• KEPCO Journal on Electric Power and Energy
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• v.5 no.4
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• pp.337-341
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• 2019

In this study, the effects of two materials, active alumina and CaO based inorganic binder, which cause the side reaction on the K₂CO₃-based solid CO₂ sorbents was investigated. K₂CO₃-based solid sorbents called KAM series was prepared by spray drying method and then measured its physical properties and CO₂ sorption capacity. Among the KAM series sorbents, KAM(0.5) maintained high CO₂ sorption capacity of 7.6 wt% after 3 cycle of sorption/regeneration reaction and showed very low attrition loss as low as 3.1 % which was measured by ASTM D5757-95.

• KEPCO Journal on Electric Power and Energy
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• v.1 no.1
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• pp.115-120
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• 2015

$K_2CO_3$-based dry regenerable sorbents were prepared by spray-drying techniques to improve mass produced $K_2CO_3-Al_2O_3$ sorbents (KEP-CO2P, hereafter), and then tested for their $CO_2$ sorption capacity by a $2,000Nm^3/h$ (0.5 MWe) $CO_2$ capture pilot plant built for Unit 3 of the Hadong thermal power station in 2010. Each of the sample sorbents contained 35 wt.% $K_2CO_3$ as the active materials with various support materials such as $TiO_2$, MgO, Zeolite 13X, $Al_2O_3$, $SiO_2$ and hydrotalcite (HTC). Their physical properties and reactivity were tested to evaluate their applicability to a fluidized-bed or fast transport-bed $CO_2$ capture process. The $CO_2$ sorption capacity and percentage utilization of $K_2CO_3$-MgO based sorbent, Sorb-KM2, was $8.6g-CO_2/100g$-sorbents and 90%, respectively, along with good mechanical strength for fluidized-bed application. Sorbs-KM2 and KT were almost completely regenerated at $140^{\circ}C$. No degradation of Sorb-KM by $SO_2$ added as a pollutant in flue gas was observed during a cycle test.

• Analytical Science and Technology
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• v.30 no.1
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• pp.20-25
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• 2017

An analytical method for determining potential endocrine disruptors (bisphenol A, 2-chlorophenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol, pentachlorophenol, p-t-butylphenol, p-pentylphenol, p-hexylphenol, p-t-octylphenol, p-heptylphenol, nonylphenol) by solid-phase extraction (SPE) and High Perfomance Liquid Chromatography(HPLC) equipped with fluorescence and variable wavelength detector has been developed. The SPE process for sample concentration was performed on a commercially available Oasis HLB cartridge packed with polymeric sorbents. The effect of elution solvent and elution volume on the recoveries of the analytes were investigated with HPLC. Average recovery of >85% was achieved with 60mg sorbents using 5mL of methanol as elution solvent. Phenolic compounds in canned drinks, beverages and water samples were surveyed by this proposed method.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 1994.04a
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• pp.51-58
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• 1994

• Korean Chemical Engineering Research
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• v.50 no.4
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• pp.654-658
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• 2012

In this study, $CO_2$ capture efficiency in relation to the inlet moisture content of the regenerator was investigated using potassium-based sorbents in the continuous process composed of two bubbling fluidized-bed reactors, where solid outlet configuration in the regenerator was converted from underflow to overflow. XRD (X-ray Diffraction), SEM (Scanning Electron Microscope) and TGA were performed to find out the effect of water pre-treatment according to inlet moisture content in the regenerator. The $K_2CO_3{\cdot}1.5H_2O$ structure of solid sorbents has been increased as inlet moisture content of the regenerator increased. As a result, the $CO_2$ capture efficiency increased as the $K_2CO_3{\cdot}1.5H_2O$ structure of solid sorbents increased since the reactivity of the sorbents has been improved by that structure generated by the water pre-treatment. And $CO_2$ capture efficiency increased about 3~8% after sorbent outlet configuration of the regenerator was changed underflow to overflow.

• Journal of Hydrogen and New Energy
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• v.25 no.5
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• pp.482-490
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• 2014

Gaseous sulfur compound such as $H_2S$ or COS in coal- or biomass-derived hot syngas can be purified by solid sorbents at high temperatures. In this study, we investigated the physical properties and reactivity of solid regenerable desulfurization sorbents with 37.2, 41.9, and 46.5wt% ZnO to look into the ZnO content effect. The sorbents were produced by spray-drying method to apply to a fluidized-bed process. Sulfidation and regeneration reaction were carried out using a thermogravimetric analyzer. Sorbent prepared with 46.5wt% ZnO had physical properties suitable for a fluidized-bed process applications such as spherical shape, sufficient mechanical strength and density, high porosity and surface area. It showed high sulfur sorption capacity of 10.4wt% (ZnO utilization of 57%) at reaction temperatures of 500 and $650^{\circ}C$ for sulfidation and regeneration, respectively. However, the sulfur sorption capacity and ZnO utilization were significantly reduced and dimple shape appeared when the ZnO content decreased to 37.2 and 41.9wt%. Sulfur sorption capacity and regenerability were improved as reaction temperature increased within the experimental temperatures used in this work. The reaction temperature zones of $1500{\sim}550^{\circ}C$ and $650{\sim}700^{\circ}C$ are recommended for sulfidation and regeneration, respectively, to lead best reaction performances of the ZnO-based spray-dried sorbents developed in this work.

