Molecular Modeling Study to the Relation between Structure of LPEI, Including Water-Induced Phase Transitions and CO 2 Capturing Reactions

• Main Author: W. Buijs (11173138)
• Format: Dataset
• Language: unknown
• Published: 2021
• Subjects: Biophysics; Biochemistry; Microbiology; Genetics; Cancer; Environmental Sciences not elsewhere classified; Biological Sciences not elsewhere classified; Chemical Sciences not elsewhere classified; Information Systems not elsewhere classified; LPEI; H-bridged amine carbonic acid complexes; carbamic acid formation; Molecular Modeling Study; physisorption CO 2; Water-Induced Phase Transitions; H 2 O; CO 2 Capturing Reactions; CO 2; carbonic acid formation; Carbonic acid
• Online Access: https://doi.org/10.1021/acs.iecr.1c00846.s001

A molecular modeling study was carried out on linear polyethyleneimine (LPEI) to determine the CO 2 capturing process taking into account structural changes of the material at various amounts of H 2 O. Until now, CO 2 capture by LPEI was described as a combination of carbamic and carbonic acid formation. It was found that humidification below the melting point of LPEI leads to the formation of an LPEI/0.5H 2 O type of phase. Such a type of phase leads to CO 2 capture exclusively via carbonic acid formation, stabilized by secondary amines via ammonium bicarbonate and H-bridged amine carbonic acid complexes. Both the strong physisorption CO 2 complex and the low activation barrier for carbonic acid formation contribute to the overall process. Only in the absence of H 2 O, carbamic acid formation is possible. Thus, under CO 2 capturing process conditions, carbonic acid formation seems to be the only option as H 2 O will be present in flue gas.