Brothers on the Haichuan Forum, does that guy have any professional materials related to direct coal liquefaction that he can share? Looking forward eagerly!

It’s too general. If you explain it more clearly, maybe someone can help you. For example: what do you need it for, for research? Give a presentation? Write an article? Start a project? Working on design? ? ? ?

There’s so much information on this topic; I’m not sure what you’re looking for

Direct coal liquefaction is one of the clean coal technologies. As an effective technique for producing alternatives to oil, it holds great strategic and practical significance for addressing China’s oil shortage, balancing the energy structure, ensuring energy security, and promoting the sustained and stable development of the national economy. Direct coal liquefaction involves, under high temperature and pressure, the use of hydrogen-supplying solvents and catalysts to introduce hydrogen atoms into the molecular structure of coal and its derivatives, thereby converting coal into liquid fuel for transportation or chemical raw materials. Through direct coal liquefaction, it is possible to produce gasoline, diesel, liquefied petroleum gas, and jet fuel, as well as to extract BTX (a mixture of benzene, toluene, and xylene) and obtain raw materials for important olefins such as ethylene and propylene. In the direct coal liquefaction process, 99% of the sulfur in coal is recovered in the form of sulfur, making it an advanced technology for the utilization of clean coal. I. Current Development Status and Progress 1. Comparison with Indirect Liquefaction Technology Coal indirect liquefaction and direct liquefaction are two completely different technical approaches. Indirect liquefaction is a technology that first gasifies coal to produce syngas (CO+H2), and then uses this syngas, either directly or through methanol synthesis, to produce liquid fuel hydrocarbons. Indirect liquefaction has low requirements for the feed coal, and low-quality coal with high ash content can be utilized ； The process maturity and technical reliability are relatively high, with South Africa having nearly 50 years of experience in long-term production ； The post-processing of the product is relatively simple, but its thermal efficiency is lower than that of direct liquefaction ； The original Fischer-Tropsch synthesis reaction had poor selectivity, but technologies such as the Mobi1 methanol conversion method and improved Fischer-Tropsch synthesis developed later essentially solved this problem ； The octane number of the resulting gasoline is low, while the cetane number of diesel is high; the direct liquefaction method is the exact opposite. Our country has completed the fundamental research on coal direct liquefaction technology, laying a solid foundation for further process scaling up and industrial production. 2. Research and development progress: The first generation of coal direct liquefaction technology in the 1930s – the direct hydrogenation coal liquefaction process – was industrialized in Germany. However, the coal liquefaction conditions at that time were quite stringent, with a reaction temperature of 470°C and a reaction pressure of 70 MPa. The 1973 world oil crisis led to a renewed focus on the research and development of new processes for direct coal liquefaction. Most of the research efforts focus on alleviating the reaction conditions, that is, reducing the reaction pressure, in order to lower the production cost of coal liquefied oil. With the development of catalysts, hydrogen-supplying solvents, and technologies for their heavyfaction and solid-liquid separation, various second-generation coal direct liquefaction processes have been developed, such as the Hydrogen-Coal process (H-Coa1) in the United States, the Solvent-Refined Coal processes (SRC-I, SRC-II), the Energy-Dense Solvent process (EDS), as well as the new German process developed in West Germany. All of these processes have undergone large-scale pilot tests, and the technical requirements for building factories are met; however, due to high investment costs and elevated production costs for coal liquefied oil, they have not yet been put into industrial use. The common drawback of the second-generation direct coal liquefaction process is that, due to poor reaction selectivity, there is a large amount of gaseous hydrocarbons and high hydrogen consumption, resulting in high costs ； Although solid-liquid separation technology has seen improvements, it has not yet been fundamentally resolved ； The catalysts are not ideal: iron catalysts lack sufficient activity, while