Research On Evaluation And Early Warning System Of Waste-to Energy Development Based On Life Cycle Process

The mass production of domestic waste has brought serious negative impacts on my country’s environmental safety and residents’ health.How to properly dispose of it is a huge challenge currently facing.According to statistics,the volume of domestic waste removal and transportation in my country has increased from 15.576 million tons in 2005 to 242.062 million tons in 2019,a growth rate of 155%.Compared with other waste treatment methods,waste-to-energy has outstanding advantages in terms of"disposal harmlessness,resource and reduction",and can realize the recycling of energy by recovering heat.However,the promotion and development of waste-to-energy in China has encountered various obstacles represented by the NIMBY(Not In My Back Yard).Some projects even have to be successfully constructed under the mediation and communication of the government.It is urgent and necessary to evaluate the rationality of the development degree of waste-to-energy,clarify the main factors affecting its development and quantify the degree of influence,and establish an early warning system to improve the development safety of waste-to-energy.This study takes the life cycle process of waste-to-energy as the research object.Starting from the planning phase,construction phase and operation phase of waste-to-energy,37 indicators are determined to constitute the indicator system of waste-to-energy early warning system.Combining with the complex and numerous indicators of the actual development of waste-to-energy,this study divides its development level into five evaluation levels:"no alarm,light alarm,medium alarm,high alarm and heavy alarm".The TOPSIS evaluation method based on entropy weight is used to diagnose the current situation of the development of waste-to-energy by defining the early warning index.During the period from 2005 to 2019,the safety of the planning phases and construction phases of waste-to-energy is steadily increasing,and both are in a state of "medium alarm";the evolution trend of the operation phase and the overall process fluctuates greatly.Among them,the operation phase in 2005,the safety level was 0.640,which was a "light alarm" status.In the next few years,the safety level fell to 0.288,which was a "high alarm" status.Although the safety level was high in the following years it rebounded,and the safety level reached 0.364 in 2019,but it is still in a "high alarm" state.In 2005,the safety level of the overall process was 0.517,which was considered to be "medium alarm" status.In the next few years,the safety level fell to 0.402.In the following years,the safety level was barely maintained as "medium alarm"status.On the whole,the development situation of waste-to-energy is not optimistic.Based on the DPSIR model,the indicator system of waste-to-energy early warning system is constructed,and the main factors affecting its development are explored through factor analysis.According to the factor score table,there are three factors that have eigenvalues greater than 1,and their variance contribution rates are 84.354%,7.959%,and 4.555%.The cumulative contribution rate is 96.869%.These three factors are named Comprehensive factors,Reality Demand factor and Technological Development factor.From the result of factorization method,in addition to the actual domestic waste generation,the factors that affect the safety of the development of waste-to-energy are mainly concentrated in three aspects:technological development,actual demand and market prospects.The improved Grey Markov model is used to predict the development of waste-to-energy from 2020 to 2025.At the same time,set a goal of the development of waste-to-energy reach "light alarm" status in 2025.A comprehensive discussion on the regulation and control target of its alarm situation.According to the calculation results,if the waste-to-energy still maintains the current development conditions in the future,according to the Gray Markov prediction model,the planning phase will continue to maintain the status of "medium alarm" and will close to the status of "light alarm".The construction phase will be changed from"medium alarm" to "light alarm",but the safety level will continue to decline during the operation phase and remain in a "high alarm" state.The overall process safety level will increase slightly,and it will remain in a "medium alarm" state.If the waste-to-energy still maintains the current development conditions,there is a gap between the expected goal of reaching the "light alarm" status in 2025.The further optimization and control are needed.Set by the scenario,during the operation phase in the future,the degree of safety can increase at an annual rate of 8.69%,which is the most effective means to promote the overall process to quickly reach the "light alarm" state.The optimization path is to accelerate the implementation of the policy and strengthen supervise the industry,do a good job in garbage classification and improve supporting facilities.