Preparation Of SrA Adsorbents For Separation Of Hydrogen And Methane From Coke Oven Gas

Coke oven gas,a byproduct of coking process,is high-potential hydrogen source because it contains nearly 50%hydrogen and 20%methane.So recovering hydrogen from coke oven gas is a significant application of coke oven gas.Hydrogen separation from coke oven gas is primarily through pressure swing adsorption(PSA)currently and zeolite A is the most commonly used adsorbent for its easily achieving high hydrogen product purity.According to reducing zeolite crystal size and introducing mesopores into zeolite crystals can improve the adsorption ability,in this paper,submicron zeolite SrA and hierarchical zeolite SrA were prepared and tested as absorbents for PSA separation of H₂ and CH₄.The submicron particle zeolite A with average particle size about 200～400 nm was synthesized with polyethyleneglycol(PEG-1000)as surfactant and the hierarchical zeolite A was synthesized with[3-(trimethoxysilyl)propyl]octadecyldimethylammonium chloride (TPOAC)as mesopore directing agent.Both of the zeolites A were ion exchanged with strontium nitrate.The prepared products were characterized by XRD,nitrogen sorption,SEM, TEM and laser particle size analyzer and confirmed as submicron particle zeolite SrA and hierarchical zeolite SrA.The adsorption measurements of submicron SrA,hierarchical SrA and commercial 5A adsorbents were tested by dynamic and static methods.The results show that compared with commercial 5A,both of the submicron SrA and hierarchical SrA show higher adsorption capacity of CH₄(and H₂)and higher separation factor of CH₄/H₂.Submicron SrA shows the highest adsorption capacity of CH₄(and H₂)and separation factor of CH₄/H₂.The breakthrough curves of simulated coke oven gas on submicron SrA,hierarchical SrA and commercial 5A adsorbents were measured.The results show that hydrogen separation factors of all adsorbents increase in the following order:α_N2/H2＜α_CH4/H2＜α_CO/H2＜α_CO2/H2.Both of the submicron SrA and hierarchical SrA show higher hydrogen separation factors than commercial 5A and submicron SrA shows the highest hydrogen separation factor.The hydrogen separation factors of submicron SrA and hierarchical SrA are higher than 3,indicating both of the prepared SrA adsorbents have better adsorption performance for PSA separation of hydrogen from coke oven gas.