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The purpose of obtaining stable carbon isotope analyses of coprocessing products is to determine the amount of coal (or petroleum) carbon that is present in any reaction product. This carbon-sourcing of distillate fractions, soluble resid, and insoluble organic matter, etc. is useful in modeling reactions, and evaluating synergistic effects if they exist.

Solid- and liquid-state 13 C n.m.r. measurements were made on a suite of samples obtained from different stages of a coal liquefaction run at the Wilsonville Two-Stage Advanced Coal Liquefaction Research and Development Facility. The n.m.r. measurements were combined with elemental analysis and mass balance data to measure aromatic carbon balances and hydrogen utilization for Wilsonville coal liquefaction run 259G. This was a catalytic/catalytic integrated two-stage liquefaction run on a deeply cleaned, Pittsburgh seam, high volatile bituminous (hvAb) coal from the Ireland mine in West Virginia, USA. The n.m.r. measurements showed that on the basis of the feed coal, about 58% of the aromatic carbons in Pittsburgh coal were hydrogenated during two-stage liquefaction, and 55% of the hydrogenation occurred during the second stage. A net of 68.1 mol of hydrogen per 100 mol of coal carbon was consumed during the first stage of Wilsonville run 259G. This amounted to 69% of the total overall two-stage hydrogen consumption. Matrix cleavage and hydrogenation reactions accounted for 31% and 27%, respectively, of the total first-stage hydrogen consumption. Hydrogenation reactions accounted for most (69%) of the hydrogen consumed during the second stage, and accounted for 40% of the overall two-stage total hydrogen consumption. Most of the total hydrogen consumed for hydrocarbon gas generation (70%), and for heteroatom removal and heterogas production (71%) occurred in the first stage. Overall hydrogen consumption was 14% for hydrocarbon gas production and 27% for heteroatom removal and heterogas production.

Laboratory experiments demonstrated that low-rank coals can be cleaned by agglomeration with distillate coal liquefaction recycle oils. Materials tested included a lignite, three subbituminous coals, a bituminous coal, two petroleum oils, and three coal liquefaction recycle oils. Ash rejections obtained were as high as ~ 50% for Texas lignite and 15–20% for two Wyoming subbituminous coals. A Montana subbituminous coal showed no ash rejection, though physical agglomeration occurred. Organic recoveries for the low-rank coal tests were always > 98%. All three liquefaction recycle distillates tested were effective agglomerating agents for low-rank coals. In the few cases tested, adjustment of the slurry pH to 2.0 or addition of cresylic acid to the slurry had beneficial effects for the lignite agglomeration. Selectively retained in the product ash were Fe (a potential liquefaction catalyst), Ti, Ca, and Mg, whereas Na was selectively rejected.

Following the petroleum price and supply disruptions of 1973, the U.S. government began a substantial program to fund the development of alternative fuels. Direct coal liquefaction was one of the potential routes to alternative fuels. The direct coal liquefaction program was funded at substantial levels through 1982, and at much lower levels thereafter. Those processes that were of most interest during this period were designed to produce primarily distillate fuels. By 1999, U.S. government funding for the development of direct coal liquefaction ended. Now that the end of this campaign has arrived, it is appropriate to summarize the process learnings derived from it. This report is a summary of the process learnings derived from the DOE direct coal liquefaction process development campaign of the late twentieth century. The report concentrates on those process development programs that were designed to produce primarily distillate fuels and were largely funded by DOE and its predecessors in response to the petroleum supply and price disruptions of the 1970s. The report is structured as chapters written by different authors on most of the major individual DOE-funded process development programs. The focus of the report is process learnings, as opposed to, say, fundamental coal liquefaction sciencemore » or equipment design. As detailed in the overview (Chapter 2), DOE's direct coal liquefaction campaign made substantial progress in improving the process yields and the quality of the distillate product. Much of the progress was made after termination by 1983 of the major demonstration programs of the ''first generation'' (SRC-II, H-Coal, EDS) processes.« less

This report describes the assessment of the physical and chemical properties of the jet fuel (180-300 C) distillation fraction of nine direct coal liquefaction products and compares those properties to the corresponding specifications for aviation turbine fuels. These crude coal liquids were compared with finished fuel specifications specifically to learn what the refining requirements for these crudes will be to make them into finished fuels. The properties of the jet fuel fractions were shown in this work to require extensive hydrotreating to meet Jet A-1 specifications. However, these materials have a number of desirable qualities as feedstocks for the production of high energy-density jet fuels.

This is the Technical Progress Report for the sixteenth quarter of activities under DOE Contract No. DE-AC22-94PC93054. It covers the period April 1 through June 30, 1998. Described in this report are the following activities: (1) CONSOL characterized nine process stream samples received from Exxon Recycle Coal Liquefaction Unit (RCLU) operations conducted in 1994 with Rawhide Mine Wyoming subbituminous coal and all-dispersed Fe and Mo catalysts. (2) The University of Delaware subcontract related to resid reactivity was completed with issuance of the Topical Report covering work performed by Delaware. (3) Computational studies of the coal liquefaction resid models developed at the University of Delaware were continued at CONSOL R and D. The two reaction models, consisting of the reaction optimization and reaction once-through programs, were the focus of these studies. The updated resid structure data and results were used in the reaction models to predict percent conversion values that were compared with the experimentally-measured values from the University of Delaware. (4) Small samples of high-sulfur Hondo resid and anthracene oil were shipped to John Verkade of Iowa State University at his request. Verkade is testing a desulfurization method.

