Integrated process and apparatus for producing coal-based jet fuel, diesel fuel, and distillate fuels

Abstract

Coal-based jet fuel, diesel fuel and/or distillate fuels are produced by selectively introducing a coal-based product directly into the petroleum refinery process flow to thereby create an integrated refinery process for producing the distillate fuels.

Description

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. provisional application Ser. No. 60/907,882, entitled “INTEGRATED PROCESS AND APPARATUS FOR PRODUCING COAL-BASED JET FUEL, DIESEL FUEL, AND DISTILLATE FUELS,” and filed on Apr. 20, 2007, the entire contents of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The inventions described relate to the field of fossil fuels. More specifically, they relate to fossil fuels derived from coal and converted into various fuel products, including jet fuels, diesel fuels, and other distillate fuels.

2. Description of the Related Art

As the worldwide industrial demand for energy continues to grow annually, each country continues to expand its efforts to find and develop new sources of petroleum as well as alternative sources of energy. In the US, there is a rapidly expanding effort to become more insulated from dependency on oil imports and to stabilize and eventually lower escalating fuel costs.

It is estimated the United States Air Force currently uses in the order of three billion gallons of jet fuel annually. The majority of their demand will be subject to stringent standards in the future, including an operating temperature capability in the range of 900 degrees Fahrenheit. These stringent military standards for jet fuels reflect many advances in aircraft and in the performance of advanced gas-turbine engines and their thermal stability. The Energy Institute at Penn State University in University Park Pennsylvania has been a leader for many years in research aimed at providing new and more efficient distillate fuels. See, for instance, Appendix I titled “JP-900 Technology Overview” and Appendix 2 titled “The Coal-Based Jet Fuel Program” for examples of high technology studies in the field of fuels derived from coal products, and in particular, a jet fuel notionally known as JP-900 to reflect the desired upper temperature range capabilities of the fuel.

In response to the ever increasing need to import larger volumes of foreign oil, many governmental and commercial entities are exploring alternative energy sources and researching diverse, lower cost alternatives to petroleum based products. It was recently reported in the press that approximately $800 million dollars per day flows out of the United States economy to purchase oil imports.

SUMMARY OF THE INVENTION

As is well known to those skilled in the energy exploration and production arts, coal has for years been a reliable and secure domestic energy resource. Further, coal is the one energy source worldwide for which it is currently possible to obtain long term supply contracts at guaranteed supply arrangements, often for twenty years or more.

To consider and evaluate the value of a coal-based jet fuel, it is first desirable to define certain terms to be used in this specification so as to more clearly delineate possible alternative processes and plant structures. For this purpose it is desirable to define the following terms:

• • (A) A “coal-derived fuel” is a fuel product produced entirely from coal. This product may be obtained by the so-called direct liquefaction of coal.
  • (B) A “coal-based fuel” is a fuel containing a significant proportion of components produced from coal, and additionally containing components from other sources, such as petroleum.

As is known to those skilled in the fuel energy arts, a coal-based jet fuel manufactured using existing refinery operations and infrastructure with relatively minor modifications or retrofitting, as will be further defined hereinafter, will be substantially less expensive since substantially all of the refining process steps are consistent with current refinery operations.

According to one aspect, at least one embodiment of the disclosed inventions economically produces high grade jet fuel and other distillate fuels utilizing existing refinery infrastructure with minimal input type modifications or additions.

According to another aspect, at least one embodiment of the disclosed inventions economically produces high grade jet fuel and other petroleum products utilizing existing refinery infrastructure with minimal changes to the standard refinery processes.

According to still another aspect, at least one embodiment of the disclosed inventions economically produce jet fuel from coal-products utilizing existing refinery operations and infrastructure with minimal changes or additions to a standard oil refinery process and apparatus.

These and other significant improvements disclosed in Applicant's specification will become evident from the following description of the novel processes and apparatus, particularly when read in connection with the following drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other more detailed and specific features of the present inventions are more fully disclosed in the following specification, reference being had to the accompanying drawings, in which:

FIG. 1 is a schematic drawing of a basic prior art refinery layout.

