A Study on the Combustion reaction analysis of multi-stage cyclone pre-heater and pre-calcining furnace when waste plastic auxiliary fuel is used in cement firing process

Abstract

Recently, several international agreements have been concluded to recognize the seriousness of environmental problems and to solve them. In line with this, Korea also announced its 2050 carbon neutral vision and established a carbon neutral scenario. Under the carbon-neutral scenario, the cement industry must reduce its current CO2 emissions by 53% by replacing some of its fuel and raw materials with circular sources. To achieve this goal, combustible wastes such as waste tires and waste plastics, which are circulating resources, are used as auxiliary fuel in the firing process, which generates the most CO2 in the cement manufacturing process. However, the domestic circulating resource replacement rate is 35% as of 2021, which is significantly lower than the average replacement rate in the European Union. The reason is that the chlorine component of the waste plastic corrodes the inside of the kiln and the calcium chloride produced by reacting with the calcium contained in the raw material causes a coating phenomenon, which adversely affects the quality of cement. Therefore, this study analyzed the combustion reaction of cement kiln when using waste plastic auxiliary fuel for 2050 carbon neutral realization by using CFD analysis program ANSYS 2021 R2.