USDOE-Pittsburgh & CoalTL Research

 
We have previously cited the USDOE's Bockrath and Noceti, of the Pittsburgh, PA, Energy Technology Center, relative to their research into the practical liquefaction of coal, and herein is more documentation of their work, and their accomplishments.
 
Though the following excerpts from the enclosed link might seem lengthy, they are just an abbreviated example of what is available;.we were compelled to edited out much overly-technical detail. 
 
With comment appended:
 
"Evaluation of the Donor Ability of Coal Liquefaction Solvents
 
Bradley C. Bockrath and Richard P. Noceti
 
United States Department of Energy
Pittsburgh Energy Technology Center
P. 0. Box 10940
Pittsburgh, Pennsylvania 15236  

Hydrogen donor solvents are used in most processes for the direct liquefaction of coal. The overall performance of these solvents depends on several qualities, including. the abilities to physically solvate coal and its liquefaction products, to hold coal particles in suspension, to assist transfer of hydrogen from the gas phase to coal by dissolving molecular hydrogen or undergoing hydrogenation/dehydrogenation cycles (hydrogen shuttling), and to donate hydrogen directly to coal. Unknown factors may also be involved. In addition, in the case of commercial application, the solvents must be derived from coal and be suitable for recycle operation as well. In order to fully understand the function and importance of liquefaction solvents, the influence of each property must be studied separately. As a step towards this goal,we have developed a method by which the relative hydrogen donor ability of liquefaction solvents may be evaluated.
 
Our method of evaluation is based on a generally accepted hypothesis -of the mechanism of coal liquefaction that has been used to rationalize the kinetics of coal liquefaction (1,2) and has been discussed several times in recent reports (for example (3,4,5). According to this mechanism, the initial act is rupture of the weaker covalent bonds in coal. This produces two free radicals in close proximity. These radicals may either abstract hydrogen from any available source (donor solvent, coal or molecular hydrogen), undergo
rearrangement, or add to some other site on either coal or solvent. Recbmbination or addition may lead to production of insoluble or char-like residues that are dearly undesirable. One critical function of the donor solvent is to provide a source of hydrogen. Abstraction of hydrogen by coal-derived free radicals prevents retrogressive reactions that lead to higher molecular weight products, and it directs more coal along the desired pathways to lower molecular weight products. Thus, donors with high potential for hydrogen
transfer are regarded as beneficial to increased liquefaction yields.
 
Our approach to evaluation of the donor property was to devise a test that embodies the main features of the free radical mechanism of coal liquefaction. The basic idea is shown in Figure 1. Benzyl radicals are generated by the thermolysis of' a convenient precursor at relatively low temperatures. These radicals then behave like the free radicals generated by the thermolysis of coal at liquefaction temperatures. When benzyl radicals are generated in a donor solvent, the relafive amounts of toluene and bibenzyl produced reflect the relative ability of the solvent to donate hydrogen and to prevent reco'mbination. A variable amount of benzyl radical is also lost, which presumably represents that amount which adds to or combines with the solvent.
 
Other methods have been used in the past to provide a "solvent quality index. ... Notably, measurement of liquefaction yields produced under specified conditions and with a specified coal has been used to provide a direct empirical evaluation of solvent quality.
 
Various spectroscopic methods have also been used to estimate the relative amount of benzylic or hydroaromatic hydrogen available for transfer (10,11,l2). These methods serve their intended purposes well. In the present work, we airn at developing a better understanding of the chemistry of liquefaction and the overall performance of liquefactionsolvents by isolating the hydrogen donor ability and free radical scavenger ability for study.
 
RESULTS AND DISCUSSION
 
Since many of the cornpounds to be tested as rnodel hydrogen donors are solids at room temperature, it was worthwhile to use an inert liquid as a diluent. Tert-butylbenzene served this purpose well. It possesses only relatively inert aromatic and primary aliphatic hydrogen and sufficient solvent power to dissolve most of the donor solvents to be tested. Decomposition of either benzyl radical precursor in lert-butylbenzene solution produced only srnall yields of toluene.
 