CONSOL characterized 38 process strea m samples from HTI Run PB- 04, in which Black Thunder Mine Coal, Hondo vacuum resid, autom obile shredder residue (ASR), and virgin plastics were used as liquefaction feedstocks with dispersed catalyst. A paper on kinetic modeling of resid reactivity was presented at the DOE Coal Lique -faction and Solid Fuels Contractors Review Conference, September 3- 4, 1997, i n Pittsburgh, PA. The paper, "The Reactivity of Direct Coal Liquefaction Resids", i s appended (Appendix 1). Three papers on characterization of samples from coal/ resid/ waste p lastics co- liquefaction were presented or submitted for presen tation at conferences. Because of their similarity, only one of the papers is appended to this report. The paper, "Characterization o f Process Samples From Co- Liquefaction of Coal and Waste Polymers", (Appendix 2) was presented at the DOE Coal Liquefaction and Solid Fuels C ontractors Review Conference, September 3- 4, 1997, in Pittsburgh, PA. The paper, "Characterization of Process Stream Samples From Bench- Scale Co -Liquefaction Runs That Utilized Waste Polymers as Feedstocks" was presented at the 214th National Meeting of the Ameri can Chemical Society, September 7- 11, 1997, in Las Vegas, NV. The paper, "Characterization of Process Oils from Coal/ Waste Co- Liquefaction" wa s submitted for presentation at the 14th Japan/ U. S. Joint Technical Meeting on Coa l Liquefaction and Materials for Coal Liquefaction on October 28, 1997, in Tokyo, Japan. A joint Burns and Roe Services Corp. and CONSOL pap er on crude oil assays of product oils from HTI Run PB- 03 was presented at the DOE Coal Liquefaction and Solid Fuel s Contractors Review Conference, September 3- 4, 1997, in Pittsburgh, PA. The paper , "Characterization of Liquid Products from All- Slurry Mode Liquefaction", is appende d (Appendix 3).

Described in this report are the following activities: CONSOL characterized process stream samples from HTI Run ALC-2, in which Black Thunder Mine coal was liquefied using four combinations of dispersed catalyst precursors. Oil assays were completed on the HTI Run PB-05 product blend. Fractional distillation of the net product oil of HTI Run POC-1 was completed. CONSOL completed an evaluation of the potential for producing alkylphenyl ethers from coal liquefaction phenols. At the request of DOE, various coal liquid samples and relevant characterization data were supplied to the University of West Virginia and the Federal Energy Technology Center. The University of Delaware is conducting resid reactivity tests and is completing the resid reaction computer model. The University of Delaware was instructed on the form in which the computer model is to be delivered to CONSOL.

The report presents the findings of work performed under DOE Contract No. DE-AC22 -95PC95050, Task 3 - Flow Sheet Development. A novel direct coal liquefaction technology was investigated in a program being conducted by CONSOL Inc. with the University of Kentucky Center for Applied Energy Research and LDP Associates. The process concept explored consists of a first-stage coal dissolution step in which the coal is solubilized by hydride ion donation. In the second stage, the products are catalytically upgraded to refinery feedstocks. Integrated first-stage and solids-separation steps were used to prepare feedstocks for second-stage catalytic upgrading. An engineering and economic evaluation was conducted concurrently with experimental work throughout the program. Parameters were established for a low-cost, low-severity first-stage reaction system. A hydride ion reagent system was used to effect high coal conversions of Black Thunder Mine Wyoming subbituminous coal. An integrated first-stage and filtration step was successfully demonstrated and used to produce product filtrates with extremely low solids contents. High filtration rates previously measured off-line in Task 2 studies were obtained in the integrated system. Resid conversions of first-stage products in the second stage were found to be consistently greater than for conventional two-stage liquefaction resids. In Task 5, elementally balanced material balance data were derived from experimental results and an integrated liquefaction system balance was completed. The economic analysis indicates that the production of refined product (gasoline) via this novel direct liquefaction technology is higher than the cost associated with conventional two-stage liquefaction technologies. However, several approaches to reduce costs for the conceptual commercial plant were recommended. These approaches will be investigated in the next task (Task 4) of the program.

This is the Technical Progress Report for the eleventh quarter of activities under DOE Contract No. DE-AC22-94PC93054. It covers the period January 1 through March 31, 1997. Described in this report are the following activities: (1) CONSOL characterized process stream samples from HTI Run ALC-2, in which Black Thunder Mine coal was liquefied using four combinations of dispersed catalyst precursors. These results are described in the Results and Discussion section of this report. (2) Oil assays were completed on the HT I Run PB-05 product blend. Background information is presented in the Results and Discussion section of this report. The results are presented in Appendix 1. (3) Fractional distillation of the net product oil of HTI Run POC-1 was completed. Background information is presented in the Results and Discussion section of this report. The results are presented in Appendix 2. (4) CONSOL completed an evaluation of the potential for producing alkylphenyl ethers from coal liquefaction phenols. Those results are described briefly in the Results and Discussion section of this report. The full report is presented in Appendix 3. (5) At the request of DOE, various coal liquid samples and relevant characterization data were supplied to the University of West Virginia and the Federal Energy Technology Center. These activities are described in Appendix 4. (6) The University of Delaware is conducting resid reactivity tests and is completing the resid reaction computer model. A summary of Delaware's progress is provided in the Results and Discussion section. (7) The University of Delaware was instructed on the form in which the computer model is to be delivered to CONSOL (Appendix 5). (8) The University of Delaware submitted a paper on the resid reactivity work for presentation at the 213th National Meeting of the American Chemical Society, April 13-17, 1997 in San Francisco, California. The paper, ''Kinetics of Hydroprocessing of Coal-Derived Vacuum Resids'', is appended (Appendix 6).

