Simulação da transferência de calor em um biorreator de leito empacotado operado em modo pseudo-contínuo (BLEPC) para fermentação em estado sólido (FES)

Abstract

The pursuit of renewable energy sources and economically viable methods in energy production has become imperative nowadays. In developing countries with high availability of arable land, there is the possibility of exploring agricultural and forest crops to obtain biomass with potential for bioenergy production. Producing enzymes necessary for the synthesis of biofuels may represent an important step for the economic viability of the production routes. Due to the need for acid and/or hot pretreatment in the biomass used for second generation bioethanol and biodiesel production, solid state fermentation emerges as an alternative bioprocess for the production of these enzymes, as it favors the adaptation of thermophilic filamentous fungi that produce thermostable enzymes, which may act at acidic pHs. The absence of movement in packed-bed bioreactors is ideal for the growth of shear-sensitive filamentous fungi. However, using such reactors is likely to result on reduced yield due to overheating and drying of the medium due to air percolation, and their industrial applicability is hampered by not allowing a continuous process. This paper presented data obtained via computational simulation on MATLAB of a pseudo-continuous process, aiming to describe temperature and growth profiles along a modular packed-bed reactor, which promotes an intermittent semi-continuous plug-flow on a solid-state fermentation. Two filamentous fungi - Myceliophthora thermophila and Aspergillus niger - were studied for different modular exchange times, obtaining up to 1.67% of maximum bioreactor temperature reduction when compared to the traditional batch process. Although it still needs further studies of its applicability to industrial processes, the modular bioreactor proved to be a promising alternative to solid-state fermentation, as it presented reduction in maximum bioreactor temperature and it allows for a semi-continuous process mode with removal of fermentation product on intervals equal to the time between modular change.