Modelling of a Fluidized Bed Membrane Reactor for Steam Methane Reforming Process using Aspen PLUS®-Excel Interfacing

Abstract

Hydrogen being a green fuel is rapidly gaining importance in the energy sector. Steam methane reforming is one of the most industrially important chemical reaction and a key step in the production of high purity hydrogen. Due to inherent deficiencies of conventional reforming reactors, a new concept based on fluidized bed membrane reactor is getting focus of researchers. However, most of the research work on membrane reactors is still carried out only on lab-scale experimentations or simulated models. This work focuses on the development of fluidized bed membrane reactor model in the Aspen PLUS® process simulator. A user defined membrane module is embedded in the Aspen PLUS® through its interface with MS Excel. Then a series combination of Gibbs reactors and the membrane modules are used to develop palladium-based fluidized bed membrane reactor. The developed model is validated through experimental data available in literature and a close agreement is observed between simulated results and experimental data. In addition, nickel-based fluidized bed membrane reactor model is developed and simulated. The simulated results of the model are compared with palladium-based fluidized bed membrane reactor for methane conversion and hydrogen yield. This comparison showed that, nickel based fluidized bed membrane reactor should be operated at higher temperature than palladium based fluidized bed membrane reactor to achieve a specific methane conversion. While for a fixed methane conversion, nickel based fluidized bed membrane reactor requires 6.1 times greater surface area than palladium based fluidized bed membrane reactor. Although the surface area is several times higher than palladium based fluidized bed membrane reactor but the cost analysis (in terms of membrane material) showed a notable reduction in capital cost of the reactor by using nickel membrane inside fluidized bed membrane reactor.