US20110211997A1

US20110211997A1 - Apparatus for liquefaction of carbonaceous material

Info

Publication number: US20110211997A1
Application number: US13/056,493
Authority: US
Inventors: Peter John O'Dowd
Original assignee: Forbes Oil and Gas Pty Ltd
Current assignee: Forbes Oil and Gas Pty Ltd
Priority date: 2008-07-28
Filing date: 2009-07-28
Publication date: 2011-09-01
Also published as: AU2009276282A1; US20150101792A1; EA201100292A1; US20130315792A1; CN102165036B; NZ591171A; WO2010012026A1; ZA201101467B; ZA201101486B; EP2326696A1; JP2011529128A; EP2310471A4; US20110180262A1; CN102105559B; CA2732138A1; EP2326696A4; CN102105559A; US8727000B2; WO2010012027A1; EP2310471A1

Abstract

A carbonaceous material liquefaction apparatus which uses a nozzle assembly to supply a pressurised liquid towards a carbonaceous material as a high velocity liquid. A supply line (46, 39) supplies the high pressure liquid to the nozzle assembly (38). The high velocity liquid reacts with the carbonaceous material (35) in a reaction zone (40) to produce a processed carbonaceous material. A product return line (34, 42) returns the processed carbonaceous material and entrained liquid to a processing plant. The processing plant comprises a heat exchanger (44) to transfer heat from the product return line to the supply line, a high pressure pump (48) to provide the high pressure liquid to the supply line, a separator (52) in the product return line downstream of the heat exchanger to separate gas (54) and oil (56) product from the entrained liquid, at least part of the liquid (58) being recycled (64) to the high pressure pump. The reaction can be carried out in-situ or in an above ground reaction chamber (70).

Description

FIELD OF INVENTION

This invention relates to apparatus for the recovery of hydrocarbons from carbonaceous material.

PRIORITY DOCUMENTS

The present application claims priority from Australian Provisional Patent Application No. 2008903845 titled “METHOD FOR IN SITU LIQUEFACTION OF COAL” and filed on 28 Jul. 2008; and Australian Provisional Patent Application No. 2008903840 titled “INVENTIVE JET PUMPING” and filed on 28 Jul. 2008. The entire content of each of these applications are hereby incorporated by reference.

INCORPORATION BY REFERENCE

The following co-pending patent application is referred to in the following description:
Patent Cooperation Treaty patent application titled “METHOD OF LIQUEFACTION OF CARBONACEOUS MATERIAL TO LIQUID HYDROCARBON” filed by the present applicant on 28 Jul. 2009: The entire content of this application is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

