An overview of China’s 10-year achievements in innovation in the coal chemical industry

Thread Content

An Overview of China’s 10 Years of Innovation in Coal Chemicals Author/Source: China Chemical Industry News Date: 2017-09-29 Clicks: 10 Over the past 10 years, China’s modern coal chemical industry has developed rapidly, achieving remarkable results; it leads the world in terms of technological innovation and industrial scale. A number of demonstration projects for modern coal chemical processing, such as those for converting coal into oil, olefins, and natural gas, have been built, resulting in a certain level of industrial development. At the 2017 (6th) China International Coal Chemical Industry Development Forum held in Yinchuan on September 27, Li Shousheng, President of the China Petroleum and Chemical Industry Federation, provided an overview of the technological innovations in modern coal chemical industry in China. 　　Coal gasification has repeatedly set operational records. Coal gasification is a key core technology for the clean and efficient utilization of coal, and it has always been a focus of innovation in coal chemical technology. Its development direction is toward larger-scale equipment, diversified raw materials, and near-zero emissions, with the goal of achieving long-term, efficient, and stable operation of the facilities. At present, China has seen the emergence of many large-scale, long-cycle international leading gasification technologies. 　 　　Units such as East China University of Science and Technology have jointly developed an ultra-large-scale multi-nozzle opposed water-coal slurry gasification technology capable of processing 3,000 tons of coal per day; this technology has been adopted by 11 companies in China, with 42 gasifiers currently under construction or in operation. This technology is the only coal slurry gasification method in the world today that enables a processing capacity of 3,000 tons of coal per day per furnace, providing solid technical support for the efficient and clean development of large-scale coal chemical industries in China. 　 　　The Space Changzheng Chemical Engineering Co., Ltd.-designed and manufactured space coal pulverized pressure gasifier with a daily coal processing capacity of 2,000 tons has set the longest operating record among existing industrial gasification units in the world; the continuous (Class A) operating record for a single such gasifier is 421 days. 　 　　In addition, Shenhua Ningmei Group, in collaboration with research institutions such as China Fifth Ring Engineering Corporation, independently developed a pressurized dry coal powder gasifier capable of processing 2,200 tons of coal per day (the Shenning furnace), which has been applied in a coal-to-oil project with an annual capacity of 4 million tons. All its technical parameters meet international advanced standards. 　 　　Coal liquefaction is moving toward higher efficiency and higher standards. Vigorously developing coal liquefaction technology is a strategic choice to advance the strategy of clean and efficient utilization of coal and to enhance energy security; currently, this technology is evolving in the direction of greater efficiency and higher quality. 　 　　For example, based on the characteristics of the product distribution resulting from direct coal liquefaction, Shenhua Group has focused on developing production technologies for ultra-clean gasoline and diesel, as well as special fuels such as military diesel, high-density aviation kerosene, and rocket kerosene. To date, tests of aircraft powered by directly liquefied coal-based fuels as well as tests of rocket engines using these fuels have been completed. 　 　　Based on a comprehensive analysis of the coal liquefaction process, Zhongke Synthetic Oil Technology Co., Ltd. proposed a staged coal liquefaction process that includes three core units: mild hydrogenation liquefaction, Fischer-Tropsch synthesis, and oil processing. This process overcomes the problems associated with traditional coal liquefaction technologies, such as stringent operating conditions, poor quality of the resulting oil, and low energy efficiency; it features mild operating conditions, a rich chemical structure of the oil produced, and significant energy-saving and emission-reduction effects. At present, this technology has passed pilot tests on a 10,000-ton scale, enabling the development of a complete set of coal fractionation liquefaction technologies that are at the international leading level. 　 　　According to the reporter, the low-temperature Fischer-Tropsch synthesis technology developed by Shanghai Yankuang Energy Technology R&D Co., Ltd. has been applied in the coal indirect liquefaction project of Shaanxi Future Energy Company. The industrial test facility for high-temperature Fischer-Tropsch synthesis technology is also under construction, providing support for the production of high-value chemical products. 　　 　