Studies on Optimum Conditions of Synthesizing Theaflavins by Using Bio-Enzyme Method

2011 ◽  
Vol 138-139 ◽  
pp. 929-932
Author(s):  
Wan Ping Fang ◽  
Li Pu Wang ◽  
Jun Yu ◽  
Peng Xiang Yue ◽  
Xin Jiang ◽  
...  

Green tea powder and polyphenol oxidase extracted from eggplant has been used to explore the optimum condition for theaflavins synthesis under single factor and orthogonal experimental design. The results showed that pH value had significant effect on theaflavins synthesis. The optimum reaction condition was, under the temperature of 25°C, the system pH value 4.5, substrates concentration 2.5 g/L, and 35 mL crude enzyme with 196 U, reaction time 40 min, then the total content of theaflavins reached to 7.45 mg.

2014 ◽  
Vol 989-994 ◽  
pp. 189-193 ◽  
Author(s):  
Mei Jie Sun ◽  
Lai Shun Shi ◽  
Zhe Ying Jin ◽  
Na Li ◽  
Xiang Tao

A novel cationic asphalt emulsifier of N-(3-polyoxyethylene nonyl phenyl ether (10)-2-hydroxyl) propyl-N,N,N-triethyl ammonium chloride was synthesized by nonylphenol polyoxyethylene ether (NP-10), epichlorohydrin and triethylamine. The optimum reaction condition was obtained. The yield reaches 48.72% at the optimum conditions of the feedstock mole ratio of NaOH to NP-10 1.0, the mole ratio of epichlorohydrin to NP-10 1.2, the mole ratio of triethylamine to NP-10 1.2, reaction temperature 70°C, and reaction time 8 h. The structure of the emulsifier was identified by FTIR. The synthesis process was monitored by online FTIR technique and the intermediate was detected. Based upon the experimental data, a plausible reaction mechanism was proposed for the reaction. The emulsifier belongs to slow-set asphalt emulsifier.


2016 ◽  
Vol 26 (1) ◽  
pp. 107
Author(s):  
Linda N. Zavaleta Palomino

RESUMEN El objetivo de esta investigación es conocer el proceso de producción óptimo para generar biodiesel, por transesterificación alcalina, a partir de aceites vegetales residuales de los restaurantes del distrito de San Borja, Lima- Perú. Para ello, se analizó el aceite vegetal residual recolectado, se determinó la concentración de metanol (%v/v), la concentración de hidróxido de potasio (%p/p), el tiempo de reacción óptimo, y por último se determinó la calidad del biodiesel producido.Los resultados mostraron que es posible realizar biodiesel con el aceite recolectado, ya que su grado de acidez (1,56%) fue inferior al 3%. Las condiciones óptimas para lograr la máxima conversión de la reacción se obtuvieron cuando se usó una concentración de metanol del 30%, una concentración de hidróxido de potasio del 0,4% respecto al peso del aceite y un tiempo de reacción de 3 hrs 30 min a una temperatura constante de 60°C. Bajo estas condiciones se obtuvo un rendimiento de biodiesel del 85,97%. Al biodiesel obtenido bajo las mejores condiciones de reacción se le analizaron cuatro propiedades del combustible, encontrándose que la viscosidad cinemática fue 5,5 cSt, el número de acidez fue 0,68 mgKOH/g, la ceniza sulfatada fue 0,0478 % y el carbón conradson fue 0,142%.Palabras claves.- Transesterificación alcalina, grado de acidez, máxima conversión número de acidez, viscosidad cinemática, ceniza sulfatada, carbón conradson y postratamiento del biodiesel. ABSTRACT In this paper, it is presented an experiment carried out with the objective of knowing the optimum production process in order to generate bio diesel by alkaline transesterification, from residual vegetable oils from the Restaurants in San Borja. In order to do so, first of all of the residual vegetal oil collected was analyzed, then it was determined the concentration of methanol (%v/v), the concentration of potassium hydroxide (%p/p) and the optimum reaction time, and lastly, it was determined the bio diesel quality produced.The results showed that it is possible to generate biodiesel from the collected oil, due to its grade of acidity (1,56%) was lower than 3%. The optimum conditions to get the maximum conversion of the reaction were achieved when it was used a methanol concentration of 30%, a concentration of potassium hydroxide of 0,4% regarding the weight of the oil and a reaction time of 3:30 minutes at a constant temperature of 60%. Under these conditions it was obtained a performance of biodiesel of 85,97%. Biodiesel obtained under the best reaction conditions will be analyzed four fuel properties, finding that the kinematic viscosity was 5,5 cSt, the acid number was 0,68 mg KOH / g, the sulfated ash was 0,0478% and Conradson Carbon was 0,142%. Key Words.- Alkaline Transesterification, grade of acidity, maximum conversion, number of acidity, kinematic viscosity,    sulfated ash, conradson carbon and after treatment of biodiesel