There have been many proposals for the recovery of hydrocarbons from carbonaceous materials. These, have generally related to mining of the carbonaceous material and then heat treating in various manners to extract hydrocarbons such as oil and gas from them.
It is an object of this invention to provide an apparatus suitable for this type of process whether it be in situ or aboveground.
The term “carbonaceous material” is intended to refer to refer to an a solid, semi-solid or bituminous organic fossil fuel compound such as coal, including lignite (also known as brown coal), sub-bituminous coal, bituminous coal, anthracite and graphite, as well as oil shale, oil sands (tar sands), heavy or bituminous oil deposits, and other related substances, and combinations thereof whether mined or in situ.
The term “hydrocarbon” would be understood by a person skilled in the art to refer to an organic compound consisting of hydrogen and carbon.
The term “liquid hydrocarbon” is intended to refer to the hydrocarbons produced by the method of the invention that are suitable for use as a fuel, either directly or following an appropriate treatment, conversion or upgrade using methods well-known to those persons skilled in the cart. The liquid hydrocarbons may also comprise some solid or particulate matter, including oil-soluble solids. The liquid hydrocarbon of present invention may also be referred to as “oil”, “coal oil”, “unconventional oil”, “crude oil” or “crude oil substitute” by persons skilled in the art.
The term “in situ” as used herein is intended to limit the carbonaceous material as being in its original location, that is, within a geological deposit of carbonaceous material found naturally in the ground. A person skilled in the art would understand that an in situ deposit of carbonaceous material frequently comprises various forms of carbonaceous materials including oil shale, oil sands (tar sands), heavy or bituminous oil deposits, lignite (also known as brown coal), sub-bituminous coal, bituminous coal through to anthracite and graphite and combinations thereof.
The term “liquefaction reaction” is intended to refer to a chemical reaction wherein a solid, semi-solid or bituminous carbonaceous material is reduced to a less solid or liquid form. In the liquefaction reaction, chemical bonds between two atoms in a molecule (e.g. double bonds between two carbon atoms in a molecule of a carbonaceous material) are generally reduced by a reaction that binds hydrogen atom(s), such that the two carbon molecules previously double bonded together remain joined by a single bond and one or both are now bonded to a hydrogen (or other) atom. Alternatively, in the liquefaction reaction molecules may be separated from each other and the previous carbon or carbon-carbon bonds may now “capped” or occupied with a hydrogen atom. Carbon-carbon (CC) bonds are particularly susceptible to cleavage from OH, that is the hydroxyl radical or the hydroxyl ion or from various other free radicals. The hydroxyl radical and other free radicals effective in cleaving carbon bonds in hydrocarbons can be generated from the mobilisation of the volatiles component of the hydrocarbon typically from thermal elevation of the hydrocarbon or can be supplied by application of substances that contain OH to the hydrocarbon. Supercritical water or to a lesser degree superheated water are both a source of OH. Once this OH cleavage has occurred the severed CC bonds are able to be rapidly “capped” or stabilised by the acceptance of a hydrogen atom at each severed bond. Both supercritical water and to a lesser degree superheated water are able to provide such a hydrogen atom for transfer or capping to the carbonaceous material. The source of such a hydrogen from water is typically from a H₃0 ion which will resolve back to H₂0 after transferring one H atom in this example or from a H atom that has been ionised from its partner OH ion for example in supercritical water.
Superheated water is generally considered to contain 100 times the water ions than are found in ambient water and supercritical water is generally considered to consist of 70% water ions. If such a hydrogen atom is not immediately available for “capping” at the severed carbon bond or the severed carbon-carbon bond than there is a tendency or high likelihood that the severed C or CC bonds will rejoin to other molecules that have undergone similar bond cleavage and the resulting “uncapped” union or rejoining of molecules that have had their carbon bonds severed results in a hydrocarbon molecule that is particularly resistant to further hydrogenation or upgrading.
