Metal Oxyhydroxide Catalysts Promoted CO₂ Absorption and Desorption in Amine-Based Carbon Capture: A Feasibility Study

The huge energy penalty of CO2 desorption is the greatest challenge impeding the commercial application of amine-based CO2 capture. To deal with this problem, a series of metal oxide and oxyhydroxide catalysts were synthesized in this study to kinetically facilitate the CO2 desorption from 5.0 M monoethanolamine (MEA). The effects of selected catalysts on CO2 absorption kinetics, CO2 absorption capacity, CO2 reaction enthalpy, and desorption duty reduction of 2.0 M MEA were investigated by a true heat flow reaction calorimeter to access the practical feasibility of the catalytic CO2 desorption. The kinetic study of catalytic CO2 desorption was also carried out. CO2 desorption chemistry, catalyst characterization, and structure–function relationships were investigated to reveal the underlying mechanisms. Results show that addition of the catalyst had slight effects on the CO2 absorption kinetics and CO2 reaction enthalpy of MEA. In contrast, the CO2 desorption efficiency greatly increased from 28% in reference MEA to 52% in ZrO(OH)2-aided MEA. Compared to the benchmark catalyst HZSM-5, ZrO(OH)2 exhibited a 13% improvement in CO2 desorption efficiency. More importantly, compared to the reference MEA, the CO2 desorption duties of ZrO(OH)2 and FeOOH-aided MEA significantly reduced by 45 and 47% respectively, which are better than those of most other reported catalysts. The large surface area, pore volume, pore diameter, and amount of surface hydroxyl groups of ZrO(OH)2 and FeOOH afforded the catalytic performance by promoting the adsorption of alkaline speciation (e.g., MEA and HCO3–) onto the particle surface

The relationship of the LnR of NT/RT on CH₄ and N₂O emissions in paddy and upland fields.

<p>The relationship of the LnR of NT/RT on CH₄ and N₂O emissions in paddy and upland fields.</p

The overall effects of reduced tillage system on CH₄, N₂O and overall GWP.

<p>The overall effects of reduced tillage system on CH₄, N₂O and overall GWP.</p

Impact of agronomy practices on the effects of reduced tillage systems on CH₄ and N₂O emissions from agricultural fields: A global meta-analysis

<div><p>The effect of no- and reduced tillage (NT/RT) on greenhouse gas (GHG) emission was highly variable and may depend on other agronomy practices. However, how the other practices affect the effect of NT/RT on GHG emission remains elusive. Therefore, we conducted a global meta-analysis (including 49 papers with 196 comparisons) to assess the effect of five options (i.e. cropping system, crop residue management, split application of N fertilizer, irrigation, and tillage duration) on the effect of NT/RT on CH₄ and N₂O emissions from agricultural fields. The results showed that NT/RT significantly mitigated the overall global warming potential (GWP) of CH₄ and N₂O emissions by 6.6% as compared with conventional tillage (CT). Rotation cropping systems and crop straw remove facilitated no-tillage (NT) to reduce the CH₄, N₂O, or overall GWP both in upland and paddy field. NT significantly mitigated the overall GWP when the percentage of basal N fertilizer (P_BN) >50%, when tillage duration > 10 years or rainfed in upland, while when P_BN <50%, when duration between 5 and 10 years, or with continuous flooding in paddy field. RT significantly reduced the overall GWP under single crop monoculture system in upland. These results suggested that assessing the effectiveness of NT/RT on the mitigation of GHG emission should consider the interaction of NT/RT with other agronomy practices and land use type.</p></div

Metal Oxyhydroxide Catalysts Promoted CO₂ Absorption and Desorption in Amine-Based Carbon Capture: A Feasibility Study

The huge energy penalty of CO2 desorption is the greatest challenge impeding the commercial application of amine-based CO2 capture. To deal with this problem, a series of metal oxide and oxyhydroxide catalysts were synthesized in this study to kinetically facilitate the CO2 desorption from 5.0 M monoethanolamine (MEA). The effects of selected catalysts on CO2 absorption kinetics, CO2 absorption capacity, CO2 reaction enthalpy, and desorption duty reduction of 2.0 M MEA were investigated by a true heat flow reaction calorimeter to access the practical feasibility of the catalytic CO2 desorption. The kinetic study of catalytic CO2 desorption was also carried out. CO2 desorption chemistry, catalyst characterization, and structure–function relationships were investigated to reveal the underlying mechanisms. Results show that addition of the catalyst had slight effects on the CO2 absorption kinetics and CO2 reaction enthalpy of MEA. In contrast, the CO2 desorption efficiency greatly increased from 28% in reference MEA to 52% in ZrO(OH)2-aided MEA. Compared to the benchmark catalyst HZSM-5, ZrO(OH)2 exhibited a 13% improvement in CO2 desorption efficiency. More importantly, compared to the reference MEA, the CO2 desorption duties of ZrO(OH)2 and FeOOH-aided MEA significantly reduced by 45 and 47% respectively, which are better than those of most other reported catalysts. The large surface area, pore volume, pore diameter, and amount of surface hydroxyl groups of ZrO(OH)2 and FeOOH afforded the catalytic performance by promoting the adsorption of alkaline speciation (e.g., MEA and HCO3–) onto the particle surface

The studies used in the meta-analysis to evaluate the effectiveness of NT/RT on CH₄ and N₂O emissions.

<p>The studies used in the meta-analysis to evaluate the effectiveness of NT/RT on CH₄ and N₂O emissions.</p

Impact of tillage duration on the effects of NT and RT on CH₄, N₂O and overall GWP.

<p>Impact of tillage duration on the effects of NT and RT on CH₄, N₂O and overall GWP.</p

Impact of crop straw management on the effects of NT and RT on CH₄, N₂O and overall GWP.

<p>Impact of crop straw management on the effects of NT and RT on CH₄, N₂O and overall GWP.</p

Impact of cropping system on the effects of NT and RT on CH₄, N₂O and overall GWP.

<p>Impact of cropping system on the effects of NT and RT on CH₄, N₂O and overall GWP.</p

Impact of irrigation on the effects of NT and RT on CH₄, N₂O and overall GWP.

<p>Impact of irrigation on the effects of NT and RT on CH₄, N₂O and overall GWP.</p