also routes for direct conversion of coal into liquids (, direct coal liquefaction [DL]) involving reaction of coal at high pressures and temperatures with hydrogen (H 2 ) in the presence of solvents and catalysts, yielding synthetic crude oil that can be refined into liquid fuels.
synthetic coalbased oil process with indirect coal liquefaction technology and a synthetic ammonia process (Xie et al. 2010). The primary steps include pressurized gasication to produce synthesis gas (or syngas), gas purication, FischerTropsch (FT) synthesis to produce dierent liquid fuels and oil processing (Xie et al. 2010).
Direct coal liquefaction residue (DCLR) is a byproduct of coaltoliquid technology when raw coal is converted into liquid fuel, which is harmful to the ecological environment and human can be developed into a road asphalt modifier via different techniques, that can improve and enhance asphalt performance. In this paper, the global research status of DCLR in asphalt pavement is ...
Request PDF | Novel Use of Residue From Direct Coal Liquefaction Process | Direct coal liquefaction residue (DCLR) is, commonly, designed to be used as a feed stock for gasification or combustion.
The direct liquefaction process ( Fig. 3) employs a coal ground to a fine powder, solvent, hydrogen, and catalyst employed at elevated pressures ( psig) and temperatures (400450°C). The solvent mixed with the coal forms a pumpable paste.
water, boiler feed water, and cooling water. Process water is used in the liquefaction process and often plays a part in chemical reactions. Boiler feed water is used to produce steam, and much of it is recovered and returned to the boiler. Cooling is typically done using circulating water. Cooling water loss is often the most significant factor.
The project is based on Exxon's donor solvent coal liquefaction process. The program will involve both smallscale RD work, and the design, construction and operation of a pilot plant with a capacity of 250 tons per day. The pilot plant will be built adjacent to an Exxon refinery at Baytown, Texas. The new agreement runs through December 31, 1982.
Bergius treated a mixture of pulverized bituminous coal and coalderived heavy oil with hydrogen, at high temperature and pressure, to give a liquid product consisting of heavy oils, middle distillates, gasoline, and gases. Various metal compounds have been used to catalyze the process.
The purpose of coal conversion is the production of alternative fuels, including motor fuels, or the generation of a range of chemicals from coal by process routes, such as gasification, direct and indirect liquefaction, hydropyrolysis, and plasmapyrolysis. The application of these techniques is essential if the large reserves of coal are to be ...
Influence of coal properties on coal conversion processescoal carbonization, carbon fiber . 123 Table 5 Coal parameters with significant influence on liquefaction process
However, similar to other coal liquefaction processes, the DCL process has not been widely commercialized mainly because of economic uncertainty, high CO 2 emission, and high capital cost [1,2].
Diverse coal liquefaction procedures are tailored to the properties of the specific coal resource or desired final products: the solventrefined coal (SRC) process was developed to produce cleaner boiler fuels; whereas the Canada Centre for Mineral and Energy Technology (CANMET) hydrocracking process is intended to coprocess coal with ...
Direct coal liquefaction processes have recently been based on a twostage processing approach: coal dissolution followed by upgrading of the solubilized products. It has been found that low rank coals are more difficult to liquefy in the first (solubilization) stage under conditions optimized for bituminous coals.
As a country that is poor in petroleum yet rich in coal, it is significant for China to develop direct coal liquefaction (DCL) technology to relieve the pressure from petroleum shortages to guarantee national energy security. To improve the efficiency of the direct coal liquefaction process, scientists and researchers have made great contributions to studying and developing highly efficient ...
the process to dissolve the coal and to transfer externally produced hydrogen to the coal molecules. Catalytic liquefaction resembles solvent extraction, except that hydrogen is added to the coal with the aid of a catalyst. Figure presents the flow diagram of a typical solvent extraction or catalytic liquefaction plant. These coal ...
When considering the development of coal liquefaction process using syngas, in addition to the above typical processes, hydrothermal liquefaction process is a technology worthy of reference. Hydrothermal liquefaction [110], [111], [112] is an effective and emerging technology that can convert both coals and biomass containing high moisture ...
Current State of Direct Liquefaction of Coal 3. Indirect Coal Liquefaction FischerTropsch Synthesis Process Catalysts Process Parameters Developments in Indirect Liquefaction 4. Conclusion Glossary Bibliography Biographical Sketch Summary Coal liquefaction is an industrial process in which coal as raw material, through
the process to dissolve the coal and to transfer externally produced hydrogen to the coal molecules. Catalytic liquefaction resembles solvent extraction, except that hydrogen is added to the coal with the aid of a catalyst. Figure presents the flow diagram of a typical solvent extraction or catalytic liquefaction plant. These coal ...
The second way to utilize solvents for coal processing is the liquefaction process. A large variety of studies in the literature have investigated the liquefaction processes of diverse types of ...
Typical liquefaction process is performed at 400 °C for 60 min under 5 MPa H 2 (initial pressure) in 2:1 (solvent: coal) tetralin solvent with 5% FeS + S (an equimolar mixture of FeS and S) as catalyst. A detailed procedure of hydroliquefaction and separation can be seen elsewhere [31]. The AS and PA obtained by a batch liquefaction were ...
Library. Direct Liquefaction Processes. Reason for Discussion of Direct Liquefaction of Coal in Gasifipedia. As the following discussion of Direct Coal Liquefaction (DCL) explains, the fundamental process approach of DCL does not involve gasification at all. Therefore it would seem to be entirely out of scope of Gasifipedia.
The direct coal liquefaction process usually produces a coal liquefaction residue (CLR) of about 30% of its coal feed (Xu et al., 2014), and there is more than 80% organic matter in the CLR ...
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