Preparation Of One-dimensional Oriented Zeolite LTL Membrane And Evaluation Of Separation Performance

CO2 not only one of the main gas causing the greenhouse effect, but also the separation of CO2 from gas mixture of synthesis gas, natural gas and flue gas, is an important topic in the field of energy and environment. Inorganic membranes, such as zeolite membrane are gaining rapid attention in the industrial application of CO2 separation owing to their unique properties, such as thermal, mechanical, and chemical stability, good erosion resistance, and stability at high CO2 pressures. Zeolite L having 7.1 A pore size,the Si/Al ratio 3, therefore they both have the strong CO2 adsorption ability. Zeolite L membranes can be synthesized without the aid of the organic template, not only can be reduced the manufacturing cost of the membrane,but also avoid damage the membrane due to the removal of the templating agent.1.Firstly, the zeolite LTL crystals with regular morphology, high crystallinity and different aspect ratio were successfully synthesized by adjusting the composition of the synthesis gel. Secondly, the organolanthanide complexes were loaded inside of the zeolite LTL channels, denoted as zeolite LTL/Eu-TTA, by using the "ship-in-bottle " method. Luminescence spectra analysis results showed that the zeolite LTL/Eu-TTA crystal with 0.2 aspect ratio has the strongest emission of 5D0â†'7F2 located at 617nm, whereas the crystals with aspect ratio of 3 has the weakest one at an excitation wavelength of 350 nm. Finally, The fluorescent array extending to the centimeter scale was fabricated in an oriented way by rapid wiping the zeolite LTL/Eu-TTA crystals with 0.2 aspect ratio in 10 second on the surface of PEI coated glass substrate. The SEM results proved that nearly all zeolite LTL crystals compacted closely with their c-axial perpendicularly to the glass surface in a monolayer manner. This one-dimensional orientated fluorescent array issued a bright red light upon UV-light excitation at the wavelength of 365 nm.2. Firstly, the disc-shaped zeolite LTL seeds successfully synthesized by adjusting the composition of the synthesis gel. Secondly, increase the grain surface hydroxyl functional groups by acid treatment, the use of butanol was stirred modified 4d effectively increase the molecular sieve seed hydrophobicity. Finally, Langmuir-Blodgett (LB) technique was successfully used to fabricate dense and oriented zeolite L monolayer on various substrates. By examining the second growth temperature, composition of the synthesis gel and synthesis time, to determine the appropriate range of synthetic preparation zeolite L membrane. Synthetic ratio of:8 K20:1.0 Al2O3:25 Si20:800 H20,180℃ crystallization 44 h, on various substrates surface were synthesized dense continuous 1.5um thickness c-axis orientation zeolite L membrane, the CPO(00l) values to 0.89.3.At room temperature were tested single component gases He, H2, N2 and CO2 permeation behavior in order to evaluate the preparation of zeolite L membrane dense. Test results show that:H2/N2 ideal separation factor of less than Knudsen diffusion value, and H2/CO2 separation factor higher than Knudsen diffusion value, and increases with increasing pressure. Show zeolite L membrane having good denseness.