This is the Technical Progress Report for the twelfth quarter of activities. Described in this report are the following activities: (1) Thirty-nine samples from four run conditions of HTI Run PB-07 were received. Appropriate samples were characterized by proton NMR spectroscopy, Fourier transform infrared spectroscopy, vacuum distillation, and solvent quality tests. (2) The University of Delaware completed their subcontract this quarter. A meeting was held on April 30, 1997 at the University to close out the subcontract. (3) Twelve sets of samples were chosen from the CONSOL sample bank for the study of the insoluble and presumed unreactive material from process stream samples. Each set consists of the whole process stream and the 454 C{sup +} (850 F{sup +}) distillation resid derived from that process stream. Processing data for all samples were compiled. The samples represent four Wilsonville pilot plant runs and two HTI runs.

Microautoclave tests confirmed that first-stage subbituminous coal conversions were greater in a more aromatic first-stage solvent. First-stage liquefaction tests with hydride ion `E` showed that high coal conversions can be obtained with a number of different first-stage water-gas-shift catalysts. Eight one-liter autoclave tests were completed. All tests used Black Thunder Mine subbituminous coal and Reilly Industries anthracene oil. Differences among the tests were the hydride ion reagent used, the post-run flash of water, and the shift catalyst. Filtration tests were conducted with five one-liter autoclave products of subbituminous coal. The filtration rates were slower than those that had been obtained with North Dakota lignite products, but were still within a commercially acceptable range. The influence of the first-stage shift catalyst on filtration rates is being investigated. Second-stage hydrotreating of products of tests made to simulate the British coal LSE process and the Wilsonville pilot plant preheaters had lower resid conversion and higher hydrogen uptake than the products of the hydride ion liquefaction reaction. The 300 mL second-stage reactor system went on line this quarter. Refinements in the experimental procedures are under way. A conceptual commercial plant design for the hydride ion reagent `A` case was completed. Evaluations of hydride ion reagent `D` and `E` cases were initiated, and an integrated liquefaction system balance for the hydride ion reagent `E` case was begun. A preliminary review of the final technical and economic reports from the Alberta Research Council study of low-rank coal conversion using the CO-steam process generated a number of questions on the published reports; further analysis of the reports is planned.

A novel direct coal liquefaction technology is being investigated in a program being conducted by CONSOL Inc. with the University of Kentucky, Center for Applied Energy Research and LDP Associates under DOE Contract DE-AC22-95PC95050. The novel concept consists of a new approach to coal liquefaction chemistry which avoids some of the inherent limitations of current high-temperature thermal liquefaction processes. The chemistry employed is based on hydride ion donation to solubilize coal at temperatures (350-400{degrees}C) significantly lower than those typically used in conventional coal liquefaction. The process concept being explored consists of two reaction stages. In the first stage, the coal is solubilized by hydride ion donation. In the second, the products are catalytically upgraded to acceptable refinery feedstocks. The program explores not only the initial solubilization step, but integration of the subsequent processing steps, including an interstage solids-separation step, to produce distillate products. A unique feature of the process concept is that many of the individual reaction steps can be decoupled, because little recycle around the liquefaction system is expected. This allows for considerable latitude in the process design. Furthermore, this has allowed for each key element in the process to be explored independently in laboratory work conducted under Task 2 of the program.

This is the Technical Progress Report for the tenth quarter of activities under DOE Contract No. DE-AC22-94PC93054. It covers the period October 1 through December 31, 1996. Described in this report are the following activities: (1) CONSOL characterized two HTI coal/petroleum coprocessing samples for Ni and V concentrations, as requested by DOE. The results are reported in Appendix 1. (2) CONSOL began work to evaluate the potential for producing alkylphenyl ethers, and specifically ethylphenyl ethers, from coal liquefaction phenols. The work includes a literature review and experimentation. The status of this ongoing work is described in this report. (3) A set of samples was requested from HTI Run ALC-2 (Appendix 2). (4) The University of Delaware is conducting resid reactivity tests and is developing a kinetic mechanistic model of resid reactivity. A summary of Delaware`s progress is appended to this report (Appendix 3). (5) A paper was submitted for presentation at the 213th National Meeting of the American Chemical Society, April 13-17, 1997, in San Francisco, CA, (Appendix 4).

The objectives of this project are to support the DOE direct coal liquefaction process development program and to improve the useful application of chemical analyses to direct coal liquefaction process development. Independent analyses by well-established methods are obtained of samples produced in direct coal liquefaction processes under evaluation by DOE. Additionally, new analytical instruments and techniques to examine coal-derived samples are being evaluated. The data obtained form this study are used to guide process development and to develop an improved data base on coal and coal liquids properties. A sample bank, established and maintained for use in this project, is available for use by other researchers. The reactivity of the non-distillable resids toward hydrocracking at liquefaction conditions (i.e., resid reactivity) is being examined. From the literature and experimental data, a kinetic model of resid conversion will be constructed. Such a model will provide insights to improve process performance and the economics of direct coal liquefaction.

