural gas (SNG) while the feedstock is a combination of shale and coal. Numerals 10, 11, 12, 13, 14, and 17 represent the hydroretort, the gasifier, the HRSG, the quencher, the fractionator, and the hot lockhopper, respectively. These components were numerically identified and described in the foregoing disclosure.


Numeral 90 represents a sorbent regenerator, and 91 represents a desulfurizer which is followed by a shift converter 92, a CO2 separator 93, and a methanator 94. Other components that are illustrated include a sulfur condenser 95, a regenerator gas cooler denoted by numeral 96, and compressors 97 and 98. In the event that pure hydrogen is to be made as a side stream, separator 99 is included; it is equipped with a compressor marked by numeral 100.


While the operation of the improved method and apparatus of the instant invention may be comprehended from the foregoing description, it is believed that the operation may further be explained as hereinafter set forth.


Operation


Referring again to FIG. 8 and assuming that the process is already in progress, shale (stream 101) and coal (stream 102) form stream 103 which flows into hydroretort 10, while hot syngas is being delivered into it via conduit 19 which originates from gasifier 11 after being moderated in temperature by heat exchanger 13. The raw hot syngas is made in gasifier 11 by the injection of oxygen (stream 104) and steam (stream 105) and leaves gasifier 11 via common stream 106 which splits into streams 107 and 108. Stream 107 feeds the hot raw syngas into heat exchanger 62, and stream 108 which represents the molten slag that drops into quenching pool 13 while losing thermal energy to HRSG 12 during its free fall. Stream 109 represents the re-solidified slag.


As shown, the moderated syngas enters at the top of hydroretort 10 and flows downward with the shale/coal combination in a co-current mode while heating both the shale and coal to efficiently pyrolize them and generate a vapor product which leaves hydroretort 10 as stream 20; it is thence directed to a distillation column such as fractionator 14 which produces various liquid fractions that are characterized as stream 21 for light naphtha, 22 for heavy naphtha, 23 for light gas oil, and 24 for atmospheric heavy gas oil. The distillation bottoms are directed to gasifier 11, via stream 111 to be recycled, and the non-condensable gases inclusive of the syngas used to hydroretort the shale/coal (stream 25) are directed to gas cleanup 91 to be treated by means of a catalytic sorbent to remove the sulfur in the gas. The treated gases leave gas cleanup 91 via stream 113 and flow into shift converter 92 where the hydrogen content is brought to a level of 3 H2 to 1 CO by reacting with steam supplied via stream 114. The shifted gas (stream 115) is next directed to separator 93 to separate the CO2 produced in shift converter 92, to thus form a CO2 stream marked by numeral 116, and treated feed gas suitable for methanation as stream 117. Stream 116 may be compressed to the desired pressure by means of compressor 97 to form stream 118 to make it ready for sequestration. Stream 117 may be split into stream 119 and stream 120 if hydrogen is to be made from the treated gas in addition to the SNG; in such a case, stream 120 is directed to gas separator 99 to form a CO stream marked by numeral 121 which is compressed by compressor 100 to form stream 122 that is recycled into gasifier 11, and a hydrogen stream marked by numeral 123.


With respect to stream 119, it is directed to methanator 94 where it is reacted with a catalyst to form synthetic natural gas of pipeline quality which leaves as stream 124, and water that leaves as stream 125.


With respect to the catalytic sorbent that treats the gas in reactor 91, it leaves reactor 91 as stream 126 when it is spent; it joins catalyst make up fed via stream 127 to form together solid stream 128 which is conveyed pneumatically by compressed carrier gas stream 129 by making use of compressor 98. Solid stream 128 is fed to sorbent generator 90 where the sorbent is regenerated with an oxidant (stream 130) which may be moderated with steam (stream 131); both of these streams form a joint stream 132 which enters regenerator 90. The off-gas from regenerator 90, stream 133 is cooled in heat exchanger 96 and exits as stream 134 prior to entering sulfur condenser 95 where elemental sulfur is maintained in a molten state.


