Coal convertion

Preliquefaction at 275 C appears to have a negative effect on subsequent liquefaction when compared to results without a preliquefaction step. Preliquefaction results in up to 10% of the coal converted to gases and chloroform solubles. Most coals behaved the same and there was little effect due to the presence of either the catalyst or hydrogen. The solvent was, however, necessary to produce the chloroform extracts as none were produced by a thermal treatment in the absence of a solvent. 

Ammonia also may be produced as a by-product from gas liquor obtained from coal, gas, and coke ovens. Organic nitrogen in the coal converts to ammonium compounds which are separated from tar and distilled with an aqueous suspension of Ca(OH)2 to produce ammonia. 

In the United States, germanium is obtained as a by-product of zinc production from zinc blende ores. The ore is concentrated by the flotation process. Concentrated ore is then roasted, converting zinc and the impurity metals to their oxides. Heating the crude oxides with sodium chloride and coal converts germanium and other impurity metal oxides into their volatile chlorides. The chloride vapors are condensed and germanium chloride, GeCh, is separated from the condensate by fractional distillation. 

The weight percents of coal converted to hexane insolubles in Scheme C and to HC1 precipitates in Schemes A and B are listed in Tables VIII and IX. The extract values given for Schemes A and B have been corrected for the HC1 extract found in the liquefaction solvent. Elemental analyses of various extract and raffinate phases produced by applying Schemes A, B, and C in Table VIII are presented in Table X. 

Steel production at one time required large amounts of coke. This was prepared by heating bituminous coal to high temperatures in the absence of air. This process also favors production of coal gas and coal tar. Because of the enormous amount of coal converted to coke, coal tar was produced in large quantities. It served as a source of aromatic compounds. For each ton of coal converted to coke, about 5 kg of aromatic compounds were obtained. Today petroleum refining is the major source of aromatic hydrocarbons. 

The heat of the burning coal converts the CaC03 to calcium oxide, CaO. The calcium oxide reacts with the sulfur dioxide in the following reaction ... 

Experimental results on only the yield of methane in tests in the continuous flow unit are shown in Figure 12, a plot of the methane yield, expressed as percent of the calorific value of the coal converted into methane, vs. the precent of B.t.u. in coal converted to gas. The methane concentrations obtained in the flow unit are, as stated above, lower than those in the autoclave tests consequently, the points for the continuous flow experiments also lie below the autoclave correlation curve at all... 

C (from coal) converted into gas hydrocarbons 21.7 mass % 30.4 mass % 22.8 mass % 19.3 mass %... 

As a result, most estimates place the efficiency of full-size IGCC plants at around 45% of the total energy released from burning coal converted into usable electric power, an improvement over the 30%-40% efficiencies achievable in conventional plants but still considerably lower than the 60% electric efficiency achievable in today s most advanced combined-cycle plants. 

Acid Gas Components. The oil and gas industries have a long history of effectively removing and processing carbon dioxide, hydrogen sulfide, and carbonyl sulfide, (collectively termed acid gases because they are acidic) from fuel gas streams. It is common to remove H2S and CO2 from raw natural gas before the gas enters the natural gas pipeline system. In coal gasification, a portion of the feed coal converts to CO2. 

The battery has a pusher side and a coke side. On the pusher side of the battery there is a large machine, with an extendable ram used to push the coal converted to coke at the end of the coking cycle, from the slot-type ovens. The coke exits the ovens on the coke side of the battery, through a coke guide and into a quench car. The hot coke in the quench car is then water-cooled in a quench tower. Coke is a necessary component for the production of iron in a blast furnace. 

Coke ovens are probably one of the most complicated refractory stmctures. For those not familiar with the steel-making industry, coke ovens are used to make coke (from coal) for processing raw iron from iron ore in a blast furnace. The coke ovens are made up of primarily silica block shapes (6). The shape design of the various silica block shapes make up the walls in the coke ovens. Hot gases flow internally through chambers in the walls. The walls are heated, which in turn heat the pulverized coal, converting the coal to coke. Silica bricks are used because of the very low expansion of the brick at higher temperatures. 

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