A goal of this work was to reduce the cost associated with hydrogen ion reagent `A`. Microautoclave tests were previously conducted using `A`/dry coal = 1.0. This quarter test were completed using a ratio of 2.0. Conversion was poor at the low ratio. Additional reagents did not improve the conversion.

Activities this quarter were conducted under Tasks 2, 3, and 5. Task 2 work continued to evaluate the effects of low-severity, first-stage reaction conditions on coal conversions of lignite and subbituminous coal. Solvent type, solvent-to-dry-coal ratio, and substitution of CO and CO/methanol for hydride ion reagents were investigated in microautoclave tests. Large quantities of first-stage product were made using the one-liter reactor for subsequent filtration and catalytic upgrading tests. Filtration was performed on three one- liter autoclave products; each one requiring different filtration conditions. A second-stage catalytic upgrading parametric study was completed. In Task 3, designs were completed for both the large-scale filtration apparatus and the large-scale second-stage catalytic reactor system.

In 1991, the Department of Energy initiated the Advanced Liquefaction Concepts Program to promote the development of new and emerging technology that has potential to reduce the cost of producing liquid fuels by direct coal liquefaction. Laboratory research performed by researchers at CAER, CONSOL, Sandia, and LDP Associates in Phase I is being developed further and tested at the bench scale at HTI. HTI Run ALC-1, conducted in the spring of 1996, was the first of four planned tests. In Run ALC-1, feed coal ash reduction (coal cleaning) by oil agglomeration, and recycle solvent quality improvement through dewaxing and hydrotreatment of the recycle distillate were evaluated. HTI`s bench liquefaction Run ALC-1 consisted of 25 days of operation. Major accomplishments were: 1) oil agglomeration reduced the ash content of Black Thunder Mine coal by 40%, from 5.5% to 3.3%; 2) excellent coal conversion of 98% was obtained with oil agglomerated coal, about 3% higher than the raw Black Thunder Mine coal, increasing the potential product yield by 2-3% on an MAF coal basis; 3) agglomerates were liquefied with no handling problems; 4) fresh catalyst make-up rate was decreased by 30%, with no apparent detrimental operating characteristics, both when agglomerates were fed more » and when raw coal was fed (with solvent dewaxing and hydrotreating); 5) recycle solvent treatment by dewaxing and hydrotreating was demonstrated, but steady-state operation was not achieved; and 6) there was some success in achieving extinction recycle of the heaviest liquid products. Performance data have not been finalized; they will be available for full evaluation in the new future. « less

Activities this quarter were conducted under Tasks 2, 3, and 5. Task 2 work concentrated on evaluating the effects of low-severity, first-stage reaction conditions on coal conversions of lignite, subbituminous, and bituminous coals. The impact of artificially weathering bituminous coal was investigated. Large quantities of first-stage product were made using the one-liter reactor for subsequent filtration and catalytic upgrading tests. Test conditions and coal conversions for all microautoclave and one-liter tests made this quarter are presented. Filtration tests examined lignite, subbituminous, and bituminous coal products. The effects on resid conversion of second-stage reaction conditions and catalyst recycle were studied. Task 3 work included the successful transfer of first-stage reactor products to a receiver and the design of an interstage filter. Task 5 work included an ongoing review of the technical and patent literature and expansion of the annotated bibliography. Mass and elemental balances were obtained for selected tests.

The objectives of this project are to support the DOE direct coal liquefaction process development program and to improve the useful application of analytical chemistry to direct coal liquefaction process development. This project builds on work performed in DOE Contract No. DE-AC22-89PC89883. Independent analyses by well-established methods are obtained of samples produced in direct coal liquefaction processes under evaluation by DOE. Additionally, analytical instruments and techniques which are currently under utilized for the purpose of examining coal-derived samples are being evaluated. The data obtained from this study is used to help guide current process development and to develop an improved data base on coal and coal liquids properties. A sample bank, established and maintained for use in this project, is available for use by other researchers. The reactivity of the non-distillable resids toward hydrocracking at liquefaction conditions (i.e., resid reactivity) is being examined. From the literature and data experimentally obtained, a mathematical kinetic model of resid conversion will be constructed. It is anticipated that such a model will provide insights useful for improving process performance and thus the economics of direct coal liquefaction.

Work this quarter concentrated on evaluating the effects of low- severity, first stage reaction conditions on coal conversions, exploring the effect of solvent-to-coal ratio on filtration performance, exploring the effects of pretreatment on dispersed catalysts for hydrotreating tests, and the installation and calibration of a simulated distillation instrument. Additional work included continued review of the technical and patent literature and expansion of the annotated bibliography.

