Application Of Ceramic Microchannel Reactor Prepared By A Mesh-assisted Phase-inversion Process

Microchannel reactor is a kind of reactor with feature size between 10 and 300 microns(or 1000 microns)manufactured by precision machining technology.The channel of process fluid in micro reactor is micron level,and the reactor contains millions of micro channels,so it can also achieve high production.Compared with the traditional fixed bed reactor and fluidized bed reactor,the microchannel reactor provides much more specific surface area than the former by virtue of these tiny channels.The diameter of each micro channel is very small,and the diffusion distance of the reaction gas inside is very short,which reduces the outer diffusion distance of the reaction gas to the catalyst and greatly improves the mass transfer efficiency.In addition,each channel is an independent reaction chamber,which can maintain a certain heat stability.During exothermic reaction,the heat can be transferred out in time to prevent the catalyst from overheating and forming a vicious cycle hot spot to make the catalyst fail;during endothermic reaction,the heat can be transferred to the reaction place in time to provide enough energy to ensure the reaction.This paper focuses on the difficulty of further reducing the channel size of the microchannel reactor to improve the performance of the microchannel reactor and the single use of the microchannel reactor.A microchannel reactor with a separation channel structure smaller than 100 μm diameter was prepared by template phase transformation.The micro separation structure is formed by the convection between flocculant and solvent,and the reactor with different functions is prepared by using functional ceramic materials.The performance and application of ceramic microchannel reactor prepared by template phase transformation were studied.Firstly,the influence of the channel size of the microchannel reactor on the mass transfer performance in the reforming process of CH4 reaction and the influence of the sintering temperature on the optimization and modification of the reactor are studied.The small channel diameter provides the reactor with a large amount of internal surface area for the catalytic reaction,which cannot be achieved by conventional manufacturing methods.By comparing the two types of channel structures in methane dry reforming,the effect of channel size on reactor performance was confirmed.Another advantage of the microchannel reactor is that the microstructure of the wall can be easily optimized by changing the sintering temperature.Secondly,conductive functional ceramics are prepared into an electrically heated microchannel reactor through a one-step phase inversion method and subsequent sintering.It not only has the large internal surface area of the reactor for catalytic reactions that the small-sized channel possesses,but also has the ability to autonomously generate Joule heat.By adjusting the composition ratio of the reactor materials and controlling the sintering temperature,a fast,efficient,and controllable Joule heat microchannel reactor was successfully prepared to catalyze the complete oxidation of CO.Besides,it was found that the micro channel ceramic membrane sintered at high temperature can make the cortex of small diameter channel densify.Therefore,the ionic conductivity of LSF ceramic can be used to prepare a microchannel oxygen permeation reactor for safe production.The design of the microchannel reactor cleverly takes advantage of the oxygen permeability of the material to separate oxygen from the explosive gas methane for partial oxidation reaction of methane to produce syngas,reducing the risk caused by the reaction gas breaking through the explosion limit.