Within condenser 95, the non-condensable part of the off-gas and the molten sulfur are separated, and both leave as separate streams: stream 135 as sulfur, and stream 136 as a transport gas which, after compression in compressor 98, conveys the spent sobriety catalyst from the bottom of desulfurizer 91 to the top of regenerator 90. The sorbent catalyst which is regenerated flows from regenerator 90 into desulfurizer 91 by gravity via stream 137. The carrier gas (stream 129) which transports the spent sorbent from the bottom of desulfurizer 91 to the top of regenerator 91 after disengagement from the spent sorbent is exhausted into gasifier 11 to be recycled (stream not shown).


Using FIGS. 1 through 7 to further describe the operation of the invention, and assuming that the process is already in progress, crushed raw oil shale is discharged into hopper 138 and is elevated to lockhopper 15 by means of conveyor 16; see FIG. 1. During its ascent, it is dried and preheated by means of radiant energy (not shown) which is recovered from the process. The preheated raw shale is transferred to lockhopper 15, and by means of valves 87 and 88 together with feeder 89 the shale is introduced at the top of hydroretort 10; by means of feeder 39, situated at the bottom of hydroretort 10, the downward movement of the shale is effected by a controlled gravity feed; see FIG. 2. During the descent of the shale in hydroretort 10, hot syngas enters the top of retort 10 via port 43 and flows co-currently with the shale at such a controlled rate and at such a controlled temperature as to yield its oil as a vapor product caused by the intimate and direct contact of the hot syngas with the raw shale to result in the maximum yield of oil while at the same time converting the shale to a spent shale containing residual carbon. Shale oil (released in vapor form) together with cooled syngas leave hydroretort 10 via port 44 and conduit 20 (FIG. 2), and thence to fractionator 14; see FIGS. 1 and 2.


Reference is now made to FIGS. 5, 6, and 7. In maintaining pancake valve 79 open and pancake valve 80 closed while operating feeder 39, the spent shale is transferred from hydroretort 10 and accumulated in storage magazine 84 of hot lockhopper 17; see FIG. 6. Once magazine 84 reaches a predetermined level, feeder 39 stops, pancake valve 79 closes. While both valve 79 and valve 80 are closed (FIG. 5) steam is injected via port 87 to balance the pressure of hot lockhopper 17 to equal the pressure within gasifier 11. Next, pancake valve 80 is opened to discharge the spent shale from hot lockhopper 17 into gasifier 11; see FIG. 7. Once the spent shale is discharged into gasifier 11, pancake valve 80 is closed, the pressure in hot lockhopper 17 is equalized to the pressure of retort 10, and pancake valve 79 is opened while pancake valve 80 remains closed. Feeder 39 is activated and the operation resumes as that shown in FIG. 6 ofreceiving additional spent shale from hydroretort 10. The cycling of valves 79 and 80 with equalization is continuously performed as the operating pressure within gasifier 11 is maintained higher than that of hydroretort 10 in order to force the syngas made in gasifier 11 to flow into and through hydroretort 10 and thence, together with the vapor product which contains the oil, to fractionator 14.


Referring to FIG. 3, the spent shale discharged from hot lockhopper 17 into gasifier 11 is gasified with an oxidant (such as oxygen) which is moderated with steam to convert the carbon and residual hydrocarbons; the oxygen and steam are injected by means of injectors 54. The objective is to convert the spent shale into a slag by melting it. In cases where the carbon and residual hydrocarbons in the spent shale are inadequate to supply the thermal energy required to melt the spent shale, a supplement source of energy is supplied, such as the addition of coal with the shale. Since the percent of ash in shale is high and the percent of ash in coal is relatively low in comparison to shale, coal would be a good selection to supplement the energy required. In addition, the coal with its own volatile matter contributes to the increase in liquid yields.


As the hot spent shale descends within gasifier 11 and syngas is generated by the reaction of carbon with oxygen and steam, both the spent shale and the syngas are directed to flow co-currently towards bottom 48 of gasifier 11, with the spent shale changing state from a solid to a semi-plastic thence to a liquid slag while both the syngas and the liquid slag flow from gasifier 11 via port 18. To maintain port 18 open, the syngas and the molten spent shale which takes the form of a slag, flow together through port 18 which serves as a common port. Lance 55 serves as a means to insure that common port 18 remains open; it supplies an oxidant such as oxygen via port 59 to combust a small portion of the syngas and maintain the temperature of bottom 48 of gasifier 11 above the melting point of the slag.


