Improved catalytic converters for selective catalytic reduction

为了达到政府规定的严格的汽车排放目标和提高燃料经济性，人们对使用柴油、汽油或天然气等低油耗发动机非常感兴趣。在这种环境下，控制排放，特别是氮氧化物的排放是一项挑战，通常使用选择性催化还原（SCR）来实现。在这个反应中，氨被注入废气中，然后与氮氧化物催化反应产生氮。已经使用了几种催化剂，但它们在有水的情况下会过度失活。目前正在开发的新型催化剂是基于铜辉石的催化剂。由于它们相对较新，因此没有太多的信息可以用于反应堆的计算机建模，而这是开发新转换器中越来越重要的工具。本工作的目的是开发使用铜chapazite催化剂的SCR转化器的改进模型。这包括在代表真实驾驶循环的瞬态条件下，为含NO和NO2的废气提供铜chabazite的动力学模型的开发。该模型应捕捉到文献中发表的观察到的效应。这种模型对催化转化器行业是有益的，因为它允许通过模拟而不是实验室实验更快地设计催化转化器和催化转化器配置（即催化剂几何形状，控制系统）。这将最终帮助汽车工业在他们的废气系统设计，以满足不断更严格的政府法规。该项目的成果将是技术，允许更快地发展催化转换器的新车辆。我们的合作伙伴优尼科公司是世界三大催化转化器制造商之一，在全球范围内拥有广泛的业务。他们在加拿大有生产设施，为北美市场生产。这项技术将使优尼科在该领域具有竞争优势，从而增加加拿大的经济活动。

To meet strict government mandated automotive emission targets and improved fuel economy, there is great interest in the use of lean burn engines, either Diesel, gasoline or natural gas. Control of emissions, especially oxides of nitrogen, is challenging in this environment, and is usually achieved using selective catalytic reduction (SCR). In this reaction, ammonia is injected into the exhaust, which then catalytically reacts with NOX to produce nitrogen. Several catalysts have been used, but they suffer from excessive deactivation in the presence of water. The newest catalyst being exploited is based on copper chabazite. Because of their relative newness, there is not much information available that allows for the computer modelling of the reactor, which is an increasingly important tool used in the development of new converters. The aim of this work is to develop improved models for SCR converters that use copper chapazite catalyst. This includes the development of a kinetic model for copper chabazite for an exhaust gas feed that includes both NO and NO2 under transient conditions representative of real driving cycles. The model should capture the observed effects published in the literature. Such a model is beneficial for the catalytic converter industry, as it would allow for catalytic converters and catalytic converter configurations (i.e., catalyst geometry, control systems) to be designed more rapidly via simulations as opposed to laboratory experiments. This would ultimately assist the automotive industry in their exhaust gas system design to meet the continually more stringent government regulations. The results of this project will be technology that allows for the faster development of catalytic converters for new vehicles. Our partner, Umicore AG, is one of the three main catalytic converter manufacturers in the world, with extensive worldwide operations. They have manufacturing facilities in Canada where they build for the North American market. This technology will give Umicore a competitive advantage in the field, and as a result should yield increased economic activity in Canada.