An Investigation of the Heat Integration between the Two Riser Units Constituting a Circulating Fluidized Bed Reactor for the SE-SMR Process

Abstract

Sorption enhanced - steam methane reforming (SE-SMR) is a promising process in the search for hydrogen and synthesis gas technologies that can help reduce the amount of greenhouse gas emissions, since it allows simple CO2 capture via temperature swing. The conventional models for fluidized bed reactors, such as the Kunii- Levenspiel model, assume a stagnant, or pseudo-stagnant bed of solids. In this work, the one dimensional form of the governing twofluid equations are solved representing a step further in complexity. The model is reflecting is a compromise between accuracy and computational cost. This model is employed to achieve insight into the heat integration performance of a circulating fluidized bed reactor for the SE-SMR process, containing two riser units operated in the fast fluidization flow regime. The impact of the solid flux streams between the riser units on the inter- riser heat transfer, the heat losses to the surroundings, and the addition of fresh sorbent make-up, are analyzed. Finally, the reactor heat budget is studied, and a few ideas are given in order to minimize the energy consumption.