Dissolution, Nucleation, Crystal Growth, Crystal Aggregation, and Particle Breakage of Amlodipine Salts: Modeling Crystallization Kinetics and Thermodynamic Equilibrium, Scale-up, and Optimization

2014 ◽  
Vol 53 (26) ◽  
pp. 10762-10774 ◽  
Author(s):  
Andrej Pohar ◽  
Blaž Likozar
Keyword(s):  
Crystal Growth ◽  
Crystallization Kinetics ◽  
Thermodynamic Equilibrium ◽  
Scale Up ◽  
Particle Breakage ◽  
Crystal Aggregation ◽  
Kinetics And Thermodynamic

Cr-Substituted Mesoporous Aluminophosphate Molecular Sieve: Synthesis, Characterization, Crystallization Kinetics and Catalytic Activity

2013 ◽  
Vol 316-317 ◽  
pp. 1018-1023
Author(s):  
Xin Zhu Li ◽  
Ji Shi Zhang
Keyword(s):  
Activation Energy ◽  
Catalytic Activity ◽  
Crystal Growth ◽  
Crystallization Kinetics ◽  
Molecular Sieve ◽  
Arrhenius Equation ◽  
Degree Of Crystallinity ◽  
Tert Butylhydroperoxide ◽  
Growth Activation ◽  
Cr Map

Cr-substituted mesoporous aluminophosphate molecular sieve (Cr-MAP) was synthesized and characterized. Crystallization kinetics curves measured as an index to the relative degree of crystallinity, according to the Arrhenius equation to calculate the apparent nucleation activation energy and crystal growth activation energy of Cr-MAP, which was 63.7 and 14.7 kJ• mol-1, respectively. Cr-MAP had highly catalytic activity for fabricating acetophenone by selectively oxizing ethylbenzene. Using tert-butylhydroperoxide as oxidant and chlorobenzene as solvent at 100 °C for 8 h, acetophenone selectivity, acetophenone yield and ethylbenzene conversion reaches 85.4, 62.2 and 72.8 %, respectively.

Effect of Arenga Pinnata “Ijuk” Fiber as Nucleating Agent on Crystallization Kinetics of Impact Polypropylene Copolymer

2018 ◽  
Vol 923 ◽  
pp. 56-60 ◽  
Author(s):  
Mochamad Chalid ◽  
Evana Yuanita ◽  
Ghiska Ramahdita ◽  
Jaka Fajar Fatriansyah
Keyword(s):  
Crystal Growth ◽  
Crystallization Kinetics ◽  
Nucleating Agent ◽  
Avrami Equation ◽  
Nucleating Agents ◽  
Impact Polypropylene Copolymer ◽  
Kinetics Of

Impact Polypropylene Copolymer (IPC) is one of the PP type which is widely used. IPC was made with addition of ethylene in PP which decreases PP crystallinity. Many efforts have been made to improve the properties of PP crystallinity by addition of nucleating agents. In this study, we use Arenga Pinnata “Ijuk” fiber as PP nucleating agent. In order to determine the effect of “Ijuk” fiber as nucleating agents in kinetics aspect, we used DSC measurement based on Avrami equation. The results showed that the addition of ijuk decreases crystallizationhalf timeand dimension of crystal growth which indicate the effects of “Ijuk” fiber as a nucleating agent.

POWER RATE LAW BASED CHEMICAL KINETICS AND THERMODYNAMIC MODELING OF AFRICAN PEAR SEED OIL CONSECUTIVE IRREVERSIBLE BASE METHANOLYSIS FOR BIODIESEL PRODUCTION

2021 ◽  
Vol 36 (1) ◽  
pp. 53-66
Author(s):  
C. Esonye ◽  
O. D Onukwuli ◽  
S. O. Momoh
Keyword(s):  
Rate Constants ◽  
Seed Oil ◽  
Scale Up ◽  
Cetane Number ◽  
Calorific Value ◽  
Biodiesel Production ◽  
Rate Determining Step ◽  
Increase With Increase ◽  
African Pear ◽  
Kinetics And Thermodynamic

Currently the major challenge of biodiesel application as a replacement to petrodiesel is its industrial production sustainability.Consequently, the successful scale-up of laboratory results in transesterification requires so much information obtained through chemical kinetics.This paper presents the kinetics and thermodynamic study of alkali-homogeneous irreversible methanolysis of seed oil derived from African pear. The transesterification process was carried out from 0-100 minutes at temperature range of 55-65°C. The reaction mixture compositions were ascertained using gas chromatography- flame ionization detector (GC-FID) technique. Rate constants of the triglyceride (Tg), diglycerides (Dg) and monoglycerides(Mg) hydrolysis were in the range of 0.0140- 0.07810 wt%/min and increased with increase in temperature. The rate of reaction was found to increase with increase in temperature. Activation energies were found to be 6.14, 20.01 and 28.5kcal/mol at 55, 60 and 65oC respectively. Tg hydrolysis to Dg was observed asthe rate determining step while the reaction agreed with second order principles. A biodiesel yield of 93.02% was obtained with cloud point of 10°C , flash point of 125°C , pour point of 4°C , calorific value of 34.4MJ/kg, and cetane number of 54.90 which satisfy EN14214 and ASTM D 6751 standards. Results presented in this report would serve as idealized conditions for industrial scale up of biodiesel production from African pear seed oil. Keywords:Kinetics; methanolysis; rate constants; activation energy; African pear seed oil; biodiesel

