The ESCAPE Project: Sensor Selection for the Development of a Portable System for Landfill Surface Emission Monitoring

The ESCAPE (Environmental Sites CH4 Assessment Platform Europe) has the aim to develop an innovative environmental monitoring system based on a cloud-based online platform, combining ground and space-based datasets with AI-based solutions and algorithms for spotting emissions from landfill sites. This paper presents the research activities related to the selection of the sensors for the implementation of a portable sensor system for monitoring gaseous emissions over the landfill surface. Specifically, 6 gas sensors (2 MOX, 3 digital MOX and 1 NDIR) were selected based on a technology scouting involving the study of scientific literature and technical documentation, and then tested towards different concentrations (i.e., 10, 100, 1,000 and 10,000 ppm) of CH4 and CO2. Test results show that the MOX sensors TGS2611, SGP40 and BME688 are sensitive to CH4 at concentrations down to 10 ppm, and have no (or low) cross-sensitivity to CO2, making them suitable for the considered application. The NDIR sensor, despite being sensitive only to CH4 concentrations >1000 ppm, could be nonetheless included in the sensors toolbox because of its selectivity.