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Chemical synthesis gas


Author:CECC CreateTime:2014-02-20 Hits:

Currently most of the methane chemical synthesis of other chemical products through indirect methods of synthesis gas , but in addition to the synthesis gas from methane ( natural gas ) production, but also through the coal , residual oil , biomass gasification and other production . Natural gas shortages and price increases , which have resulted in the synthesis gas production more towards reliance on coal feedstock , and the need to protect the environment and sustainable development, and production of synthesis gas from biomass gasification have been more and more attention.


First, ammonia and hydrogen from coal


In promoting the economic and environmental multiple factors , coal gasification hydrogen and ammonia thus increasing system occupies an important position. China is rich in coal and less gas energy structure , so that the production of hydrogen have more rely on coal. Currently about 80% of ammonia coal as feedstock. Required , there are many other areas of hydrogen from coal-based routes, such as the law required Shenhua direct coal liquefaction unit large amount of hydrogen that is produced by coal gasification .


Environmentally harmful gases of coal-fired power plants present , emit large quantities of carbon dioxide , hydrogen power has been considered for replacement . Many countries are implementing "green coal" development strategy, gasification -based hydrogen production and hydrogen power , carbon dioxide separation and processing, the coal power generation to meet the requirements of sustainable development. Compared with existing coal-fired power generation , coal and hydrogen production technology can achieve higher power generation efficiency , including carbon dioxide to achieve near zero emission of pollutants , which is the existing coal-fired technology can not achieve. However , the development of the true meaning of "green coal" , there is still a long way to go .


The key is hydrogen from coal gasification technology , currently still rely mainly imported from abroad. In recent years, the domestic research and development of coal gasification technology has also made a lot of results , narrowing the gap with foreign advanced technology .


Synthesis gas is hydrogen through water gas shift reaction , so the development of high-performance conversion catalyst is also very important. Ohio State University has developed a non-toxic metal Cr high temperature hydrogen conversion catalyst , can greatly enhance the hydrogen yield. The test results showed that the catalyst compared with the conventional commercial catalyst , the hydrogen conversion rate is increased by 25 %. Although the development of China's shift catalyst has made considerable achievements , there is still the need to further improve .


Second, coal and biomass synthetic


Synthetic coal (CTL), synthetic biomass (BTL) and GTL (GTL) together , is considered the most promising energy alternative to oil for transport in the future.


Gasification reaction by FT synthetic oil has a long history of production abroad , the technology is mature , existing in South Africa, nearly 42 million tons coal , synthetic oil plant to produce synthetic oil of about 500 million tons and 2 million tons of chemicals. On the technical side , the South African company SASOL experienced fixed bed technology ( 1950 to 1980 ) , circulating fluidized bed ( 1970 to 1990 ) , a fixed fluidized bed ( 1990 ) , slurry ( 1993 - ) 4 stages. In recent years, many domestic unit plans to introduce technology to build large-scale production plant. Our self-developed technology has also made great progress in recent years , have been completed and the design of synthetic products capacity of 1,000 tons / year, 10,000 tons / year of low-temperature synthetic slurry bed ( indirect liquefaction ) pilot plant , and long cycle test run , completed the development of iron-based catalyst support , completed the 100,000 tons / year, 1 million tons / year demonstration plant technology package design and engineering studies . April 6, 2007 , 160,000 tons / year of synthetic devices has officially started construction in Shanxi Luan plans July 31, 2008 the official output of qualified products. Low slurry bed can be about 70% synthetic diesel cetane number above 70 , the other products are LPG ( about 5% to 10% ) , oxygen-containing compounds. Indirect coal liquefaction technology has a wide coal adaptability , process conditions relative ease , you can adjust the product structure by changing the production process conditions , or in the main engine fuel , or chemical -based, and therefore will be the future of coal liquefaction the main way to industrial development.


BTL (Biomass-to-liquid) based on biomass as raw materials to produce synthetic oil , is a second-generation biofuels. The main raw material for the production of BTL synthesis gas can be obtained from a variety of biomass. Compared with the natural gas or synthetic fuel from coal preparation , the unique advantages of BTL is lower carbon dioxide emissions because the carbon dioxide absorbed during the growth of biomass process, most of which can be offset by the carbon dioxide emissions from the combustion process . BTL either as an additive to be used as clean fuel for use in diesel engines. Liquid fuels with biomass renewable and environmentally friendly features , so it is valued by more and more countries .