Carbonaceous material is liquefied as it is hydrogenated, meaning that a carbonaceous material changes from a more solid state to a more liquid state, that is, a liquid hydrocarbon. Under experimental conditions, hydrogenation of coal may result in up to 96% of coal being liquefied. Hydrogenation is a strongly exothermic process. The terms “liquefying” or “liquefaction” are also intended to be referring to this process.
The term “reaction zone” is intended to refer to the in situ area in which the liquefaction reaction is occurring.
The term “aqueous solution” is intended to refer to a liquid that is water, or similar to water, or a water-based liquid in which other chemical components may be dissolved or are dissolved. However, it will be appreciated that the liquid can be a superheated or supercritical fluid. It is also to be understood that any of the aqueous solutions of the present invention may alternatively comprise components selected from the group consisting of water, hydrogen peroxide, methanol, ethanol, acetone, propane, ethylene, and propylene. The aqueous solution can further comprise an organic component, diesel fuel, or a liquid hydrocarbon. Alternatively or in addition it may contain a catalyst or a combination of catalysts to assist in the hydrogenation of the carbonaceous material.
The term “supercritical fluid” describes a fluid at a temperature and pressure above its thermodynamic critical point; wherein the term “thermodynamic critical point” refers to the conditions (i.e. temperature and pressure) at which the phase boundary between a liquid and a gaseous phases of the aqueous solution ceases to exist. A person skilled in the art will appreciate that the aqueous solution is a supercritical fluid when at or above a “critical temperature” and a “critical pressure” such that the density of the liquid phase is approximately equal to the density of the gaseous phase with no (or very little) distinction between the two phases. However, many research papers report the use of supercritical fluids when at least one of the parameters is somewhat below the critical point. Accordingly, it will be appreciated by a person skilled in the art that in practical application, a broad range of temperatures and pressures exists at which the fluid behaves as a supercritical fluid or at least in part similar to a supercritical fluid, such that the thermodynamic critical point can be thought of as a “supercritical region” consisting of a range of temperatures and pressures at which the fluid behaves as a “supercritical fluid”, rather than a distinct point, line or distinct combination of pressure and temperature. Accordingly, a “supercritical fluid” of the present invention is intended to refer to a fluid with temperatures or pressures in or around the supercritical point that behaves like a supercritical fluid or with properties at least partially of a supercritical fluid or similar to a supercritical fluid.
A “superheated fluid” is a fluid under pressure greater than atmospheric pressure at temperatures between its usual boiling point (i.e. at atmospheric pressure) and its thermodynamic critical point. For example, superheated water may have a pressure range and temperature range between 100° C. at atmospheric pressure to the point where the fluid is considered to be in the supercritical range. For example, superheated water could have a pressure of 15 MPa and a temperature of 350° C., a pressure of 10 MPa and a temperature of 350° C., a pressure of 0.5 MPa and 10 MPa and a temperature of 150° C. to 350° C., etc. A person skilled in the art will appreciated that superheated fluid can exists in a wide range of pressures and temperatures.
Similarly Supercritical water could have a temperature of 385° C. and a pressure of 22 MPa, or could have a temperature of 430° C. and a pressure of 25 MPa. A person skilled in the art will similarly recognise that supercritical water can exist in a wide range of pressures and temperatures.
It has been observed by the applicant that once a fluid, for example water or an aqueous solution has been taken into either the supercritical region or alternately beyond that fluids supercritical point, that the unique and useful properties of the superheated or supercritical fluid can be maintained for a period of time at a much lower pressure than was previously considered necessary by exchanging the previous pressure of containment for velocity as the fluid is discharged through a nozzle or orifice or similar restriction.
The following description outlines but is not restricted to methods and apparatus for the application of fluids that have been previously taken into or around the region of their supercritical point and then discharged through a nozzle or orifice or similar restriction.

