Modelling of continuous production of biogas in a tubular reactor

In this work a new model was developed, simulated and compared experimentally for the prediction of biogas production in a tubular reactor. The model presented here consider cell degradation in a tubular reactor. To test and validate this model, a prototype was built and tested. The simulation of fluid dynamics and concentration gradients was carried out in a one-dimensional system using finite elements, and, according to the results of these simulations, the production of biogas in the tubular reactor was divided into different strata. This may be due to the diffusion of the substrate through the reactor, which causes different growth rates for microorganisms which depend on the availability of the substrate. Theoretical and experimental results showed good agreement with each other. The results obtained in this work can aid in the development of a compact, simple and efficient system capable of producing biogas on a small scale and with continuous production whose use is feasible in small communities.

Keywords: biogas, tubular reactor, renewable energy, biomass, CFD.