Preventing Sox Emissions Through Process Control: Interdigital Capacitors For On-Site Monitoring Of Thiophene-Based Environmental Pollutants In Oil Refineries

The presence of organosulfur compounds in fossil fuels is a major source of environmental pollution (SOx emissions) and deteriorates the catalytic exhaust systems of automobiles. Therefore, the development of miniaturized, low-cost, robust interdigital capacitors (IDC) is required to precisely monitor organosulfur compounds in petroleum products. Based on the Pearson concept of hard/soft acids/bases (HSAB), NiS nanoparticles were prepared and integrated into chemical, heat, and wear-resistant TiO2 coatings to fabricate sensitive layers on IDC for the detection of benzothiophene (BT) and dibenzothiophene (DBT) in gasoline samples. Compared to NiS nanoparticles and pristine TiO2 sol, TiO2-NiS nanocomposites exhibit distinctive morphology with homogeneous distribution of NiS nanoparticles, high surface roughness, and greater localized nanoscale variations. Therefore, HSAB chemistry and spatially distinctive features of TiO2-NiS/IDC sensors yield excellent response and sensitivity toward BT/DBT. The reproducibility of sensor layers, selectivity, repeatability, and stability of TiO2-NiS/IDC sensor were studied before calibrating the devices for real-time measurements in refined gasoline samples. TiO2-NiS/IDC sensors exhibit a wide-range linear response, high sensitivity, and low detection limits in gasoline. Real-time sensor measurements show a 90.7% recovery of BT/DBT from gasoline samples. The sensors were calibrated in gasoline samples for potential process and quality control applications during crude oil refining. (C) 2021 The Electrochemical Society ("ECS"). Published on behalf of ECS by IOP Publishing Limited.