CO2 adsorption in amine-grafted zeolite 13X (original) (raw)

A comparative study of CO 2 capture by amine grafted vs amine impregnated zeolite 4A

Zeolite 4A was functionalized via grafting and impregnation techniques using 0.3 wt% of isopropylamine (IPA) and (3-aminopropyl) trimethoxysilane (APTMS) respectively. Physicochemical properties of zeolite 4A containing binder were changed after amine loading, as both specific surface area and pore volume was decreased by 1.52 %, 18.18 % and 28.06 %, 90.90 % for Z4A-IPA (IPA impregnated zeolite 4A) and Z4A-APTMS (APTMS grafted zeolite 4A) respectively. The adsorbed CO2 amount of Z4A, Z4A-IPA, and Z4A-APTMS were 1.58 mmol g-1 (6.95 wt%), 2.31 mmol g-1 (10.16 wt%) and 1.05 mmol g-1 (4.62 wt%) respectively at1 bar and 25 °C. Noticeably, among all the studied adsorbents, Z4A-IPA displayed the highest adsorption capacity of 1.39 mmol g-1 (6.11 wt%) at 0.15 bar, which is akin to the CO2 partial pressure of post-combustion flue gas. The multilayer tethering of the bulkier APTMS on the zeolite external surface resulted in the partial blockage of the pores and hence the facile access of CO2 inside the pores of zeolite was hindered. However, Z4A-APTMS was found to be more thermal stable than Z4A-IPA. Furthermore, we observed that physisorption was playing a vital role in CO2 adsorption for pristine zeolite 4A (Z4A), whereas, after amine incorporation, the presence of amine induced the heterogeneous interaction between CO2 and sorbents.

Technoeconomic Investigation of Amine-Grafted Zeolites and Their Kinetics for CO2 Capture

ACS Omega

Solid adsorbents with precise surface structural chemistry and porosity are of immense interest to decode the structure−property relationships and maintain an energy-intensive path while achieving high activity and durability. In this work, we reported a series of amine-modified zeolites and their CO 2 capture efficiencies. The amine impregnated molecular zeolite compounds were characterized and systematically investigated for CO 2 adsorption capacity through thermogravimetric analysis for the occurrence of atmospheric pure CO 2 gas at 75°C with diethylenetriamine (DETA), ethylenediamine (EDA), monoethanolamine (MEA), and triethanolamine (TEA)-loaded zeolite 13X, 4A, and 5A adsorbents. The kinetics of the adsorption study indicated that the adsorption capacity for CO 2 adsorption was improved with amine loading up to a certain concentration over 13X-DETA-40, showing an adsorption capacity of 1.054 mmol of CO 2 per gram of zeolite in a very short amount of time. The result was especially promising in terms of the initial adsorption capacity of zeolite, which adsorbed approximately 0.8 mmol/g zeolite within the first two minutes of experimentation. A detailed flow chart that includes a brief look into the process adopted for adsorption was included. Lagergren pseudo-first-and pseudo-second-order models of 40 wt % DETA zeolite 13X gave CO 2 adsorption capacities of 1.055 and 1.058 mmol/g and also activation energies of 86 and 76 kJ/mol, respectively. The CO 2 adsorption capacity of 13X-DETA-40 in a lab-scale reactor was found to be 1.69 mmol/g. A technoeconomic study was conducted for the solid amine zeolites to understand the investment per ton of CO 2 adsorbed. This study was used as a basis to improve cost estimates from a microscale to a lab-scale reactor. The cost of investment for 13X-DETA-40 was

Monoethanol amine modified zeolite 13X for CO adsorption at different temperatures

Energy & Fuels, 2007

Zeolite 13X has been modified with monoethanol amine (MEA). MEA loadings of 0.5-25 wt % have been achieved using the impregnation method in different solvents. The mode of incorporation based on methanol with stirring at room temperature appears to be the most feasible. The adsorbent has been characterized for crystallinity, surface area, pore volume, and pore size. The thermal stability of the adsorbent is studied using a thermal analyzer. The CO 2 adsorption capacity of adsorbents is evaluated using the breakthrough adsorption method with a packed column on a 10 g scale. The adsorption capacities of adsorbents are estimated in the temperature range 30-120°C. The adsorbents show improvement in CO 2 adsorption capacity over the unmodified zeolite by a factor of ca. 1.6 at 30°C, whereas at 120°C the efficiency improved by a factor of 3.5. For adsorption at these temperatures, different MEA loading levels were found to be suitable as per the governing adsorption phenomena, that is, physical or chemical. The adsorbent is also studied for CO 2 selectivity over N 2 at 75°C. The MEA-modified adsorbent shows better CO 2 selectivity, which was improved further in the presence of moisture.

Amine loaded zeolites for carbon dioxide capture: Amine loading and adsorption studies

Novel functionalised adsorbents have been synthesized by immobilization of various amines on synthetic zeolite 13X. Various primary and secondary amines namely monoethanolamine (MEA), ethylenediamine (ED) and isopropanol amine (IPA) have been immobilized on zeolite 13X. Quantitative estimations of the amine loadings were undertaken using different analytical techniques namely titrimetric, total organic carbon and gas chromatography analysis. Fairly good correlation was obtained for amine loadings estimated using the three techniques. Effect of various parameters like effect of solvent, shaking time, synthesis temperature, and wetting of pellets prior to amine loadings was also studied. The results revealed that maximum loading was achieved for methanol-mediated synthesis conducted using previously wetted pellets at room temperature and with 15 min of shaking time. Preliminary attempts have also been made to determine the CO 2 adsorption capacities of these newly developed materials. The adsorption capacities obtained were 16.01 mg/g for unmodified zeolite 13X and 19.98, and 22.78 mg/g for zeolite modified with monoethanol amine, and isopropanol amine.