The purpose of this coordinated research program is to explore a new approach to direct coal liquefaction in which the primary coal dissolution step is effected by chemical rather than thermal cleavage of bonds in the coal. This is done at a temperature which is significantly lower than that typically used in conventional coal liquefaction. Reaction at this low temperature results in high conversion of the coal to a solubilized form, with little hydrocarbon gas formed, and avoids the thermally induced retrograde reactions which are unavoidable in conventional thermal processes. In addition, for low-rank coals, a substantial portion of the oxygen in the coal is removed as CO and CO{sub 2} during the dissolution. The higher selectivity to liquid products and rejection of oxygen as carbon oxides should result in improved hydrogen utilization. The basis of this novel concept is the discovery made by CONSOL R&D that certain hydride transfer agents are very active for coal dissolution at temperatures in the range of 350{degrees}C. Activities during this quarter were conducted under Tasks 2 and 5. The Task 2 work was concentrated on evaluating the effects of first-stage reaction variables on coal conversion using the microautoclave, construction of a 1L reactor system for producing large quantities of first-stage reaction products, microfiltration tests with the first-stage products, and trial operation of the second-stage hydrotreater. Task 5 work was concentrated on the literature survey and defining the cost of production of the hydride ion reagent.

CONSOL Inc., the University of Kentucky/Center for Applied Energy Research (CAER), and LDP Associates are conducting a three-year research program to explore the technical and economic feasibility of a novel direct coal liquefaction concept. The purpose of this research program is to explore a new approach to direct coal liquefaction in which the primary coal dissolution step is effected by chemical rather than thermal cleavage of bonds in the coal. This is done at a temperature which is significantly lower than that typically used in conventional coal liquefaction. Reaction at this low temperature results in high conversion of the coal to a solubilized form, with little hydrocarbon gas make, and avoids the thermally induced retrograde reactions which are unavoidable in conventional thermal processes. In addition, for low-rank coals, a substantial portion of the oxygen in the coal is removed as CO and CO{sub 2} during the dissolution. The higher selectivity to liquid products and rejection of oxygen as carbon oxides should result in improved hydrogen utilization. The basis of the novel concept is the discovery made by CONSOL RD evaluation of process steps; engineering and economic study and reporting.

The objectives of this project are to support the DOE direct coal liquefaction process development program and to improve the useful application of analytical chemistry to direct coal liquefaction process development. Independent analyses by well-established methods will be obtained of samples produced in direct coal liquefaction processes under evaluation by DOE. Additionally, analytical instruments and techniques which are currently underutilized for the purpose of examining coal-derived samples will be evaluated. The data obtained from this study will be used to help guide current process development and to develop an improved data base on coal and coal liquids properties. A sample bank will be established and maintained for use in this project and will be available for use by other researchers. The reactivity of the non-distillable resids toward hydrocracking at liquefaction conditions (i.e., resid reactivity) will be examined. From the literature and data experimentally obtained, a mathematical kinetic model of resid conversion will be constructed. It is anticipated that such a model will provide insights useful for improving process performance and thus the economics of direct coal liquefaction. The paper describes activities carried out this quarter. 11 refs., 21 figs., 17 tabs.

Coal and waste materials (plastics and rubber) were co-liquefied during Run POC-2 in HRI`s 3 T/D direct liquefaction process development unit under the DOE sponsored Proof-of-Concept program. Analytical characterizations were conducted of well-defined samples from representative periods of the run to provide information on the chemical transformation of these feedstocks and their distribution in product and recycle streams. The characteristics of the products and process streams were dependent on both feedstock changes and operating conditions. Several unusual process oil characteristics were observed when wastes were coprocessed with coal, especially during the coal/plastic operation. Implications of these results for future coal/waste liquefaction development and analytical characterization of the materials are discussed.

The objectives of this project are to support the DOE direct coal liquefaction process development program and to improve the useful application of analytical chemistry to direct coal liquefaction process development. Independent analyses by well-established methods will be obtained of samples produced in direct coal liquefaction processes under evaluation by DOE. Additionally, analytical instruments and techniques which are currently underutilized for the purpose of examining coal-derived samples will be evaluated. The data obtained from this study will be used to help guide current process development and to develop an improved data base on coal and coal liquids properties. During this reporting period, CONSOL completed analyses of 81 feed and process stream samples from HTI bench Run CMSL-9. HTI liquefaction bench unit Run CMSL-9 (227-87) was operated with all-dispersed catalyst and Black Thunder Mine (Wyodak and Anderson seam) coal, with and without mixed plastics or high density polyethylene (HDPE) as coprocessing feedstocks. The dispersed catalysts used were Molyvan A and HTI`s iron catalyst, a sulfated iron hydroxide. Results are discussed in this report.

The net liquid products from modern coal liquefaction processes are lower boiling and have much lower end points (mostly under 400{degree}C) than crude petroleum. Coal liquids have very low concentrations of heteroatoms, particularly S, and metals, and are free of resids and asphaltenes. High yields of low-S (0.01--0.03 wt %) naphtha, kerosene, and diesel fuel fractions can be obtained simply by atmospheric distillation, with a total yield of light fuel fractions ranging from 68 to 82 LV% (W260D exclusive). The coal naphtha has a low aromatics content (5--13 LV%), readily meeting projected year-2000 requirements. Its low Reid vapor pressure allows light components from other sources to be blended. The coal light distillate of in appropriate boiling range will be a good low-S blending stock for the light diesel fuel pool. The heavy distillate can be refined into a low-S No. 4 diesel fuel/fuel oil. This fraction, along with the >343{degree}C atmospheric bottoms, can be catalytically cracked or hydrocracked to make light liquid fuels. Thus, modern coal liquids should no longer be envisioned as thick liquids (or even solids) with high concentrations of aromatics and asphaltenes. Products obtained from advanced coal liquefaction technologies are more like light naphthene-base petroleum, but withmore » lower heteroatoms and metals contents, and they are free of resids. Coal liquids are likely to be co-refined in existing petroleum refineries; and hydroprocessing of various severities would be needed for different fractions to produce quality blending stocks for refinery fuel pools.« less