DESCRIPTION OF THE INVENTION

In one form therefore the invention is said to reside in a carbonaceous material liquefaction apparatus comprising a nozzle assembly to supply a pressurised liquid towards a carbonaceous material as a high velocity liquid, a supply line to supply the high pressure liquid to the nozzle assembly, the high velocity liquid reacting with the carbonaceous material to produce a processed carbonaceous material, a product return line to return the processed carbonaceous material and entrained liquid to a processing plant, the processing plant comprising a heat exchanger to transfer heat from the product return line to the supply line, a high pressure pump to provide the high pressure liquid to the supply line, a separator in the product return line downstream of the heat exchanger to separate gas and oil product from the processed carbonaceous material and entrained liquid, and a recycle line to transfer at least part of the liquid from the separator to the high pressure pump.
A preferable feature of the nozzle assembly of the present invention for the delivery of the depressurised/velocity increased supercritical fluid that the nozzle extends beyond the limit of any surrounding tubular casing for in situ applications. This is, in contrast to other in situ upgrading, recovery or mining methods, that is to say that the nozzle and attached fluid supply tubing extend beyond any surrounding well casing to enable liquefaction/chemical reactions to occur on contact with the carbonaceous material and the water with supercritical properties. A locating device such as a flow through mandrel or a device similar to a twin port bridge plug or any device which allows return flow back up the annular space between the tubing and the outer well casing can be employed to stabilise the nozzle against and within the casing. By positioning the nozzle below such a bridge port or mandrel and extending beyond the casing so that the contact point of the high velocity water and the carbonaceous material is below the level of the casing, all products of reaction and also any steam formed as the water degrades to subcritical properties is able to more easily flow to the path of least resistance which is the annular space between the tubing and the casing, for ease of recovery.
This arrangement or positioning of nozzle relative to the casing is quite different for example to nozzle and tubing and casing arrangements employed in the oil industry and commonly referred to as “jet pumping”. In these conventional oil field nozzle/casing arrangements the nozzle is always positioned above not below, an isolating and centralising packer assembly. In this conventional oilfield arrangement the packer is of an isolating variety such that the fluid that is discharged from the nozzle never makes contact with the carbonaceous geological formation. In conventional operations the fluid discharged from the nozzle is never employed for reactions of a chemical nature with the returns flow in the annular space in the geological carbonaceous deposit in the well. Instead in conventional application the apparatus is employed solely to provide a lift mechanism for hydrocarbon that is typically crude oil. This conventional recovery of crude oil occurs by sucking the crude oil upwards through a one way port in the isolating packer above the geological deposit, and into the annular space of the well via the reduced pressure existing in the annular space of the well as a consequence of the high velocity discharge of a fluid through a nozzle above the isolating packer. In conventional application the crude oil is then physically entrained in the Liquid flow that has exited the nozzle and is transported physically to surface for recovery from the annulus in a liquid phase. It will be clear to anyone skilled in the art that significant differences from the conventional practices exist in this current application, by nature of the nozzle assembly being positioned below the packer assembly, the packer or stabilising assembly being of a flow through type and not an isolating type, by the nature of the nozzle discharge fluid directly contacting the carbonaceous material, by the nature of the nozzle fluid engendering chemical reactions with the carbonaceous material on contact, and by the nature of the recovery flow stream being in a vaporous medium not a liquid medium, this entrainment of recovery products into a vaporous medium enables a very efficient product recovery mechanism.
It is a preferred feature of the invention that the apparatus described enables a reaction or reactions to occur between the supercritical water and the carbonaceous material either in situ in the geological formation or alternately in an above ground surface vessel.
It is further a particular feature of the recovery method of the apparatus that the recovery stream or the “returns” of the upgraded carbonaceous material are entrained in a vaporous (steam) return stream which so enables large return flow rates with very little restriction of flow for the upgraded (hydrogenated) product return stream. This is a consequence of the supercritical fluid discharged from a nozzle contacting the carbonaceous material and reacting with/upgrading the carbonaceous material during the course of which the supercritical fluid resolves at least partially into the upgraded carbonaceous material and the remaining supercritical fluid resolves back into a subcritical state, that is to say steam. The velocity that the supercritical fluid acquires as it is discharged from the nozzle enables the fluid to exist as a liquid or at least liquid droplets even though the surrounding temperature and lower pressure would ordinarily otherwise dictate that the liquid would vaporise. This condition of a supercritical high velocity liquid existing in an environment of lower temperature and pressure which would otherwise dictate that the liquid vaporise will continue until the velocity depletes to a lower velocity at which point the supercritical liquid will become sub-critical and so vaporise. This condition is reached upon contact of the high velocity supercritical fluid with the carbonaceous material. At that point any of the high velocity supercritical fluid which has not been employed in the upgrading reactions with the carbonaceous material will vaporise into what is, essentially steam. Any entrained moisture content of the carbonaceous material or surrounding geological formation will similarly vaporise into steam, partly driven by exposure to the high velocity supercritical water and its temperature, partly due to the heat generated by the exothermic hydrogenation reactions and heat generated from exothermic oxidation and redox reactions, and also by the activation energy imparted to molecules from the transfer of the kinetic energy of velocity into internal activation energy of molecules upon the collision impact of the high velocity supercritical fluid and the stationary carbonaceous material.
