جستجوی مقالات مرتبط با کلیدواژه « آلومینای فعال » در نشریات گروه « شیمی »

Natural gas, petrochemical and some refinery feed streams have trace of mercury which threats the environment and human health. Moreover, brazed aluminum heat exchangers are susceptible to corrosive attack by this component. This study discusses adsorption performance of elemental mercury sorbents from simulated natural gas (SNG) by copper sulfide pported active alumina. All sorbents were characterized through XRD, BET, TEM, XRF, LECO carbon/sulfide analyzer. The simulated natural gas creates by evaporating the liquid mercury contained in a thermostat glass saturator at temperature of 60oC into a stream of pure nitrogen. These sorbents were loaded in a fixed-bed reactor and sulfided with a nitrogen gas containing 8 % mol of H2S at the temperature of 285oC overnight. Then, the effect of sorbent samples for removing mercury was tested at the temperature of 60oC, pressure of 1atm and SNG flowrate of 220 cm3/min, and in several steps in terms of time the results were reported. The characterization results of suitable sorbent showed its meso pore is higher and capacity is larger than other sorbent. Experiments have showed the suitable sorbent removed approximately 19 percent of mercury exist in SNG with respect to sorbent's weight.

In the present study, active carbon and active alumina adsorbents were improved using sodium hydroxide and potassium hydroxide solutions in order to increase the absorption of carbon dioxide. The effect of different operating parameters including the amount of adsorbent, concentration of hydroxide solution, temperature, and pressure on the adsorption process were investigated. The results of the adsorption experiments showed that the carbon dioxide absorption capacity increases by decreasing the temperature and increasing the pressure. The optimum conditions were 20 ° C, 6 bar, 2 g of adsorbent with 30% weight sodium hydroxide and potassium hydroxide. The maximum carbon dioxide absorption capacity for activated carbon modified with sodium hydroxide and potassium hydroxide solutions were 104.42 mg/g and 84.8 mg/g, respectively, which indicates 83 and 48 percent increase for modified activated carbon in comparison with unmodified ones. The carbon dioxide absorption capacity for activated alumina modified with sodium hydroxide and potassium hydroxide solutions were 146.70 and 130.84 mg/g, respectively, which indicates 47 and 65 percent increase for modified activated carbon in comparison with unmodified ones. As a result, generally, the modified activated alumina adsorbent revealed higher carbon dioxide absorption capacity carbon in comparison with the modified activated carbon.