• Journal of Energy Engineering
• /
• v.14 no.4 s.44
• /
• pp.219-225
• /
• 2005

for the removal of carbon dioxide in flue gas, which is the main cause of the global warming, chemical absorption methods were widely used for years. Alkanolamines such as MEA, AMP, MDEA are mainly used as an absorbent. In this study, cyclic amines - Piperazine, Piperidine and Cyclohelylamine are investigated to compare the chemical solubilities, absorption capacities and rate ot reaction. In conclusion, Piperazine is the most effective absorbent of $CO_2$ and ran be the excellent alternative to the former absorbents. Experiments were performed at 5, 10, 15 weight percent, 30, 40, $50^{\circ}C$, and the gas solubilities are determined by back-titration method, and using Gas Chromatography the absorption rate was compared.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.10 no.3
• /
• pp.602-606
• /
• 2009

The absorption capacity and initial absorption rate in 5 %, 10%, 15 % and 20% $Na_{2}CO_{3}$ under the constant temperature at $40^{\circ}C$ and the initial absorption rate in mixture of different alkaline salts such as $KHCO_3$, $CaCO_3$ and $K_{2}CO_{3}$ were measured using batch type stirred cell contractor. 10% $Na_{2}CO_{3}$ showed the highest absorption capacity and $Na_{2}CO_{3}$ and $K_{2}CO_{3}$ showed the somewhat increased absorption capacity and initial absorption rate respectively. Further more, we have studied the effect of adding Pz and Pp to $Na_{2}CO_{3}$. The result showed that absorption rate of $CO_2$ was increased by adding these additives.

• Applied Chemistry for Engineering
• /
• v.9 no.1
• /
• pp.107-114
• /
• 1998

The solubilities of $CO_2$ in 20wt% and 30wt% aqueous AMP solution were obtained from experiments at 40, 50, 60, 70, $80^{\circ}C$. Using the modified Kent-Eisenberg model, equilibrium constants and correlations were determined from the regression of experimental results of 30wt% aqueous AMP solution. There were good agreements between the predicted $CO_2$ solubilities in 20wt% aqueous AMP solution and experimented values. The prediction was conducted at the condition in the literature and the predicted values calculated from the model and correlations which were obtained from this work agree well with the prediction from Deshmukh-Mather model. Thus, the modified Kent-Eisenberg model and correlated equations suggested by this work, resonably well represent vapor-liquid equilibrium of $CO_2$ with aqueous AMP solution. The calculation of chemical species concentration in the liquid phase was performed uslng equilibrium model and from this calculation, we confirm that good absorption capacity is due to the formation of unstable carbamate. Heat of solution(${\Delta}Hs$) was calculated from the solubility data using the Gibbs-Helmholtz equation.

• Clean Technology
• /
• v.27 no.3
• /
• pp.255-260
• /
• 2021

A drawback in the CO₂ capture process using an aqueous amine solution is the high energy requirement for the regeneration process. In order to overcome this disadvantage, this study investigated CO₂ capture characteristics using a biphasic absorbent in which isopropanol (IPA) was introduced into an aqueous solution of diethylenetriamine (DETA). When the IPA composition exceeded 20 wt% in 20 wt% DETA aqueous solution, the absorbent phase was liquid-liquid separated into a CO₂-rich phase and a CO₂-lean phase because of the low solubility of the salt formed by the reaction of CO₂ with DETA in isopropanol. When the isopropanol composition in the DETA aqueous solution increased, the phase volume ratio of the CO₂-rich phase to the volume of the CO₂-lean phase increased; and, accordingly, the CO₂ in the CO₂-rich phase was more concentrated. The results of absorbing CO₂ in a packed tower using 20 wt% DETA + IPA + water absorbent confirmed that both the CO₂ absorption capacity and the absorption rate were higher than that of the 20 wt% DETA aqueous solution. When a biphasic absorbent composed of DETA + IPA + water is applied to CO₂ capture, it can be expected to concentrate CO₂ because of phase separation and thereby reduce regeneration energy owing to volume reduction of the CO₂-rich phase.

