The Source-sink Ecological Niche Analysis Of Carbon Metabolism In Iron And Steel Industry Systems:Empirical Study

Under the"dual-carbon"goal,the green and low carbon transformation and upgrading of the iron and steel industry system is imminent.However,on the premise of maintaining the service function of the iron and steel industry system,how to realize the ecological transformation of the iron and steel industry system,reduce pollution and carbon,reduce consumption and increase efficiency and achieve the goal of sustainable development through the regulation of material flow and energy flow metabolism is still a difficult problem that has not been solved.This paper takes a typical iron and steel production system as an example and constructs a symbiotic network for the iron and steel industry based on carbon sources and sinks,analyses the list of carbon sources and sinks in conjunction with the production process and carries out quantitative characterization of the symbiotic network;introduces the concept of ecological niche,constructs an ecological niche analysis framework for industrial systems,carries out source and sink ecological niche analysis of carbon metabolic flows in the iron and steel symbiosis network industry,and explores the ecological niche distribution and evolutionary characteristics of carbon metabolism.At the same time,the results of the ecological niche analysis are compared using network utility and stream information analysis,and suggestions for the optimal regulation of carbon metabolism in the iron and steel symbiosis network industry are proposed accordingly.The main findings are as follows:（1）The carbon source-sink inventory shows that the carbon source mainly comes from direct carbon emissions generated by energy consumption,with a maximum value of 1.33 tCO₂/t（cs）;the carbon sink is mainly concentrated in the recovery and utilization of coal gas,with a maximum value of 0.59 tCO₂/t（cs）.The ecological niche analysis results of the carbon metabolism source-sink show that the carbon source nodes coke ovens,sintering,shaft furnace roasting,blast furnaces and steelmaking converters dominate the system and should be prioritised for improvement.The network diagrams of different production processes all present a"multiple triangles"structure,where the homogenization competition between carbon sources and sinks inside is relatively weak;meanwhile,their ecological differentiation means unbalanced development of carbon metabolism flow and differential developmental features among production processes.（2）The ecological niche analysis results of different metabolic flows show that ironmaking is the key process of resource flow in the iron and steel production process.There is differentiation between the overall resources of the system and a single resource（iron/carbon）,implying that coordinated development of material and energy can promote sustainable and high-quality development of the system.（3）The ecological niche evolution results of metabolic flows show that industrial symbiosis measures can promote the coordinated utilization of overall material and energy in the system,as well as the internal cycling and reuse of iron/carbon resources.The degree of competition for overall resource utilization is decreasing,and the distribution characteristics of iron metabolic flows are showing a trend from concentration to dispersion.The functional ecological niche of carbon metabolism shows a decreasing trend in dependence on external input of carbon resources.（4）Based on the carbon metabolism,the comparative analysis of source-sink shows that the competition relationship and ecological niche overlap between carbon sources-sinks in network utility analysis are consistent with the homogenization competition results.The results of the flow information analysis show that the robustness of the metabolic flow network system（iron metabolism>exergy metabolism>carbon metabolism）is somewhat synchronous with the index of ecological niche differentiation.This clarifies the feasibility of analogy and application of ecological niche analysis to the industrial ecosystem.The research results of this article provide a reference for promoting the win-win situation of resource,environmental and economic development,and provide theoretical basis for the green low-carbon transformation of industries and achieving carbon neutrality.