Reaction Kinetics and Thermodynamic Equilibrium for Butyl Acrylate Synthesis from n-Butanol and Acrylic Acid

2014 ◽  
Vol 53 (16) ◽  
pp. 6647-6654 ◽  
Author(s):  
Anna M. Ostaniewicz-Cydzik ◽  
Carla S. M. Pereira ◽  
Eugeniusz Molga ◽  
Alírio E. Rodrigues
Keyword(s):  
Acrylic Acid ◽  
Reaction Kinetics ◽  
Thermodynamic Equilibrium ◽  
Butyl Acrylate ◽  
Kinetics And Thermodynamic

Kinetic aspects of major and trace elements in olivines from variably cooled basaltic melts

2020 ◽  
Author(s):  
Sarah Lang ◽  
Silvio Mollo ◽  
Lyderic France ◽  
Manuela Nazzari ◽  
Valeria Misiti ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Trace Elements ◽  
Crystal Growth ◽  
Cooling Rate ◽  
Crystallization Kinetics ◽  
Growth Rates ◽  
Crystal Surface ◽  
Major And Trace Elements ◽  
Diffusive Boundary Layer ◽  
Diffusive Boundary

<p>Olivine is an important mineral phase in naturally cooled basaltic rocks. The texture and composition of olivine are strictly related to the interplay between the degree of magma undercooling and crystal growth rate. Crystals formed at low undercoolings and growth rates generally show polyhedral-hopper textures and quite homogeneous compositions, while skeletal-dendritic textures and evident crystal zonations occur at high undercoolings and growth rates. In this context, we have performed equilibrium and disequilibrium (i.e., cooling rate) experiments to better understand, by a comparatively approach, the effects of crystallization kinetics on the incorporation of major and trace cations in olivine lattice. The experiments were carried out in a 1 atm vertical tube CO-CO2 gas-mixing furnace to perform experiment at atmospheric pressure and oxygen fugacity of QFM-2 using a basaltic glass (i.e., OIB) as starting materials. The equilibrium experiment was performed at 1175 °C. These target temperatures were kept constant for 240 h and then quenched. Conversely, the disequilibrium experiments were performed at the superliquidus temperature of 1250, and 1300 °C, which was kept constant for 2 h before cooling. The final target temperatures of 1150 (undercooling -ΔT = 50 °C), and 1175 °C (-ΔT = 25 °C) were attained by applying cooling rates of 2 °C/h, 20 °C/h, and 60 °C/h. Then the experimental charges were quenched. Results show that the olivine texture shifts from euhedral (i.e., equilibrium) to anhedral (i.e., disequilibrium) under the effect of cooling rate and rapid crystal growth. In equilibrium experiments, the composition of olivine is homogeneous and non chemical gradients are found in the melt next to the crystal surface. In contrast, a diffusive boundary layer develops in the melt surrounding the olivine crystals growing rapidly under the effect of cooling rate and degree of undercooling. The compositional gradient in the melt increases with increasing cooling rate and undercooling, causing the diffusive boundary layer to expand towards the far field melt. Because of the effects of crystallization kinetics, skeletal-dendritic olivines incorporates higher proportions of major and trace elements that are generally incompatible within their crystal lattice under equilibrium conditions.</p>

Crystallization kinetics driven by two simultaneous modes of crystal growth

2000 ◽  
Vol 80 (10) ◽  
pp. 1833-1856 ◽  
Author(s):  
M. Fontana ◽  
B. Arcondo ◽  
M. T. Clavaguera-Mora ◽  
N. Clavaguera
Keyword(s):  
Crystal Growth ◽  
Crystallization Kinetics

Crystallization kinetics of potassium chloride from brine and scale-up criterion

AIChE Journal ◽  
1987 ◽  
Vol 33 (10) ◽  
pp. 1690-1697 ◽  
Author(s):  
Ru-Ying Qian ◽  
Zu-De Chen ◽  
He-Gen Ni ◽  
Zhang-Zhang Fan ◽  
Fu-Di Cai
Keyword(s):  
Potassium Chloride ◽  
Crystallization Kinetics ◽  
Scale Up ◽  
Kinetics Of
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