Effective IoT-Based Arduino Design for Automated Bioreactor Control and Sample Collection in Biobutanol Production

A successful automatic control was developed using Arduino and ESP32 microcontrollers to operate a low-cost prototype bioreactor, which resulted in the effective production of biobutanol. The system maintained a temperature of 30.70 °C, an average pH of 6.61, and effectively reduced oxygen levels to 0% v/v within 130 s. The highest cell concentration was <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.26 \times 10^{{8}}$ </tex-math></inline-formula> CFU/mL, and GC-FID analysis showed acetone, butanol, and ethanol (ABE) concentrations of 0.3925, 0.05304, and 1.1184 g/L, respectively. In addition, a sample collector was designed to collect samples with a precision of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10 \; \pm \; 1$ </tex-math></inline-formula> mL and a time deviation of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2 \; \pm \; 13$ </tex-math></inline-formula> s. In terms of the cloud system, NETPIE was used for device management. It can effectively display real-time conditions and control equipment as required. Google Sheets collected 43 200 data points for each parameter for data analysis and observation. Moreover, the Line application was applied for message notification when a sample was collected. The cost of the automated prototype bioreactor was U.S. <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${\$}$ </tex-math></inline-formula>1093.61 for a 10-L production volume, and the automated sample was U.S. <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${\$}$ </tex-math></inline-formula>210.99 for 24 tubes, with a maximum volume capacity of 15 mL. Therefore, both the automated bioreactor and the sample collector system were effective for control and monitoring, contributing to improve the biobutanol production process.