Because there is currently no recognised description of a supercritical fluid existing outside of the pressure of confinement a new phrase has been used by the inventor to describe this new discovery, that is WSP, “water with supercritical properties”. This has become necessary because existing terminology did not foresee or does not accommodate a description of this new discovery. The current definition of supercritical water entails confinement, i.e. 375° C. at 22 MPa and does not accommodate a fluid which retains the properties of super criticality without confinement and at a lower pressure and increased velocity.
Because the now upgraded hydrocarbon liquids derived from the carbonaceous material have a higher boiling point than water, typically 300° C. to 900° C. the coal oil produced from the reactions is entrained in droplet form within the steam vapour. Any gaseous products of reaction are similarly entrained in this vapour phase. This composite steam/hydrocarbon droplet vapour is able to be easily transported either from an in situ geological formation or from an above ground vessel for further upgrading or separation and so ease of recovery is much enhanced over existing methods.
It is a further element of the invention that the apparatus so described enables for the intimate contact between the reactants, in this case supercritical water and the carbonaceous material. This intimate contact results from the atomised high velocity supercritical water contacting the carbonaceous material. This intimate contact between reactants is otherwise typically only enabled by mining or bringing to surface the raw carbonaceous material and then separating impurities from the carbonaceous material, drying or removing any moisture from the carbonaceous material and finally grinding or commutating the carbonaceous material into a smaller particle size before contact with a usually static or low velocity flow reaction fluid. Instead this grinding to a smaller particle size of the carbonaceous material is replaced by the intimate contact afforded by the high velocity contact/impact of the atomised reaction fluid i.e. supercritical water.
Preferably the apparatus further comprises an injection apparatus downstream or upstream of the high pressure pump to supply initiation chemicals and catalysts to the high pressure liquid supply line.
For above ground carbonaceous material liquefaction the apparatus further comprises a reaction vessel, means to supply a charge of the carbonaceous material to the reaction vessel and the product return line being connected to the reaction vessel, the nozzle assembly directing the high velocity liquid towards the charge of the carbonaceous material in the reaction vessel.
Preferably the apparatus further comprises means to withdraw spent residue of the carbonaceous material from the reaction vessel.
In one embodiment the nozzle assembly comprises a plurality of nozzles.
In an alternative embodiment of the carbonaceous material liquefaction apparatus for in-situ carbonaceous material liquefaction the product return line comprises a well casing and the supply line comprises a high pressure tubing within the well casing and preferably the high pressure tubing and the attached nozzle extend beyond the limit of the outer casing and the carbonaceous material is selected from coal, oil shale and tar sands.
In another alternative embodiment of the carbonaceous liquefaction apparatus for in situ carbonaceous material liquefaction the nozzle or nozzles are attached to a tubing and both are able to be moved within the carbonaceous geological deposit via control of the tubing string movement from surface. Those skilled in the art will recognise that such a moveable tubing string is commonly employed for various oil and gas operations and is commonly referred to as a coil tubing unit. In the embodiment of a moveable tubing string such as a coil tubing unit with a liquefaction nozzle attached, the recovery mechanism from the carbonaceous geological deposit in situ remains the same. That is the returns stream is still recovered via the annulus of the well and is in a substantially vapour phase.
In one embodiment the nozzle assembly is able to be variably directed towards the carbonaceous material in an in-situ reaction zone. This can be achieved by using a nozzle with a defined angle of spray pattern that is less than 360 degrees. The angle of the spray pattern of the nozzle may be rotated or advanced by any means familiar to those skilled in the art or alternately the nozzle may be replaced by another nozzle with a different angle of spray pattern to the first nozzle.
In one embodiment the nozzle assembly comprises a plurality of nozzles radiating the high velocity liquid towards the in-situ carbonaceous material. Alternately a nozzle with a complete or nearly complete 360 degree angle of spray pattern may be employed.
In one embodiment the high pressure pump to provide the high pressure liquid to the supply line provides the liquid at pressures of from 15 MPa and 35 MPa.
Preferably the apparatus further comprises a bleed off excess entrained liquid from the separator.
In one embodiment the separator comprises a multi-stage separator, a first separator comprising a flash separator to separate gases from the processed carbonaceous material and entrained liquid, a second separator comprising an oil-liquid separator to separate oil from the processed carbonaceous material and entrained liquid and a filter to separate particulate material from the processed carbonaceous material and entrained liquid.
