Study On Coupling Effect Of Solar-coal Unit Thermodynamic System With Carbon Capture

CO2, generated by the combustion of fossil fuels, is recently considered as the main factor causing global warming, which influences global climate and evironment negatively. China, the world's second largest carbon emitter, faces a huge burden of cutting emissions. Carbon capture and storage is an effective way to reduce emissions when coal takes up mainly in the energy structure. Post-combustion carbon capture based on monoethanolamine aqueous solution is a technology with prospect of development.This paper studies the thermodynamic characteristic of the unit when steam extraction and solar energy provide heat source for absorbent desorption in carbon capture system. The main achievements are as below:1. The characteristics of energy consumption during absorbent desorption are analyzed when CO2capture is based on MEA aqueous. Three schemes are proposed when steam extraction of unit provid heat source for absorber desorption and a feasible plan is defined which can also be for further optimized. The energy consumption characteristics is stuied when the carbon capture is based on MEA aqueous solution. The energy consumption for regeneration is calculated when aqueous solution is with different mass fraction. The mass flow and energy flow of power plant with CO2capture are analysed. Three schemes are proposed when absorber desorption heat source is from steam extraction and a feasible plan is defined. Based on exergy anaslysis and exergy cost anaslysis model, the irreversible exergy loss of the system is illustrated. The distribution of the thermal economics cost is studied when energy cost and non-energy costs are considered.2. Three solar-coal unit integration systems with carbon capture are proposed. Thermaldynamic property, the irreversible exergy loss and the distribution of exergy cost of the integration system are analyzed. Due to the large demand of heat for absorber desorption, energy distrabution in the unit will change dramatically if the heat is only supplied by the steam extraction. This effects negatively on the safe operation of the unit. Therefore, three solar-coal integration systems with carbon capture are proposed, and the systems'feasibilities, termodynamic property and exergy cost distrabution are analysed.3. Thermo economic optimization model of solar-coal unit integration system with carbon capture is established and its techno-economics character is analysed. The thermoeconomic characteristics of integration system are analysed when the heat source of the carbon capture system is provided by solar collctors. The mathematical model is established when objective function is the minimum thermoeconomic cost. The energy flow of the integration system is optimized and the distribution of thermoeconomic cost is illustrated. The techno-economics evaluation of the integration system reveals the change rule of power generation cost and CO2reduction cost along with carbon tax and price.