German Choren is synthetic diesel and coal- biomass conversion pioneer indirect synthetic production areas in the world , Choren in biological waste into diesel are high efficiency and high quality . Its patented Carbo-V gasification technology , namely the plant and animal waste into syngas , a leading position in the world . Choren company plans to invest 500 million euros with an annual output of nearly one million tonnes of BTL production line in Germany, is currently siting stage. Choren has and Shell ( Shell ) , Daimler - in close cooperation Chrysler, Volkswagen and other companies to promote the program smoothly. Choren in Freiberg, Germany has built an annual output of 15,000 tons of BTL production base , is expected to go into production in autumn 2007 . According Choren data , five tons of biomass fuels can produce one ton per hectare of land produces four tons of biomass can be prepared BTL fuels.


Third, coal and biomass synthesis of methanol


Foreign methanol from natural gas production is mainly due to rising gas prices and expanding methanol demand has led to an increase in the attractiveness of coal methanol , especially in our current rapid development of coal-based methanol , coal-based methanol in our country up to about 75%.


Concern for environmental protection , making the use of biomass to syngas to produce methanol can be taken seriously. The Netherlands and Belgium jointly acquired a methanol plant is located in the northeast of the Netherlands Del Fox Harbour , ready to be transformed into the world's first bio- methanol plant . Investors to Bio Methanol Chemie Holding Company . The plant raw natural gas as raw material, has been discontinued because of gas prices . Initial production of bio- methanol is expected to be 100 000 t, the latter will grow tenfold to reach millions of tons of production. " The plant will use a new high- technology , bio- methanol extract from glycerol. Glycerin is a byproduct of biodiesel is extracted from oil plants green alternative renewable fuels due to rising global biodiesel production , glycerin prices have plummeted.


Fourth, coal and biomass synthesis of DME


Coal and biomass synthesis of dimethyl ether , dimethyl ether, methanol synthesis is available via the two-step method , can also be obtained from coal or biomass syngas step synthesis . Two-step method is now widely used in the production process . Although the one-step technique currently used in industry was still small , but there are many advantages in his own home and abroad have carried out extensive research and has developed a technology for mass production and use .


Coal-based DME DME is the main direction of development of production coming period .


Fifth, mixed alcohols synthesis


Mixed alcohols is the mixture of alcohols of C1 ~ C6 . From the performance, mixed alcohols is a good gasoline additive , it has a high octane blending well with good performance gasoline , can replace MTBE as a gasoline additive. Starting from the coal mixed alcohol synthesis via Syngas is an important area C1 chemical technology development. Therefore, the positive development of coal- based synthetic mixed alcohols technology not only has important significance. In addition to mixed alcohols used as a gasoline additive , but also can be isolated lower alcohols of various chemical applications.


Mixed alcohols is currently no large-scale production plant , but at home and abroad have been conducted fairly in-depth study of the extent of the current domestic enterprises are also plans to build a large industrial installations .


Six synthetic ethanol


Synthesis gas to ethanol is also a subject of chemical research C1 , at home and abroad have developed a pilot to reach the degree of technology.


In recent years, the rapid development of ethanol fuel , again attracted the attention of the technology . There predict biomass gasification synthetic ethanol may be one of the key processes of ethanol fuel production . U.S. Department of Energy recently announced $ 385 million appropriation funded projects related to the development of six ethanol fuel , in order to promote non- conventional energy materials such as wood chips , switchgrass and citrus peels such as the production of ethanol fuel , of which three projects with the use of coal gasification industry techniques. Energy expert interpretation , said the move showed that the government attaches great importance gasification technology in the renewable energy field. Many scientists believe that , compared with the current fuel ethanol fermentation process , gasification technology will be able to provide a more efficient, more economical and more environmentally-friendly technology, but also for a variety of renewable fuel production . On the one hand , helps to reduce the cost of gasification of the fermentation process , the fermentation process to solve the problem of biological materials can not release the starch present in the fermentation process requires more expensive reactor to solve this problem . On the other hand , the synthesis gas produced by the gasification process can easily be directly converted into other fuels, chemicals and materials . In addition, long-term coal gasification technology industry applications show that it is also environmentally friendly technologies. The U.S. Department of Energy is more interested in gasification technology can solve the current over-reliance on the U.S. corn to produce ethanol fuel problems, expanding biofuel variety of sources other than corn . Application of gasification technology in the renewable energy sector has shown good feasibility . In 2001, an American with sawdust as raw material to produce ethanol fuel plants , Nissan already has the ability to 200 megawatts of electricity. However, in order to promote the competitiveness of the gasification process , which also need to increase the optimization of the catalyst to better technology to reduce production costs .


