查看更多>>摘要：A dispersion reactor model of both riser and downer reactors for the fluid catalytic cracking is proposed. The model combines the four-lump cracking kinetics, the hydrodynamic model for. both the riser and downer, and the dispersion nixing model to predict the fluid catalytic cracking reaction performance. The results show that the axial gas backmixing has a large influence on the gasoline yields of the reactor.
查看更多>>摘要：Wet oxidation and nanofikltration are employed in an integrated system for the treatment of bioresistant industrial wastewaters. The partial oxidation products formed during a brief period of pretreatment in a low pressure WO reactor are separated by nanofiltration, and larger molecules are recycled into the reactor where they undergo further oxidation. Experiments were carried out with polyethylene glycol as a model compound in aqueous solution, representing polymer manufacture wastewater.
Bernard M.KabyemelaTadafumi AdschiriRoberto M.Malaluan
p.5063-5067页
查看更多>>摘要：ew here report a continuous method in which glucose is converted by reaction with supercritical water at 400 deg C and 30 Mpa, to erythrose in as high as 50 wt /100. This method is noncatalytic and operates continuously with a reaction residence time of as low as 0.11 s. Erythrose is stable under these conditions and its selectivity changes only slightly from about 50 to 45 wt /100 over the range of glucose conversion from 50 to 90 wt /100.
查看更多>>摘要：Chemical instability of spent acids from nitration units has caused a great deal of severe accidents in the explosives industry. To cope with this hazard, safety charts have been constructed by various authors. In this work, evaluation of the three most commonly used safety charts found in the literature showed that they are not, in general, consistent with each other, due to different storing temperatures considered. Simulation of these experimental data was accomplished, based on simple reaction kinetics models.
查看更多>>摘要：A high-pressure, high-temperature continuous stirred-tank reactor (CSTR) system having approximately an ideal residence time distribution (RTD) has been set up for the polymerization of olefins utilizing metallocene catalysts. Preliminary experiments of ethylene polymerized with the metallocene catalyst system zirconocene dichloride (Cp_2ZrCl_2)/modified-methylaluminoxane (MMAO)/trimethylaluminum (TMA) in toluene at 1500 psig have been carried out.
查看更多>>摘要：Various transition-metal catalysts supported on γ-alumina were prepared and applied for the hydrodenitrogenation (HDN) of pyridine. The NiMo/Al_2O_3 catalyst showed higher activity than the Mo/Al_2O_3 catalyst. On the basis of the results of reaction experiments and measurements of IR and TPR, the enhancement in the HDN activity with nickel addition could be attributed more to the improvement in the reducibility of molybdenum than to the effect of Bronsted acid site.
查看更多>>摘要：The characteristics and the reactivity of coke formed in the pyrolysis of polyethylene (PE) were investigated. A laboratory-scale fixed-bed reactor was used for PE pyrolysis at different temperatures. The morphology of the coke collected was analyzed by scanning electron microscopy. Reactivity of the coke samples was studied by thermogravimetric analysis in oxygen and carbon dioxide. Kinetic parameters and reaction order with respect to gas partial pressure were estimated and compared to literature data.
查看更多>>摘要：Water-containing isoprene was partial hydrogenated over δ-alumina-supported eggshell Pd catalysts with a weight-hourly space velocity (WHSV) of 18 h~1 (grams of feed per hour X grams of catalyst) at 40 deg C and 30 atm (30.39 kg/cm~2) total pressure. The isoprene conversion decreased with time on stream and became almost time invariant at about 50 h, with a value of 20/100. The activity of the water-poisoned catalysts was only slightly recovered after the water-free isoprene was introduced; by this, the conversion was increased only to 24/100.
查看更多>>摘要：Various oxide-promoted Ni catalysts supported on activated carbon were prepared, and the effect of promoters on the surface structure and properties of Ni catalysts was studied. Physical adsorption (N_2 adsorption), thermogravimetric analysis (TGA), temperature-programmed de- sorption (TPD), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) were used to characterize the catalysts. It is found that nickel is fairly uniformly distributed in the pores of the carbon support.
查看更多>>摘要：The inhibiting effect of olefin on CCG HDS (found in our previous report) was further investigated from a mechanistic point of view. A small amount of thiophene (corresponding to ca. 100 wt ppm of sulfur content) and varying amounts of olefins (diisobutylene and 1-octene) dissolved in toluene were hydrotreated on Co-Mo/Ml_2O_3 at 150 deg C at 1.3 Mpa. Both the total HDS (thiophene HDS minus thiol and sulfide formation) and thiophene HDS were strongly inhibited by a small Amount of olefin (1 mol /100).
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