Lijing Gao

Catalytic pyrolysis of natural algae over Mg-Al layered double oxides/ZSM-5 (MgAl-LDO/ZSM-5) for producing bio-oil with low nitrogen content

Cyanobacteria were catalytically pyrolyzed over Mg-Al layered double oxide/ZSM-5 composites (MgAl-LDO/ZSM-5) to produce bio-oil. MgAl-LDO/ZSM-5 with a Mg/Al molar ratio of four was proved to be the best catalyst. Under the optima condition that the final temperature was 823K, heating rate was 10K/min and catalyst/algae mass ratio was 0.75, a maximum yield of liquid (41.1%) was achieved at 823K with a heating rate of 10K/min and a catalyst/algae mass ratio of 0.75, which was much higher than the one obtained without catalyst. The element analysis results proved that this bio-oil had much lower O/C molar ratio and higher HHV. The GC-MS results showed that the bio-oil had less nitrogenous compounds. MgAl4-LDO/ZSM-5 was proved to be an applicable and effective catalyst to obtain bio-oil from catalytic pyrolysis of water-blooming algae.

The comparison of mesoporous HZSM-5 zeolite catalysts prepared by different mesoporous templates and their catalytic performance in the methanol to aromatics reaction

Three kinds of mesoporous HZSM-5 were synthesized successfully by using a hydrothermal methodology with different mesoporous templates, namely, hexadecyl trimethyl ammonium bromide (CTAB), dimethyl distearylammonium chloride (DDAC) and carbon nanotube (CNT). The differences in crystallinity, textural property and acidity among these micro-mesoporous composite molecular sieves were characterized by powder X-ray diffraction, Fourier transform infrared spectroscopy techniques, transmission electron microscopy, nitrogen adsorption and NH3 temperature programmed desorption. The catalytic performances of these mesoporous HZSM-5 zeolites were evaluated by methanol to aromatics (MTA) reaction, and the conventional microporous HZSM-5 was also tested in this reaction for comparison. The results show that mesoporous HZSM-5 zeolite synthesized with CNT mesoporous templates exhibited the highest BTX yields and lowest rate of carbon deposition in MTA reaction among all catalysts. This improved catalytic performance is mainly attributed to not only the well-preserved strong acid sites, which would provide enough active sites for methanol aromatization, but also the generated intra-crystalline mesopores, which would facilitate the access of reactant to the active sites and improve the mass transfer of products. However, mesoporous HZSM-5 synthesized with CTAB and DDAC mesoporous templates did not present improved catalytic performances due to their disconnected micro-mesopores and inadequate strong acidic sites.

Preparation and characterization of polyurethane clearcoats and investigation into their antigraffiti property

A type of antigraffiti polyurethane clearcoat was prepared and characterized. Polymethylsiloxane grafted by fluorocarbon side chains (PSF) was first synthesized through hydrosilylation of polymethylhydrosiloxane with dodecafluoroheptyl acrylate. Hydroxyl fluoroacrylate resins with different hydroxyl contents were synthesized via free radical-initiated solution polymerization and further applied to prepare polyurethane clearcoats. The synthesized polymers were structurally characterized by using Fourier transform infrared and 1H nuclear magnetic resonance. The prepared polyurethane clearcoats underwent contact angle measurement, dynamic thermal mechanical analysis, nanoscratch experiments, and atomic force microscopy. The results reveal that low surface energy, high crosslink density, low coefficient of friction, and low roughness were jointly beneficial to antigraffiti properties. Antigraffiti testing was carried out on the clearcoat with 8.0 wt% PSF and 2.0 wt% active silicone fluid, and this clearcoat showed high resistance to acrylic spray paint, permanent markers, and other graffiti materials.

Ammoxidation of 3-picoline to nicotinonitrile using silica-supported VCrO catalysts

A series of vanadium–chromium oxide (VCrO) catalysts supported on silica was prepared by wetness impregnation method with different Cr/V molar ratios from 0.2 to 1.0. These catalysts were characterized by XRD, TG, temperature-programmed desorption of ammonia (NH3-TPD), X-ray photoelectron spectra (XPS), and Raman spectroscopy, and their catalytic activity was evaluated in the ammoxidation of 3-picoline (3-PIC) to nicotinonitrile (NN). The results of XRD, TG, Raman, and XPS confirmed that the active components on the silica surface were mainly amorphous V2O5 and CrVO4. The results of NH3-TPD showed that acidity of the catalysts decreased with the increase of Cr/V ratio. Catalytic results revealed that acidity of the catalysts was closely related to the catalytic performance. Low acidity gave low conversion of 3-PIC and high NN selectivity. Furthermore, the conversion of 3-PIC increased with rise in reaction temperature, and the selectivity of NN was slightly influenced by the 3-PIC conversion. Therefore, among the catalysts (Cr/V ratio was 0.2, 0.4, 0.6) tested, Cr/V-0.6 catalyst retained the lowest acidity and exhibited the highest selectivity and yield of NN in the ammoxidation of 3-PIC.

Cyanobacteria pyrolysis with methanol catalyzed by Mg-Al hydrotalcite-derived oxides/ZSM-5

ABSTRACT The Cyanobacteria was catalytically pyrolyzed in methanol atmosphere using magnesium-aluminum layered double oxide/ZSM-5 composites (MgAl-LDO/ZSM-5) as a catalyst. The largest liquid yield of 67.68% was obtained in methanol atmosphere, which was much higher than that obtained without methanol under same reaction condition. The Gas chromatography-Mass spectrometer data proved that the organics phase contained less O-compounds and N-compounds and more aromatic compounds. And the ultimate analysis results showed that this bio-oil had much higher HHV values and lower O/C molar ratio. The co-processing methanol atmosphere and bifunctional catalyst would be a promising means for improving the quality of bio-oil.