This is the eleventh Quarterly Technical Progress Report under DOE Contract DE-AC22-89PC89883. Major topics reported are: (1) The results of a study designed to determine the effects of the conditions employed at the Wilsonville slurry preheater vessel on coal conversion is described. (2) Stable carbon isotope ratios were determined and used to source the carbon of three product samples from Period 49 of UOP bench-scale coprocessing Run 37. The results from this coprocessing run agree with the general trends observed in other coprocessing runs that we have studied. (3) Microautoclave tests and chemical analyses were performed to ``calibrate`` the reactivity of the standard coal used for determining donor solvent quality of process oils in this contract. (4) Several aspects of Wilsonville Close-Coupled Integrated Two-Stage Liquefaction (CC-ITSL) resid conversion kinetics were investigated; results are presented. Error limits associated with calculations of deactivation rate constants previously reported for Runs 258 and 261 are revised and discussed. A new procedure is described that relates the conversions of 850{degrees}F{sup +} , 1050{degrees}F{sup +}, and 850 {times} 1050{degrees}F material. Resid conversions and kinetic constants previously reported for Run 260 were incorrect; corrected data and discussion are found in Appendix I of this report.

This is the third Quarterly Technical Progress Report under DOE Contract DE-AC22-89PC89883. Three major topics are reported: (1) Feed coals and process oils form Wilsonville Run 259 were analyzed to provide information on process performance. Run 259 was operated in the catalytic/catalytic Close-Coupled Integrated Two-Stage Liquefaction (CC-ITSL) mode with ash recycle. Feed coals were conventionally cleaned and deep cleaned coal from the Ireland Mine (Pittsburgh seam). The catalyst used in both reactors was Shell 324 for most of the run; Amocat IC was used for start-up and (unstable) period A. (2) A special set of samples from Wilsonville Runs 258 and 259 was analyzed to provide clues for the cause of interstage deposition problems during Run 258, which was operated with subbituminous coal. (3) Eight technical sites were visited to provide input to the Analytical Needs Assessment and to refine ideas for proposed research under the Participants Program. The site visits are summarized. 11 refs., 18 figs., 27 tabs.

Consol R&D is conducting a three-year program to characterize process and product streams from direct coal liquefaction process development projects. The program objectives are two-fold: (1) to obtain and provide appropriate samples of coal liquids for the evaluation of analytical methodology, and (2) to support ongoing DOE-sponsored coal liquefaction process development efforts. The two broad objectives have considerable overlap and together serve to provide a bridge between process development and analytical chemistry.

Consol R&D is conducting a three-year program to characterize process and product streams from direct coal liquefaction process development projects. The program objectives are two-field: (1) to obtain and provide appropriate samples of coal liquids for the evaluation of analytical methodology, and (2) to support ongoing DOE-sponsored coal liquefaction process development efforts. The two broad objectives have considerable overlap and together serve to provide a bridge between process development and analytical chemistry.

Publisher Summary This chapter explores the coal cleaning for liquefaction by selective agglomeration with recycle oils. Oil agglomeration is an attractive pretreatment for coal liquefaction. Process economic improvements can result from down-sizing or eliminating deashing equipment, improved yields, reduced erosion/abrasion, and improved organic throughput. In a study described in the chapter, Wyodak subbituminous coal was successfully agglomerated with three coal liquefaction oils and one petroleum-derived oil. Ash rejections with the coal liquefaction oils ranged from 6% to 19%. Organic recoveries were about 98% and ash balances ranged from 88% to102%. Cresylic acid was necessary for the agglomeration of the lignite with the lignite-derived oil at the conditions tested, and it appeared to improve ash rejection but not lignite. It improved the kinetics of agglomeration of the lignite, and it impaired the ash balance. The induction period for phase inversion was about 40 min in Run 30 without cresylic acid but decreased to 6 min in Run 33 with cresylic acid. The Wyodak and Kemmerer coals were less amenable to cleaning by agglomeration. Rosebud coal showed little or no cleanability under the conditions used. Ash elemental results show that iron, a potential liquefaction catalyst, is selectively retained in the ash of the agglomeration products.