As the syngas and slag flow through common port 18, the syngas is separated from the slag by leaving gasifier 11 through port 60, while the slag falls freely into water pool 69 to be fully quenched, and re-solidifies into a grit as it shatters when it comes in contact with the water. Recovery of heat from the molten slag is effected by HRSG 12, and quench water make-up is furnished from tank 30.


Referring to FIG. 4, to describe the operation of heat recovery from the conversion of the molten spent shale into solid slag, the slag is quenched as previously explained while raising steam in HRSG 12. The steam, which is of high pressure quality and used downstream of the process, is directed to steam drum 26.


The syngas leaving gasifier 11 via port 60 is moderated in temperature within heat exchanger 62; thence it is directed to hydroretort 10 (shown in FIG. 1) via conduit 19. The slag, after being quenched, is discharged into lockhopper 31 by making use of valve 73, and from lockhopper 31 into slag tank/drag conveyor 32 by making use of valve 74. In this manner the slag is taken from a pressured environment into the atmosphere with virtually no pressure loss to the system.


Using this invention with coal per se, with such coal being low in ash, the use of HRSG 12 may be obviated since the benefit derived from a HRSG would be minimal. Justification of whether to exclude or include HRSG 12 is to be examined on a case-by-case basis by giving consideration to economics. Further, whether the use of the oxidant is pure oxygen or air, or a combination thereof in gasifier 11 and in lance 55 is an option to be considered on a case-by-case basis, depending upon the ultimate product(s) to be made. Additionally, consideration is to be given whether or not fractionator 14 is to be used in the processing of coal per se. The invention may also be used to produce liquids from the syngas, in whole or in part, by employing known technologies such as the Fischer Tropsch process.


It is submitted that the presentation made herein discloses a method and apparatus which can process fossil resource(s) such as coal, oil, shale, oil sand, etc., for producing abundant energy efficiently, and in an environmentally acceptable manner.

