Analysis Of Desorption Energy Consumption Of Ionic Liquids To Capture Carbon Dioxide

The combustion of fossil fuels has led to an increase in global carbon dioxide（CO₂）emissions,which has caused serious environmental problems.The traditional alcohol amine solution capture technology has the disadvantages of large energy consumption and easy corrosion,so the green solvents ionic liquids（ILs）has attracted extensive research.However,the current researches are mainly concerned with improving the absorption of CO₂,but there are few reports on the amount of desorption energy consumption.So,this topic took synthesised choline ionic liquids（Ch-ILs）as the starting point,established a method of calculating the desorption energy consumption through experimental and simulation,and the change of the energy consumption of"ionic liquid"type deep eutectic solvent CO₂ desorption energy made by mixing Ch-ILs with ethylene glycol was studied,and this method is extended to the literature to report the energy consumption analysis of ionic liquids.The main research contents and conclusions are as follows:（1）The absorption and desorption capacity of CO₂ by seven synthesised Ch-ILs（cholineimidazole（[Ch][Im]）,cholinepyrazole（[Ch][Py]）,choline 1,2,4-Triazole（[Ch][Tri]）,cholinephenol（[Ch][Ph O]）,choline 2-hydroxypyridine（[Ch][2-Op]）,choline 3-hydroxypyridine（[Ch][3-Op]）and choline 4-hydroxypyridine（[Ch][4-Op]））were measured,and the value of their desorption energy consumption was calculated through experimental and simulation.The results showed that when the desorption temperature was 100°C,the maximum energy consumption value of[Ch][Im]in the seven Ch-ILs was2.81 GJ/t CO₂,and the minimum energy consumption value of[Ch][2-Op]was1.72 GJ/t CO₂.The energy consumption value of all Ch-ILs was less than 30wt%ethanolamine aqueous solution（4.0 GJ/t CO₂）.After the desorption temperature was reduced to 80°C,the desorption rate of Ch-ILs can still be guaranteed to be≥95%,and the energy consumption value of all Ch-ILs was reduced.Among them,the minimum energy consumption of[Ch][2-Op]was1.46 GJ/t CO₂.Compared with 30 wt%ethanolamine aqueous solution,its energy consumption value is reduced by 63.5%.（2）The ionic liquid based deep eutectic solvents（DESs）were synthesized with Ch-ILs as hydrogen bond acceptor（HBA）and organic solvent EG as hydrogen bond donor（HBD）.The influence of EG molar on desorption energy consumption was investigated.The results showed that compared with the Ch-ILs system,after mixing Ch-ILs with EG to form DESs,the desorption process was easier and the degree of desorption was greater.At desorption temperatures of 100°C and 80°C,the energy consumption value of DESs synthesized by[Ch][Im],[Ch][Py],[Ch][Tri],[Ch][4-Op]and EG massage than1:1 and 1:2 was less than the energy consumption value of pure Ch-IL at the same desorption temperature.（3）The absorption energy of ILs used for acid gas capture reported in the literature was estimated.Among the 36 ILs used to capture CO₂,[MTBDH][Ph O]has the minimum energy consumption value of 1.77 GJ/t CO₂.However,the energy consumption values of[Ch][Ph O]（1.74 GJ/t CO₂）,[Ch][2-Op]（1.46 GJ/t CO₂）and[Ch][3-Op]（1.72 GJ/t CO₂）synthesized in this paper are lower.