Use of a Robust and Inexpensive Nanoporous TiO₂ for Pre-combustion CO₂ Separation

Abstract

The objective of this research is to study the performance of an inexpensive high-surface-area nanoporous titanium oxide (TiO 2 ) on the CO 2 /H 2 separation and resulting pre-combustion CO 2 capture. The experiments were carried out at different temperatures (25, 50, 75, 100, and 125 °C) and pressures (5, 10, 15, 20, 25, 30, and 35 bar) using a fixed-bed adsorber. The data obtained for the pure component isotherms and binary gas mixtures were correlated using Sips and Langmuir−Freundlich binary-component-expanded isotherm adsorption (LFBE) models, respectively. Also, the deactivation model was used to simulate the observed CO 2 sorption breakthrough curves. Experimental results show that the capture capacities of the sorbent for both H 2 and CO 2 were improved with the increase in the pressure and decrease in the temperature. The maximum sorption capacities for pure CO 2 and H 2 were found to be 14.4 and 5.2 mmol/g of TiO 2 at 35 bar and 25 °C, respectively. The increase in the temperature and decrease in the pressure improve the sorption selectivity of TiO 2 for CO 2 . The selectivity value of TiO 2 reached 9.87 at 125 °C and 5 bar for a CO 2 /H 2 molar ratio of 50:50. TiO 2 also shows great stability and regenerability. This study indicates that nanoporous TiO 2 is potentially a cost-effective and robust CO 2 /H 2 separation agent and provides the knowledge needed for further demonstration of the nanoporous TiO 2 -based pre-combustion CO 2 separation technology.

Aminosilane‐Grafted Zirconia–Titiania–Silica Nanoparticles/Torlon Hollow Fiber Composites for CO2 Capture

“…found that ZrO 2 ‐supported potassium exhibits a higher CO 2 uptake, better thermal stability, and better regeneration characteristics than TiO 2 ‐supported potassium . Furthermore, the use of amine‐modified TiO 2 has been studied in CO 2 adsorption process by several research groups . More recently, Kapica‐Kozar and co‐workers modified bare TiO 2 with NH 4 OH and/or KOH solutions and found that the total adsorption capacity increased dramatically from 0.06 mmol g −1 in the case of bare TiO 2 to 0.53 mmol g −1 in case of the most efficient comodified sample (TiO 2 ‐2.5 % N/10 % K).…”

Opening the Toolbox: 18 Experimental Techniques for Measurement of Mixed Gas Adsorption

“…High time resolution for composition measurement is desirable, especially for mixtures containing strongly adsorbing species with sharp breakthrough profiles. This makes the MS the most popular choice, although other sensors like infrared 36 or H 2 analyzers 37 have also been used.…”

A new mesoporous amine-TiO2 based pre-combustion CO2 capture technology

“…Before adsorption started, N 2 was preferred to be introduced into the adsorber until pressure in the adsorber rose to a predetermined value and N 2 constant concentration profiles on the MS were observed. This was followed by closing the back-pressure regulator (21) and 3-way valve (8) to maintain constant pressure inside the adsorber, after which th e ou tl e t N 2 of the back-pressure regulator (13) between the back-pressure regulator (5) and (6) was maintained at the same set pressure through the back-pressure regulator (5). After the concentration of N 2 entering the MS gradually decreased to zero, the adsorbates were introduced into the adsorber to replace the filled N 2 until constant concentration profiles on the MS were observed by opening the back pressure regulator (21).…”

“…Intensive research interest has focused on the utilization of high surface areas and open pore solid sorbents for CO 2 capture. [3,7] Examples of porous inorganic materials include activated carbon [8,9], zeolites [10,11], silica [12], titanium dioxide [13], and metal-organic frameworks (MOFs) [14,15]. These sorbents are normally used in adsorption fixed bed reactors or fluidized bed reactors.…”