Coal Exxon-Donor-Solvent-process

W. N. Mitchell, K. L. Trachte, md S. Zaczepinski, "Performance of Low-Rank Coals in the Exxon Donor Solvent Process," paper presented at / 0th Biennial Eignite Symposium, Grmd Porks, N.D., May 1979. 

The development of three-phase reactor technologies in the 1970 s saw renewed interest in the synthetic fuel area due to the energy crisis of 1973. Several processes were developed for direct coal liquefaction using both slurry bubble column reactors (Exxon Donor Solvent process and Solvent Refined Coal process) and three-phase fluidized bed reactors (H-Coal process). These processes were again shelved in the early 1980 s due to the low price of petroleum crudes. 

Other processes have been developed in recent years, especially during the decades of the 1960s and 1970s, to produce liquid fuels from coal. Examples include the H-Coal, Mobil M, Solvent Refined Coal, and Exxon Donor Solvent processes. 

At our current level of understanding, all leading process candidates, H-Coal, Exxon Donor Solvent, and SRC-II all appear to... 

In 1979, because of a lack of large samples, boiler fuel test programs will be limited to small scale equipment. However, in 1980, large samples of liquids in the 5,000-10,000 barrel range should become availabel from the H-Coal pilot plant at Catlettsburg, Kentucky and the Exxon Donor Solvent process at Baytown, Texas. It would be preferable to run a number of tests utilizing different utility sites and types of electric generation... 

Exxon Donor Solvent, and SRC-II, reactors are run at high severities to maximize distillate yield. Then, in the case of the H-Coal and SRC-II processes all the vacuum tower residue is sent to a partial oxidation gasifier to produce hydrogen. The amount of residue is set by the amount of hydrogen to be generated. The Exxon Donor Solvent process differs in that all or part of the vacuum tower residue is processed in a Flexicoking unit to recover additional liquids and to produce low Btu fuel gas. Partial oxidation can be used to process the remainder of the bottom to produce hydrogen. 

Quinlan, C.W. Siegmund, C.W., Combustion Properties of Coal Liquids from the Exxon Donor Solvent Process, paper presented at the ACS National Meeting, Anaheim, CA., March 14,1978... 

The direct liquefaction technologies, which include Solvent Refined Coal, Exxon Donor Solvent and H-Coal processes have never been operated at a commercial scale. As discussed yesterday, these processes are not at advanced stages of development. The products from direct liquefaction processes are basically boiler fuels or synthetic crudes that could potentially be upgraded to... 

Quinlan, C. W. and Siegmund, C. W., "Combustion Properties of Coal Liquids From the Exxon Donor Solvent Process", ACS Meeting Anaheim, California, March, 1978. 

A related reactor is that for coal liquefaction, which can be carried out in a three-phase slurry bubble column (see Fig. 5). Hydrogen can be supplied at the bottom of a column of downcoming product—oil. The solid coal reactant is blended with the product or carrier oil and fed at the top. The generic process depicted in Fig. 5 is a generalization of the liquefaction reactor in the Exxon Donor Solvent Process. As the gas flow rate increases, the bubbles change from uniformly small to chaotic. In the H-coal process, both the gas and a coal-oil slurry are fed from the bottom in an ebullating-bed reactor. Catalyst solids are fed from the top. This reactor operates as an expanded... 

The Exxon donor solvent process (Mitchell et al., 1979 Nowacki, 1979) (Figure 19.10) involves the noncataly tic liquefaction of crushed coal in the presence of hydrogen and a hydrogen donor solvent at 425°C-470°C (800°F-880°F) and 1500-2000 psi. The donor solvent may be a mid-distillate boiling range liquid (205°C-455°C [400°F-850°F]) that is also process-derived. 

Yields for Liquefaction of Illinois No. 6 Bituminous Coal from the Exxon Donor Solvent Process... 

Furlong, L. E., Effron, E., Vernon, L. W., Wilson, E. L., Coal Liquefaction—the Exxon Donor Solvent Process, presented at the AIChE National Meeting, Los Angeles, CA, Nov. 18, 1975. 

W. R. Eppedy and J. W. Taunton, "Exxon Donor Solvent Coal Liquefaction Process Development," paper presented at Coal Dilemma II ACS Meeting, Colorado Spriags, Colo., Feb. 12, 1979. 

Fig. 17. Schematic diagram of the coal hquefaction section of the Exxon donor solvent (EDS) process. To convert MPa to psi, multiply by 145.

Several processes progressed to demonstration scales but have not been commercialized, primarily because of economic inabiHty to compete with available petroleum products. The H-Coal process developed by Hydrocarbon Research, Inc. was demonstrated at Catiettsburg, Kentucky using a 545 t/d plant and DOE support. The Exxon donor solvent Hquefaction process was not commercialized either. 

W. P. Epperly and T. W. Taunton, "Exxon Donor Solvent, Coal Liquefaction Process Development", Proceedings of the 13th Intersociety Energy Conversion Engineering Conference, Vol. 

Exxon Donor Solvent Also known as EDS. A coal liquifaction process in which coal in solution in tetrahydronaphthalene is hydrogenated, using a cobalt/molybdenum/alumina catalyst. So-called because the hydrogen is donated by the tetrahydronaphthalene to the coal. Developed from the Pott-Broche process. Piloted by Exxon Research Engineering Company in the 1970s and operated at 250 ton/day in the Exxon refinery in Baytown, TX, from 1980 to 1982. 

Pott-Broche A coal liquifaction process in which coal is dissolved in a mixture of tetrahy-dronaphthalene and cresols, and then hydrogenated. Invented by A. Pott and H. Broche at IG Farbenindustrie, Germany in 1927 used by the Ruhrol Company in Germany between 1938 and 1944. See also Exxon Donor Solvent. 

The Fluor Corporation recently reactivated and rebuilt the DOE test plant at Cresap, West Virginia, It conducted a coal liquefaction test project for DOE using Exxon s Donor Solvent Process, Oil and Gas Journal 1980, 78, p 71,... 

The relative dimension of the three systems are shown in Figure IV. Combustion test data has been collected on a large number of raw and hydrotreated product samples from the SRC-I, SRC-II, Exxon Donor Solvent, H-Coal, and other processes under development. Figure V is a plot of N0X level versus turbine inlet temperature for these fuels. The actual levels of N0X are related to the actual piece of equipment utilized for the test series but the relative rankings are consistent among the various types of equipment. 

Exxon Donor Solvent, Coal Liquefaction Process Development... 

This paper describes the status of the development of the Exxon Donor Solvent (or EDS) coal liquefaction process. It includes an overview of the jointly funded project and a brief description of the EDS process. It also includes a discussion of the project status, including a description of coal feed flexibility, hydrogen and fuel gas production alternatives and the progress in the construction of the 250 T/D pilot plant. Other communications have covered the R D program, the outlook for commercialization, and the organization of the EDS Project (1,2, 3,, 5, 6, J) ... 

Epperly, W.R. Taunton, J.W., Status and Outlook of the Exxon Donor Solvent Coal Liquefaction Process Development, paper presented at the Fifth Energy Technology Conference, February 27 - March 1, 1978, Washington, D.C. 

Combustion tests of fuel oil blends derived from the Exxon Donor Solvent (EDS) process were carried out in a laboratory 50 hp test boiler and a commercial 1425 hp boiler. All tests showed that coal derived fuel oils burn cleanly compared to petroleum fuels with low levels of smoke and particulates. Emissions of N0X were related to fuel nitrogen content for both the petroleum and coal-derived fuels. 

Figure 1. Exxon donor solvent (EDS) direct coal liquefaction process.

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