Modelling and gas–solid mixing characterization in the jiggled bed reactor (JBR)

Abstract

AbstractThe jiggled bed reactor (JBR) is a new multiphase laboratory‐scale microreactor consisting of a sealed container attached to a piston that is rapidly moved up and down by a pneumatically powered actuator. Particles and fluids in the container are mixed by this up and down motion instead of mechanical agitators or a fluidizing gas. This alternating motion provides intense mixing of all phases (gas, liquid, or solid) and intense contact between phases. Small rods inside the solids bed are heated by induction, allowing for excellent control of bed temperature and heating rate. The JBR is inexpensive and easy to operate, and it has been applied to catalytic gasification of bio‐oil, biomass pyrolysis, activated carbon production, high‐pressure oil hydrogenation, and hydrocarbons adsorption. Experiments demonstrated that solids mixing depends on the reactor platform maximum accelerations during both up and down strokes. A minimum acceleration, 55 m2/s for the tested JBR, was required to achieve good solids mixing. A physical model was developed to predict the reactor platform motion and its maximum acceleration. It requires a few preliminary experiments (around 10) to obtain its four empirical parameters. The model can then determine how to adjust the actuator compressed air pressure or modify the equipment to eliminate performance bottlenecks.