Automatic volumetric gas flow meter for monitoring biogas production from laboratory-scale anaerobic digester

Biogas rate production is a relevant variable in anaerobic digestion processing, where, an indicator of volatile solids conversion rate or an earlier indicator of digester failure is needed. Reconfigurable devices like Field Programmable Gate Arrays (FPGAs) have advantages over microprocessors and DSPs with similar logic complexity because their open architecture makes them suitable for system on-a-chip applications. The contribution of this work is the development of an improved water displacement gas flow meter, intended to be used in laboratory-scale anaerobic digestion reactors. Results show automatic gas flow meter functionality, where its calibration stability promotes reliable biogas rate production readings. The synthesis of its digital processing and control system into a low-cost FPGA platform had permitted the successful application of the digital data acquisition and processing in a standalone water displacement gas flow meter.