| Chemical absorption of CO2-containing flue gas from fossil fuel combustion using organic a mines is considered the most likely carbon capture technology to be popularized in a short period of time.To solve a series of drawbacks such as high energy consumption and large solvent loss in regeneration by traditional processes,researchers have developed a variety of new absorbents,of which organic a mine non-aqueous absorbents are typical.In this paper,microwave heating method with a series of advantages such as bulk heating,fast response and selective heating is introduced into the field of chemical absorption regeneration,and the absorption and regeneration behaviors of three typical triethylenetetetra mine(TETA)organic solvent absorbents with solvents of polyethylene glycol 200(PEG200),diethylene glycol(DEG)and ethylene glycol(EG)at high concentrations are investigated,and their absorption and regeneration behaviors at different We investigated the absorption capacity,absorption rate,phase change,regeneration rate and regeneration energy consumption at different concentrations,found suitable microwave heating conditions at different concentrations,verified the "non-thermal" effect of microwaves,and preli minarily studied the effect of common moisture in flue gas on organic a mine non-aqueous absorbers,which provides necessary data and support for further research and application of these absorbers.It provides necessary data and support for further research and application of these absorbers.The absorption experiments of organic a mine non-aqueous absorber show that when the absorber concentration increases,the viscosity of organic a mine non-aqueous absorber will have a very large increase,such as for the TETA/PEG200 system,when the concentration increases from 0.6 mol/L to 5.0 mol/L,the liquid phase viscosity increases from 26.8 mPa·s to>2000 mPa·s,so that the high concentration of the absorber The absorption regeneration behavior of the high concentration absorber was somewhat different from that at low concentration.When the absorber concentration increased from 0.6 mol/L to 5.0 mol/L,the absorption load of TETA/PEG200,TETA/DEG,and TETA/EG decreased by 50.5%,44.7%,and 43.4%,respectively,in 120 min.However,this adverse effect will gradually di minish with the increase of absorption load.The regeneration experiments of organoa mine non-aqueous absorbents show that the heating rate of the system under microwave heating is mainly affected by the polarity(dielectric constant),viscosity and heat capacity,and the high concentration will adversely affect the heating rate of organic solvent absorbers.The regeneration test of the organic a mine non-aqueous absorber was carried out using an intelligent adjustable microwave heating device,and the results showed that the regeneration effect was good,in which the TETA/PEG200 absorber still had 1.74,1.62 and 1.50 mol CO2/mol a mine and regeneration rates of 93.9%,90.7%and 86.6%,respectively.For less viscous absorbents,increasing the concentration can be traded for lower regeneration energy consumption at the cost of a very small reduction in CO2 regeneration rate.For a given concentration and type of absorber there is an optimum regeneration temperature at which the regeneration rate is high and the regeneration energy consumption is at a low point,and this optimum temperature is positively related to the absorber concentration.In the field of regeneration of organic a mine non-aqueous absorbent,microwave regeneration has obvious advantages over conduction heating regeneration,to TETA/PEG200,for example,0.6 mol/L,2.0 mol/L and 5 mol/L,the regeneration rate of microwave regeneration can reach 94.22%,91.54%and 84.73%,respectively,is 2.22 times,2.51 times and 3.96 times of conduction heating regeneration The regeneration energy consumption was 32.04,24.91 and 31.26 kJ/g CO2,which were 34.1%,18.8%and 14.0%of that of conduction heating,respectively,and the higher the absorber concentration,the greater the advantage of microwave regeneration compared with conduction heating regenerationThe exa mination of two types of microwave heating methods,pulse heating and continuous heating,proved that the regeneration rate of microwave pulse regeneration method compared to continuous microwave regeneration method is higher,while regeneration energy consumption is lower,for 2.0 mol/L concentration of TETA/PEG200 absorber,regeneration temperature of 120℃ insulation power of 400 W,the regeneration rate of pulse heating method can reach 92.70%,which is the continuous heating method 110.6%,while the regeneration energy consumption was 18.18 kJ/g CO2,which was 95.1%of that of the continuous heating method.Microwave regeneration of a mine absorber is not just to change the heating method and enhance the heating rate,at a regeneration temperature of 120℃,microwave-induced molecular oscillations and collisions in the heating system will also significantly promote the decomposition of carbamate products,thus showing a "non-thermal" effectThe effect of water content on the absorption regeneration performance of TETA/PEG200 absorber was initially studied.The results show that the increase of water content in the system leads to faster absorption rate,higher volume ratio of liquid phase and higher absorption volume ratio of liquid phase,and the absorption load increases by 68.2%,75.1%and 80.3%at 30 min,60 min and 120 min,respectively.However,the difference in water content does not lead to a difference in absorption products.The increase of water content of the system will lead to lower regeneration rate and higher regeneration energy consumption of the absorber,in the low water content range of 0-7.5 wt%,the effect on 5.0 mol/L absorber is only 16.9%,so for low and medium concentrations of absorber,the water should be removed in time or replaced with fresh absorber after the enriched water content reaches a certain level;for high concentrations of absorber,it can be considered The introduction of a lower content of water in the system to improve its absorption performance and physical properties. |
PDF Full Text Request