Influence of Moisture on CO₂ Separation from Gas Mixture by a Nanoporous Adsorbent Based on Polyethylenimine-Modified Molecular Sieve MCM-41

Abstract

Adsorption separation of CO2 from simulated flue gas containing CO2, O2, and N2 with and without moisture was investigated using a novel nanoporous adsorbent based on polyethylenimine (PEI)-modified mesoporous molecular sieve MCM-41 in a flow system. The CO2 adsorption capacity and CO2 separation selectivity of MCM-41 were greatly improved by loading PEI into its nanosized pore channels, which made the resulting adsorbent operating like a “molecular basket” for CO2. CO2 adsorption capacity of the MCM-41-PEI adsorbent for the simulated moist flue gas was higher than that for the simulated dry flue gas. CO2 separation selectivity of the MCM-41-PEI adsorbent was also improved in the presence of moisture when compared with those in the dry gas condition. The influence of moisture concentrations in the simulated flue gas on the CO2 adsorption separation performance was also examined. The results of adsorption/desorption separation cycles showed that the MCM-41-PEI adsorbent was stable over 10 cycles of adsorption/desorption operations. The hydrothermal stability of the “molecular basket” adsorbent was better than that of the MCM-41 support alone.

Adsorption of Carbon Dioxide from Gas Streams via Mesoporous Spherical-Silica Particles

“…The q e of both samples increased with temperature from 20 to 60°C but decreased with temperature from 60 to 100°C and have the maximum q e at 60°C. Similar observations on the correlation of q e with temperature had been reported in other studies of silica sorbents, 21,40 where the maximum q e was found at 75°C. This may be because of the nature of silica sorbents.…”

Near-Zero Emissions Oxy-Combustion Flue Gas Purification

“…Xu et al (80) developed a "molecular basket" adsorbent (MCM-41-PEI) for CO 2 capture from flue gas of a natural gas-fired boiler. It is claimed to have high adsorption capacity and high CO 2 selectivity.…”

Removal of CO2 in a Multi Stage Fluidized Bed Reactor by Monoethanolamine Functionalize Activated Carbon

“…For removal of CO 2 from flue gas, adsorption process is a very simple and cost-effective [2]. The activated carbon (AC) surface chemistry is also an important criteria [3][4] during adsorption process.…”