scholarly journals Conductive Polymer/SiO2 Composite as an Anticorrosive Coating Against Carbon Dioxide Corrosion of Mild Steel. A Simulation Study

2020 ◽  
Vol 22 (4) ◽  
pp. 295
Author(s):  
K. Avchukir ◽  
B.D. Burkitbayeva
Keyword(s):  
Carbon Dioxide ◽  
Corrosion Rate ◽  
Mild Steel ◽  
Flow Velocity ◽  
Carbonic Acid ◽  
Conductive Polymer ◽  
Uniform Corrosion ◽  
Partial Pressure Of Co2 ◽  
1D Model ◽  
Kinetics Of

In this work corrosion of mild steel affected by carbon dioxide was studied using a simulation model developed by Nordsveen M. and Nesic S. Using this comprehensive model of the uniform corrosion made possible to predict of corrosion rate of steel in the carbonic acid medium and the influence of different conditions on the anticorrosive property of coated electrode has been investigated. 1D model of corrosion process includes Butler-Volmer and Tafel equations and takes into account both the kinetics of anodic dissolution of an iron and electrochemical discharge of carbonic acid, water and hydrogen ions. The model has been created in COMSOL Multiphysics software and further improvement of this model allowed studying the influence of parameters such as solution composition, the partial pressure of CO2, temperature and flow velocity of the solution on the corrosion rate of the steel. The results of numerical simulation demonstrate that the use of conductive polymerpolypyrrole/ SiO2 composite as an anti-corrosive resin coating reduces the corrosion rate of mild steel by 7 times or more, depending on pH, temperature and flow rate. Furthermore, increasing of flow velocity from 0.1 to 10 m/s affects to the removal of corrosion products from the surface of mild steel and as a result corrosion rate raises from 0.3 to 0.45 mm/year at a temperature of 80 °C and pH=4.

scholarly journals The kinetics of the carbon dioxide-carbonic acid reaction

1933 ◽  
Vol 232 (707-720) ◽  
pp. 65-97 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Aqueous Solutions ◽  
Carbonic Acid ◽  
Ionization Constant ◽  
Strong Acid ◽  
Dissolved Carbon ◽  
Dissolved Carbon Dioxide ◽  
Acid Reaction ◽  
Kinetics Of ◽  
H 20

In aqueous solutions of Carbon Dioxide, the concentration of dissolved C02 as such, is, at equilibrium, far greater than the concentration of carbonic acid, [H2C03]. On this account solutions of carbon dioxide are found to be only weakly acidic, although H 2C03 itself, according to THIEL,* and THIEL and STROHECKER and later authors, is a fairly strong acid, with a true first ionization constant of about 2 X 10“4, i.e ., 2 X 10~4 [H2C03] = [H] [HC03]. The “ apparent” first ionization constant of carbonic acid, KCo2> is, however, given by the equation Kcp2 (dissolved [C02] + [H2C03]) = [H] [HODS], and since the dissolved [C02] at equilibrium is found to be of the order of 1000 times greater than the [H2C03], the value of KC02 is correspondingly smaller than 2 X 10~4, and is given as 3 X 10~7. MCBAIN, THIEL ( loc. cit. ) and others have shown that the reversible reaction C02 -f- H 20 0 H 2C03 is a relatively slow one, and hence that the neutralization of dissolved carbon dioxide by alkali differs from the neutralization of other weak acids in not being instantaneous.

scholarly journals Investigation of corrosion interaction between white tin cans and model media simulating tomato products

2020 ◽  
Vol 81 (4) ◽  
pp. 71-76
Author(s):  
O. V. Bessarab ◽  
T. F. Platonova ◽  
I. V. Protunkevitch
Keyword(s):  
Citric Acid ◽  
Corrosion Rate ◽  
Oxalic Acid ◽  
Pitting Corrosion ◽  
Corrosion Testing ◽  
Tomato Juice ◽  
Uniform Corrosion ◽  
Model Medium ◽  
Kinetics Of ◽  
Model Environment

When choosing metal packaging for canned tomatoes and in tomato pouring, it is advisable to take into account their corrosiveness, since corrosion of the inner surface is one of the factors affecting the quality of products during storage. To rationalize corrosion testing of metal packaging and materials, it is advisable to use model media instead of food products. It should be borne in mind that, due to the presence in the composition of products of substances that affect the corrosion rate, the corrosiveness of the model environment and the product may vary. The corrosion kinetics of canned tinplate (ELC) in tomato juice and in an aqueous solution containing oxalic and citric acid was studied. The composition of the model medium (0.4% citric acid + 0.3% oxalic acid) was selected based on the results of previous studies. The uniform corrosion rate of ELC was measured by the polarization resistance method, the pitting corrosion rate was measured by zero resistance amperometry. The measurements were carried out using an Expert-004 corrosion meter in automatic mode. The mass of the tin coating on the contact surface of the ELC is 5.5–5.7 g/m2. According to the results of the studies, it was found that the kinetics of the rate of uniform and pitting corrosion of the ELC when interacting with tomato juice is similar to the kinetics of the process when interacting with a model medium. For both the model environment and tomato juice, the corrosion process is uniform - the average stationary pitting rates are 7.5-7.6 times lower than the corresponding values for uniform corrosion (for the model environment – 2.73 and 20.46 ?m/year; for tomato juice - 1.12 and 8.54 ?m/year). At the same time, the corrosiveness with respect to ELC for tomato juice is 2.4 times less than for a model medium. Thus, it is advisable to use a two-component model medium containing 0.4% citric and 0.3% oxalic acid for corrosion testing of metal packaging and materials, taking into account the correction factor.