• Journal of the Korean Electrochemical Society
• /
• v.11 no.3
• /
• pp.165-169
• /
• 2008

The effect of reduction of carbon dioxide by CODH(Carbon Monoxide Dehydrogenase) was compared on glassy carbon and gold working electrodes. In case of gold electrode, the choice of the optimum applied potential is very important since $H_2$ evolution can be mixed with $CO_2$ reduction. On the other hand, efficient $CO_2$ reduction was observed up to -650 mV vs. NHE on glassy carbon in neutral solution due to the larger overpotential for $H_2$ evolution on glassy carbon surface than that on gold surface. The optimum potential for $CO_2$ reduction was found to be $-570{\sim}600\;mV$ vs. NHE. The current efficiency of $CO_2$ to CO decreased dramatically at more negative potential according to the activity of enzyme decrease and the hydrogen evolution.

• Transactions of the Korean hydrogen and new energy society
• /
• v.9 no.1
• /
• pp.8-15
• /
• 1998

The catalytic hydrogenation of carbon dioxide has been studied for the fixation of carbon dioxide to mitigate global warming problems, but it needed hydrogen, which the price is still high. Recently, the electrochemical reduction of carbon dioxide has been drawn attractions because carbon dioxide could be converted to the valuable chemicals such as methane, ethane and alcohols electrochemically in the electrolyte solution using a catalytic electrode. This system is simple because the water electrolysis and hydrogenation take place at the same time using the surplus electricity at midnight. In this work, a continuous electrochemical reduction system was fabricated, which was composed of the reduction electrode (copper or perovskite type, $2{\times}2cm^2$), reference electrode(platinum, $2{\times}6cm^2$), standard electrode(Ag/AgCl), and potassium bicarbonate electrolyte solution saturated with carbon dioxide. The quality and quantity of the products and reduction current were analyzed, according to the electrolyte concentration and electrode type.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2011.11a
• /
• pp.41-42
• /
• 2011

The purpose of this study is not only fixation of carbon dioxide using the cement-saturated solution by wet carbonating reaction but also evaluate the possibility of storage technology of Carbon dioxide. wet carbonation is reaction of CO₂ injection by CO₂ reactor. As a result of experiment, the carbon dioxide is fixed, and high-purity Calcium Carbonate is eluted.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2012.05a
• /
• pp.71-72
• /
• 2012

The purpose of this study is not only fixation of carbon dioxide using the cement-Paste solution's calcium ion by wet carbonating reaction but also quantitatively evaluate the possibility of storage technology of Carbon dioxide. wet carbonation is reaction of CO₂ injection by CO₂ reactor. As a result of experiment, the carbon dioxide is fixed, and high-purity Calcium Carbonate is eluted.

• Transactions of the Korean hydrogen and new energy society
• /
• v.19 no.4
• /
• pp.340-347
• /
• 2008

Dissolution process of serpentine in distilled water was systematically investigated for study on pre-treatment of serpentine which was a candidate material for carbon dioxide sequestration. The metallic ions(Ca, Si, Mg etc.) were dissolved in distilled water at ambient condition and their concentrations were changed with dissolution time. The precise evaluation of dissolution process for serpentine dissolved solvent was performed by ion conductivity and pH measurement. Serpentine dissolution in distilled water was evaluated as a stable pre-treatment process without changes of crystallographic structure and chemical structure changes.

• Korean Chemical Engineering Research
• /
• v.54 no.5
• /
• pp.612-620
• /
• 2016

Aqueous mineral carbonation process, in which $CO_2$ is captured through the reaction with aqueous calcium oxide (CaO) solution, is one of CCU technology enabling the stable sequestration of $CO_2$ as well as economic value creation from its products. In order to enhance the carbon capture efficiency, it is required to maximize the dissolution rate of solid reactants, CaO. For this purpose, the proper design of a reactor, which can achieve the uniform distribution of solid reactants throughout the whole reactor, is essential. In this paper, the effect of internal reactor designs on the solid dispersion quality is studied by using CFD (computational fluid dynamics) techniques for the pilot-scale reactor which can handle 40 ton of $CO_2$ per day. Various combination cases consisting of different internal design variables, such as types, numbers, diameters, clearances and speed of impellers and length and width of baffles are analyzed for the stirred tank reactor with a fixed tank geometry. By conducting sensitivity analysis, we could distinguish critical variables and their impacts on solid distribution. At the same time, the reactor design which can produce solid distribution profile with a standard deviation value of 0.001 is proposed.