scholarly journals Hydrocracking of C5-Isolated Asphaltene and Its Fractions in Batch and Semi-Batch Reactors

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4444
Author(s):  
Ngoc Thuy Nguyen ◽  
Ki Hyuk Kang ◽  
Pill Won Seo ◽  
Narae Kang ◽  
Duy Van Pham ◽  
...  
Keyword(s):  
Reaction Time ◽  
Induction Period ◽  
Reaction Rate ◽  
Coke Formation ◽  
Batch Reactors ◽  
Low Light ◽  
Asphaltene Fraction ◽  
Batch System ◽  
Liquid Products ◽  
Low Reaction Temperature

Non-catalytic and catalytic hydrocracking of C5-isolated asphaltene and its subfractions were performed in batch and semi-batch reactors at various temperatures. Catalyst and H2 played an important role in the hydrocracking of asphaltenes. In the batch system, the catalyst enhanced asphaltene conversion to light liquid products and suppressed coke formation. The coke formation was controlled at a low reaction temperature, but the reaction rate was too low. Light liquid products were also formed at the beginning of the reaction even at high temperatures, but the coke formation was predominant as the reaction time went on due to the decrease in H2 amount in the reactor. To solve these problems, H2 was continuously supplied during the reaction using the semi-batch system. Sufficient supply of H2 improved the conversion of asphaltenes to light liquid products while inhibiting the coke formation. The lightest asphaltene fraction was easily cracked into light products by inhibiting the coke formation, while the heaviest fraction tends to form coke. The lightest asphaltene fraction prolonged the coke induction period of the heaviest fraction during the catalytic hydrocracking because the lightest fraction contained a significant amount of heavy resin close to that which could prevent aggregation of the heaviest asphaltenes.

Transformation of methanol to hydrocarbons over Y zeolites with varying Si/Al ratio

1987 ◽  
Vol 52 (7) ◽  
pp. 1701-1707 ◽  
Author(s):  
Miloslav Křivánek ◽  
Nguyen Thiet Dung ◽  
Pavel Jírů
Keyword(s):  
Catalytic Activity ◽  
Reaction Time ◽  
Coke Formation ◽  
Aliphatic Hydrocarbons ◽  
Y Zeolite ◽  
Y Zeolites ◽  
Methanol To Hydrocarbons

The catalytic activity of Na, H-Y zeolite samples with a varying Si/Al ratio (2·5 to 20) in the transformation of methanol was determined. The amounts of formed individual aliphatic hydrocarbons as function of reaction time were correlated with the amount of Bronsted and Lewis centres on the catalysts. The effect of coke formation on the over-all course of the reaction has been demonstrated.

scholarly journals UNJUK KERJA REAKTOR PLASMA DIELECTRIC BARRIER DISCHARGE UNTUK PRODUKSI BIODIESEL DARI MINYAK KELAPA SAWIT

Teknik ◽  
2013 ◽  
Vol 34 (2) ◽  
pp. 116
Author(s):  
Ardian Dwi Yudhistira ◽  
Istadi Istadi
Keyword(s):  
Reaction Mechanism ◽  
Reaction Time ◽  
Product Yield ◽  
High Energy ◽  
Electrode Gap ◽  
Dbd Plasma ◽  
Electric Voltage ◽  
Batch System ◽  
Electro Catalysis ◽  
Short Time

Biodiesel is one of alternative renewable energy source to substitute diesel fuel. Various biodiesel productionprocesses through transesterification reaction with a variety of catalysts have been developed by previousresearcher. This process still has the disadvantage of a long reaction time, and high energy need. DielectricBarrier Discharge (DBD) plasma electro-catalysis may become a solution to overcome the drawbacks in theconventional transesterification process. This process only needs a short time reaction and low energy process.The purpose of this study was to assess the performance of DBD plasma rector in making biodiesel such as: theeffect of high voltage electric value, electrodes gap, mole ratio of methanol / oil, and reaction time. TheResearch method was using GC-MS (Gas Cromatography-Mass Spectrofotometry) and FTIR (FourierTransform Infrared Spectrofotometry) and then it will be analysed the change of chemical bond betweenreactant and product. So, the reaction mechanism can be predicted. Biodiesel is produced using methanol andpalm oil as reactants and DBD plasma used as reactor in batch system. Then, reactants contacted by highvoltage electric. From the results of this research can be concluded that the reaction mechanism occurs in theprocess is the reaction mechanism of cracking, the higher of electric voltage and the longer of reaction time leadto increasing of product yield. The more of mole ratio of methanol / oil and widening the gap between theelectrodes lead to decreased product yield. From this research, product yield maksimum is 89,8% in the variableof rasio mol metanol/palm oil 3:1, voltage 10 kV, electrode gap 1,5 cm, and reaction time 30 seconds.

