Aqueous-phase FTO process for green coal-to-oil production

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This post was last edited by jordan569 on 2013-1-6 at 23:24. Our country’s paper titled \"Aqueous Fischer-Tropsch Reaction Using Nanoruthenium Catalysts\" has attracted widespread attention in the international academic community, and many chemical industry giants have also shown great interest in it. The Royal Society of Chemistry’s journal, Chemical World, also reviewed this achievement under the title “Clean and Green Ferroformylation in Aqueous Media,” stating that “Chinese scientists have for the first time achieved ferroformylation in an aqueous medium, which represents a major step forward in the transition toward green production of hydrocarbon fuels.” Apart from the preparation of fine chemicals through organic synthesis, this is the first time that a water-phase reaction has been achieved in a major industrial process. 　　The School of Chemistry and Molecular Engineering at Peking University, which is working on this project, states that coal-to-oil conversion is an important option for addressing the depletion of oil resources. The products of Fischer-Tropsch synthesis represent potential alternatives to oil, and the new method for aqueous-phase Fischer-Tropsch synthesis achieves what green chemistry advocates: the use of an aqueous medium, reactions at low temperatures, and products that are not contaminated by catalysts. 　　Fischer-Tropsch synthesis uses syngas (primarily carbon monoxide and hydrogen) as a raw material to produce liquid fuels mainly composed of straight-chain hydrocarbons, under the action of catalysts; the performance characteristics of the resulting products are similar to those of petroleum-based fuels. After its invention in 1923, the Fischer-Tropsch synthesis was first industrialized in Germany in 1936; however, after World War II, production facilities were shut down due to the inability to compete with cheap oil from the Middle East. In the 1950s, due to an international energy embargo, South Africa began to utilize coal resources to produce synthetic oil with **’s strong support; Sasol became the only company in the world to industrialize coal indirect liquefaction technology through the Fischer-Tropsch reaction. 　　Due to the increasing volume of oil imports in our country, coupled with rising international oil prices, the coal-to-oil industry has become highly attractive. At present, a series of domestic research efforts and demonstration projects aimed at replacing oil with coal have already begun. Coal-rich provinces have expressed a strong desire to develop coal chemical industries, and they are reaching out to foreign energy giants that possess core technologies for clean coal utilization. What concerns industry professionals is that most of the original patents related to the Fertro process are in the hands of countries in Europe and the United States. Foreign energy giants, thanks to their core technologies, have deeply penetrated China’s industrial sector, creating significant technical barriers for the development of China’s coal chemical industry. Therefore, the development of original and innovative new water-based Fischer-Tropsch synthesis methods represents a new approach that enables China to gain independent control over coal-to-oil technology from the outset and break free from the constraints imposed by European and American patents in terms of intellectual property, which is why it attracts much attention. 　　Overall, the Fischer-Tropsch reaction has not progressed rapidly over the past 80 years, with no significant advances in catalyst improvement. In Europe and the United States, the traditional Fischer-Tropsch reaction employed relies on iron- or cobalt-based catalysts, using activated carbon, silica, and similar substances as carriers; the reaction takes place in a wax medium at temperatures between 240°C and 260°C (the low-temperature Fischer-Tropsch reaction developed by Sasol operates at around 220°C). This approach results in low reaction efficiency, numerous operational steps, a complex product composition, and difficulties in separating the products from the catalysts. This has created great opportunities for basic research in the Fischer-Tropsch synthesis. To this end, new methods for Fischer-Tropsch synthesis have also led to a rethinking of the concept of catalysts. 　　Focusing on research in low-temperature, aqueous environments, a research team from the School of Chemistry and Molecular Engineering at Peking University started with the Fischer-Tropsch reaction in ionic liquids, and in 2005 developed ultra-long-lasting nanoscale Fischer-Tropsch catalysts that remained active at 150°C. Later, the research team came up with a completely new idea of carrying out the reaction in water bodies, and achieved success two years later. The new approach proposed by this research achievement offers a new direction for the future industrial development of Fischer-Tropsch synthesis. As a key technology for the major industrial process of coal-to-oil via indirect liquefaction, once the new Fischer-Tropsch synthesis technology is scaled up for industrial use, it is entirely possible that it will replace the entire existing industrial Fischer-Tropsch synthesis system. 　　The new Fischer-Tropsch synthesis method proposed by this research group involves using ruthenium cluster metal catalysts with a particle size of about 2 nanometers to carry out Fischer-Tropsch reactions in an aqueous medium, under the protection of water-soluble polyvinylpyrrolidone. Compared to traditional Fischer-Tropsch catalysts that require temperatures of at least 220°C to function, the new catalyst exhibits a 16-fold increase in catalytic activity at 100°C, which is equivalent to the activity of traditional catalysts at 200°C ； At 150°C, its activity is 35 times that of conventional catalysts. The improvement in catalyst activity has made low-temperature Fischer-Tropsch reactions feasible. At the same time, reducing the reaction temperature lowers the energy consumption for the reaction, and the economic efficiency of the reaction is also significantly improved. Furthermore, the oil and water phases separate automatically, so the resulting liquid fuel is not contaminated by the catalyst. However, ruthenium catalysts are still too expensive for use in industrial production. The next goals will be to find ways to use cheaper catalysts such as iron, cobalt, and nickel in new FTO synthesis methods, as well as to modify the catalysts in order to alter the product distribution and increase the proportion of high-value products like olefins. 　 . Note $ # , $ $