Research On The Carbon Flow Of Iron And Steel Enterprise And The Carbon Emission Optimizing Of Iron-making System

The annual crude steel production growth rate of China reaches to15.52%since the21st century, the production of crude steel is717million tons which account for46.3percent of crude steel production of the world in2012. The rapid development of Chinese steel industry brings a series of problems of resources, energy and environment, the CO2emission amount of Chinese steel industry accounts for16.9percent of national total emission in2012in terms of CO2emission, so the CO2emission of Chinese steel industry is grim. The CO2emission amount of Chinese iron and steel industry has to reduce18percent, which birngs the huge challenge to the future development of Chinese iron and steel industry, according to "The12th Five-year Development Plan of Iron and Steel Industry". Therefore, reducing the CO2emission and decreasing the production cost play a significant roal in the future survival of Chinese iron and steel industry.In order to reduce the CO2emission amount of iron and steel industry, accurate calculation is the assurance. Based on this, we choose the typical production process(BF-BOF system)as the research boundry in this paper, parse the carbon flow regularity of the steel manufacture process, establish the appropriate CO2emission factors and the calculation formula, calculate the CO2emission amount of the production processes and the BF-BOF system, draw the carbon flow network diagram of iron and steel enterprise, and analyze the CO2emission effects from material flow and energy flow aspects.The iron-making subsystem(includiong coking process, sintering process and blast furnace process) which is the largest circulation system of material flow and energy flow, the CO2emission ammount of this system accounts for80.72percent of iron and steel industry total CO2emission. Therefore, reducting the CO2emission amount of the iron-making system becomes an outstanding question. In order to optimize CO2emission in different levels, we consider the CO2emission amount and the production cost as the objective functions of the optimization model and establish the CO2emission optimization model of sinter, blast furnace and the iron-making system based on the material conservation and the energy conservation, write the program codes respectively by using Lingo9.0and optimize three models from single objective and multiple objectives, get different results under differnet objective functions, and verify the corretness of the model.The results show that:(1) The redesigned CO2emission factors and the calculation formula apply to calculate the CO2emission of Chinese iron and steel industry.(2) The CO2emission is2.489t/t according to calculate a large domestic steel company, and the CO2emission of iron-making system accounts for80.72percent.(3) The CO2emission optimization model of iron-making system is able to consider production from the system angle, and the multiple objective model can optimize the CO2emission and the cost relatively, so the result of the multiple objective optimization model of iron system can guide the actual production of iron and steel industry.