Research On Simulation Optimization And Control Scheme Of Methanol Synthesis Process From Carbon Dioxide

With the continuous growth of China’s economy,the continuous improvement of industrialization level,the rapid advancement of urbanization,and the continuous improvement of people’s living standards,China’s electricity consumption has been increasing year by year.Among them,coal-fired power generation accounts for over 90%of the total power generation,and the amount of carbon dioxide emitted from coal-fired power generation is also increasing year by year.Under the requirements of carbon peaking and carbon neutrality,it is necessary to recycle the carbon dioxide emitted by coal-fired power plants.Methanol is an excellent fuel,energy raw material,and raw material for various chemical products.The efficient and clean synthesis of methanol from carbon dioxide is of great significance.This article designs a green methanol synthesis process using carbon dioxide captured from the tail gas of coal-fired power plants and hydrogen gas produced from solar power electrolysis water as raw materials.The process is optimized with economic and environmental indicators as the optimization objectives,and multi-objective optimization research is conducted on the process.The green methanol synthesis process is divided into three units:carbon dioxide capture,solar energy electrolysis of water for hydrogen production,and methanol synthesis.This article establishes mechanism mathematical models for carbon dioxide membrane separators and electrolytic water hydrogen production reactors,and then completes the entire process modeling and simulation calculation of carbon dioxide capture,electrolytic water hydrogen production,and methanol synthesis.A multi-objective optimization model was established with the optimization objectives of minimizing carbon dioxide emissions and minimizing annual total costs,in order to search for the optimal operating conditions for the environment and economy.The optimization results show that the carbon dioxide emissions are 1.3120×10~5t/a,the total annual cost of the process is 2.7285×10~8$/a。Finally,in order to achieve optimal economic and environmental benefits at the same time,three different control schemes were designed,and the robustness of different schemes to flow and component disturbances was quantitatively analyzed.The optimal control optimization scheme for multi loop temperature control was determined.