The Influence of Seawater Velocity to the Corrosion Rate and Paint Degradation at Mild Steel Plate Immersed in Sea Water

2014 ◽  
Vol 554 ◽  
pp. 218-221 ◽  
Author(s):  
Manuhutu Ferry ◽  
W.B. Wan Nik ◽  
Che Wan Mohd Noor
Keyword(s):  
Corrosion Rate ◽  
Mild Steel ◽  
Flow Velocity ◽  
Water Flow ◽  
Steel Plate ◽  
Sea Water ◽  
Electrochemical Impedance ◽  
Flow Speed ◽  
Plate Surface ◽  
Water Flow Velocity

Mild steel is one of the materials that used to build ships and other marine construction which go through current, streams, waves with different speed. The aim of this study is to investigate the effect of seawater flow speed on the corrosion rate of mild steel and the paint thickness degradation. The simulation is done at laboratory scale using mild steel coupons exposure under different flow velocity of seawater that are 2 m/s, 4 m/s, 6 m/s and as control is used stationary flow, 0 m/s. Electrochemical impedance spectroscopy is used to determine the corrosion rate occurred on the coupons plate surface and its paint degradation as function of immersion time. Scanning electron microscopy also is used to observe the plate surface rust and the damage of paint which occurred during the experiment. Experiment is run for thirty days for every water flow speed and the data is taken every ten days. The result of this study revealed that the corrosion rate and paint degradation are increased by the increasing of water flow velocity which is proposed to validate seawater flow rate as parameter that increased the paint damage and corrosion rate of mild steel plate.

Adsorption and corrosion inhibition characteristics of two medicinal molecules

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Hydrochloric Acid ◽  
Corrosion Rate ◽  
Mild Steel ◽  
Corrosion Inhibition ◽  
Half Life ◽  
Thermodynamic Data ◽  
Inhibition Efficiency ◽  
Gravimetric Method ◽  
Corrosive Environment ◽  
Corrosion Inhibition Efficiency

The corrosion inhibition characteristics of two medicinal molecules phenylalanine and rutin on mild steel in 1.0M Hydrochloric acid were evaluated using gravimetric method. Corrosion inhibition efficiency of 83.78 and 90.40 % was obtained respectively after seven days. However, phenylalanine showed weak accumulative higher corrosion inhibition efficiency. The presence of both molecules in the corrosive environment reduced the corrosion rate constant and increased the material half-life. Thermodynamic data calculated suggests a spontaneous adsorption of the molecules on the mild steel’s surface.

Antistaphylococcal activity of carbonic acid extract of hops

2018 ◽  
Vol 22 (2) ◽  
pp. 297-300
Author(s):  
V.V. Nevmerzhitsky ◽  
V.Yu. Ivannik ◽  
V.V. Kazmirchuk ◽  
T.N. Moiseenko ◽  
T.A. Volkov ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Antimicrobial Agents ◽  
Carbonic Acid ◽  
Inflammatory Diseases ◽  
Acquired Resistance ◽  
Biologically Active ◽  
Antibacterial Drugs ◽  
Antistaphylococcal Activity ◽  
Prevention And Treatment ◽  
Main Disadvantage

The fight against staphylococcal infection, increasing the effectiveness of methods of prevention and treatment of diseases of staphylococcal etiology is of interest to scientists and practitioners, both in Ukraine and around the world. The urgency of this problem is growing rapidly, as there is a tendency to increase the resistance of not only staphylococci, but also other gram-positive bacteria. The spread of methicillin-resistant staphylococci restricts the choice of antibiotics for the treatment of diseases of staphylococcal etiology. Staphylococcus aureus is the most common and dangerous type, which is one of the main factors of purulent-inflammatory lesions of the skin and mucous membranes. As a result of mutations, pathogenic staphylococci acquired resistance to antibacterial drugs. The main disadvantage of modern antibiotics is their non-selectivity. As a result of mutations, pathogenic staphylococci acquired resistance to antibacterial drugs. The main disadvantage of modern antibiotics is their non-selectivity. One of the unique and promising medicinal plants, which contains a rich complex of biologically active substances (BAS), is common hops (Humulus lupulus L.). The complex of BAS (flavonoids, hormones, vitamins, bitter, phenolic compounds, essential oils) causes anti-inflammatory, bactericidal, hyposensitizing and analgesic action of hops. The purpose of this work is to determine the antistaphylococcal activity of the carbon dioxide extract of hops and to justify the development on its basis of new antimicrobial agents for the prevention and treatment of infectious and purulent-inflammatory diseases. The following methods were used: microbiological (method of diffusion into agar (well method)) and mathematical and statistical. The high antimicrobial activity of the carbon dioxide extract of hops has been established for museum test strains of the genus Staphylococcus. The results of the studies testify to the prospects of further study of the bactericidal properties of the extract of hops carbon dioxide with the aim of creating effective antimicrobial agents on its basis for the prevention and treatment of infectious and purulent-inflammatory diseases of staphylococcal etiology.