It will be seen that by this invention there is provided an apparatus for liquefaction of carbonaceous material either in situ or above ground with the use of very high pressure water suitable catalysts and initiators and the like that are discharged through a nozzle or similar restriction to reduce the pressure on the downstream side of the nozzle by similarly increasing the velocity of the discharging ater there by maintaining for a period of time the supercritical properties of the water without high pressure containment of the water.
The present applicant has realized that carbonaceous materials such as coal, oil sands and/or oil shale can be efficiently liquefied in situ or in a above ground reactor using an aqueous solution that is capable of liquefying the carbonaceous material in a reaction zone.
For example, the liquefaction reaction can be initiated by applying to a carbonaceous material an aqueous solution capable of initiating liquefaction, such as an aqueous solution containing water, hydrogen peroxide and/or an alcohol such as methanol, and optionally a catalyst. Such an aqueous solution initiates a liquefaction reaction that is exothermic. Due to the insulative properties of carbonaceous material in an in situ carbonaceous material formation for instance, the temperature is raised within the reaction zone within the carbonaceous material formation as the liquefaction reaction progresses. Once the temperature is raised to a desired temperature, it becomes efficient to switch to a heated aqueous solution, as the heat of the aqueous solution will be retained within the heated reaction zone, and to continue liquefaction using the heated aqueous solution. Preferably, the heated aqueous solution will be heated to high temperatures and simultaneously be pressurized to above atmospheric pressure, for example, to obtain a superheated fluid or supercritical fluid, that is to say, water with supercritical properties. As the reaction progresses, substances may be released from the carbonaceous material, or produced by reaction, which may enhance the liquefaction process. Such substances may include methanol, hydrogen peroxide, catalysts (that were initially ingrained as impurities in the carbonaceous material), water, hydrogen gas and/or methane gas and various free radicals: The aqueous solution can be applied and the produced liquid hydrocarbons recovered using a modified conventional mining technology. In a particularly preferred embodiment, the aqueous solution is applied using a nozzle apparatus that applies the aqueous solution to the face of the carbonaceous material formation at a high velocity, that is to say, water with supercritical properties. The nozzle apparatus may also optionally or alternatively depressurize the aqueous solution immediately prior to application of the aqueous solution to the face of the carbonaceous material formation.
Thus there is provided a method of liquefying carbonaceous material in situ or in a reactor to produce liquid hydrocarbon comprising the following steps:
(a) applying a first aqueous solution to the carbonaceous material to facilitate an initial liquefaction reaction in a reaction zone in the carbonaceous material formation liquefies the carbonaceous material to liquid hydrocarbon and heats the reaction zone to a desired temperature, wherein the first aqueous solution comprises components selected from the group consisting of water, hydrogen peroxide at a (w/w) concentration range between 0.1% to 70%, methanol at a (w/w) concentration range between 0.1% to 30%, and a first catalyst; and
(b) applying a second aqueous solution, i.e. water with supercritical properties, to the reaction zone once the reaction zone reaches the desired temperature, wherein the second aqueous solution facilitates a continuing liquefaction reaction that liquefies the carbonaceous material to produce liquid hydrocarbon, and wherein the second aqueous solution comprises components selected from the group consisting of water, hydrogen peroxide at a (w/w) concentration range between 0.1% to 70%, methanol at a (w/w) concentration range between 0.1% to 30%, and a second catalyst, and wherein the second aqueous solution is a fluid selected from the group consisting of a heated fluid, a superheated fluid, a supercritical fluid and a high-velocity superheated fluid.
A person skilled in the art will appreciate that it is not necessary to heat the reaction zone using an initial liquefaction reaction described above, and that the reaction zone may be pre-heated by any means known to those skilled in the art. Alternatively, it is possible to apply the heated aqueous solution without first heating the reaction zone, as the application of the heated aqueous solution may also heat the reaction zone as the reaction progresses. The present applicant has realized that liquefying the carbonaceous material to produce liquid hydrocarbons using a high-velocity superheated fluid may provide an efficient means of liquefying a carbonaceous material to liquid hydrocarbon in situ.
Thus, in a second aspect, there is provided a method of liquefying a carbonaceous material in situ or in a reactor to produce liquid hydrocarbons using a high-velocity superheated fluid comprising the following steps:
(a) heating and pressurizing an aqueous solution to obtain a superheated fluid, or a supercritical fluid, and
(b) passing the superheated or supercritical aqueous solution through a nozzle arrangement that facilitates de-pressurizing of the supercritical water to the range of approximately between 0.5 MPa and 10 MPa immediately prior to the applying of the aqueous solution to the carbonaceous material and also facilitates the applying of the aqueous solution to the carbonaceous material at a velocity in the range between 50 m/sec and 450 m/sec, such that the aqueous solution is a high-velocity superheated or supercritical fluid that facilitates liquefaction of the carbonaceous material to produce liquid hydrocarbon, wherein the aqueous solution comprises components selected from the group consisting of water, 0.1 to 0.70% hydrogen peroxide, 0.1 to 30% methanol and a catalyst.