Material balance studies showed that not all of the benzyl radical present in the precursor was recovered as either toluene or bibenzyl. A sizeable fraction is apparently rernoved by side reactions with the solvent. In pure t-butylbenzene, this accounted for 24% of the benzyl radical, while in a 50/50 wt mixture of
t-butylbenzene and tetralin, it accounted for 32%. In the gas chromatograms of the decornposition products, new peaks appeared which were due to high boiling compounds. In the case of runs done in the
presence of tetralin, GC/MS analyses indicated that three of these peaks had the correct molecular weights for benzyltetralins, benzylnaphihalene and bitetralyl. These products must arise from radical combination and addition reactions.
 
The appearance of solvent combination and addition products is in accord with some recently reporteq results from other groups. Collins et. al. (13) reported that after they heated coal with 4C labeled tetralin at 400’ C for I hour, the pyridine solubles were 1.6 1 t. percent tetralin and the residue 2.6 wt. percent tetralin. In pother experirnent (13), “C labeled 1,3 -dipheriylpropane was heated with tetraliri at 400 C for 1 hour. Toluene and ethylbenzene were major products. In addition, methylnaphthalenes, mcthyldihy-dronap!ithalenes, phenylethyltetralins, and phenylcthylnaphthalenes were found. A mechanism was proposed that involved cornbination of phenylethyl with tetralyl radical, followed by further thermolysis to produce methyl substituted .tetralins and: naphthalenes.

Thus at higher temperatures, radical addition to solvent may he followed by (unintelligible) of the newly formed bridge. Evidence for the addition and subsequent dissociation of benzyl radical with tetrafin at temperatures of 400-450°C has also been reported by workers at Gulf (14). Another piece of evidence showing the importance of addition reactions is the report (15) that -negative solvent balances were found during preheater studies. These findings were interpreted to mean that during the initial phase of liquefaction (300’ -4OO0C), coal-derived solvent became bound to the coal so tightly that it could not be Jreed by either distillation or solvent extraction. Subsequent reaction after reaching 450 C changed the solvent balance to positive. Processes analogous to the addition/dissociation reactions described by Collins rnay Pe involved.
 
The three solvent indices were determined for the decomposition of dibenzylmercury for several solvent mixtures made from different amounts of tetralin .in t-butylbenzene. The data contained in Figure 2 show that the donor index increases with increasing tetralin concentration. Also shown in this figure are data taken from reference (16).for conversign of a bituminous coal to pyridine soluble material after reaction for three minutes at 427 F in mixtures of tetralin with methylnaphthalene, cresol, and picoline. Conversion as well as the donor index goes up as the tetralin concentration in the solvent increases. This comparison is made only to point out the qualitative similarity between the two results since we assume that both coal conversion and toluene yield are related to the relative hydrogen donor ability of the solvent. In both cases the greatest increase in conversion or toluene yield comes at relatively low tetralin concentration.
 
Tetrahydroquinoline's superior quality has been attributed to a unique combination of readily donatable hydrogen with a heightenedability to solvate coal and its liquefaction products ... an additional reason for the superior liquefaction performance of tetrahydroquinoline may be its ability to add to or combine with
free radicals initially produced by the thermolytic reactions of coal.
 
Comparison of the donor indices with other available quality criteria is made with two sets of solvents. The DCD series are recycle solvents derived from Blacksville coal under different processing conditions in the 1000 Ib/day liquefaction unit at PETC. The values of ... distillation residue from a lightly hydrogenated recycle oil made in the Wilsonville SRC pilot plant from Wyodak coal. F-14is a lightly hydrogenated recycle oil made in the Tacoma SRC pilot plant from Kentucky coal. F-16 is a coal gasification tar from an in situ gasification project near Manna, Wyoming.  
 