FIG. 2 is a block flow diagram of a coal tar blending process utilizable in accordance with an embodiment of Applicant's disclosed inventions.

FIG. 3 is a block flow diagram of a co-coking process utilizable in accordance with another embodiment of Applicant's disclosed inventions.

FIG. 4 is a block flow diagram of a solvent extraction process utilizable in accordance with another embodiment of Applicant's disclosed inventions.

FIG. 5 is a block flow diagram of a gasification by-product blending process utilizable in accordance with another embodiment of Applicant's disclosed inventions.

FIG. 6 is a schematic drawing of a modified standard refinery infrastructure illustrating an example combination of processes in accordance with yet other embodiments of Applicant's disclosed inventions.

FIG. 7 is a block flow diagram of a basic refinery layout with a coal tar blending option.

FIG. 8 is a block flow diagram of a basic refinery layout with a co-coking option.

FIG. 9 is a block flow diagram of a basic refinery layout with a solvent extraction option

FIG. 10 is a block flow diagram of a basic refinery layout with a coal gasification tie-in.

DETAILED DESCRIPTION OF THE INVENTION

In the following description, for purposes of explanation, numerous details are set forth, such as flowcharts and system configurations, in order to provide a further understanding of one or more embodiments of the present inventions. However, it is and will be apparent to one skilled in the art that these specific details are not required in order to practice the present inventions.

As herein above described, Penn State University Energy Institute has recently focused on the Development of a coal-based jet fuel process and apparatus primarily in order to take economic advantage of utilizing existing oil refinery infrastructure. This utilization of existing oil infrastructure avoids costly plant construction of an entirely new plant, as would be required with a direct coal liquefaction plant, to produce gas or other fuel. This description of Applicant's production process for jet fuel and other fuel, utilizing minor modifications or additions to an existing oil refinery infrastructure, directly results in significant savings estimated at the time of this disclosure to be approximately two billion dollars per plant.

FIG. 1 is a schematic drawing of a basic prior art refinery layout. The process routes as described below may be incorporated into existing refinery operations and infrastructure with relatively minor modifications or retrofitting. In accordance with Applicant's improved process and apparatus for producing JP 900 type jet fuel and other distillate fuels, there are four distinct process routes, each of which may be combined with other process routes, resulting in a wide variety of possible configurations beyond those specifically described below:

First Process: A coal-tar blending process, which may be better understood with reference to FIG. 2. The coal-tar blending process generally involves hydrotreating of mixtures of coal tar products (e.g., refined chemical oil) mixed with a refinery stream (e.g., light cycle oil). Preferably, coal tar blending involves the blending of a commercially available, coal-derived liquid (refined chemical oil (RCO)) with light cycle oil obtained from catalytic cracking. Light cycle oil (LCO) is a by-product of the catalytic cracking process in oil refineries.

Second Process: A co-coking process, which may be better understood with reference to FIG. 3. The co-coking process involves addition of coal to a mixer, where the coal is mixed with an oil product such as decant oil. The mixture of coal and oil product is then introduced to a delayed coker. Liquid from the coker is then fractionated and hydrotreated. In addition to the fuel product, the process produces coke which has potential as a premium carbon product for aluminum smelting anodes, as well as potential applications in the production of synthetic graphite and of activated carbon.

Third Process: A solvent extraction process, which may be better understood with reference to FIG. 4. The solvent extraction process involves extraction of coal using a light cycle oil in one or more steps at elevated temperature (200-400° C., ideally about 350° C.). The resulting extracted coal product mixture is hydrotreated and fractionated to produce the desired clean liquid fuels, and the unextracted coal may be used in a gasification by-product blending process, as described below.

Fourth Process: A gasification by-product blending process, which may be better understood with reference to FIG. 5. The gasification by-product blending process involves collecting tar produced as a by-product of coal gasification and blending it with a suitable petroleum refinery stream, such as light cycle oil. The resulting blend is hydrotreated and fractionated to produce the desired clean liquid fuels.

Referring now to FIG. 1, there is illustrated a flow diagram schematic of an oil refinery process infrastructure utilizable with the four production processes described above for introducing coal-products to produce JP-900 type jet fuel in modified oil refinery infrastructure.

