Gas-Phase Propylene Epoxidation over Ag/TS-1 Prepared in W/O Microemulsion: Effects of the Molar Ratio of Water to Surfactant and the Reaction Temperature

2004 ◽  
Vol 96 (1/2) ◽  
pp. 79-85 ◽  
Author(s):  
Chuanfu Wang ◽  
Xinwen Guo ◽  
Xiangsheng Wang ◽  
Ruipu Wang ◽  
Jingquan Hao
Keyword(s):  
Gas Phase ◽  
Reaction Temperature ◽  
Molar Ratio ◽  
Propylene Epoxidation

Simulation and Experimental Study on Methanol Recovery in Continuous Production of Biodiesel via Supercritical Transesterification

2012 ◽  
Vol 550-553 ◽  
pp. 452-457
Author(s):  
Wen Chen ◽  
Ya Li Jin ◽  
Shao Wen Liu ◽  
Zhou Hua Zeng
Keyword(s):  
Gas Phase ◽  
Reaction Temperature ◽  
Continuous Production ◽  
Tubular Reactor ◽  
Molar Ratio ◽  
Supercritical Methanol ◽  
Flash Evaporation ◽  
Reaction Pressure ◽  
One Stage ◽  
Operation Cost

Recycling excessive methanol is simulated and experimentalized by adiabatic flash evaporation. The simulated results show that: methanol recovery and methanol purity in gas phase for one-stage flash process are almost same with two-stage flash process and one-stage flash process is more beneficial by thinking of equipment and operation cost. The experimental results show that flash pressure has a significant influence on methanol recovery and methanol purity in gas phase which can be effectively improved when flashing pressure is reduced. Meanwhile, reaction temperature and reaction pressure also have important effects on methanol recovery and methanol purity in gas phase. For continuous producing biodiesel in supercritical methanol, when the reaction temperature, the reaction pressure and the molar ratio of methanol/oil are kept at 300°C, 15 MPa and 25:1, respectively, methanol recovery and methanol purity in gas phase can reach 90% and 98.8% respectively if the flashing pressure is kept at 0.2MPa. Therefore, the flash evaporation device coupled with tubular reactor for high purity separation of methanol is very effective which can realize comprehensive utilization of heat energy and separation and recycle of methanol.

scholarly journals Biogas Dry Reforming for Hydrogen through Membrane Reactor Utilizing Negative Pressure

Fuels ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 194-209
Author(s):  
Akira Nishimura ◽  
Tomohiro Takada ◽  
Satoshi Ohata ◽  
Mohan Lal Kolhe
Keyword(s):  
Energy Source ◽  
Reaction Temperature ◽  
Negative Pressure ◽  
Membrane Reactor ◽  
Reaction Chamber ◽  
Dry Reforming ◽  
Molar Ratio ◽  
Effect Of Pressure ◽  
The Impact

Biogas, consisting of CH4 and CO2, is a promising energy source and can be converted into H2 by a dry reforming reaction. In this study, a membrane reactor is adopted to promote the performance of biogas dry reforming. The aim of this study is to investigate the effect of pressure of sweep gas on a biogas dry reforming to get H2. The effect of molar ratio of supplied CH4:CO2 and reaction temperature is also investigated. It is observed that the impact of psweep on concentrations of CH4 and CO2 is small irrespective of reaction temperature. The concentrations of H2 and CO increase with an increase in reaction temperature t. The concentration of H2, at the outlet of the reaction chamber, reduces with a decrease in psweep. It is due to an increase in H2 extraction from the reaction chamber to the sweep chamber. The highest concentration of H2 is obtained in the case of the molar ratio of CH4:CO2 = 1:1. The concentration of CO is the highest in the case of the molar ratio of CH4:CO2 = 1.5:1. The highest sweep effect is obtained at reaction temperature of 500 °C and psweep of 0.045 MPa.

scholarly journals Rapid and Efficient Synthesis ofω-Alkylenediphosphoric Acids from Phosphorus Oxychloride

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Dalila Meziane ◽  
Abdelhamid Elias ◽  
Erwann Guénin
Keyword(s):  
Microwave Irradiation ◽  
Reaction Temperature ◽  
Phosphorus Oxychloride ◽  
Molar Ratio ◽  
Efficient Synthesis ◽  
Selective Method

The aim of this investigation was to develop an efficient, rapid, and selective method for the synthesis ofω-alkylenediphosphoric acids (HO)2(O)P-O-CH2n-O-P(O)(OH)2from reaction of several diols with phosphorus oxychloride. The reaction was investigated using three methodologies: (i) presence of a base, (ii) classical heating, and (iii) use of microwave irradiation. Influence of reaction temperature and molar ratio of reagents, as well as the nature of the solvent, was studied using these three different methods.