REFERENCES
1) G. P. Curran, R. T. Struck and E. Gorin, Ind. Eng. Chem., Process Des. Dev. -6, 166 (1967).
2) W. H. Wiser, Fuel, E,475 (1968).
3) D. D. Vhitehurst, T. 0. Mitchell, M. Farcasiu and 3. J. Dickert, Jr., "The Nature and Origin of Asphaltenes in Processed Coals," EPRl Final Report AF-1298 (1979).
4) R. C. Neavel, Fuel, 55, 237 (1976).
5) I. Wender and 5. Friedman, Proc. 13th. IECEC (Sin Diego, CA., Augut, 1978) Vol. 1, p. 457.
6) B. K. Bandlish, A. W. Garner, M. 1.Hodges and J. W. Timberlake, J. Am. Chem. SOC., 97,5855 (1975).
7) K. C. Bass, J. Organometal, Chern., 2,l(1965).
8) Method No. 43080-60, Analytical Department, Catalytic, Inc.,Wilsonville, Alabama.
9) 3. A. Kleinpeter, F. P. Burke, P. J. Dudt and D. C. Jones, "Process Development for Improved SRC Options," EPRl Interim Report, AF-1158, August, 1979, Palo Alto, Calif.
IO) C. H. Wright and D. E. Severson, Preprints Am. Cliem. Soc., Div. Fuel Chem-16(2), 68 (1972).
11) I<. S. Seshadri, R. G. Ruberto, D. M. Jewell and tl. P. Malone, Fuel, 57, 549 (1978). 
12) B. T. Fant, "EDS Coal Liquefaction Process Developmcnt: Phasc IIIA," Annual Technical Report, 1 Jan -31 Dec 1976, ERDA No. FE-2353-9 (1977).
13) Am. Chem. SOC., Fuel Div., g(5), 98 (1977). C. 3. Collins, B.M. Benjamin, V.F. Raaen, P. H. hlaupin and V. H.Roark, Preprints,
14) Eng. Chem., Fundam., E, 195 (1979). C. Cronauer, D. M. Jewell, Y. T. Shah, R. J. Alodi and K. Seshadri, Ind.
15) hl. G.Thomas and R. K. Traeger, Preprints, Am. Chem. SOC., Fuel Div., 2(3), 223 (1979).
16) D. D. IVhitehurst, T. 0.Mitchell, bi. Farcasiu and J. J. Dickert, Jr., "The Nature and Origin of Asphaltenes in Processed Coals, Volume I," EPKI Final Report AF-1298, pg. 1-46 (1979).
17) G. Koclling, Rrennstoff-Cherr$ie, g,23 (1965).
18) D. Hausigk, G. Koelling and F. Ztegler, Brennsroff-Chrmie, 50, S, (19b9).
19) Petrakis and D. W. Grandy, Fuel, 2,227 (1980). 
20) F. Silver and R. J. Hurtubisc, "Effect of Solvent Characteristics on Wyodak Coal Liquefaction," Final Technical Progress Report," Department of Energy Report FE-2367-9 (1979).  
21) G. Cohen, S. J. Groszos and D. Sparrow, J. Am. Chem. SOC., 72, 3947 (1950). 
22) J. R. Shelton and C. K. Liang, Synthesis, 204 (1971)."
 
First of all, an early quote: "Hydrogen donor solvents are used in most processes for the direct liquefaction of coal".
 
Did you, did anyone in Coal Country, know that there was such a multiplicity of coal liquefaction technologies that a statement like "most processes for the direct liquefaction of coal" could even be used?
 
Second, in a similar vein, note how, in an offhand manner, it is revealed that there were a number of coal liquefaction operations underway around the United States, as in:"Comparison of the donor indices with other available quality criteria is made with two sets of solvents. The DCD series are recycle solvents derived from Blacksville coal under different processing conditions in the 1000 Ib/day liquefaction unit at PETC. The values of distillation residue from a lightly hydrogenated recycle oil made in the Wilsonville SRC pilot plant from Wyodak coal. F-14 is a lightly hydrogenated recycle oil made in the Tacoma SRC pilot plant from Kentucky coal. F-16 is a coal gasification tar from an in situ gasification project near Manna, Wyoming."
 