As would be evident to those skilled in the oil refinery arts, a typical refinery structure is not constructed merely to produce jet fuel. Continued research is being conducted at the above mentioned PSU Energy Institute to further evaluate and improve a variety of different products and by-products from a combined oil and coal-product integrated refinery. Earlier research conducted at the PSU Energy Institute after substantial prior research demonstrates that coal-based jet fuel can achieve the requisite high temperature stability without compromising the requisite storage and low temperature stability. Thus it appears certain that the JP-900 jet fuel product will provide a practical solution for using the jet fuel both as a propulsion energy source and as a significant heat sink for high performance aircraft with advanced jet engine designs.

Referring now to FIG. 2, there is illustrated a coal-tar blending process block flow diagram utilizable in accordance with the first of Applicant's processes, described above, for introducing coal-products into a petroleum refinery as illustrated in FIG. 1. As illustrated in FIG. 2, coal-tar blending involves the mixing of a commercially available, coal-derived liquid, referred to as refined chemical oil, with light cycle oil from, for example, catalytic cracking. These two products are introduced to the mixer 102 via inputs 100 and 101 respectively. The output of mixer 102 is fed to hydrotreater 104 where it is mixed with hydrogen gas imported through input 103. The output of hydrotreater 104 is fed directly to fractionator 105, which has a plurality of outputs including gasoline 106, jet fuel 107, diesel 108, and fuel oil 109. Reference may be had, to further understand the flow of the various process streams through modified petroleum refinery, to FIG. 1.

Referring now to FIG. 3, there is illustrated a co-coking process block flow diagram utilizable in accordance with the second of Applicant's processes, described above, for introducing a second coal-product into the petroleum refinery as illustrated in FIG. 1. The second of Applicant's processes, co-coking, is based on the addition of coal to a mixer 202 where the coal is mixed with a readily available oil, such as decant oil. These two products are introduced to the mixer 202 via inputs 200 and 201 respectively. The output of mixer 202 is fed to delayed coker 203. The liquids from the delayed coker 203 are fed to a fractionator 205 which further feeds a process stream to a hydrotreater 206. Hydrotreater 206 has an input 208 for introducing hydrogen gas and an output 207 for the jet fuel. In addition to the fuel products output from fractionator 205 and hydrotreater 207, the coke by-product output from output 204 is a premium carbon by-product utilizable, for example, for production of aluminum anodes. Reference may be had, to further understand the flow of the various process streams through modified petroleum refinery, to FIG. 1.

Referring now to FIG. 4, there is illustrated a solvent extraction block flow diagram utilizable in accordance with the third of Applicant's processes, described above, for introducing a third alternative coal-product into the petroleum refinery as illustrated in FIG. 1. In this process, coal is extracted with light cycle oil in one or more steps at elevated temperature (200-400° C., ideally about 350° C.). The process preferably utilizes bituminous coal as the feed coal. The feed coal and light cycle oil are introduced to a solvent extraction and separation unit 302 via inputs 300 and 301 respectively. The primary product of the extraction process is a slurry of solid, unextracted residual coal in the light cycle oil. The slurry contains, in solution, various chemical compounds extracted from the feed coal. The slurry is subjected to a solid/liquid separation process, such as pressure filtration. The liquid product output of separation unit 302 is fed to hydrotreater 304 where it is mixed with hydrogen gas imported through input 303. The output of hydrotreater 304 is fed directly to fractionator 305, which has a plurality of outputs including gasoline 306, jet fuel 307, diesel 308, and fuel oil 309. The solid unextracted coal product output 310 is used as feedstock for a gasification unit, which is used to produce a portion of the hydrogen needed for the hydrotreating step, as described in more detail below, with reference to FIG. 5. Reference may be had, to further understand the flow of the various process streams through modified petroleum refinery, to FIG. 1.