Regardless of the specific technology used to produce transportation fuels from coal, the net product of the liquefaction process will have to undergo additional refining to make finished products. Consequently, there is a need to characterize the material that exits the liquefaction plant as net product and enters the refinery as feed. The net product of the Integrated Two-Stage Liquefaction (ITSL) process, as practiced at the 6 ton/day (5.5 tonne/day) Wilsonville, Alabama (USA) plant, is a distillable liquid boiling predominantly below 650{degrees}F (343{degrees}C). Products from ITSL operations at the Wilsonville plant were evaluated through the use of standard petroleum tests on several occasions. However, those evaluations were performed on materials generated much earlier in the ITSL campaign and, thus, may not be representative of products generated from the process as it is currently configured. For this work, net products were obtained for analysis from ITSL operations during fully lined-out material balance operating periods.Samples were taken fro Run 259G, which was operated with Ireland Mine coal (hvAb, Pittsburgh seam, West Virginia, USA) and from Run 260D, which was operated with Black Thunder Mine coal (subbituminous, Powder River Basin, Wyoming, USA). A complete suite of light crude oil assay tests was performedmore » on each sample. These assays included tests on the whole coal liquid, and the separated naphtha ( 510{degrees}F/266{degrees}C) fractions. The results of the assays were compared against typical petroleum product specifications. The discussion will concentrate on the test results of the bituminous coal product.« less

Operating the vapour-liquid separators in the solvent refined coal (SRC-I) process at or near the reactor temperature is desirable to retain the heat in the liquid product stream which is necessary for subsequent distillation. However, adverse changes in the product composition resulting from high temperature operation (i.e., ‘coking’) would obviate this advantage. A study of these potential retrograde reactions using a 4.5 kg h −1 bench-scale coal liquefaction unit is reported. At high pressure, separator temperatures up to 722 K and residence times in the pressure let-down system of 15 to 30 min, retrograde reactions occur as conversion of a few per cent of the product SRC to insoluble organic matter. If sufficient agitation is present in the separators these retrograde reactions would have little effect on product yields or unit operability. Coking, manifested as the accumulation of significant deposits of anisotropic carbon in the separator vessels, occurs only with the extended time-at-temperature that the solids can experience in a poorly agitated vessel.

Some 467 coal liquefaction process oils, having nominal boiling points within the range 473–808 K (200–535 °C), were assayed for donor solvent quality in 577 microautoclave tests using three different sets of reaction conditions. Proton distributions were also determined on each sample by 1 H n.m.r. Microautoclave coal conversions and proton distributions, correlated using multiple linear regressions, give similar measurements of solvent quality over a wide range of solvents. Donor solvent quality (as measured by microautoclave coal conversion) increases with increasing hydroaromatic content and with decreasing aromaticity and paraffinicity. As they were designed to do, the different microautoclave tests measure different solvent properties. Above a certain level of solvent quality, microautoclave extractions are insensitive to solvent quality differences. However, 1 H n.m.r. can differentiate between these high quality solvents, and the data can be related to differences in process performance. Advantages of using 1 H n.m.r. for donor solvent quality measurements are discussed.

Recycle distillates (‘solvents’) from the Wilsonville, Alabama, SRC-I pilot plant have been analysed by a variety of methods, and the composition data related to the performance of the solvents in both batch and continuous unit coal liquefaction. Because of its low distillate yield, solvents in the SRC-I process evolve rather slowly from the ‘anthracene oil’ start-up solvent to steady-state, process-derived distillates. As the steady-state solvent evolves it increases in saturates and mono-aromatic hetero molecules (primarily phenols and indanols), and its quality as a liquefaction medium declines. Because it is low in condensed aromatics, the steady-state SRC-I solvent cannot be greatly improved by hydrogenation. Other analytical data are provided which describe the composition of SRC-I recycle distillates. The analytical methods used in this work are of adequate simplicity that they could serve as routine monitoring methods in SRC-I liquefaction.

Recycle oils from the Integrated Two-Stage Liquefaction (ITSL), H-Coal and Solvent Refined Coal (SRC) processes were dewaxed by variants of commercial dewaxing processes—the ketone and the urea adduction techniques — yielding up to 47 wt % ‘wax’. Feed oils and product fractions were characterized by elemental analysis, 1 H n.m.r. and gas chromatography. The clean waxes were nearly pure mixtures of n -paraffins. The dewaxed oils were substantially better coal liquefaction solvents than the original (non-dewaxed) oils in batch liquefaction tests. For example, in one case, dewaxing improved the conversion of a bituminous coal to tetrahydrofuran-solubles under standard reaction conditions from 71 wt% (dafb) with the original oil to 87 wt % (dafb). These data provide a direct indication of the inimical effect of paraffinic components on solvent quality. The impact of solvent quality is particularly relevant to liquefaction processes in which thermal reactions proceed in a recycle solvent. In addition, the results indicate the technical feasibility of dewaxing coal liquefaction recycle oils by commercially available technology to improve solvent quality and to produce a useful by-product. Dewaxing could be applied in any liquefaction process that uses a deasphalted (preferably distillate) recycle stream.

Laboratory experiments demonstrated that a variety of distillate coal liquefaction recycle oils were satisfactory agents for cleaning Illinois no. 6 bituminous coal by oil agglomeration. Ash rejection up to 41% with 98% organic recovery was attained with conventionally cleaned coal, and ash rejection up to 67% with 90% organic recovery with run-of-mine coal. Agglomerates of > 1 mm average diameter were produced under a variety of conditions. Similar results were obtained in the scaled-up production of 268 kg of agglomerates. Oils with lower hydrogen aromaticities and higher hydrogen contents performed better than more aromatic oils. Fe, Ti and Mg were selectively enriched in the ash of the product coal, while Ca, Si, and Al were selectively rejected. The mineral pyrite was rejected only ≈ 30–40% as extensively as the bulk of the ashforming minerals. The coal cleaned by oil agglomeration performed similarly to the feed coal in batch donor liquefaction tests. In continuous hydroliquefaction tests, run-of-mine coal cleaned by oil agglomeration performed substantially better than coal cleaned to the same ash level by conventional means, because of the selective enrichment of catalytic iron minerals.

