Modeling and optimization of biogas production in a batch bioreactor

Abstract

Ever increasing demands for renewable energy sources are the driving force for the development of waste management technologies such as anaerobic digestion (AD) technology. For AD process understanding and optimization the numerical simulations provide a useful tool. Therefore, in this work, the main attention is focused on the development of an efficient and stable optimization approach. The optimization procedure is coupled with a suitable mechanistically inspired selfdeveloped BioModel. For BioModel calibration, a special procedure was developed which incorporates the used BioModel, a sensitivity analysis, and a gradient-based optimization algorithm. The results of numerical simulation, obtained by the AD of various animal manures in a batch lab-scale bioreactor, confirm the reliability of BioModel and the efficiency of the presented calibration procedure. Furthermore, the results of AD process optimization show that the biogas quantity and quality as well as energy used up for bioreactor heating can be improved essentially when amount of added bacteria, temperature and pH values are optimized properly.