scholarly journals OPTIMIZATION OF TECHNOLOGICAL PARAMETERS OF HYDRAGENERATION PROCESS OF ACETYLENE USING A PILOT CATALYTIC PLANT

2020 ◽  
Vol 5 (443) ◽  
pp. 134-140
Author(s):  
Tanirbergenova Sandugash Kudaibergenovna ◽  
◽  
Тugelbayeva Dildara Abdikadyrovna ◽  
Erezhep Nurzay ◽  
Zhylybayeva Nurzhamal Kydyrkhankyzy ◽  
...  
Keyword(s):  
Cobalt Catalyst ◽  
Space Velocity ◽  
Hydrogenation Reaction ◽  
Cobalt Catalysts ◽  
Side Reactions ◽  
Technological Parameters ◽  
Acetylene Hydrogenation ◽  
Before And After ◽  
Effects Of Temperature ◽  
Increasing Temperature

A pilot plant was launched and the modes of acetylene hydrogenation on cobalt catalysts were worked out. It has been found that the modified 7% Co/ SiAl cobalt catalyst is active in the process of hydrogenating acetylene into ethylene. Optimal conditions of acetylene hydrogenation on 7% Co/ SiAl catalyst were determined. The effects of temperature, space velocity and the ratio of initial components in the hydrogenation of acetylene to ethylene were investigated. The textural characteristics of cobalt catalysts before and after the hydrogenation of acetylene were investigated by the SEM method. The structure of cobalt catalysts after the hydrogenation of acetylene does not lose catalytic activity and selectivity. It has been found that catalyst samples have channels of different sizes, flaky particles and fibers located in the gaps between large aggregates are also present on the surface. The optimum temperature was 180 ° C in the hydrogenation of acetylene into ethylene at conversion 73.0%. Conversion of acetylene increases to 81.2% when temperature rises to 200°C, acetylene conversion decreases to 68% with further temperature exceeding to 220°C. Acetylene conversion again increases from 68 to 73.6% at 140°C in the ratio of acetylene to hydrogen 1:2. The selectivity of the catalyst 7%Co/SiAl to ethylene was studied depending on the temperature in the acetylene hydrogenation reaction. The selectivity to ethylene decreases with increasing temperature, since an increase in temperature activates side reactions.

scholarly journals MODIFIED COBALT CATALYSTS FOR HYDROGENATION OF HYDROCARBONS

2020 ◽  
Vol 18 (3) ◽  
pp. 156-161
Author(s):  
A.N. Aitugan ◽  
S.K. Tanirbergenova ◽  
Ye. Tileuberdi ◽  
D. Tugelbayeva
Keyword(s):  
Catalytic Activity ◽  
Aluminum Oxide ◽  
Process Parameters ◽  
Cobalt Catalyst ◽  
Cobalt Catalysts ◽  
Oxide Content ◽  
Acetylene Hydrogenation ◽  
Aluminum Oxides ◽  
Selective Hydrogenation Of Acetylene ◽  
Chemical Contents

This work is devoted to the study of the influence of aluminum oxide content on the activity of cobalt catalysts in the reaction of selective hydrogenation of acetylene to ethylene. Cobalt catalysts modified with aluminum oxide having size between 50 to 500 nm were synthesized. Chemical contents and structure of carrier were investigated.  The catalytic activity of 5 % Со /clay and 5% Co/SiAl catalysts at acetylene hydrogenation was studied in the temperature range 100-180 , with a ratio of 1:2 of acetylene and hydrogen. The ethylene yield is 87.8 % in modifying the cobalt catalyst with aluminum oxide, whereas with the same process parameters, the ethylene yield is 72 %. 5 % Cobalt catalysts modified with 1.5 % aluminum oxides are more active in hydrogenation acetylene process than 5 % Со /clay 450 ℃ catalyst.

scholarly journals Experimental Investigation of Wave Velocity-Permeability Model for Granite Subjected to Different Temperature Processing

Geofluids ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Guanghui Jiang ◽  
Jianping Zuo ◽  
Teng Ma ◽  
Xu Wei
Keyword(s):  
Particle Size ◽  
High Temperature ◽  
Wave Velocity ◽  
Pore Fluid ◽  
Rock Matrix ◽  
Permeability Model ◽  
Wave Velocities ◽  
Before And After ◽  
Different Temperatures ◽  
Increasing Temperature

