Studies On Preparation Of CO₂ Storage Material By The System Of 1,4-butanediol+ 1,2-Ethylenediamine And Its Utilization In Regulating And Controlling The Crystallization Of Alkaline Earth Carbonate

CO2 is regarded as a kind of pollutants that cause climate change,and it is also the most widely distributed and abundant carbon resource on the earth.As a result,simultaneously reduce CO2 emissions as soon as possible and convert it into energy,materials and chemical products would be great significance for the benefit mankind.At present,CO2 capture and sequestration(CCS)and CO2 capture and utilization(CCU)are still the two mainstream approaches for CO2 capture and resource.Compared with CCS,CCU is more economical and sustainable.However,the high thermodynamic stability of CO2 has thus far precluded its usage as a widespread chemical reagent.For this purpose,a novel CO2 capturing system,1,2-ethanediamine(EDA)+ 1,4-butanediol(BDO)in this study,was selected to activate and capture CO2,and it converted CO2 into a kind of solid CO2-storage material(CO2SM).Therefore,a new green CCU method was developed.Firstly,this work proposed BDO as an EDA amine-fixing agent to reduce the volatility of EDA through the interaction between BDO and EDA based on the optimization of amine high volatility problem in CO2 capturing process.By studying the thermodynamic properties,molecular structure activity relationship and the interaction mechanism of EDA+ BDO mixture,a novel CO2 activation,capture and storage method was developed.Secondly,the solid product,which obtained from EDA + BDO system activating and capturing CO2,was named as the CO2 SM,confirmed as alkyl ammonium carbonate,and could release CO2,EDA and BDO under heating.This not only provides the basis for cyclic absorption and desorption of EDA + BDO system,but also provides an ideas for CO2 non biomineralization into carbonate.To this end,this research focuses on CO2 mineralization for alkaline earth carbonates(CaCO3,SrCO3,and BaCO3)by hydrothermal method,and explores the regularity of mineralization.In this process,the CO2 SM was not only used as CO2 source,but also served as crystal modifier to regulate and control the nucleation,crystallization,growth,morphology and polymorph of alkaline earth carbonate.Additionally,the filtrate without precipitation can not only repeat absorbing CO2,but also use to prepare the same crystal phase alkaline earth carbonate.Meanwhile,the CO2 SM has generally applicability in regulating and controlling the crystallization of alkaline earth metal carbonate.Finally,it is concluded that EDA plays important roles in the process of CO2 direct mineralization and crystals growth with carbonization method.Under certain conditions,CO2 was introduced into the system of EDA + Ba(OH)2 aqueous solution,and the spindle BaCO3 crystals were effectively obtained.By analyzing the variety of CO2 pressure,pH,electrical conductivity and filtrate,the EDA regulation chemistry in the CO2 direct mineralization process was firstly proposed.Meanwhile,other alkaline earth metal carbonate were also prepared by this method,and the results indicated that this method had general applicability.