Process Design And Optimization Of Dry Ice Preparation With LNG Cold Energy

As a clean and efficient energy source,Liquefied Natural Gas(LNG)has been widely used in industrial production and daily life.And because LNG contains a lot of cold energy,more and more LNG gasification stations are carrying out LNG cold energy utilization projects,on the other hand,with the rapid development of industrialization,the consumption of fossil energy is increasing year by year,and it is produced during combustion and utilization.Exhaust gas such as carbon dioxide has caused the global greenhouse effect to increase.It aims to solve this difficulty.It uses industrial carbon dioxide as raw material,utilizes LNG cold energy to prepare dry ice,and takes advantage of low-grade LNG cold energy for direct expansion power generation,it also establishes a set of integrated process of dry ice making and power generation with strong operation and good economic benefits to improve power generation stability and system cycle efficiency.Firstly,through literature research,the research status of LNG cold energy for dry ice preparation and power generation technology is discussed.The traditional dry ice preparation process and LNG cold energy for dry ice preparation and power generation integration process are studied respectively.the two processes were compared and analyzed by process flow,The key technologies and process thermodynamic analysis,.The results show that the exergy efficiency of LNG cold energy for dry ice preparation and power generation integration process is 41.34%,and the power consumption is about 66.54 kW·h,it reduces power consumption of 78.32 kW·h and recycled water amount of 3333 kg/h during per ton of dry ice preparation.Then,For the second chapter of LNG cold energy for dry ice preparation and power generation integration process,it uses Aspen Plus' s Calculator module and sensitivity analysis for univariate analysis,then,it makes use of Genetic algorithm programming which Combines Aspen Plus with Excel VBA to calculate the optimal solution of exergy efficiency,total power consumption and expander power generation.The result shows that the system has the highest exergy efficiency of 53.57%,the electricity for per ton of dry ice preparation is 45.9 kW·h,and the maximum power produced by LNG expander is 34.45 kW·h.Finally,the integrated design of process is carried out.The 5 tons of carbon dioxide feed gas is processed every hour,and the system design is designed.When the total process power consumption is the minimum,The investment cost is 35.4 million yuan,and the economic benefit generated by the project is 34.51 million yuan,which has good economic benefits and development prospects.