Simulation of Carbon Capture Based Coal-fired Power Plant and New Process
|School||Beijing University of Chemical Technology|
|Course||Chemical Engineering and Technology|
|Keywords||carbon capture mixed solvents corrosion energy consumption ProMax|
With the constantly increase of concentration of CO2in atmospheric,its maybe an important factors causing global warming. So it is clear thatreducing emissions of carbon dioxide is particularly important. Now thecommonly method of capture carbon dioxide is based amine in coal-firedpower plant. Solvent scrubbing technology based amine has large treatmentof flue gas and effect is good. But to be a viable option for CO2capture atlarge power plants, the process will require significant improvement toreduce the energy using for amine regeneration and corrosion of equipment.The scope of this paper is designing CO2capture process using softwareProMax and studying the main parameters affecting efficiency. To search asuitable blended solvent for reducing regeneration energy consumption, thekinds of blended solvents of MEA、MDEA or PZ are investigated usingmodeling method.First comparison various process of post-combustion capture and setup the mathematical model of the process simulation. Designing a processwhose capture rate is90%can handling capacity of flue gas66000Nm3·h-1using30wt%MEA solution. Thermodynamic models used is amine sweetening that is a signifcant improvement from TSWEET, the industrystandard and calculation of more thermo-physical properties and betterintegration with hydrocarbon packages and unit operations. The result ofsimulation is reliable. So the process is optimized by analysis the inlettemperature of flue gas and solution、circulation rate of solution、theconsumption of gas steam and height of absorber. Finally energyconsumption of one kg CO2is2.007kg steam and the lean loading is0.2659mol·mol-1amine.With the optimum operating conditions, a various of blended solventscontains MEA、MDEA and PZ is explored by simulation in order to reducecorrosion. When mass fraction of blended solvents is30wt%and the ratioof MEA: MDEA: PZ equal to5:4:1, the process has minimum lean loadingthat is0.1672mol·mol-1amine. So it is clear that the lean loading isreduced.But its energy consumption of one kg CO2is2.271kg steam, so theprocess is changed by reclaiming heat energy of rich amine and acid gas.One flow lead solvent is split into two flow solvent: one is exchange heatwith rich solvent and sent to stripper; another one is exchange heat withproduct gas and then sent to stripper. The lean loading is0.1567mol·mol-1amine and the energy consumption of one kg CO2is1.989kg steam in newprocess. Finally with a low lean loading, the energy consumption of steamis successful reduce.