Mechanism and Kinetics of the Acid-Catalyzed Dehydration of 1- and 2-Propanol in Hot Compressed Liquid Water

1998 ◽  
Vol 37 (10) ◽  
pp. 3820-3829 ◽  
Author(s):  
Michael Jerry Antal, ◽  
Magnus Carlsson ◽  
Xiaodong Xu ◽  
Donald G. M. Anderson
Keyword(s):  
Liquid Water ◽  
Compressed Liquid ◽  
Mechanism And Kinetics ◽  
Acid Catalyzed ◽  
Kinetics Of

scholarly journals Kinetics Study of Acid Catalyzed Degradation of Glucose in High-Temperature Liquid Water

2020 ◽  
Vol 5 (2) ◽  
pp. 21
Author(s):  
Atiqa Rahmawati ◽  
Aulia Iin Saputri ◽  
Ignatius Gunardi
Keyword(s):  
Activation Energy ◽  
Sulfuric Acid ◽  
High Temperature ◽  
Acid Concentration ◽  
Liquid Water ◽  
Reduction Rate ◽  
Acid Catalyzed ◽  
Temperature Liquid ◽  
Kinetics Of ◽  
Time Of Reaction

Glucose is the most abundant monosaccharide in nature, glucose obtained from cellulose and starch, it is many used to degradation process, and for the production of several organic compounds, one of the degradation products of glucose is an HMF (5-hydroxymethylfurfural). HMF is a platform chemical, which can be converted into several chemical and liquid fuels through hydrogenation, oxidation, and esterification. The objective of this researches has studied the kinetics of glucose degradation using acid-catalyzed (H2SO4) in high-temperature liquid water and observe the effect of acid concentration and temperature on degradation of glucose to HMF. In this research was used reactor with pressure 10 atm, with variation time of reaction, sulfuric acid concentration, and temperature of the reaction. From this research found kinetics of glucose degradation was followed by the first-order reaction in each variable. Activation Energy (Ea) values were 7306,593 J/mol; 6341,59 J/mol; 3988,14 J/mol and 3988,14 J/mol on the concentration sulfuric acid 0,05M; 0,1 M; 0,05M, from that result indicated that reaction rate was increase when activation energy was decrease this was related to Arrhenius equation. The effect of acid concentration on degradation glucose was the higher acid concentration used, the more glucose was degraded, and more HMF was formed. Meanwhile, the effect of temperature of reaction on degradation glucose was the higher temperature of the reaction, more glucose was degraded, and more HMF was formed. The highest value of HMF was in operation condition of concentration H2SO4 0,5 M at 175°C, with a time of reaction 120 minutes. However, the reduction rate of glucose was not equal to the rate of formation of HMF (5-hydroxymethylfurfural), it can be indicated that HMF (5-hydroxymethylfurfural) was not the only product of degradation of glucose, but the others product might be formed from this operating condition. The other product that might be formed was humin and levulinic acid.

Oil extraction from the sunflower seeds, mechanism and kinetics of the process

2020 ◽  
Vol 3 (1) ◽  
pp. 155-160
Author(s):  
Ye. M. Semenyshyn ◽  
◽  
V. M. Atamanyuk ◽  
O. Ya. Dobrovetska ◽  
T. I. Rymar ◽  
...  
Keyword(s):  
Oil Extraction ◽  
Sunflower Seeds ◽  
Mechanism And Kinetics ◽  
Kinetics Of

Studies on the Behavior Some Paints in Electro-insulating Fluid Based on Vegetable Esters

2018 ◽  
Vol 69 (5) ◽  
pp. 1139-1144
Author(s):  
Iosif Lingvay ◽  
Adriana Mariana Bors ◽  
Livia Carmen Ungureanu ◽  
Valerica Stanoi ◽  
Traian Rus
Keyword(s):  
Structural Changes ◽  
Oxidation Processes ◽  
High Oleic ◽  
Painting Materials ◽  
Insulating Paper ◽  
Different Types ◽  
Mechanism And Kinetics ◽  
Kinetics Of ◽  
Natural Ester

For the purpose of using three different types of painting materials for the inner protection of the transformer vats, their behavior was studied under actual conditions of operation in the transformer (thermal stress in electro-insulating fluid based on the natural ester in contact with copper for electro-technical use and electro-insulating paper). By comparing determination of the content in furans products (HPLC technique) and gases formed (by gas-chromatography) in the electro-insulating fluid (natural ester with high oleic content) thermally aged at 130 �C to 1000 hours in closed glass vessels, it have been found that the presence the investigated painting materials lead to a change in the mechanism and kinetics of the thermo-oxidation processes. These changes are supported by oxygen dissolved in oil, what leads to decrease both to gases formation CO2, CO, H2, CH4, C2H4 and C2H6) and furans products (5-HMF, 2-FOL, 2 -FAL and 2-ACF). The painting materials investigated during the heat treatment applied did not suffer any remarkable structural changes affecting their functionality in the electro-insulating fluid based on vegetable esters.

Mechanism and Kinetics of the Hydrogen Failure of Thermoelectric Materials during Water Electrolysis

2020 ◽  
Vol 2020 (10) ◽  
pp. 1102-1115
Author(s):  
M. A. Korzhuev ◽  
I. V. Katin ◽  
M. A. Kretova ◽  
E. S. Avilov
Keyword(s):  
Thermoelectric Materials ◽  
Water Electrolysis ◽  
Mechanism And Kinetics ◽  
Kinetics Of
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