In the above exert, they note that WV - "Blacksville" - coal was liquefied in Pittsburgh. Another coal was liquefied in Alabama, in the "Wilsonville SRC" we have documented for you previously. And, coal was shipped all the way from Kentucky to be liquefied in the "Tacoma", Washington, "SRC pilot plant", another US Government coal conversion facility about which we have reported.
 
They also document "Tetrahydroquinoline's superior quality" as a coal liquefaction solvent. Also known as "Tetralin", that material is a key part of WVU's "West Virginia Process" for direct coal liquefaction.
 
Finally, make note of the sheer volume of coal liquefaction references they include.
 
The knowledge, the technology, is real. Why aren't we using it?

U of Akron: Methanol-to-Gasoline vs. DME-to-Gasoline


This, the Methanol vs. Dimethyl Ether, as a raw material from which to make gasoline, debate, might seem just an arcane scientific concern being kicked about by academic eggheads; an argument of little import to us non-ivory tower types toiling away in Coal Country - except for the fact that what these Akron University scientists are actually contending over herein is the most profitable route to follow in making gasoline from coal.
 
Read carefully, comment follows: 

"Document title

Methanol-to-gasoline vs. DME-to-gasoline. II: Process comparison and analysis

Authors

SUNGGYU LEE ; GOGATE M. ; KULIK C. J. ;

Authors Affiliations

Univ. Akron, dep. chemical eng., process res. cent., Akron OH 44325-3906, ETATS-UNIS

Journal

Fuel science & technology international; 1995, vol. 13; pp. 1039-1057 

Abstract

Methanol can be converted into gasoline boiling range hydrocarbons over zeolite ZSM-5 catalyst using the Mobil MTG process. Methanol feed in the MTG process can be derived from coal or natural gas based syngas. The Mobil MTG process involves the conversion steps of syngas-to-methanol and methanol-to-gasoline. Dimethyl Ether (DME), a product of methanol dehydrocondensation, is an intermediate species in the methanol-to-gasoline conversion. Syngas can be directly converted to DME using the Liquid Phase Dimethyl Ether Synthesis (LP-DME) process developed at the University of Akron in conjunction with Electric Power Research Institute. This direct one-step conversion of syngas-to-DME can then be an ideal front end for further conversion to gasoline. This substitution (syngas-to-methanol by syngas-to-DME) is justified because DME results in an identical hydrocarbon distribution over the ZSM-5 catalyst as methanol. The DME-to-Gasoline (DTG) process thus involves the conversion steps of syngas-to-DME and DME-to gasoline. The UA/EPRI DTG process offers advantages over the Mobil MTG process in several areas. These include heat duty and heat of reaction, adiabatic temperature rise, hydrocarbon product yield and selectivity, syngas conversion, and overall process efficiency. The conceptual benefits of the DTG process have been demonstrated experimentally in a fluidized bed reactor system operative at the University of Akron. The salient features of the DTG process and process comparison to the Mobil MTG process are discussed in this paper." 
 
Well, a few things are clear, aren't they? Let's apply some old West Virginia technology and distill the essence:
 
"Methanol can be converted into gasoline" and  "Methanol ... can be derived from coal".
 
Moreover:
 
"Syngas (from coal - JtM) can be directly converted to DME" and  "DME can then be ... ideal ... for further conversion to gasoline".
 
Actually, as opposed to spending any more of our national treasure on OPEC oil, either method sounds "ideal" to us.

Northwestern Liquefies Coal and Plastic

  
Via the enclosed link, you can access a rather compendious file, an edited and abbreviated copy of which, more than 180+ pages in it's original format, we are also attaching for your convenience, entitled: 
 
Coal/Polymer Coprocessing with Efficient Use of Hydrogen 
 
Some excerpts:

"Dr. Linda J. Broadbelt and Matthew J. De Witt
 
Northwestern University
2145 Sheridan Road
Department of Chemical Engineering
Evanston, IL 60208

This report was prepared as an account of work sponsored by an agency of the United 
States Government. 
 
