Dynamic non-isothermal trickle bed reactor with both internal diffusion and heat conduction: sugar hydrogenation as a case study

A generic approach was applied to develop a comprehensive Trickle Bed Reactor (TBR) model. The model was based on exact definition of the required equations and development of a program code (in gPROMS ModelBuilder environment) to solve them simultaneously. The model consisted of dynamic mass and energy balances in three phases of heterogeneously catalyzed reaction system. The fluid dynamics was expressed in simple terms (dispersion model, semi-empiric expressions for pressure drop and liquid hold-up) to guarantee a fast running program code. Even though a large number of articles have been published on the topic, only few of these studies penetrate into all details of the system. Most of them focus on the description of few selected physical phenomena. Including most or even all phenomena in a single model is seldom done. Most often, the published reactor models consider two dimensions only, because of mathematical simplicity (i.e. TBR axial and radial coordinates or only TBR axial coordinate and particle radius). Here an attempt was made to present a generic simulation model for tubular reactors working in non-isothermal three-phase systems (gas–liquid–solid) where three dimensions are simultaneously taken into account (TBR axial and radial coordinate and particle radius). All the model development and calculations were made by using the powerful software, which allows solving a large set of partial differential equations and algebraic equations. An example case study of hydrogenation of arabinose to arabitol on a ruthenium catalyst was included.