Research On Strengthening Reaction Processes Of Furfural Hydrogenation Based On The New Tubular Reactor

Process intensification is an important way to improve efficiency and product quality in chemical industry production,which can be divided into two fields:process strengthening equipment and process strengthening methods.Reactors,as core production equipment,are an important research direction for process enhancement.Tubular reactors are widely used in gas-liquid-solid three-phase hydrogenation reactions due to their simple structure and continuous production.However,traditional tubular reactors have problems with low conversion rate and poor selectivity in the hydrogenation of furfural.Based on the above issues,this article adopts a process strengthening approach to optimize the furfural hydrogenation reaction on a tubular reactor through structural strengthening and catalyst strengthening,and explores the impact of process strengthening on reactor performance and hydrogenation reaction.This article proposes a new type of tubular reactor,which adopts a tubular structure and adds porous inner tubes on top of a single tubular reactor.By changing the structure,the feeding method can be adjusted to improve the mixing effect of gas-liquid two-phase inside the reactor,thereby achieving the goal of strengthening the reaction process.By using CFD software,the internal flow field of the reactor was simulated and the changes in H2 and liquid components with increasing axial length of the reactor were studied.The porous area is the focus of attention.After exploring the changes in velocity and pressure drop in this area,it was found that it conforms to the characteristics of the porous area and can achieve strengthening effects.The distribution of fluid inside and outside the porous area also indicates the feasibility of the hydrogenation method.Through hydrogenation control experiments,it was preliminarily verified that structural optimization has a significant effect on improving hydrogenation performance and conversion rate.Further research was conducted on the impact of changes in reactor structural parameters on hydrogenation performance,and the effects of three important parameters,namely residence time,gas-liquid velocity matching,and reaction tube holdup,were obtained.It was demonstrated that structural optimization changes the residence time of the reaction and enhances the effectiveness of gas-liquid mixing,thereby improving the conversion rate and selectivity of hydrogenation reactions.On the basis of optimizing the reactor structure,the reaction process is strengthened from the perspective of catalysts,mainly to improve the selectivity of hydrogenation reactions.Due to the structural characteristics of the reactor,the catalyst must meet the requirements of high activity,low activation energy,and large specific surface area.Therefore,a bimetallic catalyst was designed and prepared,with Pd-Al2O3 as the base catalyst and the addition of the second active component Fe,Cu,and Co to further enhance the selectivity of the catalyst.The properties of the four catalysts were analyzed through XRD,N2 physical adsorption,SEM,and ICP.It was found that the active metals in all four catalysts were highly dispersed on the surface of the support and did not cause any damage to the structural morphology of the support.All four catalysts have mesoporous structures,and after the addition of Fe,their specific surface area has the smallest change,with a specific surface area of 224.05m2/g,which can meet the needs of reactor structure.Further exploration was conducted on the factors affecting the hydrogenation of four catalysts in a new tubular reactor,including temperature,pressure,catalyst dosage,noble metal loading,and the addition of the second active component.Within a certain range,increasing temperature,pressure,catalyst dosage,noble metal loading,and the addition of the second active component,which will increase the conversion rate and selectivity of the hydrogenation reaction.On this basis,the Pd-Fe/Al2O3 catalyst with the most excellent comprehensive performance was selected to further explore its strengthening mechanism.Through TEM,XPS,and Py-IR characterization methods,it was found that the addition of Fe reduced the interaction between Pd and the support,changed the acid properties on the catalyst surface,and only the characteristic diffraction peaks that were consistent with L-acid appeared in the catalyst.Pd formed an alloy with Fe,enhancing the adsorption of H2 on the catalyst surface.By strengthening the structure and catalyst,the process of furfural hydrogenation on a new tubular reactor was enhanced,providing a good reference example for improving reaction efficiency and product yield.