Start-up and Performance of a Novel Reactor----Jet Biogas Inter-loop Anaerobic Fluidized Bed

A novel anaerobic reactor, jet biogas inter-loop anaerobic fluidized bed （JBILAFB）, was designed and constructed. The start-up and performance of the reactor was investigated in the Process. of .artificial glucose wastewater treatment. With the wastewater recycle ratio of 2.5 ： 1, the recycled wastewater with biogas could mix sludge and wastewater in the JBILAFB reactor completely. The start-up of the JBILAFB reactor could be completed in less than 70 d through maintenance of hydraulic retention time （HR^I＂） and stepwise increase of feed total organic carbon （TOC） concentration. After the start-up, with the volumetric TOC loadings of 14.3 kg·m ^-3·d^-1, the TOC removal ratio, the effluent pH, and the volatile fatty acids （VFA）/alkalinity of the JBILAFB reactor were more than 80%, close to 7.0 and less than 0.4, respectively. Moreover, CH4 was produced at more than 70% of the theoretical value, The reactor exhibited high stability under the condition of high volumetric TOC loading. Sludge granules in the JBILAFB reactor were developed during the start-up and their sizes were enlarged with the stepwise increase of volumetric TOC loadings from 0.8 kg.m^-3.d ^-1 to 14.3 kg.m^-3.d^-1. Granules, an offwhite color and a similar spherical shape, were mainly comprised of global-like bacteria. These had good methanogenic activity and settleability, which were formed probably through adhesion of the bacteria. Some inorganic metal compounds such as Fe, Ca, Mg, Al, etc. were advantageous to the formation of the granules.

Ship-in-bottle synthesis of NaY zeolite encapsulated Cosalen complex and its catalytic performance for cyclohexane oxidation

N, N＇-bis （salicylidene） ethylenediiminocobalt （Cosalen） was encapsulated into microporous NaY zeolite via the technique of ＂ship-in-bottle＂. The encapsulated complex （Cosalen-NaY） was characterized by Fourier-transform infrared spectrum, ultraviolet-visible spectrum, Brunaner-Emmett-Teller surface areas, X-ray diffraction, thermogravimetry-differential thermal analysis and scanning electron microscope. The reaction of cyclohexane oxidation using oxygen was chosen to investigate the catalytic performance of Cosalen-NaY, and the effects of oxygen pressure, temperature and reaction time were also studied. The results show that Cosalen complex is encapsulated into the supercage of the zeolite and the structure of NaY zeolite remains integrity and the thermal stability of Cosalen is greatly enhanced after encapsulation. Cosalen-NaY shows the better activity in the oxidation of cyclohexane without reductant and solvent. The conversion of cyclohexane is up to 13.4% at 150 ℃ for 3 h under oxygen pressure of 0.85 MPa, with the higher total selectivity to cyclohexanol, cyclohexanone, cyclohexyl hydroperoxide （CHHP） and acid （79.2%） than the neat complex （55.5%）. NaY zeolite cartier maybe contributes to the results. There is no obvious induction period to initiate the reaction; furthermore, the amount of CHHP among the products is small, which indicates that the Cosalen-NaY has the strong ability to accelerate the decomposition of CHHP. Recycling tests show that the hybrid material can be used repeatedly with a negligible loss of active sites.