Limestone gypsum wet flue gas desulfurization has become the most important desulfurization process in China's power industry, which has the characteristics of stable operation and high desulfurization efficiency. The operating cost of desulfurization systems has always been a concern for power plants and other power companies. The literature points out that investment depreciation, raw material costs of desulfurizers, and operating electricity costs account for more than 90% of operating costs, with operating electricity costs accounting for more than 60% of desulfurization operating costs. The literature studied the cost of SO2 removal from coal with different sulfur contents and pointed out that the reasonable cost of flue gas desulfurization should be included in electricity prices. In 2008, the National Development and Reform Commission and the State Environmental Protection Administration issued the "Regulations on the Electricity Price and Operation Management of Desulfurization Facilities for Coal fired Power Generation Units" (Trial), which pointed out that after the installation of desulfurization facilities on new (expanded) units, the on grid electricity consumption shall be increased by 1. per kilowatt hour on the basis of the current on grid electricity price A 5-cent desulfurization markup policy.
Taking two 300 MW units in a thermal power plant as an example, calculate the operating costs and total revenue of desulfurization in the plant, and analyze its economic costs.
1. Operating cost of desulfurization
The operating cost of desulfurization C includes equipment depreciation cost, operating material consumption, operating electricity consumption cost, labor cost, maintenance cost, sewage cost, and other expenses.
1. Equipment depreciation cost
The investment in the FGD system accounts for 5% to 15% of the total investment of the power plant, and the investment in the FGD system of this plant is 1 700 million, accounting for 11% of the total investment of the factory 7%. According to the design requirements, the service life of fixed assets is 30 years. The annual equipment depreciation cost C1 is calculated according to formula (1) C1=W/n, where W is the investment in the FGD system; N is the service life of fixed assets.
1.2 Operating material consumption
For desulfurization systems, the operating material consumption C2 mainly refers to the cost of limestone and water. The limestone consumption of the factory in 2014 was 57 339 09 t, Ca/S ratio is 1 11. The unit price of limestone is 85 yuan/ton; The water consumption is 3 × 105 tons, and the unit price of water is 1 6 yuan/t. Can calculate the cost of operating materials.
1.3 Operating electricity consumption fee
The operating electricity consumption cost C3 mainly includes the electricity consumption cost of the booster fan overcoming the resistance of the FGD, the slurry circulation pump, the oxidation fan, and other pumps and fans. The power consumption of desulfurization operation in the factory in 2014 was 6 28 × 107 kW · h, accounting for 1 48%, with an on grid electricity price of 0 377 yuan/W · h. The operating electricity consumption cost of the desulfurization system can be calculated.
1.4 Labor costs
The labor cost C4 refers to the annual salary cost of the operating personnel of the desulfurization equipment. The desulfurization system of the factory is equipped with 20 operating personnel, 4 administrators, 4 maintenance personnel, and 2 cleaning personnel, totaling 30 people. Based on an average annual salary of 100000 yuan per person, the annual salary cost is 3 million yuan.
1.5 Maintenance fee
Maintenance fee C5 refers to the cost of chemical and mechanical cleaning for the blockage of the desulfurization tower during the operation of the desulfurization plant. In 2014, due to the renovation and improper operation management of the desulfurization system, the desulfurization tower nozzle was blocked twice and the tower body was blocked twice. Each cleaning cost was 1.5 million yuan, totaling 6 million yuan.
1.6 Pollutant Discharge Fees
The discharge fee C6 refers to the discharge fee paid by the factory to the government for the discharge of SO2 and desulfurization wastewater. In 2014, the factory paid a total of 3.1 million yuan in sewage fees.
Third party treatment of environmental pollution refers to a new model in which power generation companies entrust environmental service companies to carry out pollution control. From the above analysis, it can be seen that under the premise of the national electricity price subsidy policy, measures such as reducing the power consumption of the desulfurization system and improving management level can further reduce the operating costs of the desulfurization system, and thus may achieve profitability. For thermal power plants, the desulfurization system is an independent and complex system, and its normal operation has little impact on the main power generation project. Therefore, thermal power plants do not attach enough importance to the operation of the desulfurization system; Meanwhile, the desulfurization equipment of thermal power plants is generally designed, debugged, and renovated by environmental engineering companies, which have stronger professionalism. This provides possibilities for the development of third-party governance.
The third-party governance model has significant advantages compared to traditional pollution control models. Environmental engineering companies have mastered more advanced pollutant removal technologies and possess stronger professionalism, which can reduce the cost of pollutant removal; Environmental engineering companies may operate several desulfurization projects simultaneously, promoting the development of desulfurization technology in a more professional direction, which is conducive to technological innovation and the supervision of environmental protection departments; At the same time, it is conducive to the development of China's environmental protection industry.
However, there are also some issues with implementing third-party governance in our country. The laws and regulations regarding third-party governance are not yet perfect; The implementation of third-party governance in China faces obstacles in terms of responsibility transfer, taxation, financing, economic risks, and technological barriers; Although the desulfurization system is independent of the main power generation project, it must be put into operation together with the main power generation project. Poor operation of the desulfurization system may lead to blockage and threaten the operation of the entire power plant, which will also pose obstacles to third-party governance.