ABSTRACT
 
Environmental and economical concerns over diminishing landfill space and the growing 
abundance of mixed plastic waste mandate development of viable strategies for recovering high-
valued resources from waste polymers. Co-processing of waste polymer mixtures with coal 
allows for the simultaneous conversion of coal and plastics into high-valued fuels. However, there 
is limited information about the underlying reaction pathways, kinetics, and mechanisms 
controlling coal liquefaction in the presence of polymeric materials.
 
INTRODUCTION
 
Recently, concerns over the inadequacy of current treatment and disposal methods for 
mixed plastic wastes have driven the exploration of new strategies for viable plastics resource 
recovery. The emphasis of the recovery is to obtain high-valued, useful products from the waste 
polymers. Post-consumer waste plastics are a major contributor to the municipal solid waste 
(MSW) stream, constituting approximately 11% by weight and 21% by volume of waste in 
landfills [1]. Over 40% of the landfills in the United States were closed in the past decade, and it is 
estimated that over half of the remaining ones will be full by the end of the century [2]. This poses 
a significant dilemma since there appears to be no immediate decrease in the usage of plastic 
products; in fact, due to their versatility, the usage will most likely increase.
 
Coprocessing of polymeric waste with other materials may provide potential solutions to 
the deficiencies of current resource recovery processes, including unfavorable process economics. 
By incorporating polymeric waste as a minor feed into an existing process, variations in plastic 
supply and composition could be mediated and as a result, allow for continuous operation. One 
option for coprocessing is to react polymeric waste with coal under direct liquefaction conditions. 
Coprocessing of polymeric waste with coal provides for simultaneous conversion of both 
feedstocks into high-valued fuels and chemicals."
 
The book is full, detailed and complex; so much so that we will not attempt further excerpts. However, to compress it enough for transmission, we had to edit, and convert it into a "text" file, so some graphics were lost; and, the formatting doesn't enable easy browsing. Some, perhaps important, data is lost in the text version. It is not recommended reading. We send it primarily as testament to the detailed understanding which has been generated, and which does exist, about the technology for converting coal into liquid fuel raw materials, and doing so in ways that enhance and improve the efficiency of the conversion process, while utilizing a class of resources that have until now been thought of as little more than troublesome wastes.
 
We will note that Northwestern, in completing this project for the US Department of Energy, collaborated with the University of Kentucky on coal liquefaction issues.
 
Their findings echo similar research reports we've called to your attention. Liquefying coal and plastic wastes, together, is synergistic. They each provide elemental and molecular components to the liquefaction process that complement each other, and thereby enhance and maximize the production of liquid fuel raw materials.
 
This report was prepared for, and provided to, the United States Government. Why haven't we United States citizens, especially those of us resident in US Coal Country, been apprised of it's contents?
 
And, why has nothing yet been done to reduce to practice the finding that the "Coprocessing of polymeric waste with coal provides for simultaneous conversion of both feedstocks into high-valued fuels and chemicals"?
 

Kentucky Liquefies Coal and Plastic

 
In our earlier dispatch concerning the achievements of Northwestern University, who demonstrated the synergistic co-conversion of coal and plastic wastes into liquid fuel raw materials, we made note of their collaboration with the University of Kentucky in that effort.
 
Herein is some confirmation of UK's own work, confirming that coal can be synergistically combined with "oils", created by the thermal degradation of some waste plastics, to increase the yields of petroleum-type products from coal liquefaction processes.
 
Comment follows: 

Document title

Direct liquefaction of waste plastics and coliquefaction of coal−plastic mixtures

Authors

FENG Z.; ZHAO J.; ROCKWELL J.; BAILEY D.; HUFFMAN G.