New Pathways for Coal-to-Olefins Coal-to-olefins refers to the technology of using coal as a raw material to produce methanol, and then converting that methanol into olefins such as ethylene and propylene. Coal-to-olefins mainly involves two process routes, namely methanol-to-olefins (MTO) and methanol-to-propylene (MTP). These technologies are already mature and have been put into industrial use, but Chinese scientists continue to make new attempts and explorations. 　 　　Recently, the team led by Academician Bao Xinhe from the Institute of Catalysis, Chinese Academy of Sciences, has creatively developed catalysts featuring single-iron centers confined within silicide lattices, based on the new concept of \"nanolimited catalysis\". This approach enables the efficient one-step production of high-value chemicals such as ethylene and aromatics from methane under anaerobic conditions. This is a new technology that is “about to change the world,” yet another milestone-breaking innovation. 　 　　The Shanghai Advanced Institute of the Chinese Academy of Sciences has completed laboratory-scale validation of FTO catalysts for the direct production of olefins from coal via syngas in a slurry-bed process; the methane selectivity was below 5%, the total olefin selectivity exceeded 80%, and the olefin/alkane ratio was as high as over 8. Meanwhile, the carbon number of the products exhibited a highly selective distribution within a narrow range. Pilot-scale testing of this technology is about to begin. 　 　　The methanol-to-propylene (DMTP) fluidized-bed process developed by the Institute of Catalysis, Chinese Academy of Sciences, combines reactions such as methanol conversion and ethylene alkylation, resulting in a significantly improved selectivity for propylene. This process features advanced technology and performance metrics, and scale-up tests on a hundred-ton scale have already been completed. This process technology is original. 　Progress in coal-to-aromatics is rapid. As one of the five major modern approaches to coal chemical processing, coal-to-aromatics enjoys a highly positive outlook among industry professionals, and it is becoming another significant source of funding within the coal chemical industry. The core of coal-to-aromatics technology is the methanol-to-aromatics technology, and its upstream processes are essentially the same as those for coal-based olefins. 　 　　Notably, the team from Peking University/Shanxi Institute of Coal Chemistry, Chinese Academy of Sciences, and the team from Xiamen University, working in a \"back-to-back\" manner, achieved success in the direct conversion of syngas into aromatics almost simultaneously after succeeding in the direct conversion of syngas into olefins. By using novel functional catalysts, they achieved the high-selective and highly stable synthesis of aromatics (SMA) from syngas in a one-step process, with an aromatics selectivity as high as 80%. 　 　　In the area of olefin and aromatic compound co-production, the Institute of Catalysis, Chinese Academy of Sciences, has developed the DMTA fluidized-bed process for producing p-xylene from methanol and toluene; meanwhile, Shaanxi Coal Chemical Technology Engineering Center Co., Ltd. has developed a technology for producing p-xylene through selective alkylation of benzene and methanol, as well as a new technology for producing p-xylene from toluene and methanol while generating low-carbon olefins. Given the wide availability and low cost of raw materials such as methanol and toluene, as well as the fact that the resulting products like low-carbon olefins and p-xylene are bulk chemicals, China has a high degree of dependence on imports; therefore, these technologies hold great potential for application. 　 　　Coal-based ethanol has cost advantages. According to relevant plans, by 2020, ethanol gasoline for use in vehicles will be available throughout the country. In addition to biofuel ethanol, the coal-based ethanol industry in the coal chemical sector is also expected to benefit. At present, coal-based ethanol has a certain cost advantage over biomass ethanol. As the gap between the supply and demand of fuel ethanol continues to widen, innovations in coal-based ethanol technology are expected to open up new paths for its development, leading to rapid growth in the future. 　 　　