Referring now to FIG. 5, there is illustrated a gasification by-product blending process block flow diagram, utilizable in accordance with the fourth of Applicant's processes, described above, for introducing a fourth alternative coal-product into the petroleum refinery as illustrated in FIG. 1. The blending approach to the production of coal-based jet fuels requires as feedstock some source of naphthalene- and indene-type compounds that have been liberated from or formed from coal. Certain coal gasification technologies produce a coal tar as by-product. Most notably, this is the technology known as so-called fixed-bed (which is also known as moving-bed) gasification, of which the Lurgi gasifier is the best-known and most commercially successful example. In conventional coal gasification applications, the tar is either processed to obtain useful chemical products, is burned as a fuel of convenience, or is collected and disposed of as a waste material.

In the gasification by-product blending process disclosed herein, coal and a combined stream of steam and oxygen gas are fed to a coal gasifier 402 by inputs 400 and 401 respectively. The coal gasifier produces output streams of raw product gas 403, tar 405, and ash 404. The tar produced by the coal gasifier 402 is collected and blended with a suitable petroleum refinery stream, such as light cycle oil. The tar and light cycle oil are introduced to the mixing tank 407 via inputs 405 and 409 respectively. This blended tar and light cycle oil are fed to a hydrotreater 412. The raw product gas produced by the coal gasifier 402 is fed to gas clean-up and shift reactor 406, which produces output streams of carbon dioxide gas 408 and hydrogen gas 410. The hydrogen gas output stream 410 from the gas clean-up and shift reactor 406 is fed to hydrotreater 412, where it is utilized in the hydrotreating of the blended tar and light cycle oil fed to hydrotreater 412 from input stream 411. The output of hydrotreater 412 is fed directly to a fractionator, or distillation column 415, which has a plurality of outputs, including, gasoline 414, jet fuel 415, diesel 416, and fuel oil 417. An additional advantage of this process is that the gasifier itself is run to produce hydrogen, which may then be used a source of hydrogen for the hydrotreating of the tar blend downstream in the plant, as described.

As will be understood by those skilled in the oil refinery arts, the four, herein above disclosed auxiliary coal-product input apparatus and processes are structurally and operationally independent from each other in an integrated oil/coal-product refinery infrastructure.

As set forth in FIG. 6, any number of such coal-product apparatus and processes may be run or operated independently, simultaneously, or in parallel on an integrated oil/coal-product refinery infrastructure. Thus a particular configured oil refinery may be modified to include all four coal-product input apparatus/processes or may be modified to include only one or two or three of such input apparatus/processes, thus enabling great flexibility in handling certain coal-products as inputs as their unique product lines may dictate. This added flexibility can be selected to satisfy or utilize or meet various cost factors or space limitations for any particular oil refinery to be modified for one or more coal-product inputs. Thus if one oil refinery does not have economic access to a decent oil supply for a co-coker, for example, that refinery can be modified to run or concentrate on other ones of the other coal-product input apparatus or processes.

Accordingly, the apparatus and processes-as described above provide significant versatility to the fuel production industry, since there are multiple possible approaches to making coal-based jet fuel.

As an example, as illustrated in FIG. 6, a refinery that has no delayed coker, it is possible to run the blending process only. For a refinery that has no catalytic cracking unit, it is possible to run the coking process only. For a refinery that has both a catalytic cracker and a delayed coker, it is possible to run both the blending process and the coking process entirely in parallel, carrying the products from each through separate hydrotreating and fractionation steps. The products of each parallel processing train are blended at the refinery gate, unless each has special characteristics warranting their sale as separate products. Alternatively, for a refinery that has both a catalytic cracker and a delayed coker, it is possible to run blending and coking separately, but then to combine the liquid products of each of these operations. The combined products would then be hydrotreated and fractionated as one stream, as further illustrated in FIG. 6.

As is known to those skilled in the oil refinery arts, and as illustrated in FIG. 1 to FIG. 6, in various features, the oil refinery infrastructure would be under continuous control of a master control panel (not shown), comprising a commercially available digital or analog computer apparatus. The refinery infrastructure master control computer apparatus, (not shown in FIG. 1) is operationally controlled by a series of selectable software production control programs to appropriately schedule and control the variously refinery inputs of either oil and/or coal-products and the liquid flow levels in respective ones of the functional elements and flow levels of the system to produce desired distillate products during operation of the integrated refinery infrastructure.

