Development of a Continuous Biogas Pressure Measurement Device with Applications in Batch Anaerobic Digestion Tests

Area of Science:

• Environmental Science
• Biotechnology
• Chemical Engineering

Background:

• Manual manometric (MM) methods for batch anaerobic digestion tests like biochemical methane potential (BMP) and specific methanogenic activity (SMA) are prone to inaccuracies.
• Biogas loss during MM measurements leads to underestimation of biogas production and unreliable test results.

Purpose of the Study:

• To develop and evaluate an Internet of Things (IoT)-based biogas pressure measurement device for improved accuracy and reliability in batch anaerobic digestion tests.
• To compare the performance of the IoT device against the traditional MM method.

Main Methods:

• An IoT device utilizing an Arduino microcontroller was developed to monitor biogas pressure in four reactors simultaneously.
• The device was tested in 250 mL glass vessels with varying headspace and substrate/inoculum ratios using glucose and food waste as substrates.
• A direct comparison between the IoT device and the MM method was conducted over 30 hours under identical conditions.

Main Results:

• The MM method showed an average biogas loss of 50.7 ± 12.9 mbar per measurement, leading to underestimation of biogas production.
• Biogas losses in the MM method increased with higher reactor pressures.
• The IoT device provided accurate, real-time data, enabling observation of early biogas production dynamics and detection of potential issues like methanogenesis inhibition.

Conclusions:

• IoT-based monitoring significantly enhances the accuracy and reliability of BMP and SMA testing.
• The developed IoT device facilitates efficient data management, early failure detection, and real-time monitoring of anaerobic digestion processes.
• Implementing this technology offers a more robust approach to assessing anaerobic digestion performance and understanding microbial activity.