||With the rapid industrial development, excessive usage of fossil fuel, and uncontrolled forest logging, the increasing amount of GHG emissions, including CO2, CH4, N2O, PFCS, HFCS, and SF6, absorbs the radiation of infrared rays and thus causes global warming. Although Taiwan is excluded from the Kyoto Protocol, Taiwan still actively deal with the problem of greenhouse gases with great efforts. To date, Taiwan has proposed “Greenhouse Gases Emission Reduction Act”, claiming these six greenhouse gases to be criteria air pollutants needs to be well controlled.|
Taiwan Environmental Protection Administration reported that the total amount of CO2e emissions in Taiwan has increased to 2.75 million metric tons in 2010, compared to the amount of 1.28 million metric tons in 1990, ranking the twentith country in the world. Of all the greenhouse gasses, the emissions of CO2 account for about 96.48%, and the energy consumption and industrial process are the primary emission sources of CO2. With regard to the total emissions, iron and steel industry ranks the third in Taiwan. Taiwan Steel & Iron Industries Association reports that, so far, there are 19 electric arc furnace plants and 24 furnaces, and most of which are located at the central and southern Taiwan, particularly in Kaohsiung City.
This study chose 2010 as the base year, utilizing the guidelines of ISO 14064-1 for GHG emissions, reduction, and removal, to investigate the GHG emissions in a selected electric arc furnace plant. This study revealed that the total amount of CO2e emissions was about 195,749 metric tons. Of all the GHG emissions, CO2 accounts for 195,625 metric tons, which was 99.94% of total amount. In addition, with regard to the top five emissions, electricity usage accounts for 63.73%, natural gases 17.75%, iron and steel process 11.61%, kerosene 3.55%, and steam 3.33%. For the reduction strategies, the main approach for GHG reduction is the steelmaking process, and we selected the change of the traditional model of ladle preheater for high-cycle regenerative system, and kerosene to natural gases, through which the amount of GHG emissions can be reduced to 5,435 metric tons per year. In the aspect of single preheater, fuel change can reduce about 64% of total GHG emissions, whose efficacy was higher than the model change. With regard to the expected efficiency of electricity, if the pump motor of cooling system used in the steelmaking and steel-rolling process is installed with converter, presuming that the electricity can save 30%, the GHG emissions could reduce about 1,682.37 metric tons of CO2e per year. Therefore, under the above reduction strategies, the GHG emissions in the electric arc furnace plant can reduce 7,117.37 metric tons of CO2e per year, and the reduction efficacy reached to 3.6%.
In summary, the practice of GHG inspection can not only integrate the management of carbon emission and energy consumption, but also provide the industries with the reference of reduction improvement. In addition, it doesn’t make too much difference among the fuel usage, process devices, or electricity equipment during the process of producing either stainless steel or carbon steel in the electric arc furnace plants.