Ten fluid-coker tars, produced by Lummus-Crest, Inc., from coal liquefaction vacuum bottoms, were characterized to evaluate their use as liquefaction recycle oils. The primary variables in the coking tests were temperature (1000-1200 o F) and coker feedstock source. Most of the properties of the tars are principally influenced by the coking temperature. Those produced at higher temperature are more aromatic, they contain more carbon and less hydrogen, and they are principally unsubstituted and methyl-substituted condensed aromatic compounds. The heteroatom contents of the tars appear to be mainly determined by the coker feedstock

A method is described for the solvent fractionation of coal liquefaction and petroleum products which is both reproducible and considerably more rapid than many conventional solvent fractionation techniques. This method involves sequential elution of a sample injected onto an inert liquid Chromatographic column. Applications of this method to coal liquefaction and petroleum products are given.

This report includes the results of analysis of the integrated two-stage liquefaction (ITSL) process development unit (PDU) runs using Illinois 6, Burning Star coal from March 1982, to February 1983. One hundred fixty-six samples were analyzed. In addition, several sets of experiments designed to answer specific questions related to ITSL were performed, samples from H-Coal Pilot Plant Run 9 were analyzed and analytical methods were developed. Conclusions derived from this work are presented. 11 references, 5 figures, 52 tables.

Daily samples of the slurry recycle oil from the 30-day H-Coal PDU Run 5 (Syncrude mode, Illinois 6 coal) were analyzed by /sup 1/H-NMR spectroscopy GS/MS, and liquid chromatographic techniques. The recycle oils composition in PDU Run 5 reached an initial steady-state at about day 12, but this was upset when the hydrogen partial pressure was increased on day 20. The recycle oil composition was again approaching a steady-state by the end of the run. The distillates increased in aromaticity during the first 12 days of the run, as catalyst activity declined. The more aromatic distillates are better liquefaction media. Therefore, the solvent quality of the recycle distillates improved as the run progressed. The recycle distillates boiling below phenanthrene consist largely of cracking and isomerization products of hydrophenanthrenes. The relative ratios of reactants and products may be useful in establishing catalyst activity during the run. The start-up solvent had little effect on the run, because it was rapidly replaced by coal-derived recycle oils. The molecular weight distribution of the recycle resid (975/sup 0/F/sup +/, THF soluble) was relatively unchanged during the run although the ratio of benzene solubles to insolubles first decreased as catalyst activity declined, then increased with themore » increased hydrogen partial pressure during the last ten days of the run.« less

This is the first quarterly report reporting the results of analyses of recycle slurry oils in direct liquefaction processing. In the current contract we expect that the majority of samples will come from the two-stage liquefaction bench scale unit operated by Lummus at New Brunswick, New Jersey. The Lummus unit consists of a short contact time coal liquefaction, followed by Lummus solvent deashing of the short residence time product. The deashed coal liquids are the upgraded in a Lummus-Cities Service LC-fining unit. The sampling points and sample frequency necessary for the desired analytical characterization of the Lummus two-stage liquefaction bench scale unit have been identified in discussions with the Lummus project personnel. Ten samples have been distilled, and the distillate fractions analyzed by proton NMR. 35 clean oil tank (COT) samples from H-Coal PDU Run 10 have also been analyzed by /sup 1/H-NMR.

We received 69 samples of H-Coal PDU 10 recycle oils. All hydroclone overflow (HO) samples have been distilled, THF extracted and ashed. All HO soluble resids have been analyzed by solvent fractionation and the distillates by /sup 1/H-NMR. All clean oil tank (COT) samples have also been analyzed by /sup 1/H-NMR. Selected COT and HO distillate samples were analyzed by GC/MS, microautoclave (MAC) extractions and by fluorine derivatization followed by /sup 19/F-NMR. Selected HO soluble resids were analyzed by /sup 1/H-NMR. We conclude the following. Recycle distillates from PDU 10 (Wyodak, Syncrude) are extremely paraffinic, even able to form wax crystals at room temperature. The paraffin content of PDU 10 recycle distillates increased after day 20 of the run paralleling decreasing solvent quality as determined by /sup 1/H-NMR and MAC. The declining aromaticity of the recycle distillates over the end of PDU 10 is not a result of increased hydrogenation, but probably results from a decreasing removal of paraffins from the distillate recycle solvent. We have received 116 Lummus SCT, ASDA, and LC-Fining samples as of 9/15/81. As applicable, all samples have been distilled, THF extracted, ashed and analyzed by /sup 1/H-NMR and solvent fractionation. We conclude the following: Themore » solvent quality of the distillate portion of the TSL pasting solvent is very good. The first stage (short contact time or SCT unit) product quality, as preasphaltene content, is unaffected by space velocity over the range 115 to 190 lb/hr/ft/sup 3/. There appears to be no chemical alteration or physical fractionation of the 850/sup 0/F/sup +/ components during their transit through the antisolvent deashing (ASDA) unit. The coal conversion to THF solubles obtained in the process does not all occur in the first stage. In the LC-Finer operations with Wilsonville SRC feeds, low severity operation maintained product selectivity longer than high severity operation.« less