Experiment Study On Energy Consumptionof CO₂ Desorption With Phase Change Absorbent

CO2 reduction has become a global research hotspot.The chemical absorption method has been widely used in industrial CO2 capture because of its large absorption capacity and better separation effect.At present,the most commonly used chemical absorbent is ethanolamine(MEA).In the process of CO2 capture by the traditional absorbents,the high energy consumption for desorption has become a major factor restricting its development.The main ways to reduce the energy consumption of desorption are to develop new absorbents and new capture processes.Since the introduction of the phase change absorbent,it has become a hot topic in academic research.In theory,it can reduce the sensible heat and energy consumption of water evaporation by reducing the amount of material and liquid entering the desorption unit.So far,energy consumption of phase change absorbers is only the simulated,and there is no pilot experiment.Our team has been developed phase change absorbents for a long time.A series of MEA and MDEA phase change absorbers have been developed in previous experiments,but the actual energy consumption need to be further studied.Aiming at the problem that the high-viscosity system of the phase change absorbent is difficult to absorb and desorb,we have developed a new absorption and desorption process,and build a pilot device with a CO2 treatment capacity of 100t/year.The research shows that the absorption rate of the gas distributor is about 3 times higher than that of the packed tower when the gas distributor is used for the absorption experiment of the high viscosity system.The membrane flash desorption process is used for the desorption of the highly viscous system.The desorption temperature is 85?,the liquid flow rate is 5 mL/min,and the residence time on the membrane is about 10s.Under this operating condition,it has the best desorption effect.The cycle CO2 load reached 2.1mol/kg,and the energy consumption of latent heat of water evaporation was the smallest at 0.43GJ/tonCO2.The calculated value of the desorption energy consumption of the phase change absorbent was 2.33GJ/tonCO2.Pilot experiments have shown that the energy consumption value of the phase change absorbent desorption is 2.48 GJ/tonCO2,which is consistent with the theoretical calculation value.Compared with the industrial alcohol-amine method to capture CO2,the energy consumption is reduced by 40%.