China is a leading producer and consumer of coal, with coal being the dominant energy source. The accurate calculation of the mass carbon emission factor (EF_m) of coal is crucial as the carbon emissions from its combustion influence carbon emission assessment and policy formulation. However, discrepancies in EF_m values across documents, due to varying net calorific values (NCVs), carbon contents (CCs), and carbon oxidation factors (COFs), have posed challenges for enterprises in carbon emission calculations. By analyzing different coal types, it is found that for anthracite, the EF_m difference in different documents can reach 38.5%; for bituminous coal, it can reach 42.3%; and for lignite, it can reach 18.6%. These differences significantly affect carbon emission calculation accuracy, carbon allowance allocation fairness, and enterprise costs under the Carbon Border Adjustment Mechanism (CBAM). For instance, in 2023, the calculated carbon emissions of anthracite vary by over 300 million tons depending on the EF_m used. To address these issues, relevant departments should establish a unified EF_m release system, build a data sharing platform, and standardize enterprise testing standards to enhance the accuracy of carbon-related calculations and drive the low-carbon development of the coal industry.

Global efforts to achieve carbon neutrality have highlighted the critical need for accurate carbon emissions accounting in the thermal power industry, which is a major contributor to greenhouse gas emissions worldwide. Standardized and high-precision direct measurement methods are essential to support emissions reduction strategies and carbon trading systems. Accurately measuring thermal power carbon emissions is key to “carbon peaking and carbon neutrality (dual carbon)” goals. The direct measurement method, via real-time monitoring of flue gas flow and CO₂ concentration, provides high-precision data and is an important industrial direction. This paper reviews its key technologies, compares technical adaptability, anti-interference, and cost-effectiveness, sorts out domestic and international standards, and analyzes core challenges (25~50% errors from complex flow fields, environmental interference, traceability issues, high costs, and standard-engineering gaps). It forecasts future directions (flow field rectification, optical tech localization, and digital twins). The results guide enterprises to optimize monitoring, reduce carbon trading data errors, support standard formulation, and help small-medium plants promote direct measurement, accelerating the carbon neutrality process of the thermal power industry.