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Comparing Direct and Indirect Liquefaction • In Direct Liquefaction (DL) pressure, heat and catalyst are used to crack the coal to make liquids 70-75% h • In Indirect Liquefaction (IL) coal is first gasified to form syngas. Syngas is then converted to liquids by means of a catalyst and Fischer Tropsch (FT) y H 2 CO 2H 2 O 60-65% approach L
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Coal can also be liquefied directly into liquid fuels through direct coal liquefaction (DCL) processes at around 450–500 °C under 15–30 MPa H 2 in a suitable …
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The key advantages of this process over the well-known direct liquefaction processes (Bergius, NEDOL, H-Coal, SRC-II, EDS, Shenhua process, etc.) are that the addition of a catalyst and a large ...
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Section snippets Materials. The CLR from a pilot plant for direct liquefaction of Shenhua coal in China was used as the carbon precursor. It was a thermoplastic carbon matrix with a softening point of about 193 °C, crushed and sieved to be particle of 150–250 μm before use.The proximate and ultimate analyses (Table 1), ash compositions (Table …
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With the increasing demand for energy and raw materials, the importance of effective utilization of low-rank coals has been emphasized. The utilization of low-rank coals in direct liquefaction is limited by their high oxygen and moisture contents because large amounts of hydrogen and energy are required for oxygen removal and drying, …
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Brown coal liquefaction technology is intended realize the liquefaction of brown coal of Victoria, Australia, with the object of utilizing it as an energy resource. Research and Development was started in 1981 with a 50 t/d pilot plant in Victoria province. Fig. 4.68 shows the process. The initial goals of the project, 50% liquid fuel yield (actual result was …
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The direct liquefaction process (Fig. 3) employs a coal ground to a fine powder, solvent, hydrogen, and catalyst employed at elevated pressures (1000–2500 psig) and temperatures (400–450°C).The solvent mixed with the coal forms a pumpable paste. Intimate contact between solid coal and solvent is easier to achieve than that between coal and gaseous …
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The main purposes in taking coal and biomass into a liquid is to produce liquids, to remove some of the less desirable components (i.e., sulfur, oxygen, nitrogen, …
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Direct coal liquefaction has been studied and practiced since the 1930s. It was used in Germany during World War II to produce synthetic fuels when there was no oil allowed into the country. Since then, it has been studied in the United States and many different technologies have been investigated. Since the US is rich in coal resources, …
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This study is devoted to demonstrating experimentally the advantages of direct coal liquefaction residue (DCLR) on improving the slurry ability of lignite through co-slurry and microwave co-pyrolysis. The results show that: as the lignite/DCLR mass ratio decreased from 10:0–5:5 the maximum solid concentration (MSC) of the mixed slurry ...
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Liquefaction can be direct, from the coal itself, or indirect, from synthesis gas (CO and H 2) obtained by gasification of the coal. Coal liquefaction incorporates both an increase in the H/C ratio and removal of heteroatoms (S, N, O) and inorganic oxides (ash). ... Sometimes there are advantages to processing coal simultaneously with other ...
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Indirect liquefaction processes require first gasifying the solid feedstocks into a syngas. Therefore, while direct coal liquefaction (DCL) takes coal directly into a liquid phase, indirect coal liquefaction (ICL) consists of two major steps: (a) gasification to produce a synthesis gas (syngas); and (b) conversion of the carbon monoxide (CO) and hydrogen …
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Compared with indirect coal liquefaction, direct coal liquefaction has higher efficiency and more product types, and it is a reductive pyrolysis process that converts coal directly to liquids (–CH 2 –) by reaction with hydrogen [1, 2]. The production process realizes the clean transformation and utilization of coal resources, and its …
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A mechanistic simulation of direct coal liquefaction was developed which utilizes the technique of Monte Carlo simulation for both: (1) the creation of a molecular coal structure and (2) modelling of its subsequent pyrolysis under liquefaction conditions. ... Investigators have studied model reactivi- ties of coal by exploiting the advantages ...