Authors Affiliation

CFFLS, 533 South Limestone St., Room 111 University of Kentucky, Lexington, KY 40506-0043
 
(Note: "CFFLS" stands for "Consortium for Fossil Fuel Liquefaction Science", which at some time, for some reason, in the subsequent decade, became abbreviated to the, perhaps, in light of a Big Oil presidential regime, more discreet, but less informative, "CFFS", the "Consortium For Fossil Fuel ... Science" - JtM)

Journal

Fuel processing technology; 1996, vol. 49, n1-3, pp. 17-30 

Abstract

We have conducted further investigations of the direct liquefaction reactions of waste plastics, medium and high density polyethylene, polypropylene; and coal−plastic mixtures, varying the catalyst, temperature, gas, pressure, time and solvent. The experiments used four types of catalysts: a commercial HZSM-5 zeolite catalyst, and three catalysts synthesized in our laboratory, ferrihydrite treated with citric acid, coprecipitated Al2O3−SiO2, and a ternary ferrihydrite−Al2O3−SiO2. For direct liquefaction of plastics alone, a solid acid catalyst such as HZSM-5 or Al2O3−SiO2 markedly improves oil and total liquid yields, as determined by pentane and THF solubility, respectively. Yields are higher when using either a waste oil solvent or no solvent than using tetralin as the solvent. For PE, temperatures of 430 °C or higher are required for good yields, while PPE gives excellent yields at 420 °C. A commingled plastic provided by the American Plastics Council exhibited peak oil and total liquid yields at 445−460 °C. The oil yields and total liquid from PE ... and the APC commingled waste plastic decreased only slightly with decreasing hydrogen pressure (from 800 to 100 psig H2 ... . Furthermore, yields were as high under nitrogen (200−600 psig) as under hydrogen. Coliquefaction experiments were conducted on 50−50 mixtures of PE, PPE and the APC plastic with Black Thunder coal. For these experiments, the best results were obtained when the solvent was tetralin or a mixture of tetralin and waste oil. Lower yields were observed with only waste oil or with no solvent. Either HZSM-5 or Al2O3−SiO2−ferrihydrite increased oil and total yields by approximately 10% at 460 °C. Under the same conditions, yields from a PPE−coal mixture were substantially higher than those from a PE−coal mixture."
 
First, note that both WVU's coal liquefaction solvent, tetralin, specified in their "West Virginia Process" for direct coal liquefaction, and Exxon-Mobil's "HZSM-5", the zeolite  catalyst specified in their "MTG"(r), "methanol-to-gasoline" Process, wherein the methanol is posited to be made from coal, both of which we have previously documented, were utilized in these University of Kentucky developments.
 
Also note, somewhat importantly we think, that the use of hydrogen-rich plastics, in the liquefaction of Black Thunder Coal, enabled the liquefaction, the hydrogenation, to proceed just as effectively under an inert atmosphere as under one that might have been expected to increase liquid hydrogenation yields, but would have been far more difficult, and far more expensive, to use industrially, as in: "yields were as high under nitrogen (200−600 psig) as under hydrogen". 
 
It's all just more evidence that the technology does exist which would enable us to effectively combine our abundant coal with some of our, unfortunately, abundant and persistent wastes to manufacture the liquid fuels we grow increasingly short of, and increasingly dependent on other nations, many of whom we can't really call our friends, for the supply of.

Penn State Writes CoalTL "Book"

Enclosed are a set of links and excerpts that are just samples of what is available from Penn State University, on their technical research, some of it done in partnership with Gulf Oil, into the detailed reality of coal-to-liquid conversion technology.
 
Again, these are just samples of what is available. But, note that the work spans decades. And, the only documented public presentation of any of it was two decades ago, in an obscure conference on the other side of the world. It might as well have been on the far side of the moon.
 
