Process Optimization And Dynamiccontrol Of Coal Chemical Looping Process Combined With Cycle Power Generation System

With the increasing requirement of living standards,the demand of electricity production has a significant growth.Coal is the main energy source for power generation,its combustion generates a large amount of carbon dioxide（CO₂）and casuses climate change and affects people’s lives adversely.Chemical looping technology（CLT）avoides directly contact between fuel and air by oxygen carrier transfering lattice oxygen,which can achieve CO₂ capture.In this paper,coal chemical looping process combined cycle power generation system with Fe₂O₃/Al₂O₃ as oxygen carrier（OC）is proposed.The captured CO₂ is used to produce methanol while obtaining high power output to achieve zero-energy-penalty CO₂ capture and utilization.First,the coal chemical looping process combined cycle power generation system is simulated by Aspen Plus.The effect of steam/coal ratio on coal gasification（CG）process is studied by sensitivity analysis,and the optimal steam/coal ratio is determined.Then,an optimal chemical looping system is deisigned by solving a multi-objective optimization problem for minimizing the total exergy loss and the total reactor volume.Under the optimal conditions,the total exergy loss and total reactor volume are 531MW and 9259m³respectively.The heat exchange area of gas turbine heat recovery steam generator（HRSG）system is optimized by heat exchange network synthesis.The results show that 28.54%of the heat transfer area can be saved under the optimized configuration.In addition,the dynamic control of the proposed system is studied in this work.The effect of different temperatures on the surface sintering of iron oxide clusters are studied by Materials Studio（MS）software based on molecular dynamics（MD）method,and the upper limit of air reactor temperature is determined as 1200℃.The key variables in HRSG system are selected based on transfer entropy method,which are used for dynamic control scheme design.Finally,one control scheme is propsed,which shows high stability in the face of disturbance of feed flow,and provides improtant guidance for actual industrial application.