Semiconductor Sensor-Based Online Monitoring System for VOCs Unorganized Emission Discharge

Currently, two technologies, FID and PID, are mainly employed for online continuous monitoring of VOCs in China. Nonetheless, for the goal of long-term online monitoring of VOCs in the field environment, the equipment of FID technology costs high, in addition to the need to consume hydrogen as a consumable, leading to higher operation and maintenance costs. The life span of the PID sensor is extremely short and it cannot measure gases larger than the PID lamp value. Numerous materials sensitive to volatile organic compound (VOCs) gases exist, along with a diverse range of monitoring technologies for assessing the concentration of uncontrolled emissions of VOC gases in industrial settings. In this paper, an online monitoring system for VOCs unorganized emission gas concentration based on metal oxide semiconductor sensor technology is designed, as well as compared with the VOCs handheld instrument on the basis of PID to test the two gases of isobutene and toluene. Moreover, the test results indicate that the online monitoring system has more advantages than the traditional PID concerning data coincidence results, which is suitable for continuous monitoring and mass deployment of unorganized emissions of VOCs in complex industries.