Biogas production using cheese whey in a bioreactor controlled by an Arduino-based system

Implementation of a bioreactor with control and data capture to produce biogas from cheese whey in a dark fermentation process is presented. Sensors MQ8 for hydrogen and MQ4 for methane (to determine composition), ultrasound (for biogas volume), pressure, temperature and pH, were integrated into a single Arduino card, plus two peristaltic pumps for pH control and feeding. A single block programming allows data capture and pH control, while Excel interface allows a single screen visualization of response graphs in real time. For start-up and testing, granular activated sludge was used as inoculum, under anaerobic conditions, at pH 5.5 and 35 °C. 240 h batch operation gave a production of 73 L H2 Kg-1 CODlactose. In later stages, the H2 production kinetics will be carried out with the aim of optimizing, as well as the use of IoT for remote monitoring of the system.