Abstract

The paper demonstrates a set of rapid tests that can be easily conducted at coal-fired power stations (CFPSs) to ensure the quality of thermal coal, which is crucial for efficient power generation and emissions reduction. The researchers performed proximate and chemical analyses on coal samples obtained from a conventional CFPS that operates on bituminous coal. They also conducted similar chemical analyses on coal ash samples to assess the propensity for slagging and fouling. The coal currently used in the CFPS is of high quality, belonging to the high-volatile B bituminous variety, with a gross calorific value of 26.3 MJ/kg and minimal sulphur content. The ash primarily consists of quartz and kaolinite, with a fusion temperature exceeding 1300°C. The ash's low slagging and fouling indices indicate a minimal occurrence of related boiler issues. However, the observed low boiler efficiencies can be attributed to suboptimal combustion, as evidenced by the high percentage of unburnt carbon. Optimizing coal combustion can enhance the average specific coal consumption and consequently reduce greenhouse gas emissions. It is recommended that all CFPSs adopt this demand-side coal quality assurance scheme if it is not already part of their standard operating procedures. The results can be integrated with Supervisory Control and Data Acquisition (SCADA) systems for streamlined emission accounting and reporting, as well as optimizing combustion control.

Key words: Demand-side coal quality, coal proximate analysis, ASTM D388-19a, 2019 standard, ash slagging and fouling indices, greenhouse gas emissions abatement, UN SDGs 7 and 13, net zero by 2050, coal phase-out.