Meizhen Lu

The Effects of Trace Elements on the Lipid Productivity and Fatty Acid Composition of Nannochloropis oculata

The effects of trace elements on the lipid productivity and fatty acid composition of Nannochloropis oculata (N. oculata) were studied. The results showed that trace elements had a strong influence on not only the lipid productivity but also the fatty acid composition. The addition of Fe3

Decomposition treatment of SO2F2 using packed bed DBD plasma followed by chemical absorption

The technology of packed bed dielectric barrier discharge (DBD) plasma followed by a chemical absorption has been developed and was found to be an efficient way for decomposition treatment of sulfuryl fluoride (SO2F2) in simulated residual fumigant. The effects of energy density, initial SO2F2 concentration, and residence time on the removal efficiency of SO2F2 for the DBD plasma treatment alone were investigated. It was found that the SO2F2 could be removed completely when initial volume concentration, energy density, and residence time were 0.5%, 33.9 kJ/L, and 5.1 s, respectively. The removal mechanism of SO2F2 in the packed bed DBD reactor was discussed. Based on the detailed analysis of SO2F2 molecular stability and its exhaust products in the DBD plasma reactor, it was concluded that the energetic electrons generated in the packed bed DBD reactor played a key role on the removal of SO2F2, and the major decomposition products of SO2F2 detected were SO2, SiF4, and S (Sulfur). Among these products, SiF4 was formed by the F atom reacted with the filler-quartz glass beads (SiO2) in the packed bed DBD reactor. Aqueous NaOH solution was used as the chemical absorbent for the gaseous products of SO2F2 after plasma pretreatment. It was found that the gaseous products in the plasma exhaust could be absorbed and fixed by the subsequent aqueous NaOH solution.

A Green Strategy to Enhance a Liquid–Liquid Heterogeneous Reaction with a Magnetic Recyclable Pickering Emulsion

This work described a general strategy to enhance a typical organic–aqueous heterogeneous green oxidation reaction by introducing surface tunable magnetic nanoparticles into liquids to form a controllable Pickering emulsion. We synthesized cross‐linked polystyrene (PS)‐covered Fe3O4 nanoparticles grafted with different N‐alkyl imidazoles and systematically discussed the effect of surface properties on the formation of emulsions. By loading such particles, the dichloromethane–water‐based 2,2,6,6‐tetramethylpiperidine‐1‐oxyl‐mediated Montanari oxidation system was converted from the unstable millimeter‐scale dispersion into a stable micrometer‐scale emulsion, which significantly reduced the reactant transfer distance and resulted in a significantly high overall reaction rate. This reaction efficiency is elucidated in terms of unique properties inherent in an emulsion, including the self‐assembly of Fe3O4/PS and Fe3O4/PS[im‐Cn]Cl (n=1, 4, 6, and 10) nanoparticles, well ensuring a large specific surface area of the water–oil interface.

Microwave-assisted pyrolysis of methyl ricinoleate for continuous production of undecylenic acid methyl ester (UAME)

Undecylenic acid methyl ester (UAME) was continuously produced from methyl ricinoleate using a microwave-assisted pyrolysis system with atomization feeding. The UAME yield of 77 wt.% was obtained at 500°C using SiC as the microwave absorbent and heating medium. The methyl ricinoleate conversion and UAME yield from microwave-assisted pyrolysis process were higher than those from conventional pyrolysis. The effect of temperature on the pyrolysis process was also investigated. The methyl ricinoleate conversion increased but the cracking liquid yield decreased when the temperature increased from 460°C to 560°C. The maximum UAME yield was obtained at the temperature of 500°C.

Hydrocracking of bio-alkanes over Pt/Al-MCM-41 mesoporous molecular sieves for bio-jet fuel production

Bi-functional catalysts consisting of platinum on aluminosilicate MCM-41 materials with Si/Al ratios between 10 and 30 were prepared via direct mixed-gel synthesis. The catalysts were tested in the hydrocracking of bio-alkanes, produced from biodiesel hydrodeoxygenation and composed of n-hexadecane and n-octadecane, for the production of bio-jet fuel. The effects of temperature, pressure, weight hourly space velocity (WHSV), and H2/n-paraffin weight ratio on bio-alkanes conversion and product distribution were examined. The conversion was found to be dependent on the acid strength of the catalyst supports which were proportional to the Al content. However, the catalyst selectivity decreased with the increasing Al content. The optimal Si/Al ratio, temperature, pressure, WHSV, and H2/n-paraffin weight ratio were determined to be 20, 330 °C, 2 MPa, 1 h−1, and 0.20, respectively. Under these conditions, the bio-alkanes conversion and kerosene/gasoline ratio in the product reached 65.62% and 1.96, respectively.