Research On The Evaluation Of Yulin Coal Input And Output Based On EROI Method

Financial indexes were often chosen as the evaluation standard in the evaluation of coal production feasibility.However,the financial indexes can only evaluate the economic value of coal production,but ignore the ecological value of coal as natural resources.The method of EROI(energy return on investment)can not only evaluate the economic efficiency of coal production activities,but also evaluate the ecological value of coal production activities.Therefore,this paper takes Yulin city as the object of study,and uses the third-order EROI model to do empirical research on the input and output of coal production.The main work and conclusions are as follows:(1)The status of coal resources and the status of coal mining in Yulin are analyzed systematically.Through field investigation and literature review,the paper analyzes the existing conditions of coal resources in Yulin,the coal mining technology,cost,funds and environmental carrying conditions,it is pointed out that environmental pollution is serious,ecological imbalance is increasing,and input-output efficiency is not high,which is the main problem that restricts the sustainable development of Yulin coal industry.(2)The third-order EROI evaluation model of coal production in Yulin city is constructed.According to the characteristics of coal industry and the status of coal production in Yulin,coal mining and washing industry was taken as the boundary of EROI research.The third-order EROI evaluation model of coal production,which can take environmental governance costs into account,is constructed.The energy outputs of the third-order EROI evaluation model includes raw coal,and energy input includes direct energy input,indirect energy input,labor input and environmental governance costs.(3)This paper makes an empirical analysis on the third-order EROI evaluation model of coal production in Yulin city.First of all,based on historical data from 1995 to 2015,the historical trend of the third-order EROI value of coal production in Yulin city was analyzed.Secondly,the ARMA model,grey GM(1,1)model and combination of ARM A model and grey GM(1,1)model is adopted to predict the third-order EROI value of coal production in Yulin city.The third-order EROI predicted values calculated with heat equivalent method showed less than 1 during the period from 2018 to 2020.The third-order EROI predicted values calculated with Divisia method showed less than 1 during the period from 2016 to 2020.Because the EROI value is less than 1,energy input of coal production activities is greater than the energy output,and the coal production activities in Yulin can't bring net energy to society.The above research results have important reference value for the evaluation of input and output of coal production in coal rich areas.