Synthesis Of Zeolites And Biodiesel In Microchannel Reactors

Since 1990s, the development of nano-technology and microelectronic mechanic systems spurred trend of traditional chemical engineering to miniaturization. Compared to traditional chemical reactors, microchannel reactors exhibited supernormal heat and mass transfer capacity, resistant to high temperature and high pressure, and precise control of process conditions. Nowadays, they have been widely and successfully applied to the preparation of micro to nano-materials and chemical reactions. Micro to nano-materials with various shapes, particle sizes and particle size distributions could be synthesized, as well as the growth mechanism of the particles could be studied in the microchannel reactors. On the other hand, when the microchannel reactors are applied to the chemical reaction progresses, isothermal operation for the intense exothermic reaction can be put into practice, and some dangerous reactions referring with the combustible, explosive, or virulent materials have turned to be safe. Besides, the conversion and selectivity can be enhanced efficiently. However, up to now, there is no report on the preparation of zeolites and biodiesel in microchannel reactors.Zeolites, as very important microporous materials in industry, are synthesized by a batch hydrothermal process within a long crystallization time. Obviously, this process is time and energy consumption during repeated heat-up and cool-down operation, and it's not easy to control the product property. On the other hand, the increasing demands and the decreasing reserves of the fossil energy, as well as the anabatic environmental pollution, spur the increasing interests and concerns on biodiesel, a kind of renewable, environment friendly energy. At present, the industrial biodiesel production mainly takes the base-catalyzed transesterification method, which has several disadvantages, such as long reaction time, dissatisfactory mass transfer during agitation, etc.In this thesis, we demonstrated the application of a stainless steel microchannel reactor for the continuous synthesis of zeolite NaA and nanosized silicalite-1 for the...