Influence Factors of Denitration Study on Catalyst Mn-Ce/TiO2

2013 ◽  
Vol 634-638 ◽  
pp. 526-530
Author(s):  
Chun Xiang Geng ◽  
Qian Qian Chai ◽  
Wei Yao ◽  
Chen Long Wang
Keyword(s):  
Reaction Temperature ◽  
Catalytic Reduction ◽  
Removal Rate ◽  
Load Capacity ◽  
Fixed Bed ◽  
Influence Factors ◽  
Space Velocity ◽  
Molar Ratio ◽  
Impregnation Method ◽  
Ammonia Gas

Selective Catalytic Reduction (SCR) processes have been one of the most widely used denitration methods at present and the property of low tempreture catalyst becomes a hot research. The Mn-Ce/TiO2 catalyst was prepared by incipient impregnation method. The influence of load capacity, reaction temperature, O2 content, etc. on denitration were studied by a fixed bed catalyst reactor with ammonia gas. Results showed that catalyst with load capacity 18% performed high NO removal rate of 90% at conditions of reaction temperature 160°C, low space velocity, NH3/NO molar ratio 1: 1, O2 concentration 6%.

scholarly journals Gas phase synthesis of dimethyl carbonate from CO2 and CH3OH over Cu-Ni/AC. A kinetic study

2019 ◽  
pp. 88-99 ◽  
Author(s):  
Oscar Felipe Arbeláez-Pérez ◽  
Sara Dominguez Cardozo ◽  
Andrés Felipe Orrego-Romero ◽  
Aida Luz Villa Holguin ◽  
Felipe Bustamante Londoño
Keyword(s):  
Carbon Dioxide ◽  
Catalytic Activity ◽  
Activated Carbon ◽  
Gas Phase ◽  
Dimethyl Carbonate ◽  
Direct Synthesis ◽  
Dispersion Analysis ◽  
Molar Ratio ◽  
Rate Determining Step ◽  
Carbonate Formation

The catalytic activity for dimethyl carbonate formation from carbon dioxide and methanol over mono and bimetallic Cu:Ni supported on activated carbon is presented. Bimetallic catalysts exhibit higher catalytic activity than the monometallic samples, being Cu:Ni-2:1 (molar ratio) the best catalyst; X-Ray diffraction, transmission electron microscopy, and metal dispersion analysis provided insight into the improved activity. In situ FT-IR experiments were conducted to investigate the mechanism of formation of dimethyl carbonate from methanol and carbon dioxide over Cu-Ni:2-1. The kinetics of the direct synthesis of dimethyl carbonate in gas phase over Cu:Ni-2:1 supported on activated carbon catalyst was experimentally investigated at 12 bar and temperatures between 90 oC and 130 oC, varying the partial pressures of CO2 and methanol. Experimental kinetic data were consistent with a Langmuir–Hinshelwood model that included carbon dioxide and methanol adsorption on catalyst actives sites (Cu, Ni and Cu-Ni), and the reaction of adsorbed CO2 with methoxi species as the rate determining step. The estimated apparent activation energy was 94.2 kJ mol-1.

scholarly journals Triethanolamine as an efficient cosolvent for biodiesel production by CaO-catalyzed sunflower oil ethanolysis: An optimization study

2019 ◽  
Vol 73 (6) ◽  
pp. 351-362 ◽  
Author(s):  
Dusica Djokic-Stojanovic ◽  
Zoran Todorovic ◽  
Dragan Troter ◽  
Olivera Stamenkovic ◽  
Ljiljana Veselinovic ◽  
...  
Keyword(s):  
Reaction Temperature ◽  
Sunflower Oil ◽  
Acid Ethyl Ester ◽  
Fatty Acid Ethyl Ester ◽  
Biodiesel Production ◽  
Molar Ratio ◽  
Calcium Leaching ◽  
Stirred Reactor ◽  
Optimization Study ◽  
Purification Stage

Triethanolamine was applied as an efficient ?green? cosolvent for biodiesel production by CaO-catalyzed ethanolysis of sunflower oil. The reaction was conducted in a batch stirred reactor and optimized with respect to the reaction temperature (61.6-78.4?C), the ethanol-to-oil molar ratio (7:1-17:1) and the cosolvent loading (3-36 % of the oil weight) by using a rotatable central composite design (RCCD) combined with the response surface methodology (RSM). The optimal reaction conditions were found to be: the ethanol-to-oil molar ratio of 9:1, the reaction temperature of 75?C and the cosolvent loading of 30 % to oil weight, which resulted in the predicted and actual fatty acid ethyl ester (FAEE) contents of 98.8 % and 97.9?1.3 %, respectively, achieved within only 20 min of the reaction. Also, high FAEE contents were obtained with expired sunflower oil, hempseed oil and waste lard. X-ray diffraction analysis (XRD) was used to understand the changes in the CaO phase. The CaO catalyst can be used without any treatment in two consecutive cycles. Due to the calcium leaching into the product, an additional purification stage must be included in the overall process.

scholarly journals Optimization of Enzymatic Synthesis of Betulinic Acid Amide in Organic Solvent by Response Surface Methodology (RSM)

