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Lignite mining, western North Dakota, US (c. 1945). Lignite is brownish-black in color and has a carbon content of 60–70 percent on a dry ash-free basis. However, its inherent moisture content is sometimes as high as 75 percent [1] and its ash content ranges from 6–19 percent, compared with 6–12 percent for bituminous coal. [5]
As early as the 1920s, the concept of using hot water and alkali catalysts to produce oil out of biomass was proposed. [6] In 1939, U.S. patent 2,177,557, [7] described a two-stage process in which a mixture of water, wood chips, and calcium hydroxide is heated in the first stage at temperatures in a range of 220 to 360 °C (428 to 680 °F), with the pressure "higher than that of saturated ...
This coal is also amongst the world's 'wettest' coal, with a typical moisture content of 60 per cent water by weight. High moisture content makes Victorian brown coal an inefficient fuel source and is the primary reason why the Hazelwood power station in the Latrobe Valley is regarded as the world's dirtiest coal-fired power station. The Coldry ...
Coal liquefaction is a process of converting coal into liquid hydrocarbons: liquid fuels and petrochemicals. This process is often known as "coal to X" or "carbon to X", where X can be many different hydrocarbon-based products. However, the most common process chain is "coal to liquid fuels" (CTL). [1]
The fixed carbon content of the coal is the carbon found in the material which is left after volatile materials are driven off. This differs from the ultimate carbon content of the coal because some carbon is lost in hydrocarbons with the volatiles. Fixed carbon is used as an estimate of the amount of coke that will be yielded from a sample of ...
In materials science, liquefaction [1] is a process that generates a liquid from a solid or a gas [2] or that generates a non-liquid phase which behaves in accordance with fluid dynamics. [3] It occurs both naturally and artificially. As an example of the latter, a "major commercial application of liquefaction is the liquefaction of air to ...
Carbochemistry is the branch of chemistry that studies the transformation of coal (bituminous coal, coal tar, anthracite, lignite, graphite, and charcoal) into useful products and raw materials. [1] The processes that are used in carbochemistry include degasification processes such as carbonization and coking , gasification processes, and ...
Carbonization is a pyrolytic reaction, therefore, is considered a complex process in which many reactions take place concurrently such as dehydrogenation, condensation, hydrogen transfer and isomerization. Carbonization differs from coalification in that it occurs much faster, due to its reaction rate being faster by many orders of magnitude.