Claims
  • 1. A method for processing a fossil resource to recover energy therefrom comprising the following steps: feeding the resource into a first vessel which serves as a containment vessel and as a hydroretort; directing a hot gas to said hydroretort and passing it through the resource contained in said hydroretort to heat it directly in order to cause the release of its volatile matter while producing a residual material; exhausting said gas together with said volatile matter which is released within said hydroretort, into downstream processing means; feeding said residual material from said hydroretort into a second vessel which serves as a gasifier that is capable of: (i) producing a hot gas; and (ii) melting said residual material while converting it into a molten slag; operating said gasifier at a higher pressure than the pressure in said hydroretort to force the hot gas produced in said gasifier to flow to said hydroretort and pass through the resource contained in said hydroretort to cause the release of said volatile matter while producing said residual material; and cooling said molten slag to convert it to a solid, non-leaching frit.
  • 2. The method as set forth in claim 1 wherein the step of operating said gasifier at a higher pressure than the pressure in said hydroretort to force the hot gas produced in said gasifier to flow to said hydroretort is further characterized by the steps of moderating the temperature of the hot gas prior to its entry into said hydroretort to effect the efficient release of volatile matter from said resource.
  • 3. The method as set forth in claim 1 wherein the step of feeding the resource is accomplished via a lockhopper to prevent the loss of pressure from said hydroretort.
  • 4. The method as set forth in claim 1 wherein the step of feeding said residual material from said hydroretort into said gasifier is further characterized by the step of locating said hydroretort above said gasifier to enable the feed of said residual material by gravity.
  • 5. The method as set forth in claim 1 wherein the step of operating said gasifier at a higher pressure than the pressure in said hydroretort is further characterized by the step of interposing a lockhopper that operates at an elevated temperature, between said hydroretort and said gasifier to maintain the pressure within said gasifier higher than the pressure within said hydroretort while transferring said residual material from said hydroretort to said gasifier via said lockhopper.
  • 6. The method as set forth in claim 1 wherein the step of producing a hot gas is further characterized by producing a hot synthesis gas.
  • 7. The method as set forth in claim 1, wherein the step of cooling said molten slag includes the quenching of the molten slag in a water pool.
  • 8. The method as set forth in claim 1 includes the recovering of heat from the molten slag.
  • 9. The method as set forth in claim 8 wherein the recovery of heat from the molten slag includes the step of raising steam.
  • 10. The method as set forth in claim 1 includes the step of discharging the hot gas together with the molten slag produced in said gasifier via a common port.
  • 11. The method as set forth in claim 1 includes the step of enhancing the downward flow of said resource within said hydroretort by providing relief via the divergence of the walls of said hydroretort by a dimensional increase in the downward direction to prevent bridging.
  • 12. The method as set forth in claim 1 includes the step of enhancing the downward flow of said residual material within said gasifier by providing relief via the divergence of the walls of said gasifier by a dimensional increase in the downward direction to prevent bridging.
  • 13. The method as set forth in claim 6 wherein said synthesis gas is converted to a synthetic natural gas.
  • 14. The method as set forth in claim 6 wherein said synthesis gas is converted to a liquid.
  • 15. The method as set forth in claim 1 wherein said resource is coal.
  • 16. The method as set forth in claim 1 wherein said resource is oil shale.
  • 17. The method as set forth in claim 1 wherein said resource is oil sand.
  • 18. The method as set forth in claim 1 wherein said resource constitutes any of the following combinations: coal and oil shale, coal and oil sand, shale and oil sand.
  • 19. The method as set forth in claim 1 wherein the step of exhausting said gas together with said volatile matter which is released within said hydroretort, into downstream processing means is further characterized by the step of converting said volatile matter into liquid fractions while producing a non-condensable component.
  • 20. The method as set forth in claim 19 comprises the converting of said non-condensable component into clean gases or liquids.
  • 21. The method as set forth in claim 10 wherein the step of discharging the hot gas together with the molten slag produced in said gasifier via a common port is further characterized by the step of supplying supplemental heat to said common port in order to maintain said port at a temperature above the freezing point of slag.
  • 22. The method as set forth in claim 21 comprising the step of adding an oxidant in the vicinity of said common port to combust a portion of said gas to generate the thermal energy required to maintain said port open for the free flow of said slag.
  • 23. The method as set forth in claim S wherein the step of transferring said residual material from said hydroretort to said gasifier via said lockhopper includes the injection of an oxidant to react with said residual material to convert it to a hot gas while producing a molten slag.
  • 24. The method as set forth in claim 23 includes the adding of steam with said oxidant.
  • 25. The method as set forth in claim 1 wherein said residual material comprises the remainder from shale, coal, oil sand, or a combination thereof-.
  • 26. The method as set forth in claim 6 wherein said synthesis gas is cleaned.
  • 27. Apparatus for recovering energy from a fossil resource comprising: a hydroretort adapted to pyrolize a resource to produce a volatile matter and a residual material; means adapted to process said volatile matter; a gasifier adapted to convert said residual material to a hot gas while producing a molten slag; means adapted to separate said hot gas from said molten slag; means adapted to direct said hot gas to said hydroretort to supply the thermal energy required to pyrolize said resource; and means adopted to cool said molten slag to solidify it.
  • 28. The apparatus as set forth in claim 27 includes a lockhopper adapted to feed the resource into said hydroretort in such a way as to prevent loss of pressure from said hydroretort.
  • 29. The apparatus as set forth in claim 28 includes means adapted to maintain the pressure in said gasifier higher than the pressure in said hydroretort to force the flow of gas from said gasifier into said hydroretort.
  • 30. The apparatus as set forth in claim 27 wherein said means adapted to direct said hot gas to said hydroretort includes heat exchanging means which moderates the temperature of said hot gas.
  • 31. The apparatus as set forth in claim 27 wherein said means adapted to cool said molten slag to solidify it includes a water quench means.
  • 32. The apparatus as set forth in claim 31 wherein said water quench means includes a heat recovery steam generator which is disposed ahead of said water quench in order to recover thermal energy prior to the slag coming in contact with said water quench.
  • 33. The apparatus as set forth in claim 27 wherein said means adapted to process said volatile matter includes fractionator means adapted to produce liquids and a non-condensable gas.
  • 34. The apparatus as set forth in claim 37 includes means adapted to treat gas in order to produce a clean gas.
  • 35. The apparatus as set forth in claim 34 includes means for methanating said clean gas to a synthetic natural gas.
  • 36. The apparatus as set forth in claim 35 includes means for converting said clean gas into a liquid.