2011 ◽  
Vol 284-286 ◽  
pp. 2404-2408 ◽  
Author(s):  
You Ming Cao

Pd catalyst is very active in Suzuki reaction. As a heterogeneous catalyst, SWNTs/Pd shows highly catalytic ability with Suzuki reaction. We will demonstrate the effect of catalyst’s amount, the reaction time and temperature on Suzuki reaction in this work. In comparison, a control experiment used commercial Pd/C as catalyst in Suzuki reaction has been done. An optimum reaction condition of about reacting 60 min at 50°C with 5% (mass%) catalyst is confirmed finally, and a better catalytic ability of SWNTs/Pd than commercial Pd/C is also observed.


2013 ◽  
Vol 781-784 ◽  
pp. 2324-2327
Author(s):  
Xu Zheng ◽  
Xiao Cai Yu ◽  
Yun Qing Liu ◽  
Xiao Xv ◽  
Jin Fang Chen

Sea water joining diesel was selected to prepare simulated marine oil pollution. With the target of removing diesel from seawater, the influence of various factors on the laccase-catalyzed degradation process was discussed. The experimental results show that the laccase-catalyzed degradation process was significantly affected by laccase dosage, reaction temperature, reaction time, pH of the solution and initial concentration of diesel in the oily wastewater. A systematic optimization study was carried out through a orthogonal test on the basis of the results of the single-factor experiments,and the optimum reaction conditions of laccase catalytic degradation diesel pollutants in seawater was determined. The results indicate that under the conditions of diesel initial concentration of 0.1g/L, laccase dosage of 8mg/L, pH value of 6, the reaction temperature of 25°C and the reaction time of 4h, laccase catalytic degradation rate of diesel pollution can be up to 63.85%.


2011 ◽  
Vol 117-119 ◽  
pp. 807-810
Author(s):  
Ji Wen Li ◽  
Yan Hua Ma ◽  
Fang Fang Gong ◽  
Guo Shang Zhang ◽  
Liu Jie Xu ◽  
...  

The technique of hydrothermal synthesis is used to prepare nanometer molybdenum trioxide through controlling the parameters such as the acidification condition, the reaction temperature, the reaction time and so on. The technique is under high temperature and high pressure by water as the solvent. Synthesized molybdenum trioxide powder is characterized by XRD, SEM, and HRTEM. The optimal reaction time is 40h, the optimum reaction temperature is 170°C, and the optimum pH value is 1.0. The results indicate that powder has an ultrafine particle size, high purity, and narrow size distribution, good fluidity, light agglomerate and is perfect in crystal.


2012 ◽  
Vol 610-613 ◽  
pp. 2367-2371 ◽  
Author(s):  
Ming Zhong Hu ◽  
Zhen He Shi ◽  
Hong Yan Zhao

The effects of the oxidation of potassium ferrate and the flocculation on cresol wastewater water were evaluated. This research aimed at determining the optimum conditions for the COD removal rate duing cresol wastewater water process. The results showed that potassium ferrate dosage of 1.1g/L, the pH value of 5, reaction time 15min, m-cresol initial concentration of 200 mg/L were the optimum conditions. Under the optimum conditions, COD removal rate was over 67%.


