Kinetic evaluation of sterically hindered amines under partial oxy‐combustion conditions

Abstract

BACKGROUND Carbon capture and storage is considered one of the pillars that should support greenhouse gas (GHG) emission mitigation by 2050. In this sense, partial oxy‐combustion emerges as a promising alternative. Its advantages rely on the production of a higher CO2 concentration flue gas than these provided by conventional air‐firing processes. The use of higher CO2 concentrations should improve the solvent kinetic and the CO2 cyclic capacity. RESULTS The kinetic behaviour of two representative sterically hindered amines, namely 2‐amino‐2‐methyl‐1‐propanol (AMP) and isophrondiamine (IF), were studied under partial oxy‐combustion conditions in a laboratory‐scale semi‐batch reactor. The CO2 concentration varied from 15%v/v to 60%v/v. The kinetic enhancement experienced by AMP at high CO2 concentration was slightly >60%, instead of 70–80% for IF. AMP also improved its CO2 absorption capacity by 24.7%, from 15%v/v to 60%v/v, almost doubled the improvements achieved by monoethanolamine (MEA). In the case of IF experiments, the CO2 loading increased ≈10% from 15%v/v to 60%v/v CO2 and it changed from 1.10 to 1.34 mol CO2 mol–1 solvent, representing a >20% increase. CONCLUSIONS The presence of higher CO2 concentrations accelerated CO2 absorption and provided higher CO2 absorption rates. In addition, the evolution of the CO2 loading also exhibited higher values in the experiments using higher CO2 concentration flue gas. The steric hindrance causes a hybrid behaviour in these solvents, between both fast and slow kinetic solvents. The kinetic rates observed using AMP were slightly higher than MEA, but lower than IF which showed the fastest kinetics. © 2020 Society of Chemical Industry

Investigation of Biocatalytic Absorption and Ultrasound-Assisted Desorption Performance of CO2 Capture

“…SHAs have a functional group located close to the amino group. The resulting steric hindrance produces weaker C-N bonds upon reaction with CO 2 , because of which lower energy is required for solvent regeneration [19]. SHAs have been strongly recommended as potential absorbents due to their high theoretical loading capacity of up to 1.0 mol CO 2 /mol amine [20].…”

The enhanced enzymatic performance of carbonic anhydrase on the reaction rate between CO2 and aqueous solutions of sterically hindered amines

“…Moreover, such a solution has low CO 2 loadings (the theoretical maximum amount is 0.5 mol CO 2 /mole amine) due to its stable carbamate ion 12–15 . In contrast, certain sterically hindered amines (SHAs) have higher loading capacities, as much as approximately 1, due to their unstable carbamate ions 16,17 . Reduced carbamate stability may allow the existence of a high free amine concentration in solution, which results in rapid amine‐CO 2 reaction rates 16 .…”

In Focus: ANQUE‐ICCE‐CIBIQ 2019

“…Overall, this In Focus presents an exciting collection of works covering relevant topics connected to the fields of process technology and environmental and sustainable technology. Particularly, several papers focus on technological advances and challenges for cleaner energy production, which involves several capture technologies at different levels of maturity . First, process intensification in post‐combustion carbon capture is considered by combining the use of ionic liquids and membrane technology .…”

“…First, process intensification in post‐combustion carbon capture is considered by combining the use of ionic liquids and membrane technology . In addition, the evaluation of the CO 2 absorption capacity of sterically hindered amines under partial oxy‐combustion conditions and the thermochemical assessment of the susceptibility of oxygen transport membranes under oxy‐combustion conditions in a pilot‐scale facility are addressed. Moreover, utilization of CO 2 captured from combustion processes is a promising option that is attracting increasing attention.…”

“…Particularly, several papers focus on technological advances and challenges for cleaner energy production, which involves several capture technologies at different levels of maturity. [1][2][3] First, process intensification in post-combustion carbon capture is considered by combining the use of ionic liquids and membrane technology. 1 In addition, the evaluation of the CO 2 absorption capacity of sterically hindered amines under partial oxycombustion conditions 2 and the thermochemical assessment of the susceptibility of oxygen transport membranes under oxycombustion conditions in a pilot-scale facility 3 are addressed.…”