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In direct coal liquefaction, finely divided coal is mixed with a solvent and heated under pressure in a hydrogen atmosphere and in the presence of a catalyst. After separation from ash and unconverted coal, the resulting liquids are usually further refined to produce finished products. Indirect liquefaction is a two-step process.
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The lessons learned from the direct coal liquefaction work have been summarized as being technically feasible but the process for producing synthetic crudes is not economic . In summary, advantages of DCL include: High-octane gasoline is produced. More energy efficient than ICL. Products have a higher energy density than indirect …
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Intimate contact between solid coal and solvent is easier to achieve than that between coal and gaseous hydrogen; therefore, in addition to serving as vehicle and solvent, the coal …
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An advantage of coal liquefaction over gasification is the thermal efficiency of fuel production, with the former being 60–70% and the latter no higher than 55% (Research Reports International 2006). ... Direct coal liquefaction can be traced back to the work of the German chemist Friedrich Bergius, who, in approximately 1913, began studying ...
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Abstract. Direct coal liquefaction has been studied and practiced since the 1930s. It was used in Germany during World War II to produce synthetic fuels when there …
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A million-ton/year direct coal liquefaction (DCL) plant using Shenhua's subbituminous coal, which was built by Shenhua Group Co. since late 2008, has recently become operational and profitable in Inner Mongolia Autonomous Region of China, notably marking the beginning of a new stage of industrial DCL (Shui et al., 2010).
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Direct coal liquefaction (DCL): The conversion of coal to liquids via dissolution and/or hydroprocessing, without first gasifying the coal. DOE: United States Department of …
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Coal to Liquids Technologies. Table 2 Typical operating conditions for direct coal liquefaction. Full size table. For the most highly developed processes, coal conversion can be as high as 90% on a mineral ash free basis, with a C 5+ distillate yield up to 75% and hydrogen consumption of 5–7% wt.
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Direct coal liquefaction (DCL) technology is an important and effective way to convert coal into high-value-added chemicals and fuel oil [1], [2]. Due to high reaction temperature (such as 723 K) and hydrogen pressure (such as 19 MPa) [3], [4], the cost of energy and equipment in the traditional DCL process remains high, making it difficult to ...
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Direct coal liquefaction (DCL) could become a viable option to produce liquid fuels [1]; however, the high operational costs and the variable price of a barrel of oil make difficult its economic viability. ... [25], having as advantages over traditional supports the fact that they facilitate the recovery of the active phase, decrease the ...
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Direct coal liquefaction is a process in which the small molecules in coal pyrolysis are subjected to hydrogenation reactions to prepare high-performance liquid fuels (Shu et al. 1997; Shi 2012.;Qian et al. 2023) Since the solvent is pre-hydrogenated before entering the reactor, the amount of hydrogen dissolved in the liquefaction oil or solvent …
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This study is devoted to demonstrating experimentally the advantages of direct coal liquefaction residue (DCLR) on improving the slurry ability of lignite through co-slurry and microwave co-pyrolysis. The results show that: as the lignite/DCLR mass ratio decreased from 10:0–5:5 the maximum solid concentration (MSC) of the mixed slurry …
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Direct coal liquefaction in the system containing water and syngas or CO (DCLS) is an economical and effective method that can convert low-rank coals into fuels …
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Direct Liquefaction Benefits irect liquefaction efficiency may be higher than indirect technology. One ton of a high volatile bituinto hifor refinery upgrading and blending irect …
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This study is devoted to demonstrating experimentally the advantages of direct coal liquefaction residue (DCLR) on improving the slurry ability of lignite through co-slurry and microwave co-pyrolysis. The results show that: as the lignite/DCLR mass ratio decreased from 10:0–5:5 the maximum solid concentration (MSC) of the mixed slurry ...
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Coal-to-liquids (CTL) technology enables conversion of abundant coal into valuable liquid fuels such as gasoline, diesel, and jet fuel. Methods include indirect conversion (coal to …
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