Rates of Reaction of Dissolved Oxygen With Scavengers in Sweet and Sour Brines

CORROSION ◽  
1969 ◽  
Vol 25 (10) ◽  
pp. 397-404 ◽  
Author(s):  
E. S. SNAVELY ◽  
F. E. BLOUNT
Keyword(s):  
Transition Metal ◽  
Dissolved Oxygen ◽  
Metal Ions ◽  
Induction Period ◽  
Natural Waters ◽  
Reaction Rate ◽  
Transition Metal Ions ◽  
Zero Order ◽  
Laboratory Apparatus ◽  
High Ph

Abstract Rates of reaction of dissolved oxygen with H2S were measured in a laboratory apparatus using a polarographic type instrument for the measurement of oxygen concentrations. Results show that oxidation occurs only at high pH in the absence of catalytic species. The reaction is catalyzed by transition metal ions in the order Ni++>Co ++>Mn++>Cu++>Fe++. In all cases, the reaction rate increases with pH and is at first complex but becomes zero-order with respect to oxygen after a brief induction period. Some natural waters contain sufficient catalysts that additional amounts are not required for scavenging O2 with SO2 or Na2SO3. Sour waters cannot be scavenged with SO2 or Na2SO3 because of ineffectiveness of catalysts.

scholarly journals Photocatalytic Degradation of Naphthalene By UV/Zno: Kinetics, Influencing Factors and Mechanisms

2021 ◽  
Vol 37 (1) ◽  
pp. 65-70
Author(s):  
Aram Dokht Khatibi ◽  
Kethineni Chandrika ◽  
Ferdos Kord Mostafapour ◽  
Ali Akbar Sajadi ◽  
Davoud Balarak
Keyword(s):  
Wastewater Treatment ◽  
Reaction Time ◽  
Aqueous Solutions ◽  
Aromatic Hydrocarbons ◽  
Contact Time ◽  
Initial Concentration ◽  
Applied Study ◽  
Batch System ◽  
Initial Ph ◽  
Conventional Wastewater Treatment

Conventional wastewater treatment is not able to effectively remove Aromatic hydrocarbons such as Naphthalene, so it is important to remove the remaining antibiotics from the environment. The aim of this study was to evaluate the efficiency of UV/ZnOphotocatalytic process in removing naphthalene antibiotics from aqueous solutions.This was an experimental-applied study that was performed in a batch system on a laboratory scale. The variables studied in this study include the initial pH of the solution, the dose of ZnO, reaction time and initial concentration of Naphthalene were examined. The amount of naphthalene in the samples was measured using GC.The results showed that by decreasing the pH and decreasing the initial concentration of naphthalene and increasing the contact time, the efficiency of the process was developed. However, an increase in the dose of nanoparticles to 0.8 g/L had enhance the efficiency of the process was enhanced, while increasing its amount to values higher than 0.8 g/L has been associated with a decrease in removal efficiency.The results of this study showed that the use of UV/ZnOphotocatalytic process can be addressed as a well-organized method to remove naphthalene from aqueous solutions.

scholarly journals Process Analysis of PMMA Dental Resins Scraps Depolimerization: Optimization of Reaction Time and Temperature

2021 ◽  
Author(s):  
Paulo Bisi dos Santos Jr. ◽  
Haroldo Jorge da Silva Ribeiro ◽  
Armando Costa Ferreira ◽  
Caio Campos Ferreira ◽  
Lucas Pinto Bernar ◽  
...  
Keyword(s):  
Refractive Index ◽  
Reaction Time ◽  
Liquid Phase ◽  
Kinematic Viscosity ◽  
Process Analysis ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Dental Resins ◽  
Liquid Products ◽  
The Cross

