The Effect of the Carbon Tax Value on the Optimal Parameters and Characteristics of Coal Power Plants

The paper investigates the effect of the carbon tax on the optimal parameters and indicators of two coal power plants: a steam turbine power unit with coal dust burning in a steam boiler and an internal gasification combined cycle power plant. Sufficiently detailed mathematical models have been developed for the considered plants that are focused on calculating the flow rates of working fluids and coolants and thermodynamic parameters at all points of the flowcharts, as well as the structural characteristics of the plant elements. The problems of optimizing the parameters of these plants related to the problems of nonlinear mathematical programming are formulated. As an efficiency criterion, the price of electricity is used at given value of the internal rate of return on investment. Optimization calculations were carried out with a carbon tax in the range from 0 $/t to 140 $/t in increments of 20 $/t. It is shown that with an increase in the charge for emissions, the optimal efficiency of the plants increases, as well as the specific investment. Specific CO₂ emissions are reduced. Throughout the entire range of carbon tax values, IGCC power plant has the best economic and environmental indicators.