Seven synthetic olefin


Syngas can be prepared by reaction of olefins is C1 chemical in a challenging task , due to the product distributed by Andorson-Sohulz-Flory law ( depending on the number of batches descending chain molar distribution ) limits , you want a high selectivity olefins have been quite difficult .


Shenyang Branch of Chinese Academy of Sciences has developed a new K-Fe-MnO Si-2 zeolite catalysts supported to improve dispersion and stability of the metal catalyst active component ; developed in a salt bath heated to molten salt as the heat carrier and tube single-tube reactor expand experimental device, to control the heat and the strong reaction runaway phenomenon bed , bed control the reaction temperature, single-tube to expand the experiment to ensure the successful completion of research studies ; resolved catalyst reaction amplification and scale up problems, catalyst preparation good reproducibility, good stability properties of the reaction , to the CO conversion rate> 70% , the olefin selectivity is greater than 70% , space time yield of light olefins was 0.114 ~ 0.12g/g-cat · h., expanding the tube in a single experimental One-way continuous operation life over 1000h. Reaction pressure often carried out with the process is simple , easy to industrial operations , investment advantages.


In the process of FT synthetic oil , a cobalt -based catalyst , the ratio can be made relatively high value of C4 ~ C20 α- olefins.


Eight , OXO synthesis


Olefin and synthesis gas (CO + H2) can be synthesized by reaction of the aldehyde product number , which can be synthesized by hydrogenation of the corresponding alcohols . The reaction has been widely applied in the industrial synthesis of propionaldehyde , butyraldehyde and butyl , and octyl .


An important application of the recent reaction of ethylene oxide and synthesis gas based raw materials for the production of 1,3 - propanediol , 1,3 - propanediol as raw PTT polyester , excellent performance , is considered very promising .


Nine , synthetic natural gas


Coal via synthesis gas into synthetic natural gas is a long- technology industrial applications , in 1978 , the United States ' Great Plains Coal Gasification Association, " the joint several companies began to build the world's first synthetic natural gas plant , put into operation in 1984 , but long-term since a loss due to low natural gas prices , making it Arrested Development . With the pressure on natural gas prices increased significantly and reduce emissions of carbon dioxide , this technique again attracted attention.


North Dakota coal gasification plant in Beulah , 18,000 tons of lignite per day will be converted into 4.8 million m3 of synthetic natural gas . Although current technology , economy, synthetic natural gas can not compete with natural gas, but since the construction of the plant in September 2000 after the sale of a carbon dioxide pipeline to Canada for oil exploration , not only so that the plant profitability, and also allow the plant to get rid of the carbon dioxide emissions of coal gasification plant pollutant burden.


Topsoe has recently re- launched its TREMPTM coal gas technology projects , the technology through a patented catalyst coal or biomass gasification system of synthetic gas into pipeline quality natural gas. The technology has been selected Jefferson County, Illinois, United States Power Holdings Company gasification plant , with a total investment of 10 billion U.S. dollars, 4 million t of coal per year will be converted to pipeline quality natural gas. The last five years the United States has doubled gas prices , which are making from coal or biomass synthesis gas technology economically attractive .


DOE is implementing a 10-year period, known as the " future of coal power generation plan " (FutureGen). This envisages the use of coal synthesis gas, and then stores the generated carbon dioxide into the ground , so both the coal power stations , but also to achieve the goal of zero emissions.


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