At present, alternative fuels, as one of the important ways for cement enterprises to reduce carbon emissions and achieve the goal of double carbon, have attracted much attention. With China Building Materials, Conch Cement , Huaxin and other cement giants as representatives, the utilization rate of alternative fuels in the domestic cement industry is constantly increasing.
Recently, China Cement Network interviewed Wang Junjie, a thermal expert at the Institute of Engineering Thermophysics, Chinese Academy of Sciences, focusing on the cost reduction analysis of alternative fuels and the selection of alternative fuel types, and sharing the ideas of cost reduction of advanced alternative fuels and the logic of enterprise adaptation.
1. Analysis
of cost reduction achieved by enterprises through rational use of alternative fuels In theory, cement enterprises can achieve 100% fuel substitution. But why do so few companies do this? For cement companies, economy is the key to using alternative fuels. If 100% substitution is needed, the requirements for the quality, storage, transportation and measurement accuracy of alternative fuels will be very high. How much cost an
enterprise can reduce by using alternative fuels mainly depends on three points:
1) the unit calorific value cost of alternative fuels and the unit calorific value cost of coal (including their respective treatment costs after entering the plant);
2) the heat substitution rate (TSR) of alternative fuels;
3) The impact of alternative fuel use on production (including clinker production, equipment operation and maintenance, bypass, refractory materials, clinker quality, fan power consumption, ammonia consumption, etc.).
Among them, with the increase of TSR, the impact of alternative fuels on production will be greater, which may lead to a series of problems, such as the reduction of clinker production, the decline of quality, the shortening of refractory life, and the reduction of equipment reliability.
For enterprises, corresponding accounts can be established to cover the types, components, costs, TSR and the impact on production of alternative fuels, so as to facilitate comprehensive analysis and judgment. It may be found that even if the cost per unit calorific value of the alternative fuel is constant, it is not the case that the more the alternative fuel is used, the lower the cost per unit clinker. For cost, there may be an optimal range of alternative fuel heat substitution rates where the cost reduction is most significant. For each enterprise, this range is not consistent because of its own characteristics, alternative fuels and the cost of pulverized coal.
2. Enterprises should select alternative fuel types
suitable for their own needs 1. First of all, they should define the "bottom line" and determine the "bottom line" according to their own characteristics, such as the lowest calorific value of 1500 kcal/kg and the highest chlorine content of 1.0%. Some enterprises may need to impose more stringent restrictions on chlorine because the chlorine content of raw materials is already relatively high; otherwise, the chlorine content can be appropriately relaxed.
2. With the "bottom line", enterprises need to organize forces to investigate all alternative fuels that can meet the "bottom line" within a certain range, such as biomass, industrial derived fuels, waste spinning, plastics, building demolition materials, and collect the parameters of each alternative fuel. These include cost, calorific value, chlorine content, mercury content, distance, annual supply, morphology, particle size, moisture, ash, volatiles, bulk density, trace element content (as).
3. On this basis, we can make a comprehensive analysis according to the operating cost, the initial investment cost, the impact on production, the impact on environmental protection and many other dimensions to determine several types of alternative fuels suitable for ourselves.
At present, the cement industry is facing the double test of energy saving, environmental protection and industrial intelligence upgrading. In order to implement the relevant policy requirements and accelerate the green low-carbon transformation and high-quality development of the cement industry, China Cement Network is scheduled for September 23-24. The 14th China Cement Energy Conservation and Environmental Protection Technology Exchange Conference and the 6th Intelligent Summit Forum were held in Zibo, Shandong Province. This conference will bring together industry experts, enterprise representatives and many industry stakeholders to gather group wisdom and promote energy-saving, environmental protection and intelligent transformation and upgrading of the cement industry. During
the meeting, we will also organize a visit to the demonstration project of Qingzhou Zhonglian Cement Co., Ltd. with an annual output of 200000 tons of carbon dioxide oxy-fuel combustion coupled carbon capture.
浙公网安备33010802003254号