Researchers from Southwest Jiaotong University developed a 12 m3 multiphase flow anaerobic digester (MFD) to enhance biogas production rate and maintain constant temperature digestion during winters
Biogas is a type of biofuel that is naturally produced from the decomposition of organic waste and is an environmentally-friendly energy source as it alleviates two major environmental problems simultaneously: The global waste epidemic that releases dangerous levels of methane gas every day and the dependence on fossil fuel energy to meet global energy demand. According to Environmental and Energy Study Institute 2017, the U.S. has 2,200 operating biogas systems across all 50 states and has the potential to add over 13,500 new systems.
Now, a team of researchers from Southwest Jiaotong University developed a multiphase flow digester (MFD) and dynamic anaerobic digestion system. Dynamic digestion and static digestion groups were compared and a multiphase flow technology was used in the research. The team compared two groups and found that the conversion rate of the slurry biomass increased due to the enhancement of the heat and mass transfer rates. The total rate of production for dynamic digestion was of 4.12 m3 of biogas per day. The energy efficiency ratio increased and reached its maximum value in accordance with an increase in the digestion temperature.
The biogas production rate of the dynamic digestion group increased rapidly from the beginning of the digestion, and then reached the biogas production peak at day 22. Using MATLAB software analysis, the value of the economical digestion temperature was found to be 27.2 °C. When the phenolic resin was selected, the economic digestion temperature was highest and the net biogas production rate was largest. Therefore, different insulation materials and thicknesses must be selected according to the needs of the application process to achieve the optimal operating conditions. The team applied biogas production law of the dynamic digestion experiment to enhance the system. The research was published in the journal MDPI Energies on May 22, 2019.