Study On Reducing Energy Consumption Of Amine Solution Desorption By SBA-15 And Compound Catalysts

Based on the background of global warming and the multi frequency occurrence of extreme climate,it is of great practical significance and industrial demand to develop CCUS with low cost and advanced technology.At present,the technology of carbon dioxide capture by amine is one of the most mature,advanced and widely used carbon capture technologies.However,its large energy consumption has become a major technical bottleneck restricting its large-scale application.The desorption temperature of amine regeneration process in the traditional industry is higher than 373.15 K and the most of the energy is used for gasification,resulting in low energy efficiency.Moreover,the energy consumption of the regeneration process accounts for more than two-thirds of the total energy consumption of the decarburization system.Therefore,it is very important to develop energy-saving and efficient rich amine regeneration technology.In this paper,the traditional Monoethanol（MEA）solution was taken as the research object.In order to promote the desorption reaction of the primary amine solution to proceed quickly,in addition to inputting a sufficiently high amount of heat to drive,it is also possible to add protons that promote Amine-COO-cleavage and basic groups that promote deprotonation reactions to the rich amine solution.The SBA-15 molecular sieve has a large mesopore specific surface area and good thermal stability.In this paper,the modified SBA-15 molecular sieve and its composite catalyst are designed and prepared,and then added to primary amine solution.The study on reducing energy consumption for regeneration of SBA-15 and its composite catalyst was carried out.The main research content of this topic is as follows:The acid-base bifunctional catalyst SO₄^2-/Zr O₂/SBA-15 was designed and synthesized by hydrothermal method,and the effect of these catalysts,SBA-15and HZSM-5 on the regeneration performance of MEA rich solution was studied.The experimental results showed that the desorption energy consumption of rich MEA solution was reduced by 20-26.5%with catalysts of SO₄^2-/Zr O₂/SBA-15,indicating that the developed SO₄^2-/Zr O₂/SBA-15 catalyst had a good catalytic effect.In addition,X-ray diffraction（XRD）,Fourier transform infrared spectroscopy（FT-IR）,N₂ adsorption desorption experiment（BET）,ammonia and CO₂ programmed desorption（NH₃/CO₂TPD）,pyridine adsorption infrared spectroscopy（Py-IR）were used to characterize the physical and chemical properties of the catalyst.It was found that the acid sites,specific surface area and alkaline sites had the greatest influence on the regeneration performance of MEA rich solution.Finally,based on the experimental results and characterization results,the possible reaction mechanism of regeneration of rich MEA solution catalyzed by acid-base bifunctional catalyst was proposed.Composite catalysts（Fe₃O₄-ZrO₂@SBA-15/Beta、Zr O₂@SBA-15/Beta and SBA-15/Beta）were designed and synthesized by post-synthesis method,and the effect of the series of composite catalysts and SBA-15 and Beta catalysts on the regeneration performance of the rich MEA solution was explored.The results showed that the addition of Fe₃O₄-Zr O₂@SBA-15/Beta catalyst reduced the desorption energy consumption by 33%and improved the regeneration performance by 216%,indicating that the designed composite catalyst had a good catalytic effect.In addition,XRD,FT-IR,BET,NH₃/CO₂-TPD and Py-IR characterization methods were also used to analyze the micro composition and chemical properties of the catalyst.The results showed that the acid sites,specific surface area and strong acid site had the greatest influence on the regeneration performance of the rich MEA solution.Finally,based on the results of experiment,the possible regeneration mechanism of the rich MEA solution catalyzed by the composite catalyst was proposed.