Application of Disk Aerators to Recarbonation of Alkaline Wastewater from Wet Gasification of Carbide

1991 ◽  
Vol 24 (7) ◽  
pp. 277-284 ◽  
Author(s):  
E. Gomólka ◽  
B. Gomólka
Keyword(s):  
Carbon Dioxide ◽  
Liquid Phase ◽  
Gas Phase ◽  
Flue Gas ◽  
Carbonic Acid ◽  
Low Cost ◽  
Flue Gases ◽  
Carbon Dioxide Content ◽  
Patent Claim ◽  
Phase Dispersion

Whenever possible, neutralization of alkaline wastewater should involve low-cost acid. It is conventional to make use of carbonic acid produced via the reaction of carbon dioxide (contained in flue gases) with water according to the following equation: Carbon dioxide content in the flue gas stream varies from 10% to 15%. The flue gas stream may either be passed to the wastewater contained in the recarbonizers, or. enter the scrubbers (which are continually sprayed with wastewater) from the bottom in oountercurrent. The reactors, in which recarbonation occurs, have the ability to expand the contact surface between gaseous and liquid phase. This can be achieved by gas phase dispersion in the liquid phase (bubbling), by liquid phase dispersion in the gas phase (spraying), or by bubbling and spraying, and mixing. These concurrent operations are carried out during motion of the disk aerator (which is a patent claim). The authors describe the functioning of the disk aerator, the composition of the wastewater produced during wet gasification of carbide, the chemistry of recarbonation and decarbonation, and the concept of applying the disk aerator so as to make the wastewater fit for reuse (after suitable neutralization) as feeding water in acetylene generators.

Kinetics of temperature-programmed reactivation of a hydrodesulphurization catalyst

1983 ◽  
Vol 48 (12) ◽  
pp. 3340-3355 ◽  
Author(s):  
Pavel Fott ◽  
Pavel Šebesta
Keyword(s):  
Carbon Dioxide ◽  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Thin Layer ◽  
Kinetic Parameters ◽  
Diffusion Region ◽  
Reaction Heat ◽  
Gaseous Products ◽  
Temperature Programmed ◽  
Kinetics Of

The kinetic parameters of reactivation of a carbonized hydrodesulphurization (HDS) catalyst by air were evaluated from combined thermogravimetric (TG) and differential thermal analysis (DTA) data. In addition, the gaseous products leaving a temperature-programmed reactor with a thin layer of catalyst were analyzed chromatographically. Two exothermic processes were found to take part in the reactivation, and their kinetics were described by 1st order equations. In the first process (180-400 °C), sulphur in Co and Mo sulphides is oxidized to sulphur dioxide; in the second process (300-540 °C), in which the essential portion of heat is produced, the deposited carbon is oxidized to give predominantly carbon dioxide. If the reaction heat is not removed efficiently enough, ignition of the catalyst takes place, which is associated with a transition to the diffusion region. The application of the obtained kinetic parameters to modelling a temperature-programmed reactivation is illustrated on the case of a single particle.

scholarly journals Investigation of Corrosion Rate and Rust Expansion Form of Segment Reinforcement for Shield Tunnel by Combined Action of Soil Loading, Chloride Ion and Stray Current

2021 ◽  
Vol 13 (6) ◽  
pp. 3444
Author(s):  
Zheng Li ◽  
Hao Jin ◽  
Shuo Yu
Keyword(s):  
Corrosion Rate ◽  
Steel Corrosion ◽  
Chloride Ion ◽  
Shield Tunnel ◽  
Uniform Corrosion ◽  
Stray Current ◽  
Soil Loading ◽  
Capacity Degradation ◽  
Expansion Form ◽  
Combined Action

Segment reinforcement corrosion can cause bearing-capacity degradation of shield tunnel, which is unsafe for the metro operation. Therefore, a three-dimensional computational model was proposed in this paper to study the corrosion rate and rust expansion form of segment reinforcement by the combined action of soil loading, chloride ion and stray current. The results show that the arch waist segment steel corrosion rate in the middle is larger than the ends. The rust expansion form of segment reinforcement appears be an eccentric circle. The radius size and circular center are related to the non-uniform corrosion coefficient and the maximum corrosion current density.

Sign in / Sign up

Export Citation Format

Share Document