Understanding the change of permeability of rocks before and after heating is of great significance for exploitation of hydrocarbon resources and disposal of nuclear waste. The rock permeability under high temperature cannot be measured with most of the existing methods. In this paper, quality, wave velocity, and permeability of granite specimen from Maluanshan tunnel are measured after high temperature processing. Quality and wave velocity of granite decrease and permeability of granite increases with increasing temperature. Using porosity as the medium, a new wave velocity-permeability model is established with modified wave velocity-porosity formula and Kozeny-Carman formula. Under some given wave velocities and corresponding permeabilities through experiment, the permeabilities at different temperatures and wave velocities can be obtained. By comparing the experimental and the theoretical results, the proposed formulas are verified. In addition, a sensitivity analysis is performed to examine the effect of particle size, wave velocities in rock matrix, and pore fluid on permeability: permeability increases with increasing particle size, wave velocities in rock matrix, and pore fluid; the higher the rock wave velocity, the lower the effect of wave velocities in rock matrix and pore fluid on permeability.

Survival of Endocronartium harknessii teliospores in a simulated airborne state

1989 ◽  
Vol 67 (3) ◽  
pp. 928-932 ◽  
Author(s):  
Kan-Fa Chang ◽  
P. V. Blenis
Keyword(s):  
Relative Humidity ◽  
Liquid Nitrogen ◽  
Long Distance ◽  
Spider Webs ◽  
Considerable Potential ◽  
Good Ability ◽  
Endocronartium Harknessii ◽  
Spore Longevity ◽  
Effects Of Temperature ◽  
Increasing Temperature

The effects of temperature and relative humidity (RH) on the survival of Endocronartium harknessii teliospores and the longevity of these spores out of doors during daylight hours were studied. In one experiment, fresh and liquid-nitrogen-stored spores of E. harknessii were impacted onto spider webs or plastic threads and incubated in darkness at temperatures of 6, 15, and 24 °C and RHs of 39 and 98%. Survival was measured after 1, 2, 4, 8, and 16 days. Spore longevity decreased with increasing temperature and was lower at 98 than at 39% RH. In a second experiment, spores were impacted onto spider webs and placed out of doors on clear days. Viability decreased linearly with time and averaged 33% after 12 h. The data suggest that E. harknessii has relatively good ability to survive in an airborne state and thus would have considerable potential for long distance spread.

Effects of Temperature on Leaf Expansion in Sunflower

1982 ◽  
Vol 9 (2) ◽  
pp. 209 ◽  
Author(s):  
HM Rawson ◽  
JH Hindmarsh
Keyword(s):  
Field Studies ◽  
Leaf Expansion ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Leaf Position ◽  
Leaf Emergence ◽  
Temperature Regimes ◽  
Effects Of Temperature ◽  
Increasing Temperature ◽  
Relative Change

Five commercial cultivars of sunflower were grown in cabinets at three temperature regimes, 32/22, 27/17 and 22/12°C, and with 15-h and 11-h photoperiods, and expansion of leaves 5-15 was followed. Leaves appeared faster with increasing temperature (0.022 leaves day-1 °C-1) and with increasing daylength. Areas of individual leaves increased linearly up the plant profile and, although final area per leaf (Amax) decreased with increasing temperature, the relative change was similar for each leaf position. Cultivars maintained their ranking for Amax across temperatures, and these rankings agreed with those in previous field studies. Within each temperature regime, both the expansion rate of leaves and the duration of expansion increased with leaf position. As temperature increased, leaves grew for shorter periods with a change of 1.04 days °C-1, but under the photon flux density used (500 �mol m-2 s-1, or about 25% full sunlight) expansion rates were greatest at the lowest temperature. Expansion rates were only one-third of those in field studies at comparable temperatures, but durations were similar. Cultivars that achieved the largest Amax did so via faster rates of expansion and not via longer durations: only one cultivar differed from the mean (20 days) duration of leaf expansion. All cultivars reached floral initiation progressively earlier with extension of photoperiod from 10 to 15 h, with the change for the most sensitive cultivars being 8 days and for the least sensitive 5 days. Rates of leaf emergence were linked with this sensitivity.

scholarly journals Effect of Process Parameters on Catalytic Incineration of Solvent Emissions

