Solvent refined lignite

Baltisberger, R. J. Kaba, R. A. Klabunde, K. J. Saita, K. Sukalski, W. Stenber, V. I. Woolsey, N. F. Comparison of Solvent-Refined Lignite with Solvent-Refined Bituminous Coals. Fuel, 1978, 57 (9), 529-532. 

When solvent refined lignite (SRL) produced from North Dakota lignite was treated with liquid sulfur dioxide, the bulk of the coal liquid dissolved except for the saturated hydrocarbons and the mineral rich residue. The S02-solublc part did not contain any saturated hydrocarbons. The THF extract of the insolubles was mostly alkanes ranging from n-dodecane (C 2H26 to n tetra tetrancontane (C44Hgg). 

Some coal liquefaction methods, such as the Synthoil (5) process and the CO-steam (6) process, are similar to solvent refining in their approach, but more severe conditions or a catalyst are used to give a fiuid product. In the Synthoil reaction, bituminous coal is pulverized, dispersed in a vehicle oil, and hydrogenated in a packed tubular reactor with or without added catalyst. The CO-steam process uses lignite coal and less expensive synthesis gas. The intended product is a heavy liquid fuel having ash, sulfur, and nitrogen contents suflBciently low to avoid stack-gas cleaning. Reactor temperature and pressure are normally 400°-450°C and 4000 psi, respectively. 

Source of Sample Project Lignite, University of North Dakota, Grand Forks, ND 58202 Pittsburgh Solvent-Refined Coal Pilot Plant, Dupont, WA 98327 (near Tacoma, WA)... 

In this paper, we have described how minerals in coal can be quantitatively determined by the combination of SEM-AIA and Mi5ssbauer spectroscopy. These techniques can be applied to all coals, from lignite to anthracite, with little or no modification. Although such applications are not discussed in any detail here, these techniques can also be applied to cokes, chars, solvent-refined coals, and other products of coal conversion. 

Solvent-refined lignite (SRL) University of North Dakota Plug flow 370-480 700-895 1000-3000 -1.4... 

The solvent refined lignite (SRL) process (Figure 19.13) is a noncatalytic process that is claimed to recover approximately 70% of the lignite feed as a solid product (m.p. 150°C-200°C [300°F-390°F]) as well as quantities of liquids and gases. 

Solvent refined lignites (SRL) sample (M-llA) and two solvent refined coal (SRC) samples (AMAX, and Indiana) were ground to about 40 mesh for the study (13). Elemental analysis of the samples was performed by Spang Micro-Analytical Laboratory. 1-l C-Acetlc anhydride (ca 10 Ci/ml) and 1- C-acetlc acidl (ca 10 Ci/ml) were used for radio labeled study. High-volatile bituminous coal, seam 6, from a West Central Illinois mine was ground to about 160-350 mesh for the study. Ethanol-l- C and methanol- C (ca 5.5 Ci/ml)... 

Montan wax is obtained by solvent extraction of certain types of lignite or brown coal. It has a dark colour when not treated, but it is lighter when refined. Its chemical composition includes esters of C22 C32 acids (53%), free acids (17%), free alcohols (1 2%), ketones (3 6%) and terpenoids (20 23%) [85]. 

The method of extraction and refining is basically the same, both in this country and in Europe. The waxy part is extracted from the lignites crushed to a powder form) by selective solvents. Then the wax is purified. 

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