乳酸-异辛基乙二胺型低共熔溶剂吸收CO2/SO2/H2S混合气体的MD模拟OA

With the large-scale emission of acidic gases such as CO2,SO2 and H2S,significant negative impacts on the environment have been caused,thereby making the development of efficient and environmentally friendly gas absorbents a research hotspot.Lactic acid(LAC)was used as a hydrogen-bond donor and 2-ethylhexylethylenediamine(EtHexen)as a hydrogen-bond acceptor to prepare a deep eutectic solvent(DES)via a mixed-heating method,and the absorption performance of the LAC-EtHexen DES for SO2/CO2/H2S mixed-gas was investigated.First,FT-IR and 1H NMR analyses were employed to verify whether the DES was successfully prepared.Then,molecular dynamics(MD)simulations using GROMACS were performed to study the absorption of SO2/CO2/H2S mixed-gas by the DES,followed by analyses of gas absorption rates,interaction energies and number-density distributions.The results show that the absorption rates of the DES for the gases are 95%(SO2),63%(CO2)and 50%(H2S).MD simulations further reveal that there exists a strong interaction energy between the DES and SO2(-2700.60 kJ/mol),which is significantly stronger than that with CO2(-1051.53 kJ/mol)and H2S(-618.53 kJ/mol).This strong interaction causes absorbed SO2 molecules to mainly aggregate within the liquid phase of the DES,whereas CO2 and H2S are mainly distributed at the gas-liquid interface.This work provides a reference for studying the gas absorption and separation behavior of this type of DES.