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With efficient energy recovery, calcium-oxide-based absorbents that operate at elevated temperatures have an advantage over absorbents that operate at lower temperatures for CO 2 capture from coal power plants. The major limitation of these absorbents is that the carbonation and decarbonation reactions of CaO and CaCO 3 are far from complete or reversible. Rapid loss of CO 2 capacity over many carbonation/ decarbonation cycles is always observed because of severe absorbent sintering. We have found that this sintering effect can be effectively mitigated by properly mixing calcium oxide precursors with small rod-like MgAl 2 O 4 spinel nanoparticles. A new class of CaO-based absorbents with much improved hightemperature durability was developed by wet physical mixing of calcium acetate with nano MgAl 2 O 4 spinel particles followed by high-temperature calcination. CaO-MgAl 2 O 4 (32 wt % spinel content) material provides 34 wt % CO 2 capacity after 65 carbonation-decarbonation cycles (650 and 850 °C, respectively), corresponding to 63% CaO use. Under the same test conditions, the CO 2 capacity of natural dolomite (35 wt % MgO and 65 wt % CaO) decreases rapidly from 25 wt % for the 1st cycle to less than 5 wt % for the 50th cycle.

In the base catalyzed ethanol condensation reactions, the calcined MgO-Al 2 O 3 derived hydrotalcites used broadly as catalytic material and the calcination temperature plays a big role in determining the catalytic activity. The characteristics of the hydrotalcite material treated between catalytically relevant temperatures 450 and 800°C have been studied with respect to the physical, chemical, and structural properties and compared with catalytic activity testing. With the increasing calcination temperature, the total measured catalytic basicity dropped linearly with the calcination temperature and the total measured acidity stayed the same for all the calcination temperatures except 800°C. However, the catalyst activity testing does not show any direct correlation between the measured catalytic basicity and the catalyst activity to the ethanol condensation reaction to form 1-butanol. The highest ethanol conversion of 44 % with 1-butanol selectivity of 50 % was achieved for the 600°C calcined hydrotalcite material.

We report a hierarchically structured catalyst with steam reforming and hydrodeoxygenation functionalities being deposited in the micropores and macropores, respectively. The catalyst is highly efficient to upgrade the pyrolysis vapors of pine forest product residual, resulting in a dramatically decreased acid content and increased hydrocarbon yield without external H2 supply.

High temperature (800 °C) pre-calcination of CeO2 support decreases the surface defects and improves the mobility of surface lattice oxygen. As a result, the supported Pt clusters have higher oxygen coverage and superior HC oxidation activity.

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