Poly(ethyleneimine)-Loaded Silica Monolith with a Hierarchical Pore Structure for H₂S Adsorptive Removal

Abstract

Poly(ethyleneimine) (PEI) loaded hierarchical porous silica monolith has been developed as a recycle H 2 S sorbent at low temperature. The sorbent was characterized by N 2 adsorption, scanning electron microscope, transmission electron microscope, Fourier transform infrared spectra, and activity tests. The effects of the amount of PEI loading, the operating temperature, and the PEI polymerization degree on H 2 S removal were studied. The sorbent demonstrated a large H 2 S breakthrough capacity of 1.27 mmol of H 2 S/(g of sorbent) at 22 °C, which is about 60% larger than that of PEI-loaded SBA-15 or MCM-41 sorbent. The optimal PEI loading is 65 wt %, and the most ideal PEI molecular weight is 600. As the decrease of the temperature, the sorption performance of the sorbent increases greatly. There are two important factors affecting the performance of H 2 S sorption: the amount of available PEI in the sorbent and the interaction between H 2 S and amine functional groups of PEI. In addition, the developed sorbent can be regenerated easily at 75 °C, and it exhibits excellent regenerability and stability. These results indicate that PEI-loaded hierarchical porous silica sorbent will be promising for removing H 2 S in the future.

Development of amine-functionalized hierarchically porous silica for CO2 capture

“…For adsorbents modified with different mass fraction TEPA, wave numbers at 1231 cm À1 , 1312 cm À1 and 3348 cm À1 are connected with the stretching vibration of CÀ ÀN, the bending vibration of NÀ ÀH from the secondary amine (N(R)H) in TEPA, respectively [28,47]. Wave numbers at 2922 cm À1 and 2834 cm À1 are due to the symmetric and non-symmetric stretching vibrations of ÀCH in TEPA [48]. The new bands at 1570 cm À1 , 1470 cm À1 correspond to the symmetric and non-symmetric stretching vibrations of NÀ ÀH in the primary amine (ÀNH 2 ) in TEPA, indicating that TEPA was successfully impregnated into the HPS.…”

Poly(ethylenimine)‐Functionalized Monolithic Alumina Honeycomb Adsorbents for CO2 Capture from Air

“…Specifically, the functionalization of porous monolithic structures with polymeric amines for CO 2 capture has been explored only to a very limited degree. Meso‐macroporous silica monoliths prepared by lab‐scale techniques have been impregnated with PEI and tetra(ethylenepentamine) (TEPA) and investigated for gas adsorption in several studies . Higher adsorption capacities were observed with the monolithic supports than with amine/oxide powders, a phenomenon that has been largely explained by the increased total pore volume and pore connectivity in the structured materials.…”

Effect of pH and chitosan concentration on precipitation and morphology of hierarchical porous silica

“…Several Researchers have focused on the improvement of surface chemistry, molecular structure, morphology and porosities of silica materials in order to obtain the best performance for each application [3][4][5]. Traditional syntheses of silica-based materials require elevated temperature, high pressure, strongly acidic or alkaline media, and a long time for the synthesis process [6].…”