Ethanol conversion over Ga2O3-ZrO2 solid solution: empirical evidences of the reaction pathway, the surface acid–base property, and role of isolated gallium ion

Ethanol conversion by Ga2O3-ZrO2 solid solution was examined in the temperature range 573–773 K, and acetone/isobutene formation was confirmed under cofeeding of H2O vapor. The reaction pathway was empirically investigated...

Molecular Dynamics Simulation to Investigate the Interaction of Asphaltene and Oxide in Aggregate

The asphalt-aggregate interface interaction (AAI) plays a significant role in the overall performances of asphalt mixture, which is caused due to the complicated physicochemical processes and is influenced by various factors, including the acid-base property of aggregates. In order to analyze the effects of the chemical constitution of aggregate on the AAI, the average structure C65H74N2S2is selected to represent the asphaltene in asphalt and magnesium oxide (MgO), calcium oxide (CaO), aluminium sesquioxide (Al2O3), and silicon dioxide (SiO2) are selected to represent the major oxides in aggregate. The molecular models are established for asphaltene and the four oxides, respectively, and the molecular dynamics (MD) simulation was conducted for the four kinds of asphaltene-oxide system at different temperatures. The interfacial energy in MD simulation is calculated to evaluate the AAI, and higher value means better interaction. The results show that interfacial energy between asphaltene and oxide reaches the maximum value at 25°C and 80°C and the minimum value at 40°C. In addition, the interfacial energy between asphaltene and MgO was found to be the greatest, followed by CaO, Al2O3, and SiO2, which demonstrates that the AAI between asphalt and alkaline aggregates is better than acidic aggregates.

Using ozonation to eliminate the inhibition of soluble algal products (SAP) of Scenedesmus sp. LX1 on its growth in microalgal cultivation for biomass/bioenergy production

Water recycling is an effective way to reduce water consumption in the industrialization of microalgae-based biomass/bioenergy production. The soluble algal products (SAP) which inhibit the microalgae growth will accumulate in the recycled water. Therefore, the ozone oxidation treatment of SAP produced by Scenedesmus sp. LX1 was studied to reduce the inhibition of SAP. The experimental results showed that there was almost no change in the content of SAP (counted by dissolved organic carbon) after ozonation, but the inhibition of SAP on microalgae growth disappeared. The intrinsic growth rate (r) of Scenedesmus sp. LX1 in the cultivation solution containing untreated SAP was 0.52 d−1, and it rose to 0.95 d−1 after SAP was ozonized. The maximum population growth rate (Rmax) followed a similar trend, increasing from 9.19 × 105 to 13.0 × 105 cells mL−1 d−1. It was suggested that the changes of fluorescence and hydrophilic–hydrophobic/acid–base property of SAP after ozonation leads to the disappearance of SAP inhibition on microalgae growth.