• Corrosion Science and Technology
• /
• v.6 no.5
• /
• pp.227-232
• /
• 2007

The corrosion behavior of carbon steel (N80) in carbon dioxide saturated 1%NaCl solution with and without acetic acid or acetate was investigated by weight-loss test, electrochemical methods (polarization curve, Electrochemical impedance spectroscopy). The major objective is to make clear that the effect of acetic acid and acetate on the corrosion of carbon steel in $Co_2$ environments. The results indicate that either acetic acid or acetate accelerates cathodic reducing reaction, facilitates dissolution of corrosion products on carbon steel, and so promotes the corrosion rate of carbon steel in carbon dioxide saturated NaCl solution. All Nyquist Plots are consisting of a capacitive loop in high frequency region, an inductive loop in medial frequency region and a capacitive arc in low frequency region. The high frequency capacitive loop, medial frequency inductive loop and low frequency capacitive arc are corresponding to the electron transfer reaction, the formation/adsorption of intermediates and dissolution of corrosion products respectively. All arc of the measured impedance reduced with the increase of the concentration of Ac-, especially HAc. However, the same phenomenon is not notable after reducing pH value by adding HCl. HAc is a stronger proton donor and can be reduced directly by electrochemical reaction firstly. Ac- can't participate in electrochemistry reaction directly, but $Ac^-$ an hydrate easily to create HAc in carbon dioxide saturated environments. HAc is as catalyst in $Co_2$ corrosion. As a result, the corrosion rate was accelerated in the presence of acetate ion even pH value of solution increased.

• Carbon letters
• /
• v.1 no.1
• /
• pp.31-35
• /
• 2000

[ $SO_2$ ]and NO gases that come from the flue gases of most of all industrial combustion processes are harmful to everything include person and industrial facilities. For the simplification of the environmental clean-up processes, we studied the decomposition process by microwave. The microwave can destroy molecules into elementary atoms and offers energy to the atoms to react with carbons. Since the microwave is not absorbed into quartz tube and metallic chamber, the air pollution gases can be removed with much lower energy than in the case of conventional methods. We studied the decomposition of $SO_2$ and NO gases on the carbon beds by microwave. In the microwave field, the gases can be decomposed to form other compounds, such as elementary sulfur, nitrogen, carbon monoxide and carbon dioxide. It was found that CO gas is formed at higher temperature than is $CO_2$ gas, so it needs to control the bed temperature depend on products that we want to get.

• Clean Technology
• /
• v.24 no.4
• /
• pp.275-279
• /
• 2018

In this study, microemulsion formation of water and carbon dioxide was investigated by using surfactant as one of the methods for increasing the mutual solubility between water and carbon dioxide. The surfactant 2,2,3,3,3-Pentafluoro-1-propanol was added to form a microemulsion of water and carbon dioxide. The cloud point change and trend of micro emulsion were investigated by adding water and a certain amount of surfactant, 2,2,3,3,3-Pentafluoro-1-propanol to supercritical carbon dioxide. In the case of surfactant + carbon dioxide system, it was 8.35 ~ 12.69 MPa in temperature range of 313.2 ~ 353.2 K. In the case of water + surfactant + carbon dioxide system, the temperature ranged from 318.2 ~ 338.2 K to pressure range 7.83 ~ 17.28 MPa.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.20 no.2
• /
• pp.44-52
• /
• 2012

As an alternative strategy in the era of high level petroleum cost, the study focused to suggest the way on the revitalization of renewable energy through the impact on introduction effect of renewable energy in green village. Total feasible solar energy production is 6.73 GWh/yr along with the biomass energy producing electric power energy is 134.06 GWh/yr, the two category's total electric power energy is 233.19 GWh/yr, which is possible to achieve the selfsufficiency of energy by 33% for total energy consumption of 705.80 GWh/yr in the region. The calculated feasibility on the carbon dioxide reduction, carbon dioxide reduction level is 1,891 ton_$CO_2$ by agricultural byproducts, 43,635 ton_$CO_2$ by livestock waste, 395 ton_$CO_2$ by municipal waste, 50,324 ton_$CO_2$ by forest byproducts, the total biomass shows 96,245 ton_$CO_2$, while the carbon dioxide reduction of solar light energy is 2,251 ton_$CO_2$, 1,383.3 ton_$CO_2$ by solar heat energy, the total solar energy shows 3,634 ton_$CO_2$. So total carbon dioxide reduction effect shows 99,879 ton_$CO_2$.