2019 ◽  
Vol 19 (4) ◽  
pp. 849
Author(s):  
Nurul Atikah Amin Yusof ◽  
Nursyamsyila Mat Hadzir ◽  
Siti Efliza Ashari ◽  
Nor Suhaila Mohamad Hanapi ◽  
Rossuriati Dol Hamid
Keyword(s):  
Response Surface Methodology ◽  
Reaction Time ◽  
Response Surface ◽  
Reaction Temperature ◽  
Betulinic Acid ◽  
Enzymatic Synthesis ◽  
Acid Amide ◽  
Molar Ratio ◽  
Percentage Yield ◽  
Substrate Molar Ratio

Optimization of the lipase catalyzed enzymatic synthesis of betulinic acid amide in the presence of immobilized lipase, Novozym 435 from Candida antartica as a biocatalyst was studied. Response surface methodology (RSM) and 5-level-4-factor central-composite rotatable design (CCRD) were employed to evaluate the effects of the synthesis parameters, such as reaction time (20–36 h), reaction temperature (37–45 °C), substrate molar ratio of betulinic acid to butylamine (1:1–1:3), and enzyme amounts (80–120 mg) on the percentage yield of betulinic acid amide by direct amidation reaction. The optimum conditions for synthesis were: reaction time of 28 h 33 min, reaction temperature of 42.92 °C, substrate molar ratio of 1:2.21, and enzyme amount of 97.77 mg. The percentage yield of actual experimental values obtained 65.09% which compared well with the maximum predicted value of 67.23%. The obtained amide was characterized by GC, GCMS and 13C NMR. Betulinic acid amide (BAA) showed a better cytotoxicity compared to betulinic acid as the concentration inhibited 50% of the cell growth (IC50) against MDA-MB-231 cell line (IC50 < 30 µg/mL).

scholarly journals Thermodynamic characterization of Mexico City aerosol during MILAGRO 2006

2007 ◽  
Vol 7 (3) ◽  
pp. 9203-9233 ◽  
Author(s):  
C. Fountoukis ◽  
A. Nenes ◽  
A. Sullivan ◽  
R. Weber ◽  
T. VanReken ◽  
...  
Keyword(s):  
Gas Phase ◽  
Mexico City ◽  
Thermodynamic Equilibrium ◽  
Phase State ◽  
Molar Ratio ◽  
Inorganic Species ◽  
Equilibrium Calculations ◽  
Thermodynamic Equilibrium Model ◽  
Thermodynamic Equilibrium Calculations

Abstract. Fast measurements of aerosol and gas-phase constituents coupled with the ISORROPIA-II thermodynamic equilibrium model are used to study the partitioning of semivolatile inorganic species and phase state of Mexico City aerosol sampled at the T1 site during the MILAGRO 2006 campaign. Overall, predicted semivolatile partitioning agrees well with measurements. PM2.5 is insensitive to changes in ammonia but is to acidic semivolatile species. Semi-volatile partitioning equilibrates on a timescale between 6 and 20 min. When the aerosol sulfate-to-nitrate molar ratio is less than 1, predictions improve substantially if the aerosol is assumed to follow the deliquescent phase diagram. Treating crustal species as "equivalent sodium" (rather than explicitly) in the thermodynamic equilibrium calculations introduces important biases in predicted aerosol water uptake, nitrate and ammonium; neglecting crustals further increases errors dramatically. This suggests that explicitly considering crustals in the thermodynamic calculations are required to accurately predict the partitioning and phase state of aerosols.

Synthesis of light-colored rosin glycerol ester

Holzforschung ◽  
2007 ◽  
Vol 61 (5) ◽  
pp. 499-503 ◽  
Author(s):  
Shifa Wang
Keyword(s):  
Reaction Time ◽  
Reaction Temperature ◽  
Softening Point ◽  
Acid Number ◽  
Total Weight ◽  
Molar Ratio ◽  
Optimal Dosage ◽  
Weight Percentage ◽  
Glycerol Ester ◽  
Ring Method

Abstract A light-colored rosin glycerol ester was synthesized from gum rosin and glycerol in the presence of a highly effective decolorizing agent. The effects of the type and dosage of the decolorizing agent and the reaction temperature and time on the yield, softening point, color, and acid number of the rosin glycerol ester were investigated. Experimental results showed that 4,4′-thio-bis(6-tert-butyl-3-methyl phenol) was the best decolorizing agent. It promoted esterification at an optimal dosage of 0.5% (based on the weight percentage of starting material rosin). Suitable conditions for esterification of rosin and glycerol were: reaction temperature, 260–270°C; reaction time, 6–8 h; and rosin/glycerol molar ratio, 2.5:1 (mol mol-1). The characteristics of the rosin glycerol ester obtained under these conditions were as follows: softening point, 90–94°C (ball and ring method); color, 1–2 (Gardner value); acid number, 7–8; and yield, >88% (based on the total weight of rosin and glycerol). The selected additive has a multifunctional effect involving bleaching, disproportionation, and catalysis.

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