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Zhang X.,Taiyuan University of Technology | Zhang X.,Shanxi Institute of Mechanical and Electrical Engineering | Huang W.,Taiyuan University of Technology
Journal of Natural Gas Chemistry

MgO-CaO/SiO2 solid catalysts derived from waste slag (WS) of metal magnesium plant were prepared. The catalytic performances were evaluated in the transesterification of rapeseed oil with methanol to biodiesel in a 500 mL three-necked reactor under atmospheric pressure. The basic strengh of the catalyst reached 22.0 measured by indicators accroding to Hammett scale. The results show that the MgO-CaO/SiO2 is an excellent catalyst for transesterification, and the conversion of rapeseed oil reach 98 under the optimum condition. © 2011 CAS/DICP. Source

Sun J.,Dalian University of Technology | Zhang F.,Dalian University of Technology | Zhang F.,Shanxi Institute of Mechanical and Electrical Engineering | Song J.,Dalian University of Technology | And 5 more authors.
Applied Surface Science

A superhydrophobic surface with a water contact angle of 165.3° and a tilting angle of 2° was fabricated on a zinc substrate by electrochemical processing using a mixed electrolyte composed of NaCl and NaNO3, followed by overcoating with a fluorinated polymer. The fabrication process is based on the electrochemical processing of Zn under an applied electric field. Scanning electron microscope (SEM) and X-ray diffractometer system (XRD) were used to characterize surface morphology and crystal structures. Micrometer-scale pits, protrusions and numerous nanometer-scale dendrite structures were found on the surface. XRD results indicated that the new products formed on the treated surface. The anodic dissolution mechanism of Zn in the electrolyte was analyzed. The effects of processing time, processing current, electrolyte type and electrolyte concentration on surface micromorphology and superhydrophobicity of the samples were also investigated. The results show that the electrochemical processing does not require exacting processing parameters. This method is highly efficient and environmental friendly. The ideal processing conditions to create the optimum superhydrophobic surface are a processing time of 20 min, a current density of 0.2A/cm2, and a mixed electrolyte of 0.1 mol/L NaNO3 and 0.05 mol/L NaCl. © 2014 Elsevier B.V. All rights reserved. Source

Liu Y.,Jilin University | Zhang J.,Jilin University | Cui L.,Jilin University | Xiong M.,Peking University | And 2 more authors.
Harbin Gongcheng Daxue Xuebao/Journal of Harbin Engineering University

To provide some references for the selection of proper mixing ratio of the biological diesel engine, under the condition of not changing the structural parameters of the engine, while conducting the engine performance tests, the authors analyzed such indices as the engine power, consumption of fuel oil, consumption rate, emission concentration of CO, HC, NOx, PM, SOF, DS of the engine under different conditions, and studied the effects caused by the biodiesel with eight different mixture ratios on the power, economy and emission performance of the engine. The purpose was to provide reference data for the reasonable selection of the mixture ratio of the biodiesel. The results show that the changing trends of the engine power and torque when biodiesel mixing fuel was applied are roughly the same as those when 0 # petrochemical diesel oil was used. Following the increase of the mixture ratio of biodiesel, the engine power and the torque decreased by a small amount. When the mixture ratio was less than 20%, the effects on engine power were slight; simultaneously, under the condition of a full load, the consumption and the consumption rate of the fuel oil increased gradually, however, the range of increase was small. The biodiesel and petrochemical diesel were similar in economy; the emission concentration of CO, HC, PM, SOF, DS and soot were reduced greatly, and the emission concentration of the NOx increased slightly. Source

Zhang X.-W.,Taiyuan University of Technology | Zhang X.-W.,Shanxi Institute of Mechanical and Electrical Engineering | Huang W.,Taiyuan University of Technology
Energy Sources, Part A: Recovery, Utilization and Environmental Effects

A statistical approach was used for optimization of the transesterification reaction from cottonseed oil, and the effects of five-level-four-factors and their reciprocal interactions were estimated. Thirty individual trials were designed in this experiment. The reaction temperature, methanol/oil molar ratio, catalyst amount, and reaction time were optimized using a central composite design. A statistical model predicted that the highest conversion yield of biodiesel from cottonseed oil would be 98.67%, at the following optimized conditions: the reaction temperature is 65°C, the methanol/oil molar ratio is 7:1, the catalyst amount is 1.0 wt%, and the reaction time is 60 min. The reaction temperature is the most important factor, having a positive influence on conversion yield of biodiesel. The six independent experiments were replicated under experimental conditions using these optimal factor values, and an average content of 97.8 ±0.6% was achieved. This value was well within the range predicted by the model. Copyright © Taylor & Francis Group, LLC. Source

Zhang X.,Taiyuan University of Technology | Zhang X.,Shanxi Institute of Mechanical and Electrical Engineering | Huang W.,Taiyuan University of Technology
Procedia Environmental Sciences

In this study, biodiesel was product by transesterification of Chinese tallow kernel oil with methanol in a heterogeneous system, using magnesium oxide loaded with potassium nitrate as a solid catalyst. After calcination, the dependence of the conversion of Chinese tallow kernel oil on the reaction variables such as the catalyst loading, reaction temperature, the molar ratio of methanol/oil, the reaction time was studied. The conversion was over 94% under the conditions of 340K, the molar ratio of methanol/oil 8:1, reaction time 3h. Catalyst reusability was also studied. © 2011 Published by Elsevier Ltd. Source

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