工場廃熱を利用したCO₂回収無公害高効率火力発電システムの構成と特性

抄録

A novel carbon dioxide-recovering gas turbine power generation system is proposed in which carbon dioxide (CO₂) generated is recovered by adopting the oxygen (0₂) combustion method and no thermal nitrogen oxide is generated. In the system, super heated steam produced by utilizing waste heat from a factory is used as working fluid of the gas turbine. Thus, the compressing process of the working fluid gas, which is the most energy-consuming process in generating power by using gas turbine, is not needed, and this makes the system to be extremely high-efficient. By taking a garbage incineration plant as an example of waste heat emitting factories, the characteristics of the system was simulated. Gross thermal efficiency has been estimated to be 88.0%, and the power generation efficiency to be 70.4% by subtracting the electric power required not only to generate O₂ and to compress it but also to liquefy the recovered CO₂. The net power generation efficiency was calculated to be 47.8% when the energy supplied by the garbage incineration plant is taken into account. This value is higher than the efficiency, 44.5%, of the most advanced large scale thermal power generation plant using the same natural gas, and is 23.5% higher than its efficiency of 38.7%, the one estimated if the CO₂ is removed and recovered from the stack gas by using alkanolamine-based solvent and the recovered CO₂ is liquefied.