The four coal-to-ethanol technologies currently under development at the Institute of Coal Chemistry, Chinese Academy of Sciences, are respectively in the stages of industrialization, industrial demonstration, pilot-scale industrial testing, and side-stream single-tube scale-up testing. Among these, the technology for producing isopropanol and ethanol through acetic acid-acrylate hydrogenation, developed in collaboration with Jiangsu Feixiang Chemical Group, saw an industrial-scale plant with a capacity of 300,000 tons per year built at Kailing (Zhangjiagang) Chemical Co., Ltd. in 2015; this plant was able to produce high-quality ethanol and isopropanol with a purity of over 99.9% ； The syngas-to-ethanol production process technology, developed in collaboration with Yanchang Petroleum Group, was used to build the world’s first industrial demonstration plant for syngas-to-ethanol production with an annual capacity of 100,000 tons at Yanchang Petroleum ； The acetic acid hydrogenation to ethanol technology developed in collaboration with Jiangsu Supor Group saw the construction of an industrial demonstration plant with a capacity of 30,000 tons per year for this process at Jiangsu Supor Group, which was brought online successfully on the first attempt ； The technology for producing methyl acetate via multiphase carbonylation of methanol, developed in collaboration with Shandong Lianmeng Chemical Co., Ltd., has demonstrated good operational stability through pilot-scale tests, thus completing the development of a new process for methanol multiphase carbonylation. 　 　　Resource recovery through pyrolysis of low-rank coal: Low-rank coal has a high volatil content and high reactivity; its direct use (for combustion or gasification) is inefficient, and its economic value is much lower than that of high-rank coal. It is necessary to process it to improve its quality before it can be utilized on a large scale. One of the most scientific and commonly used methods is pyrolysis, that is, dry distillation or thermal decomposition, and Chinese companies have recently made new breakthroughs in this area. 　 　　In response to issues such as low tar yield and difficulties in converting semi-coke in the utilization of coal technology at home and abroad, Yanchang Petroleum has independently developed the coal powder pyrolysis-gasification integrated technology (CCSI) by drawing on concepts from petrochemical engineering. CCSI carries out the pyrolysis and gasification of coal in a single reactor, with heat being shared between these processes to maximize the utilization of coal resources. To date, an industrial-scale test facility with a capacity of ten thousand tons has been built and is operating successfully. 　　 　The industrial trial of the dual-circulation rapid pyrolysis technology using gas-solid heat carriers for low-grade pulverized coal, carried out jointly by Shanghai Shengbang Chemical Technology Co., Ltd. and Shanbei Qianyuan Energy Chemical Co., Ltd., achieved rapid and efficient pyrolysis of low-grade pulverized coal, paving a new path for the pyrolysis of such coal. Positive results from the comprehensive utilization of CO2 Carbon dioxide (CO2) is well-known as a greenhouse gas, but in fact it is a resource that has been misunderstood and misjudged. In our country, there are also many institutions conducting research on the utilization of carbon dioxide. 　 　　The key technology for producing syngas through the autothermal reforming of methane and carbon dioxide, developed through a collaboration among the Shanghai Advanced Research Institute of the Chinese Academy of Sciences, Shanxi Lu’an Mining (Group) Co., Ltd., and the Dutch company Shell, has led to the construction of the world’s first industrial pilot plant capable of producing syngas at a rate of 10,000 standard cubic meters per hour through this process; this plant is currently operating stably, enabling the efficient utilization of carbon dioxide as a resource. 　 　　The Shanghai Institute of Advanced Technology, Chinese Academy of Sciences, in collaboration with Shanghai Huayi Group, has carried out research on the technology for producing methanol from carbon dioxide and hydrogen, and has achieved a complete and stable operation of the pilot-scale production process. The Shanghai Institute of Advanced Research, Chinese Academy of Sciences, has also carried out research on the direct synthesis of liquid fuels from carbon dioxide via hydrogenation. A new type of bifunctional catalyst was developed, enabling the direct and highly selective synthesis of gasoline hydrocarbon components from carbon dioxide for the first time; the selectivity for these gasoline hydrocarbon components could reach up to 81%, while the selectivity for methane was less than 1%. The relevant results were recently accepted for publication in the journal Nature Chemistry, and are considered a major breakthrough in the field of carbon dioxide conversion, providing an important platform for converting carbon dioxide into chemicals and fuels. 　 　　In addition, the Shanxi Institute of Coal Chemistry, Chinese Academy of Sciences, has completed industrial single-tube experiments on the conversion of carbon dioxide into methanol via hydrogenation, achieving stable operation, which marks a significant step forward in the industrialization of this technology.