In this work, the cross-linked PMMA-based dental resins scraps were submitted to pyrolysis to recover MMA (Methylmethacrylate). The thermal degradation of cross-linked PMMA-based dental resins scraps was analyzed by TG/DTG to guide the operating conditions in pilot scale. The pyrolysis experiments carried out in a reactor of 143L, at 345, 405, and 420°C, 1.0 atmosphere. The reaction liquid products obtained at 345°C, physicochemical characterized for density, kinematic viscosity, and refractive index. The chemical composition of liquid products obtained at 345°C, 30, 40, 50, 60, 70, 80, and 110 minutes, at 405°C, 50, 70, and 130 minutes, and at 420°C, 40, 50, 80, 100, 110, and 130 minutes determined by GC-MS. The experiments show that liquid phase yields were 55.50%, 48.73%, and 48.20% (wt.), at 345, 405, and 420°C, respectively, showing a smooth sigmoid behavior, decreasing with increasing temperature, while that of gas phase were 31.69%, 36.60%, and 40.13% (wt.), respectively, increasing with temperature. The liquid products density, kinematic viscosity, and refractive index obtained at 30, 40, 50, 60, 70, 80, and 110 minutes, varied between 0.9227 and 0.9380 g/mL, 0.566 and 0.588 mm2/s, and 1.401 and 1.414, respectively, showing percentage deviations between 0.74 and 2.36%, 7.40 and 10.86%, and 0.00 and 0.92%, respectively, compared to standard values for density, kinematic viscosity, and refractive index of pure MMA at 20 °C. The GC-MS identified in the reaction liquid products at 345, 405, and 420°C, 1.0 atm, esters of carboxylic acids, alcohols, ketones, and aromatics, showing concentrations of MMA between 83.454 and 98.975% (area.). For all the depolymerization experiments, the concentrations of MMA in the liquid phase, between 30 and 80 minutes, reach purities above 98% (area.), decreasing drastically with increasing reaction time after 100 minutes, thus making it possible to depolymerize the cross-linked PMMA-based dental resins scraps by pyrolysis to recover MMA. The optimum operating conditions to achieve high MMA concentrations, as well as elevated yields of liquid reaction products were 345 °C and 80 minutes.

Gold nanoparticles-coated chemically-reactive polymer colloids and the study of their catalytic kinetics

2014 ◽  
Vol 1641 ◽  
Author(s):  
Maolin Li ◽  
Vivian Zhong ◽  
Guofang Chen
Keyword(s):  
Gold Nanoparticles ◽  
Reaction Time ◽  
Rate Constant ◽  
Apparent Rate Constant ◽  
Reaction Rate ◽  
Catalytic Efficiency ◽  
Reduction Reaction ◽  
Assembly Method ◽  
Nitrophenol Reduction ◽  
Time Average

ABSTRACTRaspberry-like composite spheres based on chemically-reactive poly(glycidyl methacrylate) (PGMA) colloids as the cores coated with tunable size of gold nanoparticles were synthesized via a controlled assembly method. Kinetic study of 4-nitrophenol reduction by NaBH4 in the presence of poly(allylamine hydrochloride)-modified PGMA composite with tunable size of AuNPs (PGMA@PAH@AuNPs) was demonstrated. Effects of gold nanoparticles size and PGMA colloid diameter on the reaction time, average reaction rate and average turnover frequency (TOF), order of reaction (n) and apparent rate constant (kapp) were systematically investigated. Experimental results of our study showed composites with 3.4 ± 0.9 nm AuNPs have the best catalytic efficiency with the highest reaction order and apparent rate constant. The poisoning of product 4-aminophenol on PAH-modified PGMA colloid-supported gold nanocatalysts was evaluated using 4-nitrophenol/NaBH4 reduction reaction for the reaction time, average reaction rate, average TOF, order of reaction and apparent rate constant.

Study on Liquefaction of Corncob in Polyhydric Alcohols

2011 ◽  
Vol 183-185 ◽  
pp. 1110-1113
Author(s):  
Yuan Bo Huang ◽  
Yun Wu Zheng ◽  
Hao Feng ◽  
Zhi Feng Zheng ◽  
Ying Zi Jiang
Keyword(s):  
Sulfuric Acid ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Acid Number ◽  
Mass Ratio ◽  
Hydroxyl Number ◽  
Catalyst Amount ◽  
Peg 400 ◽  
Polyhydric Alcohols ◽  
Liquid Products

The liquefaction of corncob in polyhydric alcohols was investigated by using sulfuric acid as a catalyst. Results showed that the best liquefaction could be obtained with residue percent of 4.5% under the conditions with the corncob/polyhydric alcohols mass ratio of 1/5, reaction temperature of 150°C, reaction time of 60 min, catalyst amount of 3% (based on the weight of corncob), PEG 400/glycerin mass ratio of 7/3 in the polyhydric alcohols, respectively. The liquefied liquid products had acid number of 18.9 mg KOH/g and hydroxyl number of 616.3mg KOH/g, respectively.

