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The first time a catalyst was used in the industry was in 1746 by J. Roebuck in the manufacture of lead chamber sulfuric acid. Since then catalysts have been in use in a large portion of the chemical industry. In the start only pure components were used as catalysts, but after the year 1900 multicomponent catalysts were studied and are now commonly used in the industry.〔Leach, Bruce. E.,(1983) Industrial Catalysis: Chemistry applied to your life-style and environment, In ''Applied industrial catalysis'', vol 1, New York,Academic press, Inc.〕〔Jacobs, G., Davis, B. H.,(2007) Low temperature water-gas shift catalysts, In ''Catalysis'', vol 20, Spivey, J.J and Dooley, K.M (Ed), Cambridge, The royal society of chemistry〕 In the chemical industry and industrial research, catalysis play an important role. Different catalysts are in constant development to fulfill economic, political and environmental demands. When using a catalyst it is possible to replace a polluting chemical reaction with a more environmentally friendly alternative. Today, and in the future, this can be vital for the chemical industry. In addition it’s important for a company/researcher to pay attention to market development. If a company’s catalyst is not continually improved, another company can make progress in research on that particular catalyst and gain market share. For a company, a new and improved catalyst can be a huge advantage for a competitive manufacturing cost. It’s extremely expensive for a company to shut down the plant because of an error in the catalyst, so the correct selection of a catalyst or a new improvement can be key to industrial success. To achieve the best understanding and development of a catalyst it is important that different special fields work together. These fields can be: organic chemistry, analytic chemistry, inorganic chemistry, chemical engineers and surface chemistry. The economics must also be taken into account. One of the issues that must be considered is if the company should use money on doing the catalyst research themselves or buy the technology from someone else. As the analytical tools are becoming more advanced, the catalysts used in the industry are improving. One example of an improvement can be to develop a catalyst with a longer lifetime than the previous version. Some of the advantages an improved catalyst gives, that affects people’s lives, are: cheaper and more effective fuel, new drugs and medications and new polymers. Some of the large chemical processes that use catalysis today are the production of methanol and ammonia. Both methanol and ammonia synthesis take advantage of the water-gas shift reaction and heterogeneous catalysis, while other chemical industries use homogenous catalysis. If the catalyst exists in the same phase as the reactants it is said to be homogenous; otherwise it is heterogeneous. == Water gas shift reaction == The water gas shift reaction was first used industrially at the beginning of the 20th century. Today the WGS reaction is used primarily to produce hydrogen that can be used for further production of methanol and ammonia.〔Ruettinger, Wolfgang. & Ilinich, Oleg. (2006), Water gas shift reaction, Encyclopedia of chemical processing, Vol 5, Taylor & Francis, 3205-3214〕 WGS reaction: :(1) CO + H2O ↔ H2 + CO2 The reaction refers to carbon monoxide (CO) that reacts with water (H2O) to form carbon dioxide (CO2) and hydrogen (H2). The reaction is exothermic with ΔH= -41.1 kJ/mol and have an adiabatic temperature rise of 8–10 °C per percent CO converted to CO2 and H2. The most common catalysts used in the water-gas shift reaction are the high temperature shift (HTS) catalyst and the low temperature shift (LTS) catalyst. The HTS catalyst consists of iron oxide stabilized by chromium oxide, while the LTS catalyst is based on copper. The main purpose of the LTS catalyst is to reduce CO content in the reformate which is especially important in the ammonia production for high yield of H2. Both catalysts are necessary for thermal stability, since using the LTS reactor alone increases exit-stream temperatures to unacceptable levels. The equilibrium constant for the reaction is given as: :(2) Kp=(pH2 x pCO2)/ (pCO x pH2O) : (3) Kp=e((4577.8K/T-4.22)) Low temperatures will therefore shift the reaction to the right, and more products will be produced. The equilibrium constant is extremely dependent on the reaction temperature, for example is the Kp equal to 228 at 200 °C, but only 11.8 at 400 °C.〔 The WGS reaction can be performed both homogenously and heterogeneously, but only the heterogeneously way is used commercially. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Industrial catalysts」の詳細全文を読む スポンサード リンク
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