For additional background on process control specifically applicable for oil refineries, Applicant refers interested parties to Royal Dutch Shell, The Petroleum Handbook. 6^th edition, Elsevier Science Publishers, Amsterdam, 1983 (ISBN 0-444042118-1), especially pages 331 to 335, which are incorporated herein by this reference. Another useful handbook on process control generally, Applicant suggests reference to Perry's Chemical Engineers' Handbook. 7^th edition. McGraw-Hill, New York (ISBN 0-07-049841-50, especially Chapter 8 which is incorporated herein by this reference.

FIG. 7 is a block flow diagram of a standard refinery layout incorporating a coal tar blending process option. The coal tar blending process is shown with greater particularity in FIG. 2.

FIG. 8 is a block flow diagram of a standard refinery layout incorporating a co-coking process option. The co-coking process is shown with greater particularity in FIG. 3.

FIG. 9 is a block flow diagram of a standard refinery layout incorporating a solvent extraction process option. The solvent extraction process is shown with greater particularity in FIG. 4.

FIG. 10 is a block flow diagram of a standard refinery layout incorporating a gasification by-product blending process tie-in. The gasification by-product blending process can be better understood with reference to FIG. 5.

In the description herein, numerous specific details are provided, such as examples of components and/or methods, to provide a thorough understanding of embodiments of the present invention. One skilled in the relevant art will recognize, however, that an embodiment of the inventions can be practiced without one or more of the specific details, or with other apparatus, systems, assemblies, methods, components, materials, parts, and/or the like. In other instances, well-known structures, materials, or operations are not specifically illustrated or described in detail to avoid obscuring aspects of embodiments of the present invention.

Although the present inventions have been described in considerable detail with reference to certain embodiments thereof, the inventions may be variously embodied without departing from the spirit or scope of the inventions. Therefore, the following claims should not be limited to the description of the embodiments contained herein in any way.

Claims

1. In a petroleum refinery flow process comprising at least one fractionation unit and at least one hydrotreating unit, an improvement comprising a selectable process for introducing a coal-based product directly into the petroleum refinery flow process thereby to create an integrated refinery process for producing a coal-based jet fuel and other distillate fuels.

2. The integrated refinery process of claim 1, wherein said process for introducing said coal-based product comprises a selectable coal-tar blending process.

3. The integrated refinery process of claim 1, wherein said process for introducing said coal-based product comprises a selectable co-coking process.

4. An integrated petroleum and coal-based product refinery apparatus comprising:

at least one fractionation unit,

at least one hydrotreating unit, and

apparatus for selectively introducing a coal-based product directly into a petroleum refinery flow process that includes said at least one fractionation unit and at least one hydrotreating unit, to thereby enable the integrated petroleum and coal-based refinery apparatus to produce a coal-based jet fuel and other distillate fuels.

5. The integrated petroleum and coal-based product refinery apparatus of claim 4, wherein said apparatus for selectively introducing said coal-based product into said petroleum refinery flow process comprises a coal tar blending apparatus.

6. The integrated petroleum and coal-based product refinery apparatus of claim 4, wherein said apparatus for selectively introducing said coal-based product into said petroleum refinery flow process comprises a co-coking introducing apparatus.

7. The integrated petroleum and coal-based product refinery apparatus of claim 4, wherein said apparatus for selectively introducing said coal-based product into said petroleum refinery flow process comprises a solvent extraction apparatus.

8. The integrated petroleum and coal-based product refinery apparatus of claim 4, wherein said apparatus for selectively introducing said coal-based product into said petroleum refinery flow process comprises a gasification by-product blending apparatus.

9. The integrated petroleum and coal-based product refinery apparatus of claim 4, wherein said apparatus for introducing said coal-based product into said petroleum refinery flow process comprises at least two selected apparatus from a group comprising a coal-tar blending apparatus, a co-coking apparatus, a solvent extraction apparatus, and a gasification by-product blending apparatus.

10. The integrated petroleum and coal-based product refinery apparatus of claim 9, wherein refined liquids extracted from said coal-based products are directly introduced into said integrated petroleum and coal-based product refinery process.