drill-molybdenum catalysts are expensive. To further improve and refine coal direct liquefaction technology, reduce the cost of liquefied oil, and enhance the economic viability of the process, several major industrial countries around the world are continuing to research and develop new third-generation coal direct liquefaction processes. These new liquefaction processes feature mild reaction conditions, high oil yield, and relatively low oil prices. The main reason for the lack of coal direct liquefaction plants at present is considered to be economic factors rather than technical ones. II. Several Advanced Processes The most representative and advanced coal direct liquefaction processes currently available in the world include the two-stage catalytic liquefaction processes developed by IGOR (Integrated Gross Oil Refine) in Germany and HTI (Hydrocarbon Technology Inc.) in the United States. 1. The German IGOR process: In the early 1990s, the German Company for Mining and Metallurgical Research and Testing (DMT) improved the original German process, developing the more advanced IGOR process. Research and development tests on the IGOR process technology were carried out on a 0.2 t/d PDU and a 200 t/d pilot plant, with a reaction pressure of 30 MPa; the raw coal used was high-volatility bituminous coal from the Ruhr region. Red mud is used as a catalyst in the coal conversion process, while a commercial catalyst Ni-MO-Al2O3 is employed in the fixed-bed hydrorefining reactor. The IGOR process integrates cyclic solvent hydrogenation and liquefied oil upgrading with direct coal liquefaction within a single high-pressure system; as a result of this improvement, the total investment in the liquefaction plant can be reduced by about 20% ； The IGOR process has the highest coal processing capacity (the space velocity of other coal direct liquefaction reactors is 0.24–0.36 tm3•h, whereas that of the coal liquefaction reactor in the IGOR process is 5 t/m3•h) ； The N and S contents in the coal liquefied oil produced by the IGOR coal liquefaction process have been reduced to the 10-5 order of magnitude; the coal liquefied oil not only features high yield but also excellent quality ； It reduces the number of process steps and equipment, the amount of circulating oil, the generation of gaseous hydrocarbons, and the volume of wastewater to be treated. 2. Two-stage catalytic process: As early as the early 1960s, the American company HTI developed a hydrogen-coal process for the catalytic hydrogenation liquefaction of coal, based on the petroleum residue hydrocracking process (hydrogen-oil method). They also designed a coal liquefaction plant with a capacity of 5,000 tons per day. Since 1980, HTI has focused its efforts on improving the economic viability of the direct coal liquefaction process; in 1983, it developed a two-stage liquefaction technology that involves thermal melting of coal in the first stage and catalytic hydrogenation in the second stage ； Conduct the thermolysis and catalytic hydrocracking reactions, which have different reaction properties, under different reactor and process conditions ； Further research later found that carrying out moderate hydrogenation simultaneously during the coal thermal liquefaction process was superior to performing thermal liquefaction followed by hydrogenation; in 1985, an advanced catalytic two-stage liquefaction process was developed. Subsequently, with funding from the U.S. Department of Energy, HTI conducted extensive research and improvements on the catalytic two-stage liquefaction process, switching from a light oil cycle to a heavy oil cycle, which led to significant advancements and improvements in the technology and economics of direct coal liquefaction. In 1988, based on the liquefaction test results using this process in a 2t/d PDU unit, as well as the experience gained from hydrogen-coal pilot plants and commercial plant designs, HTI Company developed the technology for catalytic two-stage liquefaction and prepared a preliminary design for a coal liquefaction plant. The main technical features of HTI’s catalytic two-stage liquefaction process are as follows: both the first and second stages of coal liquefaction utilize bubbling-bed reactors equipped with highly active hydrogenation and hydrocracking catalysts (Ni, MO, or Co, Mo). These two reactors are separate yet closely connected, allowing the hydrocracking and catalytic hydrogenation reactions to take place under their optimal conditions respectively. The liquefied product is first quenched with hydrogen; the heavy oil is recovered as a solvent, and the solid waste