Removal of ammonium as struvite using magnesite as a source of magnesium ions

2010 ◽  
Vol 5 (1) ◽  
Author(s):  
H. M. Huang ◽  
X. M. Xiao ◽  
L. P. Yang ◽  
B. Yan
Keyword(s):  
Reaction Time ◽  
Reaction Rate ◽  
Low Cost ◽  
Magnesium Ions ◽  
Batch Experiments ◽  
Optimum Conditions ◽  
Ammonium Removal ◽  
Time Required ◽  
Solid Liquid ◽  
Operation Cost

In this study, magnesite was used as a low-cost magnesium source to remove ammonium as struvite from the wastewater generated in the rare-earth elements separation process. Since the solubility of magnesite is low, before it was used it was decomposed to magnesia which has a higher reaction rate than magnesite. To optimize its usage, the optimum temperature of decomposition of magnesite and the time required for the process were determined by batch experiments to be 700 °C and 1.5 h, respectively. Besides, batch experiments using the residues of magnesite decomposed under optimum conditions were undertaken to investigate the effects of solid (magnesite)/liquid (wastewater) ratio and reaction time on ammonium removal as struvite. Results indicated that for the solid/liquid ratios tested and for a reaction time of 6 h, phosphorus concentrations fell steeply from the initial 9105 mg/L to a range of 198.8–29.8 mg/L, and ammonium concentrations from the initial 5287 mg/L to 540–520 mg/L. An economic analysis conducted indicated that the operation cost of the struvite process could be reduced by about 34% using decomposed magnesite instead of pure MgCl2.

The Influence of the Hydrothermal Conditions on the Morphologies of β-Ni(OH)2

2012 ◽  
Vol 562-564 ◽  
pp. 494-497
Author(s):  
Xiao Ming Fu
Keyword(s):  
Electron Microscope ◽  
High Temperature ◽  
Reaction Time ◽  
Scanning Electron Microscope ◽  
Reaction Temperature ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
X Ray ◽  
Low Reaction Temperature ◽  
Scanning Electron

Flower-like β-Ni(OH)2 and nanoflakes have been successfully synthesized with nickel nitrate as nickel source and stronger ammonia water as precipitant via the hydrothermal method. The phase and the morphologies of the samples have been characterized and analyzed by XRD (X-ray diffraction) and SEM (Scanning electron microscope), respectively. XRD shows that the phase of the samples is β-Ni(OH)2. SEM confirms that The low reaction temperature is propitious to the synthesis of flower-like β-Ni(OH)2, and with the increase of the reaction time the nanoflakes of flower-like β-Ni(OH)2 become much thinner. However, The high temperature is in favor of the synthesis of β-Ni(OH)2 nanosflakes, and with the further increase of the reaction temperature.

scholarly journals Carbonization of Palm Oil Empty Fruit Bunch (EFB) in Hydrothermal Processes to Produce Biochar

2016 ◽  
Vol 18 (02) ◽  
pp. 116-123
Author(s):  
Rakhman Sarwono ◽  
Silvester Tursiloadi ◽  
Kiky Corneliasari Sembiring
Keyword(s):  
Reaction Time ◽  
Palm Oil ◽  
Hydrothermal Carbonization ◽  
Water Soluble ◽  
Energy Market ◽  
Empty Fruit Bunch ◽  
Operation Conditions ◽  
Hydrothermal Processes ◽  
Yellow Color ◽  
Liquid Products

ABSTRACT Empty fruit bunch (EFB) of palm oil is a waste from the palm oil industries which in a large amount, those waste is not properly utilized yet. EFB is a lignocelluloses waste as a polymer with big molecule such as cellulose, lignin, and hemicelluloses that can be degraded into smaller molecules in hydrothermal carbonization (HTC) process. The HTC process of EFB will result three fractions such as gas, organic water soluble and biochar as solid residue or bio-char-water-slurry. EFB degradation is influenced by the operation conditions such as temperature, pressure, catalysts, reaction time, stirring and ratio liquid and solid. The HTC process involved many routes of reaction such as liquefaction, hydrolysis, dehydration, decarboxylation, condensation, aromatization, and polymerization. In this experiment 60 ml closed vessel was used as the HTC reactor to degrade of EFB. EFB concentration of 6.44% resulted 62% of conversion. Reaction time of 6 hours resulted 62 % of conversion. Increasing the reaction time and temperature increase the conversion of EFB. Liquid products of organic water soluble has cleared yellow color, after several hours the color become darkness that is further reaction still occurs in that solution. Solid products is biochar as brown coal, that can be easily separated and processed into powder, pellet or briquette form with outstanding storage and transport characteristics. For further economic development, biochar with excellent transport characteristics, the possibility of exporting this commodity to the worlds energy market is possible. Key words: EFB, hydrothermal, carbonization, conversion, biochar

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