In order to meet the 1.5−2C target, with CCU, it is necessary to close the carbon cycle, and avoid partial decarbonisation scenarios. In this context, direct air capture appears more effective than CCU.
Chemical looping processes based on multiple-step reduction and oxidation of metal oxides hold great promise for a variety of energy applications, such as CO2 capture and conversion, gas separation, energy storage, and redox catalytic processes. Copper-based mixed oxides are one of the most promising candidate materials with a high oxygen storage capacity. However, the structural deterioration and sintering at high temperatures is one key scientific challenge. Herein, we report a precursor engineering approach to prepare durable copper-based redox sorbents for use in thermochemical looping processes for combustion and gas purification. Calcination of the CuMgAl hydrotalcite precursors formed mixed metal oxides consisting of CuO nanoparticles dispersed in the Mg-Al oxide support which inhibited the formation of copper aluminates during redox cycling. The copper-based redox sorbents demonstrated enhanced reaction rates, stable O2 storage capacity over 500 redox cycles at 900 °C, and efficient gas purification over a broad temperature range. We expect that our materials design strategy has broad implications on synthesis and engineering of mixed metal oxides for a range of thermochemical processes and redox catalytic applications.
Measurements for the density and viscosity of partially carbonated solutions containing water, piperazine (PZ), and a tertiary amine, which was either dimethylaminoethanol (DMAE) or 2-diethylaminoethanol (DEAE), were conducted with total amine mass fractions of 30% and 40% over a temperature range from 298.15 to 353.15 K. Density and viscosity correlations of these mixtures were developed as functions of amine mass fraction, CO2 loading, and temperature. For both systems investigated, the average absolute relative deviations of the experimental data from these correlation are approximately 0.2% for density and 3% for viscosity. The correlations will be useful for thermodynamic analysis and computer simulations of carbon capture processes utilizing these promising blended amine systems
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