discharged consists mainly of unreacted coal and ash. Compared with the hydrogen-coal process, the C4 402°C distillate increases by 53%, and the amount of distillate produced from liquefied anhydrous ash-free coal (daf) rises from 3.3 barrels to 5.0 barrels ； The yield of C1–C3 gaseous hydrocarbons decreased from 11.3% to 8.6%, while the hydrogen utilization rate increased from 8.4% to 10.7% ； The quality of the oil products has improved, with nitrogen and sulfur heteroatoms reduced by 50%, thereby significantly enhancing the economic viability of coal liquefaction; the cost of the liquefied oil has been reduced by 17%. In addition, there is also the Japanese NFDOL process, and the American kerosene co-processing process COP (CoAl CoProcessing), among others. 5. Domestic research status: China resumed research on direct coal liquefaction technology in 1980, with the aim of producing transportation fuels such as gasoline and diesel, as well as chemical raw materials like aromatics from coal. This research is primarily carried out by the Beijing Institute of Coal Chemistry under the China Coal Research Institute. After nearly 20 years of effort, laboratories for direct coal liquefaction, oil product upgrading processing, and analysis and testing at an advanced level have been established ； Through direct coal liquefaction tests on hundreds of coal varieties in China, 15 coal types suitable for liquefaction were identified, with a liquefaction oil yield of over 50%; in addition, process conditions for the direct liquefaction of 4 coal types were studied ； Highly active catalysts for direct coal liquefaction have been developed ； Using domestically produced hydrogenation catalysts, research was conducted on the upgrading of coal liquefied oil. Through a combination of processes such as hydrogenation refining, hydrocracking, and reforming, coal liquefied oil was successfully transformed into high-quality gasoline, diesel, and aviation fuel. In June 1997, direct coal liquefaction tests were conducted on Yunnan Xianfeng lignite using the 200 kg/d PDU unit of DMI’s IGOR process in Germany. The results showed that Xianfeng lignite is a suitable coal type for the IGOR coal liquefaction process; the oil yield obtained was 53%, with nitrogen and sulfur contents in the oil being 2 mg/kg and 17 mg/kg respectively. Coal liquefied oil can be converted into qualified 0# diesel through simple distillation, and into qualified 90# lead-free gasoline through reforming. In March 1997, the China Coal Research Institute formally signed an agreement with German companies RUR and DMT regarding a feasibility study project for the Yunnan Pioneer coal liquefaction plant; the Second Design Institute of the former Ministry of Chemical Industry participated in some of the work. Through the joint efforts of China and Germany, the feasibility study report for the Yunnan Coal Liquefaction Plant was completed in April 1999. The proposed Yunnan Pioneer coal liquefaction plant is designed to process 2.57 million tons of lignite per year for liquefaction, and it will use 2.53 million tons of bituminous coal for gasification to produce hydrogen (with power generation of 170,000 kW); in total, 5.1 million tons of bituminous coal will be used ； Once completed, the liquefaction plant will produce 353,400 tons of gasoline per year, 530,400 tons of diesel, 67,500 tons of liquefied petroleum gas, 39,000 tons of ammonia, 25,300 tons of sulfur, and 8,800 tons of benzene. In addition, China and the United States also conducted a feasibility study on Shenhua’s coal liquefaction project. Shenhua Group Co., Ltd. has also held consultations with the New Energy and Industrial Technology Development Organization of Japan (NEDO) regarding coal liquefaction projects, and an agreement has been reached. In summary, advanced direct coal liquefaction processes such as Germany’s IGOR process, the two-stage catalytic liquefaction process in the United States, the kerosene co-processing process in the United States, and Japan’s NEDOL process have made significant progress in terms of technical efficiency and economic viability. The development direction of direct coal liquefaction technology is to reduce reaction pressure, increase the yield and quality of coal liquefied oil, lower the hydrogen efficiency to further improve its technical and economic viability, and produce various transport fuel oils. As a measure to ensure energy security in our country, producing liquid fuels from coal, which is an abundant resource, through direct liquefaction is not only technically feasible but also offers good economic benefits.