Deactivation behaviour of modified ZSM-5 zeolite catalysts to conversion of ethanol: mechanism, control and monitoring

促进生物乙醇作为碳源，特别是将其转化与高效的汽油精炼过程相结合，有望改善化学工业的经济和生态状况。一个重要的步骤可能是通过应用木头发酵技术而不是糖等食品成分来摆脱可食用农作物。此外，这可能会使化学公司从处理化石石油过渡到利用可再生碳源。数十年来，乙醇的转化(所谓的ETH过程)一直从实验的角度进行研究和优化。然而，数学和分子模拟的潜力还没有得到充分的开发。将不同的模型应用于H-ZSM-5催化剂，可能会深入了解物理化学性质和反应路线之间的相互作用，从而使定制催化剂的合成成为可能。本项目旨在从科学和实验的角度对改性催化剂样品的失活、结焦和产物形成行为有一个基本的了解。这将允许对催化剂和反应条件进行有针对性的修改，以提高长期稳定性和产品馏分选择性。下一步，在乙醇原料中添加水将作为催化剂在生物乙醇转化中的适用性的指示，而不需要进行初步精馏。最后，只使用不同来源的机械处理发酵液将显示生物乙醇和汽油化学直接相互作用的经济和能量潜力。用乙烯和水的混合物进行几个实验将完成对催化剂材料内部反应路线的理解。乙烯和水在这一反应中起着关键作用，因为乙醇的脱水是反应机理中不可避免的第一步。通过使用固态和物理化学表征方法，在微型工厂试管反应器上进行催化试验，以及不同的数学和分子模拟方法，可以确保对催化剂性能的可靠理解。

Economical and ecological improvements within the chemical industry are expected from the promotion of bioethanol as carbon source; especially by combining its conversion with highly efficient petrol refining processes. An important step will probably be the independence from edible agricultural crop by application of technologies for fermentation of wood instead of food ingredients like sugar. Furthermore, this could smooth the transition for chemical companies from processing fossil oil to utilizing regenerative carbon sources.The conversion of ethanol (so-called ETH process) has been investigated and optimized from an experimental point of view for decades now. However, the potential of mathematical and molecular modelling is not fully exploited yet. The application of different models to H-ZSM-5 catalysts will probably lead to detailed insights into the interplay of physicochemical properties and reaction routes, which will render the synthesis of tailored catalysts possible.This project aims to achive a fundamental understanding of deactivation, coking and product formation behaviour of modified catalyst samples from a scientific and experimental viewpoint. This will allow for targeted modifications of the catalyst and reaction conditions to improve long-term stability and product fraction selectivity. As next step, addition of water to the ethanol feed will serve as indication of the catalyst's suitability in the conversion of bioethanol without preliminary rectification. Finally, usage of only mechanical pretreated fermentation broths of different origin will show the economic and energetic potential of a direct interaction between bioethanol and petrol chemistry.A few experiments with mixtures of ethene and water will complete the understanding of reactions routes inside the catalyst material. Ethene and water have a key role in this reaction because the dehydration of ethanol is the inevitable first step in the reaction mechanism.A solid understanding of the catalyst's properties is ensured by usage of solid-state as well as physicochemical characterization methods, catalytical tests on a microplant test-tube reactor as well as different methods of mathematical and molecular modelling.