2008 ◽  
Vol 2008 ◽  
pp. 1-7 ◽  
Author(s):  
Satu Ojala ◽  
Ulla Lassi ◽  
Paavo Perämäki ◽  
Riitta L. Keiski
Keyword(s):  
Laboratory Experiments ◽  
Butyl Acetate ◽  
Space Velocity ◽  
Optimal Operation ◽  
Process Conditions ◽  
Statistical Experimental Design ◽  
Operation Conditions ◽  
A Minor ◽  
Increasing Temperature ◽  
By Products

Catalytic oxidation is a feasible and affordable technology for solvent emission abatement. However, finding optimal operation conditions is important, since they are strongly dependent on the application area of VOC incineration. This paper presents the results of the laboratory experiments concerning four most central parameters, that is, effects of concentration, gas hourly space velocity (GHSV), temperature, and moisture on the oxidation of n-butyl acetate. Both fresh and industrially aged commercial Pt/Al2O3catalysts were tested to determine optimal process conditions and the significance order and level of selected parameters. The effects of these parameters were evaluated by computer-aided statistical experimental design. According to the results, GHSV was the most dominant parameter in the oxidation of n-butyl acetate. Decreasing GHSV and increasing temperature increased the conversion of n-butyl acetate. The interaction effect of GHSV and temperature was more significant than the effect of concentration. Both of these affected the reaction by increasing the conversion of n-butyl acetate. Moisture had only a minor decreasing effect on the conversion, but it also decreased slightly the formation of by products. Ageing did not change the significance order of the above-mentioned parameters, however, the effects of individual parameters increased slightly as a function of ageing.

The neutron irradiation effects on the temperature dependencies of the electrical conductivity of nanosilicon particles

2017 ◽  
Vol 31 (28) ◽  
pp. 1750257 ◽  
Author(s):  
Elchin Huseynov ◽  
Aydan Garibli
Keyword(s):  
Electrical Conductivity ◽  
Neutron Flux ◽  
Neutron Irradiation ◽  
Silicon Nanoparticles ◽  
Activation Energies ◽  
Radiation Defects ◽  
Irradiation Effects ◽  
Active Radiation ◽  
Before And After ◽  
Effects Of Temperature

The effects of temperature and neutron irradiation on the silicon nanoparticles have been studied at different frequencies. It has been defined that additional electro-active radiation defects occur in the silicon nanomaterial after neutron irradiation. Therefore, the change of neutron flux at the interval of [Formula: see text]–[Formula: see text] increases the conductivity of nanosilicon. Activation energies of the silicon nanoparticles were calculated for 10 different constant frequencies according to Arrhenius approach before and after neutron irradiation. The mechanism of electrical conductivity which explains results has been established.

scholarly journals Effects of WMA Additive on the Rheological Properties of Asphalt Binder and High Temperature Performance Grade

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Jiupeng Zhang ◽  
Guoqiang Liu ◽  
Li Xu ◽  
Jianzhong Pei
Keyword(s):  
Critical Temperature ◽  
Rheological Properties ◽  
Asphalt Binder ◽  
Aging Effect ◽  
Asphalt Binders ◽  
Short Term ◽  
Performance Grade ◽  
Temperature Performance ◽  
Effects Of Temperature ◽  
Increasing Temperature

Sasobit additives with different dosages were added into 70# and 90# virgin asphalt binders to prepare WMA binders. The rheological properties, includingG∗andδ, were measured by using DSR at the temperature ranging from 46°C to 70°C, and the effects of temperature, additive dosage and aging onG∗/sin⁡δ, critical temperature, and H-T PG were investigated. The results indicate that WMA additive improvesG∗but reducesδ, and the improvement on 70# virgin binder is more significant.G∗/sin⁡δexponentially decreases with the increasing temperature but linearly increases with the increasing additive dosage. Aging effect weakens the interaction between binder and additive but significantly increases the binder’s viscosity; that is whyG∗/sin⁡δis higher after short-term aging. In addition, the critical temperature increases with the increasing additive dosage, and the additive dosage should be more than 3% and 5% to improve H-T PG by one grade for 70# and 90# virgin binder, respectively.