Brief comment follows: 
 
------------
 
 
Dependence of coal liquefaction behaviour on coal characteristics. 1. Vitrinite-rich samples
 
Peter H. Given, Donald C. Cronauer, William Spackman, Harold L. Lovell, Alan Davis and Bimal Biswas 

College of Earth and Mineral Sciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA

Gulf Research and Development Co., Pittsburgh, Pennsylvania, USA

Abstract

The liquefaction behaviour of a number of vitrinite-rich coals has been determined in batch autoclaves at temperatures of 385–425 °C and pressures of about 8.6 MPa (85 atm) of hydrogen. In one set of experiments, impregnated ammonium molybdate was used as catalyst, with no added liquid as vehicle. In a second set, a proprietary catalyst was used and anthracene oil served as vehicle. Lignites, sub-bituminous, medium-volatile and low-volatile bituminous coals gave relatively poor conversions. However, a lignite sample that had been subjected to ion-exchange treatments gave high conversion, and the viscosity and structural parameters of the products varied with the nature of the treatment. In general the highest conversions were observed for coals in the high-volatile bituminous range, but within this broad range and for the comparatively small set of samples studied neither these data nor the structural characteristics of the products show any very evident correlation with rank parameters or with the geological history of the sample. Two geologically young bituminous coals from the Pacific Coal Province gave excellent conversions; both had very high mineral-matter contents, a fact that may be very relevant.

 
Dependence of coal liquefaction behaviour on coal characteristics. 2. Role of petrographic composition  

Peter H. Given, Donald C. Cronauer, William Spackman, Harold L. Lovell, Alan Davis and Bimal Biswas

College of Earth and Mineral Sciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA

Gulf Research and Development Co., Pittsburgh, Pennsylvania, USA


June 1974. 

Abstract

The techniques used were the same as those used in Part 1 (p 34). Comparison of the liquefaction behaviour of two lithotypes from a Kentucky bituminous coal indicated that in this process pseudovitrinite is a reactive maceral. The hydrogenation of sets of maceral concentrates obtained from a New Mexico sub-bituminous and a Kentucky bituminous coal showed fair correlations between conversion and the total concentration of the presumed reactive macerals (vitrinite, pseudovitrinite and sporinite). Similar concentrates from a Montana lignite showed no such correlation; the one sample that showed a high conversion was a high-density fraction that had a high mineral-matter content and in which nearly all the pyrite in the coal had accumulated. Two samples that have boghead and cannel characteristics gave quite different results on hydrogenation. Both were highly aliphatic in structure and had unusually high hydrogen contents and volatile matter. One, which contained appreciable proportions of sporinite, alginite and resinite, gave essentially no conversion to oil. The other, predominantly vitrinitic but containing alginite as the second most abundant maceral, gave an excellent yield of an oil of low viscosity and aromaticity. It was concluded that although rank, petrographic composition and perhaps geological history are important factors determining liquefaction behaviour, there are other characteristics of coals that may at times override these basic parameters, and the composition of the inorganic matter may be the most significant of these other characteristics.

 
Dependence of coal liquefaction behaviour on coal characteristics. 5. Data from a continuous flow reactor
 
Peter H. Given, Ronald Schleppy and Ajay Sood
 
Department of Materials Science and Engineering, Pennsylvania State University, University Park, Pa. 16802, USA

November 1979
 

Abstract

A classification of coals in which conversion in batch reactors at 400 °C with tetralin (but no H2 gas) is one classifying parameter, is shown to be highly significant when the coals are hydrogenated in a 1 kg h−1 continuous flow reactor at 440 and 455 °C with 20.7 MPa of hydrogen. Regressions of the two sets of data against each other show variances explained of 86.5 and 88%, respectively. The yield of material distillable under standard conditions in a vacuum varies over the range 12–60% of dmmf coal.




 
Dependence of coal liquefaction behaviour on coal characteristics. 8. Aspects of the phenomenology of the liquefaction of some coal 

John S. Youtcheff and Peter H. Given

Department of Materials Science and Engineering, College of Earth and Mineral Sciences, Pennsylvania State University, University Park, Pa. 16802, USA

Presented at International Workshop on the ‘Science of Coal Liquefaction’, Lorne, Victoria, Australia, 24–28 May, 1982.