BRIEF DESCRIPTION OF THE DRAWINGS

This then generally describes the invention but to assist with understanding reference will now be made to the accompanying drawings which show preferred embodiments of the invention.

In the drawings:

FIG. 1 shows a schematic arrangement of a process accordingly to one embodiment of the invention;

FIG. 2 shows a schematic view of the apparatus suitable for the in-situ processing embodiment of the present invention;

FIG. 3 shows a schematic view of an apparatus suitable for the aboveground liquefaction of carbonaceous materials according to the present invention; and

FIG. 4 shows a detail of a portion of the in situ processing apparatus of the present invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.
Rather, the embodiments herein presented are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
Now looking at FIG. 1 it will be seen that schematic apparatus of the present invention includes an input apparatus section 2 and an output apparatus section 4. Between the input apparatus section 2 and the output apparatus section 4 is the liquefaction stage 6.
In the input apparatus section 2 high pressure pump arrangement means 10 are provided to supply high pressure liquid such as an aqueous solution at high pressure. The high pressure liquid is directed along line 12 and catalysts, initiators and/or other components are added through line 14 from supply 16. A heater arrangement 17 is also provided on line 12 to optionally heat the high pressure liquid to a desired temperature. Line 18 provides the high pressure liquid such as the aqueous solution at high pressure to a liquefaction stage 6.
In the liquefaction stage 6, the aqueous solution is directed through a nozzle assembly which may be a single nozzle or multiple nozzles towards the carbonaceous material as a high velocity fluid, for example, a high velocity superheated or supercritical fluid. The nozzle is capable of depressurising the aqueous solution. When the aqueous solution has been heated and pressurised to or near supercritical conditions and is depressurised, the aqueous solution may be delivered to the carbonaceous material as a high velocity superheated fluid with retained supercritical properties. The aqueous solution reacts with the carbonaceous material and causes liquefaction of the carbonaceous material to produce an upgraded or liquefied carbonaceous material which is composed of a hydrocarbon liquid and gases along with entrained liquid and particulate residues. These are transferred by line 20 to the output apparatus section 4.
Product from the liquefaction stage 6 exits by line 20 to a recovery apparatus 22 and from which is extracted gas 24, solids 26 and oil 28. Excess liquid is transferred to waste liquid tank 30 and some liquid can be transferred on recycle line 32 back to the high pressure pump arrangement means 10 in the input apparatus stage 2.
Product from the liquefaction stage 6 exits by line 20 to a recovery apparatus 22 and from which is extracted gas 24, solids 26 and oil 28. Excess liquid is transferred to waste liquid tank 30 and some liquid can be transferred on recycle line 32 back to the high pressure pump arrangement means 10 in the input apparatus stage 2.
The high pressure liquid is essentially water but can include other compounds such as initiators, catalysts and the like as required.
FIG. 2 shows the apparatus of the present invention for use with in situ liquefaction of a carbonaceous material such as coal. In this embodiment a coal seam 30 is situated below an overburden layer 32. A well casing 34 is extended through the overburden 32 into the coal seam 30. Through the well casing 34 a high pressure tubing 36 extends with a nozzle 38 which extends below the well casing 34. The space between the well casing and the high pressure tubing 36 provides an annular return space 39 for product from the in situ reaction zone 40.
In the aboveground portion of the apparatus, the reaction product of processed carbonaceous material (such as liquid hydrocarbon) which exits through the annular space 39 is transferred via pipe 42 to a heat exchanger 44. In the heat exchanger, heat from the reaction product is transferred to the aqueous solution in the high pressure liquid pipe 46 which directs aqueous solution, optionally at high pressure, into the high pressure tubing 36. The high pressure aqueous solution is supplied by high pressure pump 48. The aqueous solution can then optionally be heated by a boiler to the desired temperature.
Reactant components and catalysts can be provided from supply 50 into the high pressure line 46 to facilitate the liquefaction reaction. The nozzle 38 may be capable of depressurising a high pressure fluid to a lower pressure fluid, for example, depressurising as supercritical fluid at 25 MPa to a fluid having a pressure of 0.5 MPa to 10 MPa. The nozzle 38 is also capable of delivering the fluid at high velocity, for example 50 to 450 msec. The nozzle 38 may also be capable of delivering the fluid as a high velocity spray.
After the reaction product has been cooled in the heat exchanger 44 it goes to a gas, liquid and oil separator 52 in which gas 54, oil 56 and liquid 58 are separated and solid residue 60 is also filtered out.
A proportion of the liquid the liquid 58 is transferred by line 64 to the high pressure pump for reuse and the rest goes to waste. Carbonaceous material seams often have a high water content and hence there will be excess water to recover or send to waste.
FIG. 3 shows an aboveground apparatus according to the present invention. In this embodiment the same reference numerals will be used for corresponding items to those shown in FIG. 2.
In this embodiment a reaction vessel 70 has an input apparatus 72 and a residue withdrawal apparatus 74. These input apparatus 72 and residue withdrawal apparatus 74 are provided with supply vanes 76 to enable continuous charging of carbonaceous material into the reaction vessel without the loss of pressure and desired reaction product. Other forms of charging and removal apparatus may also be used according to the present invention. A nozzle assembly 78 provides multiple jets 80 of high pressure liquid to engage with carbonaceous material within the reaction vessel 70. Take off 82 withdraws reacted product from the reaction chamber.
The reaction product of processed carbonaceous material which exits reaction chamber is transferred via pipe 42 to a heat exchanger 44. In the heat exchanger heat from the reaction product is transferred to the liquid in the high pressure liquid pipe 46 which directs high pressure liquid into reaction chamber 70. The high pressure liquid is supplied by high pressure pump 48.
Initiation chemicals and catalysts are provided from supply 50 into the high pressure line 46.
After the reaction product has been cooled in the heat exchanger 44 it goes to a gas, liquid and oil separator 52 in which gas 54, oil 56 and liquid 58 are separated and any solid residue 60 is also filtered out.
A proportion of the liquid the liquid 58 is transferred by line 64 to the high pressure pump for reuse and the rest goes to waste. Carbonaceous material often has a high water content and hence there will be excess water to send to waste.
FIG. 4 shows detail of the underground portion of the apparatus suitable for in situ carbonaceous material liquefaction. The apparatus includes a well casing 34 through which is directed the high pressure tubing 36 with a nozzle 38 extending below the end of the well casing 34. A spacer 90 in the well casing supports the high pressure tubing in the well casing and has apertures 92 for the return of reacted product into the annular space 39. In this embodiment the nozzle 38 is directed laterally away from the well casing and means can be provided to rotate the high pressure tubing as indicated by the arrows 94 and move it vertically as indicated by the arrow 96 so that the region of carbonaceous material which can be treated can be varied.

