CFD Modelling of a lignocellulosic biomass oxidative pyrolysis reactor for biochar and syngas production

Abstract

Biomass pyrolysis is a promising technology for producing biofuels, biochemicals, and bioproducts, as well as for energy cogeneration. However, the use of an external heat source for biomass decomposition is one of the major challenges associated with scaling up pyrolysis. As the first step of gasification, pyrolysis produces biochar, water, permanent gases and tar, which is a challenge for commercialising gasification because of the high costs of downstream gas-cleaning systems. Unlike conventional pyrolysis in an inert atmosphere, oxidative pyrolysis is autothermal and produces less tar. In this study, we developed a CFD model to investigate a fixed-bed oxidative pyrolysis reactor. The CFD model predicted the temperature profile, permanent gas composition, biochar and tar. The model was validated using published experimental results. The modelling approach offers a powerful tool for analysing the biomass oxidative pyrolysis of different feedstocks and optimising operating conditions.