Non edible oil sources have the potential to lower the cost of biodiesel. However, they usually contain significant high amounts of free fatty acids (FFA) that make them inadequate for direct base catalyzed transester...Non edible oil sources have the potential to lower the cost of biodiesel. However, they usually contain significant high amounts of free fatty acids (FFA) that make them inadequate for direct base catalyzed transesterification reaction (where the FFA content should be lower than 3%). The present work reviews chemical re-esterification as a possible method for the pre-treatment of high FFA feedstock for biodiesel production. The effects of temperature, amount of glycerol, type and amount of catalyst have been discussed. Chemical re-esterification lowers FFA to acceptable levels for transesterification at the same time utilizing the glycerol by product from the same process. Further researches have been proposed as a way forward to improve the process kinetics and optimization so as to make it more economical.展开更多
针对中国石油化工股份有限公司广州分公司的1.5 Mt/a S Zorb装置,考察了影响装置长周期平稳运行的因素。采取使用国产高通量滤芯及在转剂线上使用耐磨管件,对再生取热盘管进行改造,对闭锁料斗程控阀进行预防性维修等措施解决了装置长周...针对中国石油化工股份有限公司广州分公司的1.5 Mt/a S Zorb装置,考察了影响装置长周期平稳运行的因素。采取使用国产高通量滤芯及在转剂线上使用耐磨管件,对再生取热盘管进行改造,对闭锁料斗程控阀进行预防性维修等措施解决了装置长周期运行瓶颈,实现了在95.06%设计负荷工况下连续平稳运行超过49个月的目标,关键设备反应器过滤器运行超过4 a,期间压差未超过30 kPa。展开更多
Ni-Cr based nanostructured feedstock powder was prepared by mechanical milling technique involving repeated welding, fracturing, and re-welding of powder particles in a planetary ball mill. The milled nanocrystalline ...Ni-Cr based nanostructured feedstock powder was prepared by mechanical milling technique involving repeated welding, fracturing, and re-welding of powder particles in a planetary ball mill. The milled nanocrystalline powders were used to coat carbon steel tubes using high velocity oxygen fuel（HVOF） thermal spraying process. The characterization of the feedstock powder and HVOF coated substrates was performed using optical microscope, X-ray diffractometer（XRD）, scanning electron microscope（SEM）, high resolution transmission electron microscope（HR-TEM）, energy dispersive spectrometer（EDS） and microhardness tests. The coated and uncoated samples were subjected to different thermal cycles and characterized for their phase changes, metallurgical changes and microhardness variations. Ni-Cr nanostructured coated samples exhibited higher mechanical and metallurgical properties compared to their conventionally coated counter parts. The results showed that the nanostructured coating possessed a more uniform and denser microstructure than the conventional coating.展开更多
The conversion of rice hulls into fermentable saccharides was explored through steam pretreatment employing 2.5% SO_(2).The in teraction between temperature and time was assessed by means of the response surface metho...The conversion of rice hulls into fermentable saccharides was explored through steam pretreatment employing 2.5% SO_(2).The in teraction between temperature and time was assessed by means of the response surface method to achieve optimum contents of C6-sugars in water-insoluble solids(WIS)and C5-sugars in the liquor.Pretreatment carried out at 218℃ for 2.3 min released liquor containing 55.4 g/L of sugars(29.1 g/L of xylose).In parallel,the WIS was subjected to enzymatic saccharification using different solid and enzyme loads via an experimental design:assays using 22.0% WIS and 20.0 filter paper units(FPU)/g led to 90.6 g/L of glucose,corresponding to a yield of 86.4% and an overall yield of 72.4%.The data reported are the highest ever found for such raw material,making it attractive to compete with conventi on al lig no cellulosic biomass.展开更多
文摘Non edible oil sources have the potential to lower the cost of biodiesel. However, they usually contain significant high amounts of free fatty acids (FFA) that make them inadequate for direct base catalyzed transesterification reaction (where the FFA content should be lower than 3%). The present work reviews chemical re-esterification as a possible method for the pre-treatment of high FFA feedstock for biodiesel production. The effects of temperature, amount of glycerol, type and amount of catalyst have been discussed. Chemical re-esterification lowers FFA to acceptable levels for transesterification at the same time utilizing the glycerol by product from the same process. Further researches have been proposed as a way forward to improve the process kinetics and optimization so as to make it more economical.
基金supported and funded from consultancy project of Bharath Heavy Electricals Limited, Tiruchirappalli,India
文摘Ni-Cr based nanostructured feedstock powder was prepared by mechanical milling technique involving repeated welding, fracturing, and re-welding of powder particles in a planetary ball mill. The milled nanocrystalline powders were used to coat carbon steel tubes using high velocity oxygen fuel（HVOF） thermal spraying process. The characterization of the feedstock powder and HVOF coated substrates was performed using optical microscope, X-ray diffractometer（XRD）, scanning electron microscope（SEM）, high resolution transmission electron microscope（HR-TEM）, energy dispersive spectrometer（EDS） and microhardness tests. The coated and uncoated samples were subjected to different thermal cycles and characterized for their phase changes, metallurgical changes and microhardness variations. Ni-Cr nanostructured coated samples exhibited higher mechanical and metallurgical properties compared to their conventionally coated counter parts. The results showed that the nanostructured coating possessed a more uniform and denser microstructure than the conventional coating.
基金supported by Coordination for the Improvement of Higher Education Personnel Foundation,Mmistry of Education in Brazil(Grant No.POS-DOC-88881.170076/2018-01).
文摘The conversion of rice hulls into fermentable saccharides was explored through steam pretreatment employing 2.5% SO_(2).The in teraction between temperature and time was assessed by means of the response surface method to achieve optimum contents of C6-sugars in water-insoluble solids(WIS)and C5-sugars in the liquor.Pretreatment carried out at 218℃ for 2.3 min released liquor containing 55.4 g/L of sugars(29.1 g/L of xylose).In parallel,the WIS was subjected to enzymatic saccharification using different solid and enzyme loads via an experimental design:assays using 22.0% WIS and 20.0 filter paper units(FPU)/g led to 90.6 g/L of glucose,corresponding to a yield of 86.4% and an overall yield of 72.4%.The data reported are the highest ever found for such raw material,making it attractive to compete with conventi on al lig no cellulosic biomass.