Composite materials based on Al2O3‒SiC‒TiB2 obtained by SHS extrusion and their hightemperature annealing

2021 ◽  
pp. 51-55
Author(s):  
A. P. Chizhikov ◽  
A. S. Konstantinov ◽  
M. S. Antipov ◽  
P. M. Bazhin ◽  
A. M. Stolin
Keyword(s):  
Heat Treatment ◽  
High Temperature ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Pressing Pressure ◽  
Technological Parameters ◽  
Temperature Synthesis ◽  
Shs Extrusion ◽  
High Temperature Synthesis ◽  
Before And After

As a result of the combination of the processes of selfpropagating high-temperature synthesis (SHS) and shear high-temperature deformation, realized in the method of SHS-extrusion, ceramic rods based on Al2O3‒SiC‒TiB2 were obtained. The influence of technological parameters of the process (delay time, pressing pressure) on the length of the obtained rods has been studied. The obtained materials were annealed in the range 1000‒1300 °C, and the microstructure and phase composition of the materials were studied before and after heat treatment.

Temperature effects on pH of mitochondria isolated from carp red muscle

1988 ◽  
Vol 254 (4) ◽  
pp. R611-R615 ◽  
Author(s):  
C. D. Moyes ◽  
L. T. Buck ◽  
P. W. Hochachka
Keyword(s):  
Intracellular Ph ◽  
Temperature Effects ◽  
Respiratory Control ◽  
Ph Gradient ◽  
Carp Cyprinus Carpio ◽  
Red Muscle ◽  
Effects Of Temperature ◽  
Increasing Temperature ◽  
Induced Changes

Mitochondria isolated from red muscle of carp (Cyprinus carpio) were used to investigate the effects of temperature and extramitochondrial pH (pHe) on the mitochondrial pH gradient and respiratory properties. Mitochondria from animals acclimated to 10 degrees C were isolated and incubated in KCl-based media with 0.2 mM lauroylcarnitine (C-12) as substrate. Maximal respiratory control ratios (RCR = state 3/state 4) were 16-18 between pH 6.7 and 7.4 at 10 degrees C; RCR values were 9-12 between pH 6.5 and 7.1 at 30 degrees C. Changes in RCR values were due primarily to changes in the state 3 rate (in the presence of ADP). Mitochondrial pH was determined by measuring 5,5-[2-14C]dimethyloxazolidine-2,4-dione distribution, using [14C]sucrose as an extramatrical marker. The pH gradient was inversely related to pHe. At any particular pHe, the mitochondrial pH gradient decreased with increasing temperature. However, if pHe was varied in the same manner that intracellular pH changes with temperature in vivo, the pH gradient was maintained constant at approximately 0.4 U at 10, 20, and 30 degrees C. These data suggest that carp red muscle mitochondria defend an appropriate mitochondrial pH gradient with temperature-induced changes in intracellular pH.

scholarly journals Effects of Temperature on Wear Properties and Mechanisms of HVOF Sprayed CoCrAlYTa-10%Al2O3 Coatings and H13 Steel

Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1224
Author(s):  
Zheng Wei ◽  
Yuping Wu ◽  
Sheng Hong ◽  
Weihua Yang ◽  
Wei Shi
Keyword(s):  
Wear Rate ◽  
Wear Properties ◽  
H13 Steel ◽  
Hvof Spraying ◽  
Different Temperatures ◽  
Effects Of Temperature ◽  
Increasing Temperature ◽  
Worn Surface ◽  
Oxygen Fuel ◽  
Better Than

In this study, the CoCrAlYTa-10%Al2O3 coatings were prepared by the high-velocity oxygen-fuel (HVOF) spraying. A series of ball-on-disk sliding wear tests were conducted to evaluate the tribological properties of the coatings at different temperatures (25 °C, 200 °C, 400 °C, and 600 °C). The results showed that the average coefficients of friction (COFs) of the CoCrAlYTa-10%Al2O3 coatings were lower than that of H13 steel at different temperatures. The average COFs of the CoCrAlYTa-10%Al2O3 coatings and H13 steel both decreased with increasing temperature. The wear rate of the CoCrAlYTa-10%Al2O3 coatings increased first and then decreased. The microhardness of worn surface of the CoCrAlYTa-10%Al2O3 coatings increased with increasing temperature, while the microhardness of worn surface of H13 steel at 25 °C and 200°C was higher than that at 400 °C and 600 °C. The wear mechanism of the two materials was mainly abrasive wear. The tribofilms were formed on the worn surface of the CoCrAlYTa-10%Al2O3 coatings, which had a good protective effect. Due to thermal softening and low binding strength of debris, it was difficult for H13 steel to form the tribofilms. The wear rate of H13 steel was much higher than that of the CoCrAlYTa-10%Al2O3 coatings at 400 °C and 600 °C, indicating that the high temperature wear resistance of the coatings was much better than that of H13 steel.

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