Abstract

Steps are now being taken to define in more detail the phenomenology of coal liquefaction and to provide a scientific basis for empirical correlations previously established between liquefaction conversion and basic compositional characteristics of coals. The rates of production of oils, asphaltenes and preaphaltenes have been determined at four temperatures for three coals, two of Carboniferous and one of Creaceousage. Products are formed more slowly from the younger coal (which is of slightly lower rank) than from the others, but oxygen, partly as OH but probably mostly in a type of ether, is lost more rapidly. It is estimated that the maximum content of O as cleavable ether is 7.7 atoms/100 C atoms for the younger coal (from Wyoming) and 4.1 and 5.1 for the other two (from Oklahoma and Ohio, respectively). Until ≈ 50% of the amount present in the Oklahoma coal is lost, the rates of removal of oxygen and organic sulphur are approximately equal; beyond this level, the removal of S is more rapid. The loss of organic sulphur from the Ohio coal is slightly faster. Even so, the data do not support the idea that cleavage of thioethers is more rapid than that of ethers and that this is the basic reason why a high organic sulphur content tends to promote liquefaction. Conversion of the pyrite in the Ohio coal to pyrrhotite occurs considerably more rapidly than the pyrite in the Oklahoma coal. In preliminary experiments, it is shown that a curve-resolving programme allows two aromatic and five aliphatic C-H stretching vibrations to be distinguished in FTIR spectra of the hexane-insoluble products, and the distribution changes with degree of conversion. In particular, there is evidence that new aryl methyl are generated during liquefaction, in agreement with evidence from oxidation studies.

ScienceDirect - Fuel : Dependence of coal liquefaction behaviour on coal characteristics : : 9. Liquefaction of a large set o.  

Dependence of coal liquefaction behaviour on coal characteristics: 9. Liquefaction of a large set of high-sulphur coal samples

Paul H. Neill, Lawrence J. Shadle and the late Peter H. Given

College of Earth and Mineral Sciences, Pennsylvania State University, University Park, PA 16802, USA


April 1988
 
 

Abstract

Previous attempts to relate quantitatively coal liquefaction yields to properties considered only total yields of products and basic compositional data. This effort has now been renewed by the incorporation of analyses of liquefaction products and of coal structural characteristics. A set of 26 high volatile bituminous coals, with sulphur contents ranging from 2.8 to 7.9% and a mean mineral matter content of 15.3 ± 4.2% has been liquefied in tubing bombs with tetralin and hydrogen. There was a tendency for total conversion to decrease with increasing rank, but with much scatter. No marked trends of yields of asphaltene, oils or gas (directly measured) with rank or sulphur content were seen. The sum of the yields of these fractions and of the insoluble residue from the liquefaction was only 85–95%; it was shown that most of the missing material represented volatile coal products lost in the evaporation of the ethyl acetate extractant or in the vacuum distillation of naphthalene and excess tetralin.

----------

First, note the last word: "Tetralin", the hydrogen-donor solvent used by WVU in their direct coal liquefaction technology, "The West Virginia Process".

Like much other US coal liquefaction research we've reported to you, such as the University of Kentucky's "H-Coal" CTL pilot plant, all these efforts seem to have winked out in the late 1980's - early 1990's.

Why?

But, we urge you to follow up on this Penn State research, if Big Oil, through Gulf, hasn't already collected all the printed works and had a big bonfire somewhere. If that hasn't happened, it's far past time Big Oil did get his marshmallows toasted.

The technology that would enable us to convert our abundant domestic coal into needed liquid fuels exists; it is well-developed and well-understood. It would enable us to free ourselves from overseas oil power drains on our economy, and, through associated carbon dioxide recycling technologies, some of those patented by our own, US, Department of Defense, further enable us to establish an industrial basis of sustainability and environmental responsibility.