The experiments of one-stage semi-circular and two-stage semi-circular impinging stream drying as well as the vertical and semi-circular combined impinging stream drying were carried out. The velocity distribution and...The experiments of one-stage semi-circular and two-stage semi-circular impinging stream drying as well as the vertical and semi-circular combined impinging stream drying were carried out. The velocity distribution and the mean residence time of particles, and the influence of various factors on drying characteristics were studied. A mathematical model of granular material drying in a semi-circular impinging stream dryer was proposed, in which the flow characteristics as well as the heat and mass transfer mechanisms were considered. Reasonable numerical methods were used to solve the equations. Under various conditions, the calculated results agree well with the experimental data. The unsteady-state drying dynamic equation, as well as the variations of drying rate and moisture content versus time were obtained. The results indicate that constant drying rate period does not exist in a semi-circular impinging stream dryer. Appropriate semi-circular stage number and curvature radius, flow-rate ratio, air velocity, and higher inlet air temperature should be used for enhancing the drying process.展开更多
The main propose of this research was to develop a two-step biodiesel production technique from animal fat as a raw material. The developed process consists ofesterification and transesterification steps. With special...The main propose of this research was to develop a two-step biodiesel production technique from animal fat as a raw material. The developed process consists ofesterification and transesterification steps. With special attention to optimize the first step is acid catalyzed esterification to reduce free fatty acid content and the second step is alkali catalyzed transesterification for converting triglyceride to fatty acid methyl ester or biodiesel. Animal fat containing 78.80 mg KOH/g of high acid value and molecular weight of 851 g/mol with the highest oleic acid content was used as raw material. Respond surface methodology （RSM） was applied for the experiment design. This were 20 experiments involving the three investigated variables of methanol to animal fat ratio, amount of sulfuric acid catalyst and reaction time that were studied on esterification to optimize the condition for decreasing acid value in animal fat less than 2 mg KOH/g. The animal fat with low acid value was further experimented in transesterification step to obtain fatty acid methyl ester or biodiesel. Animal fat biodiesel is further investigated by determining its fuel properties according to the ASTM standard test method.展开更多
基金Supported by the State Key Fundamental Research Plan of China (No. G20000263) and the Director Foundation of Institute of Engineering Thermophysics, Chinese Academy of Sciences.
文摘The experiments of one-stage semi-circular and two-stage semi-circular impinging stream drying as well as the vertical and semi-circular combined impinging stream drying were carried out. The velocity distribution and the mean residence time of particles, and the influence of various factors on drying characteristics were studied. A mathematical model of granular material drying in a semi-circular impinging stream dryer was proposed, in which the flow characteristics as well as the heat and mass transfer mechanisms were considered. Reasonable numerical methods were used to solve the equations. Under various conditions, the calculated results agree well with the experimental data. The unsteady-state drying dynamic equation, as well as the variations of drying rate and moisture content versus time were obtained. The results indicate that constant drying rate period does not exist in a semi-circular impinging stream dryer. Appropriate semi-circular stage number and curvature radius, flow-rate ratio, air velocity, and higher inlet air temperature should be used for enhancing the drying process.
文摘The main propose of this research was to develop a two-step biodiesel production technique from animal fat as a raw material. The developed process consists ofesterification and transesterification steps. With special attention to optimize the first step is acid catalyzed esterification to reduce free fatty acid content and the second step is alkali catalyzed transesterification for converting triglyceride to fatty acid methyl ester or biodiesel. Animal fat containing 78.80 mg KOH/g of high acid value and molecular weight of 851 g/mol with the highest oleic acid content was used as raw material. Respond surface methodology （RSM） was applied for the experiment design. This were 20 experiments involving the three investigated variables of methanol to animal fat ratio, amount of sulfuric acid catalyst and reaction time that were studied on esterification to optimize the condition for decreasing acid value in animal fat less than 2 mg KOH/g. The animal fat with low acid value was further experimented in transesterification step to obtain fatty acid methyl ester or biodiesel. Animal fat biodiesel is further investigated by determining its fuel properties according to the ASTM standard test method.