2011 ◽  
Vol 332-334 ◽  
pp. 1816-1819 ◽  
Author(s):  
Quan Xiao Liu ◽  
Wen Cai Xu ◽  
Yu Bin Lv ◽  
Jin Li Li

In this paper, super absorbent polymer was prepared through graft copolymerization by cellulose and acrylic acid (AA), acrylamide (AM), and butyl methacrylate (BMA) and its properties were determined. It showed that optimum reaction condition is the amount of cellulose, AA, AM and BMA is 10g, 4.5g, 2g and 1.5g respectively, the amount of initiator (potassium persulfate) and N,N'-methylene bisacrylamide is 0.01g and 0.012g, the pH value of AA after neutralization is 7. The water absorbency to distilled water, tap water and salt solution of super absorbent polymer which was prepared under these conditions is 770g/g, 113g/g and 86g/g respectively. The water retention rate of super absorbent polymer gel drops to 3% needs 130 hours under natural condition. It was expected that super absorbent polymer can be used for preservation processing of fruits.


2011 ◽  
Vol 236-238 ◽  
pp. 428-431
Author(s):  
Ying Xiao Mu ◽  
Hong Xiang Zhu ◽  
Hui He ◽  
Hai Nong Song ◽  
Shuang Fei Wang ◽  
...  

The effect of the reaction time, the amount of enzyme, the reaction temperature and the pH value system, also the substrate size on bagasse pulp cellulose hydrolysis in the rate of reducing sugar was studied. And the optimum conditions response was researched. Under these conditions, we also studied the percent conversion of reducing sugar, and analyzed the changes of crystallinity after the bagasse pulp cellulose hydrolysis.


2011 ◽  
Vol 287-290 ◽  
pp. 2565-2568 ◽  
Author(s):  
Hao Zhang ◽  
Rui Wang ◽  
Jian Kun Wang

Cationic starch is a kind of sizing agent which have good prospect of application, but its high viscosity limits its use. In this work low substitution degree cationic starch (DS=0.03) was hydrolyzed with HCL to reduce the viscosity. The acidolysis factors on cationic starch viscosity such as reaction time, reaction temperature and concentration of HCL has been studied. The results revealed that the optimum reaction condition was 1.83% HCL for dry cationic starch, under 55°C for 5 hours, the product viscosity was 11.5mpa.s. By choosing different process parameters can get products of series viscosities.


2019 ◽  
Vol 264 ◽  
pp. 03006
Author(s):  
Xue-Di Gong ◽  
Lai-Shun Shi ◽  
Tian-Yao Wang ◽  
Xiao-Meng Yu

A new cationic asphalt emulsifier of N,N-dimethyl-N-(3-(N',N'-dimethyl amido)-2-hydroxy propyl)- coconut oil amide propyl-1-ammonium chloride was synthesized by two steps reaction of coconut oil acyl propyl dimethyl tertiary amine (PKO), epoxy chloropropane and dimethylamine. The chemical structure of the key intermediate of N,N-dimethyl-N-(ethylene oxide-2-methylene)-coconut oil amide propyl-1-ammonium chloride was confirmed by FTIR, 1H NMR and elemental analysis. The optimum reaction condition of first step was obtained by single factor analysis: reaction time 5 h, reaction temperature 50 °C, feedstock mole ratio of epoxy chloropropane to PKO 1.05. The reaction yield is 82.15% and the epoxy value is 40.39% at the optimum conditions. The critical micelle concentration (CMC) of the asphalt emulsifier is 7.80×10-2 mol/L. The surface tension at CMC is 24.57 mN/m. The emulsifier showed excellent emulsification effect for the asphalt. The prepared bituminous emulsion had higher storage stability. The emulsifier belongs to medium-set asphalt emulsifier.


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