No abstract

A novel solid amine sorbent was prepared using KIT-6-type mesoporous silica modified with tetraethylenepentamine (TEPA). Its adsorption behavior toward CO(2) from simulated flue gases is investigated using an adsorption column. The adsorption capacities at temperatures of 303, 313, 333, 343, and 353 K are 2.10, 2.29, 2.58, 2.85, and 2.71 mmol g(-1), respectively. Experimental adsorption isotherms were obtained, and the average isosteric heat of adsorption was 43.8 kJ/mol. The adsorption capacity increases to 3.2 mmol g(-1) when the relative humidity (RH) of the simulated flue gas reaches 37%. The adsorption capacity is inhibited slightly by the presence of SO(2) at concentrations lower than 300 ppm but is not significantly influenced by NO at concentrations up to 400 ppm. The adsorbent is completely regenerated in 10 min at 393 K and a pressure of 5 KPa, with expected consumption energy of about 1.41 MJ kg(-1) CO(2). The adsorption capacity remains almost the same after 10 cycles of adsorption/regeneration with adsorption conditions of 10 vol % CO(2), 100 ppm SO(2), 200 ppm NO, 100% relative humidity, and a temperature of 393 K. The solid amine sorbent, KIT-6(TEPA), performs excellently for CO(2) capture and its separation from flue gas.

No abstract

No abstract

Mn 3 O 4 , FeMnO x , and FeO x catalysts synthesized via a solvothermal method were employed for catalytic oxidation of methyl−ethyl−ketone (MEK) at low temperature. Mn 3 O 4 with sphere-like morphology exhibited the highest activity for MEK oxidation, over which MEK was completely oxidized to CO 2 at 200°C, and this result can be comparable to typical noble metal loaded catalysts. The activation energy of MEK over Mn 3 O 4 (30.8 kJ/mol) was much lower than that of FeMnO x (41.5 kJ/mol) and FeO x (47.8 kJ/mol). The dominant planes, surface manganese species ratio, surface-absorbed oxygen, and redox capability played important roles in the catalytic activities of catalysts, while no significant correlation was found between specific surface area and MEK removal efficiency. Mn 3 O 4 showed the highest activity, accounting for abundant oxygen vacancies, low content of surface Mn 4+ and strong reducibility. The oxidation of MEK to CO 2 via an intermediate of diacetyl is a reaction pathway on Mn 3 O 4 catalyst. Due to high efficiency and low cost, sphere-shaped Mn 3 O 4 is a promising catalyst for VOCs abatement.