Lignite liquids

Acid Fractions. The acid contents, as shown in Table V, account for about 0.4 to 0.6 percent of the 325° to 425° C coal liquid distillates except for the lignite liquid (0.76). The acid content for the 425° to 540° C distillates mostly fall in the range of 0.50 to 0.59 percent except for Pittsburgh (0.29) and Wyodak run 1 (0.34). The total acids from the 325° to 425° C and the 425° to 540° C distillates plus the oxygenate material from the 200° to 325° C distillate (19) expressed on a total liquid basis, correlated fairly well with the total coal liquid oxygen content (Table II) (correlation coefficient 0.82). The data are plotted in Figure 5. 

Feeds. During the course of the investigation, the following feeds were used supercritical extracted lignite liquid,... 

Sohds are hard coal, lignite, peat, and oil shale. Liquids are cmde petroleum and natural gas Hquids. Gases are natural gas. 

Traditionally, active carbons are made in particulate form, either as powders (particle size < 100 pm, with an average diameter of -20 pm) or granules (particle size in the range 100 pm to several mm). The main precursor materials for particulate active carbons, PAC, are wood, coal, lignite, nutshells especially from coconuts, and peat. In 1985, 360 kt of such precursors (including 36 % wood and 28 % coal) were used to make active carbons [10], of which nearly 80 % were used in liquid-phase applications, with the rest being used in gas-phase applications. Important factors in the selection of a precursor material for an active carbon include availability and cost, carbon yield and inorganic (mainly mineral) matter content, and ease of activation. 

Neutralized sulfonated asphalt (i.e., salts of sulfonated asphalt and their blends with materials such as Gilsonite, blown asphalt, lignite, and mixtures of the latter compounds) are commonly used as additives in drilling fluids. These additives, however, cause some foaming in water or water-based fluids. Furthermore, these additives are only partially soluble in the fluids. Therefore, liquid additives have been developed to overcome some of the problems associated with the use of dry additives. On the other hand, with liquid compositions containing polyglycols, stability problems can arise. Stable compositions can be obtained by special methods of preparation [1407]. In particular first the viscosifier is mixed with water, then the polyglycol, and finally the sulfonated asphalt is added. 

South America and Western Europe). But the large reserves of near-surface subbituminous coals and lignites are also being looked upon as future sources of synthetic fuel gases and liquid hydrocarbons that would augment production of synthetic crude oils from, e.g., Northern Alberta s oil sands (4). 

In most experiments the sulfur removed from the Mequinenza lignite appeared in two products, hydrogen sulfide and liquid organosulfur compounds (LOG) present in the THF-soluble extract There are three mechanisms by which these two sulfur-containing products could be produced from the lignite ... 

These results, particularly the indication of a sequential mechanism involving an initial production of liquids which are subsequently hydrotreated on the molybdenum catalyst, were the experimental basis for probing further into the first step - liquids formation - with particular interest in whether the unusually high concentration of organic sulfur in the Mequinenza lignite might have some effect on the liquefaction behavior. 

Figure 3. Liquids yield as a function of sulfur content for Hagel, ayhiran, and Mequinenza lignites, no catalyst, H2 atmosphere, 275 C.

Lignite GAC This presents a total surface area of 650 m2/g and an apparent density of 0.50 g/cm3, approximately. It is usually used for liquid-phase adsorption, and specifically, in decolorizing applications because it has a higher percentage of meso (transitional) and macro pores than bituminous GAC, and therefore is appropriate for larger molecules. 

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