Review of carbon emission accounting methods in coal enterprises

Carbon emission accounting of coal enterprises is the foundation and prerequisite for formulating reasonable carbon emission reduction measures. Scholars in China and abroad have proposed and adopted many methods to account for the carbon emissions of coal enterprises. However, the accounting process, characteristics, and the scope of application of different methods lack systematic summary. The process of carbon emission accounting of coal enterprises is sorted out by reviewing relevant literature in China and internationally: determining the target, determining the accounting boundary, identifying the emission source, establishing the accounting model, collecting data, calculating carbon emission, and evaluating the accounting accuracy. The carbon emission accounting methods of different coal enterprises (mining and open-pit coal mines) are organized and summarized, and the characteristics and scope of application of different accounting methods are clarified: The emission factor method is simple and most widely used, and the collection and acquisition of energy consumption data and emission factors is the key to accurate carbon emission, emission factors accounting model was improved by taking carbon emissions from water consumption for dust abatement, oxidation of coal seams and land-use change were into account. The material balance approach is based on the mass balance principle, which can differentiate carbon emissions from specific facilities or processes, but data is diverse which is difficult to obtain. Carbon emission estimation based on the actual measurement method is carried out through real-time monitoring of flue gas emission parameters or CO₂ emission fluxes and then the carbon emission is obtained with the help of relevant estimation models, which is a powerful tool to reflect the characteristics of changes of carbon emissions in coal enterprises, but it cannot distinguish the emissions of various carbon emissions. The lifecycle analysis expands the boundary of carbon accounting of coal enterprises and can reflect the emission characteristics of coal enterprises in their whole life cycle, and the accounting boundaries of the whole life cycle and its subsystems for coal enterprises was further clarified. Based on the current carbon emission accounting demand of coal enterprises, the refined observation and recording of energy consumption data of coal enterprises, and the correction of emission factors are the keys to improving the accuracy of carbon emission accounting of coal enterprises. It is more conducive to understanding the carbon emission characteristics of different carbon sources of coal enterprises by selecting representative mining and open-pit coal mines respectively to improve and optimize the carbon emission accounting model and using them as the blueprint for coal enterprise carbon emission accounting. An important development direction of dynamic characteristics monitoring of carbon emission in coal enterprises is to simultaneously perfect the carbon emission accounting system based on energy consumption data and the real-time carbon emission monitoring system based on “fixed observation-satellite observation-drone inspection-aerial monitoring”, and then realize the serialization and gridding of carbon emission in coal enterprise.