TiO(OH)2 – highly effective catalysts for optimizing CO2 desorption kinetics reducing CO2 capture cost: A new pathway

Abstract

The objective is to find a new pathway for significant reduction in CO2 capture energy consumption. Specifically, nanoporous TiO(OH)2 was used to realize the objective, which was desired as a catalyst to significantly accelerate the decomposition of aqueous NaHCO3, essentially CO2 desorption – the key step of Na2CO3/NaHCO3 based CO2 capture technologies from overall CO2 energy consumption perspective. Effects of several important factors on TiO(OH)2-catalyzed NaHCO3 decomposition were investigated. The quantity of CO2 generated from 0.238 mol/L NaHCO3 at 65 °C with catalyst is ~800% of that generated without the presence of catalyst. When a 12 W vacuum pump was used for carrying the generated CO2 out of reactor, the total amount of CO2 released was improved by ~2,500% under the given experimental conditions. No significant decrease in the catalytic effect of TiO(OH)2 was observed after five cyclic CO2 activated tests. In addition, characterizations with in-situ Fourier transform infrared spectroscopy, thermal gravity analysis and Brunauer-Emmett-Teller of TiO(OH)2 indicate that TiO(OH)2 is quite stable. The discovery in this research could inspire scientists’ interests in starting to focus on a new pathway instead of making huge effort or investment in designing high-capacity but expensive CO2 sorbent for developing practical or cost-effective CO2 technologies.

A Review on Enhancing Solvent Regeneration in CO2 Absorption Process Using Nanoparticles

“…The basic reaction chemistry for potassium carbonate (K 2 CO 3 ) solvent or Sodium Carbonate (Na 2 CO 3 ) solvent and CO 2 is represented in the overall reaction as shown in Equation (12), where M represents Na or K [38][39][40].…”

“…6.1.5. TiO(OH) 2 TiO(OH) 2 is a fundamentally different metal oxide nanoparticle that was recently studied for the regeneration process of solvents in an absorption based process for CO 2 capture [24,38,110]. The past studies proposed a catalytic behavior instead of a heat and mass transfer enhancement.…”

“…In 2017, Yao et al [38] studied the employment of nanoporous TiO(OH) 2 on the regeneration of aqueous Na 2 CO 3 . At 65 • C, the quantity of CO 2 desorbed is approximately 800% more than the case without the presence of TiO(OH) 2 .…”

Cost-Effective Nanoporous Hypercross-linked Polymers Could Drastically Promote the CO2 Absorption Rate in Amine-Based Solvents, Improving Energy-Efficient CO2 Capture

“…Among them, the development of energyefficient solvents with more desirable properties is the most popular strategy. 3,4 Tertiary amines such as N-methyldiethanolamine (MDEA) are alternative solvents with favorable thermodynamic properties that provide lower regeneration energy and higher CO 2 absorption capacity compared with conventional monoethanolamine (MEA), but they are limited by slow reactivity with CO 2 . 5 This limitation increases equipment size and investment costs, resulting in restricting their large-scale utilization.…”

The effect of solid adsorbents in Triethanolamine (TEA) solution for enhanced CO2 absorption rate

“…Much effort has been made in this regard to reduce CO 2 desorption energy consumption. The most common strategy is the producing of energy-efficient solvents with more desirable properties [17][18][19][20]. Compared to monoethanolamine, tertiary amines have better thermodynamic properties and have lower regeneration energy and higher CO 2 absorption potential [20].…”