Preparation Of TEPA-grafted PAN-PMMA Hollow Fiber Membrane And Its Low-concentration CO₂ Adsorption/desorption Performance

The increasing global CO₂ concentration has caused a series of serious harms to the global climate,and this phenomenon has already attracted increasing attention.However,what people neglect is that the increase of CO₂ concentration also causes great harm to health in a confined space.There were few technologies to remove low-concentration CO₂ in a confined space,in order to solve this problem,a new type of solid amine sorbent was synthetized for low concentration CO₂ capture at ambient temperature.Tetraethylenepentamine has higher amine group content,tetraethylenepentamine was used as the amine-based adsorbent.When polyacrylonitrile(PAN)is used as the matrix,hollow fiber membrane has a porous membrane structure,polymer polymethyl methacrylate(PMMA)reacts more easily with amine-based adsorbents than polyacrylonitrile,this article uses polyacrylonitrile and polymer polymethyl methacrylate as the matrix.Different pore-forming additives were used to prepare hollow fiber membranes.hollow fibers membranes were firstly prepared by a wet-spinning process.TEPA was grafted onto the hollow fiber membranes,TEPA@PAN-PMMA hollow fibers membranes were used.PAN-PMMA hollow fibers membranes and TEPA@PAN-PMMA hollow fibers membranes were characterized by Brunauer-Emmett-Teller(BET),the Fourier transform infrared spectroscopy(FT-IR),element analysis,scanning electron microscopy(SEM)and thermo-gravimetric analysis(TGA)methods.Performance of the TEPA@PAN-PMMA hollow fibers membranes for CO₂ capture was evaluated by passing a 0.3% CO₂-N₂ gas mixture through the porous matrix of the hollow fibers at ambient temperature.The CO₂ adsorption capacity of TEPA@PAN-PMMA(4:1)-PEG-7%hollow fiber membrane reached up to 1.72 mmol/g for dry feed,and 3.60 mmol/g for wet feed,respectively.The CO₂ adsorption capacity of TEPA@PAN-PMMA(2:1)-PEG-7%hollow fiber membrane reached up to 1.69 mmol/g for dry feed,and 3.49 mmol/g for wet feed,respectively.Cyclic CO₂ adsorption-desorption test indicated that TEPA@PAN-PMMA(4:1)-PEG-7% and TEPA@PAN-PMMA(2:1)-PEG-7% hollow fiber membranes are stable and regenerable.