11. The integrated petroleum and coal-based product refinery apparatus of claim 10, wherein the extracted liquids are subsequently introduced sequentially into a hydrotreating unit and then into a fractionation unit, thereby generating jet fuel and other distillate fuels.

12. The integrated petroleum and coal-based product refinery apparatus of claim 4, wherein said apparatus for selectively introducing said coal-based product into said petroleum refinery flow process comprises a solvent extraction apparatus that is remote from said integrated petroleum and coal-based product refinery apparatus.

13. The integrated petroleum and coal-based product refinery apparatus of claim 12, further including an input for introducing product of the solvent extraction apparatus into said integrated petroleum and coal-based product refinery apparatus.

14. The integrated petroleum and coal-based product refinery apparatus of claim 4, wherein said apparatus for introducing said coal-based product into said petroleum refinery flow process comprises at least one selected apparatus from a group comprising a coal-tar blending apparatus, a co-coking apparatus, a solvent extraction apparatus, and a gasification by-product blending apparatus, and wherein said at least one selected apparatus is remote from said integrated petroleum and coal-based product refinery apparatus.

15. The integrated petroleum and coal-based product refinery apparatus of claim 4, wherein liquids extracted from coal are introduced into said petroleum refinery flow process as said coal-based product.

16. The integrated petroleum and coal-based product refinery apparatus of claim 15, wherein said liquids extracted from coal are produced remotely from said integrated petroleum and coal-based product refinery apparatus.

17. The integrated refinery process of claim 1, wherein said process for introducing said coal-based product comprises a solvent extraction process.

18. The integrated refinery process of claim 17, wherein said solvent extraction process is carried out remotely from a refinery that provides said petroleum refinery flow process.

19. The integrated refinery process of claim 1, wherein said process for introducing said coal-based product comprises a gasification by-product blending process.

20. The integrated refinery process of claim 1, wherein said process for introducing said coal-based product comprises at least one process selected from a group comprising a coal-tar blending process, a co-coking process, a solvent extraction process, and a gasification by-product blending process, and wherein said at least one process is carried out remotely from a refinery that provides said petroleum refinery flow process.

21. The integrated refinery process of claim 1, wherein liquids extracted from coal are introduced into said petroleum refinery flow process as said coal-based product.

22. The integrated refinery process of claim 21, wherein said liquids extracted from coal are produced remotely from a refinery that provides said petroleum refinery flow process.

23. A method of producing a coal-based fuel, comprising:

providing at least one coal-based product; and

introducing the coal-based product into a petroleum refinery flow process to thereby create an integrated refinery process for producing the coal-based fuel.

24. The method of claim 23, wherein the step of providing at least one coal-based product comprises providing a coal-derived liquid and mixing the coal-derived liquid with a light cycle oil.

25. The method of claim 23, wherein the step of providing at least one coal-based product comprises providing coal and oil, mixing the coal with the oil to create a mixture of coal and oil, and introducing the mixture of coal and oil to a delayed coker.

26. The method of claim 23, wherein the step of providing at least one coal-based product comprises providing coal and a solvent and contacting the coal with the solvent to thereby extract the coal-based product from the coal.

27. The method of claim 23, wherein the step of providing at least one coal-based product comprises providing coal and a mixture of steam and oxygen and contacting the coal with the mixture of steam and oxygen.

28. The method of claim 23, wherein the step of providing at least one coal-based product comprises selectively operating at least one of a plurality of auxiliary coal-based product input processes.

29. The method of claim 28, wherein the plurality of coal-based product input processes comprises at least two of the group consisting of coal-tar blending, co-coking, solvent extraction, and coal-gasification.

30. The method of claim 23, wherein the petroleum refinery flow process comprises at least one fractionator.

31. The method of claim 23, wherein the petroleum refinery flow process comprises at least one hydrotreater.

32. The method of claim 23, wherein the petroleum refinery flow process comprises a hydrotreater and a fractionator connected in series.

33. The method of claim 23, wherein the step of providing at least one coal-based product comprises operating at least one auxiliary coal-based product input process at a location remote from the petroleum refinery flow process.

34. The method of claim 28, wherein the plurality of auxiliary coal-based product input processes is located remotely from the petroleum refinery flow process.