The Capture Of CO₂ By Novel Amine Solvents And The Research On Catalytic Desorption Process

High energy penalty in amine-based solvent regeneration process is a critical challenge in industrial application for post-combustion CO₂ capture technology.In this research,a novel amine solution of 3-（diethylamino）propylamine（DEAPA）was investigated to capture CO₂,and then three catalysts(SAPO-34,MCM-41 and SO₄^2-/TiO₂)were introduced to DEAPA solution to further decrease the heat duty in amine regeneration process.This paper compared NMR spectroscopy,pH+NMR analysis,and model prediction techniques for determining the speciation of CO₂ loaded amine solution,to qualitatively and quantitatively analyze the ions of the amine solution in the process of absorbing and desorbing carbon dioxide,and to identify the chemical reactions that may occur in the process.In addition,the concentration of carbamate and HCO₃^-ions,which affect the energy consumption of solvent regeneration,is analyzed to obtain its synergistic conversion relationship,which is beneficial for effectively reducing the heat duty of the CO₂ desorption process and improving thermal efficiency.After that,a new and efficient chemical solvent DEAPA was proposed in this paper,and its CO₂ capture performance was investigated,and then the effect of catalyst on its desorption performance was also discussed.The ions in the system were qualitatively and quantitatively analyzed by pH+NMR combined analysis technology,and the desorption energy consumption was recorded by electric energy meter.Compared with MEA,DEAPA solution can increase CO₂ desorption rate by 37.28%,increase cycle capacity by 38.02%,and reduce heat load by 14.85%,which means that DEAPA is a potential diamine solvent and has high industrial application value.On the basis of the above,this research explored a plausible catalytic desorption mechanism over various catalysts（including Br（?）nsted/Lewis acid catalysts,acid-base bifunction catalysts and transition metal oxide catalysts）in CO₂ loaded amine solution.Analyzing catalytic desorption mechanism could get the characteristics that the high-efficiency catalysts have and provide theoretical support for the use,design,synthesis and development of high-efficiency catalysts.At the same time,the study of the catalytic desorption mechanism is helpful to infer the reason why the catalysts can actively catalyze the amine solvent regeneration process,and to obtain the relationships between the catalyst characteristics and the high-efficiency catalytic performance,which is of great significance to the subsequent research of this paper.After that,three different catalysts were used in DEAPA system to further reduce the energy penalty of amine regeneration process.In this system,DEAPA-SAPO-34,DEAPA-MCM-41and DEAPA-SO₄^2-/TiO₂ could respectively lower the heat duty by 33.08%,27.79%,and22.41%compared with the blank MEA run.Among the three catalysts,SAPO-34catalyst exhibits a higher efficiency for increasing the CO₂ desorption rate and cyclic capacity.Additionally,two plausible catalytic desorption mechanisms for CO₂desorption from the DEAPA-catalyst system is proposed.Then,by comparing the parameters of each catalyst,the mesopore surface area（MSA）and the total acid sites（TAS）are regarded as the critical factors for an efficient catalyst,and the combination of MAS*TAS could act as a key value to evaluate the performance of a catalyst for catalytic CO₂ desorption.