Claims

1. A carbonaceous material liquefaction apparatus comprising a nozzle assembly to supply a pressurised liquid with superheated or supercritical properties towards a carbonaceous material as a high velocity liquid, a supply line to supply the high pressure liquid to the nozzle assembly, the high velocity liquid reacting with the carbonaceous material to produce an upgraded or liquefied carbonaceous material, a product return line to return the processed carbonaceous material and entrained liquid to a processing plant, the processing plant comprising a heat exchanger to transfer heat from the product return line to the supply line, a high pressure pump to provide the high pressure liquid to the supply line, a separator in the product return line downstream of the heat exchanger to separate gas and oil product from the processed carbonaceous material and entrained liquid, and a recycle line to transfer at least part of the liquid from the separator to the high pressure pump.

2. A carbonaceous material liquefaction apparatus as in claim 1 further comprising an injection apparatus downstream of the high pressure pump to supply initiation chemicals and catalysts to the high pressure liquid supply line.

3. A carbonaceous material liquefaction apparatus as in claim 1 for above ground carbonaceous material liquefaction further comprising a reaction vessel, means to supply a charge of the carbonaceous material to the reaction vessel and the product return line being connected to the reaction vessel, the nozzle assembly directing the high velocity liquid with superheated or supercritical properties towards the charge of the carbonaceous material.

4. A carbonaceous material liquefaction apparatus as in claim 3 further including means to withdraw spent residue of the carbonaceous material from the reaction vessel.

5. A carbonaceous material liquefaction apparatus as in claim 3 where in the nozzle assembly comprises a plurality of nozzles.

6. A carbonaceous material liquefaction apparatus as in claim 1 for in-situ carbonaceous material liquefaction wherein the product return line comprises a well casing and the supply line comprises a high pressure tubing within the well casing with the nozzle assembly attached to the tubing to enable the fluid within the tubing to exit the nozzle with a reduced pressure and increased velocity and so retaining the properties of superheated or supercritical water for a period of time and the carbonaceous material is selected from coal, oil shale and tar sands.

7. A carbonaceous material liquefaction apparatus as in claim 6 wherein the nozzle assembly is able to be directed towards the carbonaceous material in an in-situ reaction zone.

8. A carbonaceous material liquefaction apparatus as in claim 6 where in the nozzle assembly comprises a plurality of nozzles radiating the high velocity liquid towards the in-situ carbonaceous material.

9. A carbonaceous material liquefaction apparatus as in claim 1 wherein the high pressure pump to provide the high pressure liquid to the supply line provides the liquid at pressures of from 15 MPa and 35 MPa.

10. A carbonaceous material liquefaction apparatus as in claim 1 further including a bleed off excess entrained liquid from the separator.

11. A carbonaceous material liquefaction apparatus as in claim 1 wherein the separator comprises a multi-stage separator, a first separator comprising a flash separator to separate gases from the processed carbonaceous material and entrained liquid, a second separator comprising an oil-liquid separator to separate oil from the processed carbonaceous material and entrained liquid and a filter to separate particulate material from the processed carbonaceous material and entrained liquid.

12. A carbonaceous material liquefaction apparatus as in claim 1 wherein the upgraded or liquefied carbonaceous material in the product return line is in whole or in part substantially in a vapour phase, the vapour phase also entraining liquid and solid particles or droplets and whereby vapour phase recovery providing a more efficient recovery mechanism for upgraded or liquefied carbonaceous material than a conventional liquid phase recovery mechanism.

13. A carbonaceous material liquefaction apparatus as in claim 1 wherein the superheated or supercritical properties of the water are maintained for a period of time after exiting the nozzle assembly thereby enabling liquefaction reactions to occur upon contact of the water with supercritical properties and the carbonaceous material.

14. A carbonaceous material liquefaction apparatus as in claim 6 wherein the nozzle assembly comprises a nozzle or nozzles are attached to a tubing or supply line that may be moved within the carbonaceous material and wherein such movement controlled from surface.