Synthesization And Basic Study Of CO₂ Absorption For Amine-immobilized Ionic Liquid

A new amine-immobilized ionic liquid was synthesized by organic-inorganic graft method. It was characterized by FT-IR, BET, NMR, TG and so on and was studied by CO2 absorption method. Meanwhile, CO2 adsorption kinetic equation was also attained. This ionic liquid that had great effect on CO2 adsorption was a new organic-inorganic hybrid material.Three synthetic technologies were designed to synthesize this ionic liquid. The carrier was porous silica, and the functionalized reagent was 3-bromopropylamine hydrobromide. In first method, the silicane coupling agent was CG-54. The organic chain was immobilized in silica to synthesize intermediate product, and this product was reacted with imidazole to synthesize another intermediate product. At last, it was functionalized by amide to acquire ionic liquid. In second method, the intermediate product of CG-54 reacted with silica was reacted with 1-(β-cyanogenethyl) imidazole to make a new intermediate product, and it was washed by potassium hydroxide in third method to acquire another intermediate product. Finally, it was functionalized to synthesize ionic liquid. The third method was same as the first, except the silicane coupling agent was KH-560. The ionic liquid of three synthetic technologies designed was characterized by IR,13CNMR and elementary analysis to confirm its structure, and were characterized by TG and TG-MS to show its heat stability and structure. Specific surface area and pore size were calculated by N2 adsorption and desorption experiment. The result was that this kind of ionic liquid was succeed in preparation and it had a high specific surface area, formal pore size and high thermal stability. The amount of amine in silica surface is maximum in second method, because the intermediate product A reacted with 1-(β-cyanogenethyl) was better than imidazole. The molecular of KH-560 was larger than CG-54, so the ionic liquid for using CG-54 had higher specific surface area and bigger pore size than using KH-560.The change of ionic liquid structure in CO2 adsorption was characterized by In-situ IR and TPD experiment. The adsorption amount of ionic liquid was 0.04mmol/g for TPD method. The experiment of CO2 adsorption was exerted in a equipment which was designed by myself at high pressure, and the absorbent amount of CO2 was 0.068mmol/g,0.103mmol/g and 0.405mmol/g in 0.4Mpa,0.5Mpa and 1.0MPa pressure respectively. Meanwhile, a dynamic equation was calculated through adsorbent kinetic experiment of CO2. The apparent rate constant was 0.00123s-1.