• Journal of Sensor Science and Technology
• /
• v.29 no.2
• /
• pp.128-132
• /
• 2020

Total organic carbon (TOC) analysis equipment, which was previously used to prevent eutrophication in advance, is heavy, bulky, and expensive; therefore, so it is difficult to be carried and has been used as an experimental unit. In this study, a through-carbon analysis chip that integrates pretreatment through photocatalytic oxidation and carbon dioxide measurement using a pH indicator was investigated. Both the total carbon - inorganic carbon method and the nonpurgeable organic carbon (NPOC) measurement method require an acidification part for injecting an acid solution for inorganic carbon measurement and removal, an oxidation part for total carbon or NPOC oxidation and a measurement part for Carbon dioxide (CO₂) measurement. Among them, the measurement of oxidation and CO₂ requires physical technology. The proposed TOC analysis chip decomposed into CO₂ as a result of the oxidizing of organic carbon using a photocatalyst, and the pH indicator that was changed by the generated CO₂ was optically measured. Although the area of the sample of the oxidation part and the pH indicator of the measurement part were distinguished in an enclosed space, CO₂ was quantified by producing an oxidation part and a measurement part that shared the same air in one chip. The proposed TOC analysis chip is less expensive and smaller, cost and size are disadvantages of existing organic carbon analysis equipment, because it does not require a separate carrier gas to transport the CO₂ gas in the oxidation part to the measurement part.

• Journal of the Korean Society of Industry Convergence
• /
• v.10 no.2
• /
• pp.89-96
• /
• 2007

For the environment protection, carbon dioxide as a natural refrigerant has been studied to use in an automotive air conditioning system. Hence, a numerical model has been developed to describe the evaporation phenomena of carbon dioxide flowing through very small diameter tubes. The two dimensional low-Reynolds $k-{\varepsilon}$ model was used to predict the flow phenomena of carbon dioxide in the two phase during its evaporation. Furthermore, the results obtained from the model were compared with the experiments for the validation. The heat transfer coefficient is lower, as the tube inner diameter becomes smaller. However, the amount of heat absorbed by a unit mass of carbon dioxide is greater due to more surface area. Therefore, the small diameter tube has advantage in terms of compact design of evaporator. When the inlet condition of pressure and temperature is low, the heat transfer coefficient is slightly high at the same size of tube because of the thermal properties of carbon dioxide.

• Journal of Navigation and Port Research
• /
• v.43 no.2
• /
• pp.79-85
• /
• 2019

Climate change is a very vital issue that can be no longer avoided. Korea has been a top-level country Iin dealing with carbon dioxide emissions since 1960. Many studies have been conducted to suppress or eliminate carbon dioxide emissions, which account for a large portion of greenhouse gases. Carbon Capture and Storage (CCS), the most practical method of them, plays a significant role. However, these methods have the disadvantage of the limits of geographical distribution and high possibility of re-emission into the atmosphere. Recently, ocean storage has been studied using Accelerated Weathering of Limestone (AWL), a technique for storing carbon dioxide in the ocean as an alternative to CCS, an underground storage. AWL is a method of converting carbon dioxide into concentrated water in the form of bicarbonate ion and discharging it to the ocean to dilute and store it. It does not cause re-emission to the atmosphere, and the discharged concentrated water increases the alkalinity of the ocean to prevent marine acidification. The objective of this study was to understand the behavior of DIC (Dissolved Inorganic Carbon) including carbon dioxide during the ocean discharge of bicarbonate ion concentrated water in AWL method. This study area was set near Ulleung-do where sufficient water depth and operational efficiency were secured. CORMIX model was used to calculate the material diffusion by submerged discharge using ship.

• KSBB Journal
• /
• v.18 no.4
• /
• pp.277-281
• /
• 2003

The study of growth characteristics for Spirulina platensis were carried out in 400 mL cylindrical photobioreactor and the effects of carbon dioxide concentration and flow rate during the growth of Spirulina platensis were investigated. The results showed that relatively low carbon dioxide concentration and high flow rate forced the growth of Spirulina platensis in experiment conditions. The pH analysis showed that different carbon dioxide concentration might form particular aqueous carbonate system in culture medium and affect the growth of Spirulina platensis. In addition, the possibility of limiting light radiation by cell density was investigated by the analysis of specific growth rate. The result intimated that the cause of decrease of specific growth rate at exponential phase was due to the limitation of light radiation by Spirulina platensis cell density in cylindrical photobioreactor.

• Environmental and Resource Economics Review
• /
• v.32 no.1
• /
• pp.27-46
• /
• 2023

This paper investigates how interfuel substitution affects carbon dioxide (CO₂) emissions with a focus on the use of biodiesel blended fuels. The results show that the Divisia elasticity of diesel demand is the greatest because the transportation sector relies heavily on diesel. Also, while the own-price elasticity of each fuel demand is negative, the results reveal that diesel demand is more inelastic than the demand for gasoline and LPG. Moreover, gasoline is a substitute for diesel and electricity, and diesel is a substitute for LPG and a complement for electricity. Regarding the effects on carbon dioxide emissions, this paper computes the potential CO₂ emissions associated with interfuel substitution using the coefficients of CO₂ emissions. The results show that using biodiesel blended fuels contributes to reducing CO₂ emissions, but it appears that the price-induced interfuel substitution is a main factor affecting CO₂ emissions.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2011.11a
• /
• pp.117-118
• /
• 2011

South Korea is a ninth greenhouse gas emission nation in the world(2007) and is certainly to perform a duty to conduct reduction role by the Kyoto Protocol in 2013. waste concrete produced in the country is 45 million tons per year and these two issues are being came to the fore as major problems of society. However, if it utilizes wet carbonation system carbon using carbon dioxide and waste concrete as raw material it can expect effect of environmental protection and resource recycling. Furthermore, it can exploit another industry production.