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| Nippon Kasei Chemical Co., Ltd. |
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| December 2005 |
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| A new engine exhausts treatment system provides the answer to the world's most stringent NOx standards |
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| In October 2005, the "New Long-term Diesel Exhaust Emission Standards" were put into effect. Nippon Kasei's high-grade aqueous urea solution, AdBlue is used in a urea-SCR (selective catalytic reduction) system that provides a timely response to the new regulations. Let us take a closer look at this state-of-the-art product in the field of environment protection that is drawing increasingly greater attention. |
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| What is a urea-SCR system? |
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Nippon Kasei's high-grade aqueous urea solution AdBlue and the urea-SCR system in which AdBlue is used are the focus of increasingly greater attention as a solution to reducing the amount of NOx (nitrogen oxides) contained in the exhaust fumes produced by diesel engine vehicles.
NOx is the collective name for nitrogen monoxide (NO) and nitrogen dioxide (NO2); NO is generated during the process of combustion of fuel light oil in a diesel engine, and NO2 is produced by oxidation in the atmosphere of the NO. NO2, in particular, is known to cause respiratory diseases and has increasingly been the subject of stepped up regulations.
In October 2005, the New Long-term Diesel Exhaust Emission Standards were put into effect in Japan, representing the world's most rigorous regulations. The standards provide for an 85% reduction of PM (particulate matters) in diesel engine exhaust fumes from the previous control level and a 40% cut in the amount of NOx emitted. The urea-SCR system has been developed in response to the tightened regulations. Nissan Diesel Motor Co., Ltd. has adopted this system in its ultra-low emission diesel trucks.
In principle, PM emissions can be lowered by high temperature combustion, whilst low temperature combustion is required to reduce NOx emission. It is therefore very difficult to reduce PM and NOx at the same time. By the use of the urea-SCR system, fuel light oil is injected into the engine at high pressure to permit high temperature combustion to minimize PM generation, and then aqueous urea solution is sprayed to the exhaust fumes to cause the decomposition (emission reduction) of NOx by chemical reaction.
NOx has been known to decompose into non-toxic water and nitrogen when reacted with ammonia in the presence of a certain catalyst. But ammonia is classified as a toxic and dangerous substance and could not be easily put as such into vehicles. This is why aqueous urea solution has drawn so much attention, because it decomposes into ammonia by the addition of heat. Aqueous urea solution is widely used in cosmetics and pharmaceuticals, and is safe and easy to handle. Thus, these advantages led to the development of the urea-SCR system. (See the above diagram.)
There is a similar emissions reduction system known as the 'EGR+DPF' method, but the urea-SCR system has the advantage of achieving over 10% improvement in fuel consumption and reduced CO2 emissions, thanks to the high combustion temperature of the fuel.
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The stable supply of high quality product is the mission of the Kurosaki Plant. |
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R&D team analyzing samples at Kurosaki Plant. |
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Product loading at Onahama Plant. It is shipped out in plastics pales, drums, containers or tank trucks, depending on customer requirements. |
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| What is the history of development? |
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Dissolution tank in production plant of high grade aqueous urea solution AdBlue. |
AdBlue is a high-grade aqueous urea solution for exclusive use in the urea-SCR system that has been developed and standardized in Europe. The door to this highly promising market was opened for Nippon Kasei when Mitsubishi Chemical Corporation joined the 'Advanced Clean Energy Vehicle Project' of New Energy and Industrial Technology Development Organization (NEDO), along with the Japan Automobile Research Institute and four Japanese automotive manufacturers, and others. Subsequently, in view of the increased pressure for tighter emissions reduction as described above, the decision was taken to conduct aggressive research and development of aqueous urea solution for the enhancement of the automotive market, capitalizing on the profound expertise and know-how on urea that the Mitsubishi Chemical Group has accumulated over many years. Today, Nippon Kasei is the market leader in the aqueous urea solution field with a total supply capacity of 33,000 kiloliters per year at its two plants located in Kurosaki and Onahama. In the area of technology too, Nippon Kasei has successfully developed a novel technology that is currently patent pending. Conventionally, there is the problem of nozzle clogging by substances that are formed as a result of reactions between impurities and carbon dioxide from the aqueous urea solution. Nippon Kasei has developed special additives to the aqueous urea solution that prevent formation of carbonates, preventing nozzle clogging.
Quality specifications for AdBlue were added to JASO standards in September, 2004. Quality is controlled very stringently in order to prevent catalyst poisoning and clogging by impurities.
To achieve a stable level of quality in its product, Nippon Kasei keeps a tight control on the supply sources of raw material urea. Furthermore, from the aspects of production and storage, it is committed to maintaining a high, stable level of quality through its excellent plant operation and purification technology, backed up by its abundant know-how on the prevention of urea degradation. |
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| In practical use of the urea-SCR system, the aqueous urea solution tank is typically filled up every other time the fuel light oil tank is filled up. A full filling of the 33-liter tank corresponds to approximately 1,900 kilometers on the road for a standard vehicle. Two distribution channels are being considered. One is the fuel light oil distribution route that is led by Nippon Tansan Company Limited, and Itochu Enex Co., Ltd. The other is Nippon Kasei's own route to be constructed in collaboration with Mitsubishi Chemical Group companies (Mitsubishi Chemical Agri, Inc., Mitsubishi Chemical Logistics Corporation). In the future, it will be marketed directly to truck stations and large transportation operators throughout the country, and trucks will be filled with it just like fuel light oil. |
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| What are the future prospects? |
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| It is believed that the urea-SCR system will be adopted worldwide as the next-generation environmentally-friendly standard system. When Nissan Diesel Motor and the three other major diesel vehicles manufacturers all adopt the urea-SCR system, the total demand for aqueous urea solution in Japan will amount to approximately 600,000 kiloliters per year. Nippon Kasei has positioned this aqueous urea solution a 'nurture' business, and in cooperation with automotive manufacturers, it will redouble its effort to expand this business as the leading manufacturer in Japan. |
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Nippon Kasei Chemical Company Limited
8-8 Shinkawa 1-chome, Chuo-ku, Tokyo 104-0033
TEL: [+81] (0)3-5540-5861 |
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