• Korean Chemical Engineering Research
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• v.48 no.2
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• pp.140-146
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• 2010

This paper addresses recent status and trends of carbon dioxide capture technologies using dry sorbents in the flue gas. The advantages of dry sorbent $CO_2$ capture technology are broader operating temperature range, less energy loss, less waste water, less corrosion problem, and natural properties of solid wastes. Recently, U.S.A. and Korea have been developing processes capturing $CO_2$ from real coal flue gas as well as sorbents improving sorption capacity to decrease total $CO_2$ capture cost. New class of dry sorbents have been developed such as chemisorbents with alkali metals of which material cost is low, amines physically adsorbed on silica supports, amines covalently tethered to the silica support, carbon-supported amines, polymer-supported amines, amine-containing solid organic resins and metal-organic framework. The breakthrough is needed in the materials on dry sorbents to decrease capture cost.

• Analytical Science and Technology
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• v.28 no.6
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• pp.370-376
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• 2015

An analytical method for determining phenol considered priority pollutants of the US EPA and precursor of toxic phenolic compounds by solid-phase extraction (SPE) and high performance liquid chromatographic systems (HPLC) equipped with fluorescence and mass selective detectors have been developed. The SPE process for sample preconcentration was performed on a commercially available Oasis HLB cartridge packed with polymeric sorbents. The effect of pH, elution solvent, and elution volume on the recoveries of the analytes were investigated with HPLC/FLD. Average recovery of >87.0% was achieved with 60 mg sorbents using 5 mL of methanol as an elution solvent at pH=3.

• Korean Chemical Engineering Research
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• v.48 no.4
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• pp.499-505
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• 2010

In this study, hydrodynamics and reaction characteristic of K-based solid sorbents for $CO_2$ capture were investigated using a continuous system composed of two bubbling fluidized-bed reactors(1.2 m tall bed with 0.11 m i.d.). Potassium-based dry sorbents manufactured by the Korea Electric Power Research Institute were used, which were composed of $K_2CO_3$ of 35% for $CO_2$ absorption and supporters of 65% for mechanical strength. The continuous system consists of two bubbling fluidized-bed reactors, solid injection nozzle, riser, chiller, analyzer and heater for regeneration reaction. The minimum fluidizing velocity of the continuous system was 0.0088 m/s and the solid circulation rate measured was $10.3kg/m^2{\cdot}s$ at 1.05 m/s velocity of the solid injection nozzle. The $CO_2$ concentration of the simulated gas was about 10 vol% in dry basis. Reaction temperature in carbonator and regenerator were maintained about $70^{\circ}C$ and $200^{\circ}C$, respectively. Differential pressures, which were maintained in carbonator and regenerator, were about $415mmH_2O$ and $350mmH_2O$, respectively. In order to find out reaction characteristics of dry sorbents, several experiments were performed according to various experimental conditions such as $H_2O$ content(7.28~19.66%) in feed gas, velocity (0.053~0.103 m/s) of simulated gas, temperature($60{\sim}80^{\circ}C$) of a carbonator, temperature($150{\sim}200^{\circ}C$) of a regenerator and solid circulation rate($7.0{\sim}10.3kg/m^2{\cdot}s$). The respective data of operating variables were saved and analyzed after maintaining one hour in a stable manner. As a result of continuous operation, $CO_2$ removal tended to increase by increasing $H_2O$ content in feed gas, temperature of a regenerator and solid circulation rate and to decrease by increasing temperature of a carbonator and gas velocity in a carbonator.

• Bulletin of the Korean Chemical Society
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• v.34 no.8
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• pp.2353-2357
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• 2013

The objective of this study was to develop a simple, less time-consuming and accurate sampling technique based on solid-phase sorption with activated carbon as the sorbents. The results from solid-phase sorption techniques were compared to that from a conventional solvent impinger-based technique to confirm the efficacy of the proposed method. The laboratory results indicated that the solid-phase sorption method was suitable for the determination of siloxanes as the measured concentrations were similar to that from a solvent impinge method. The data from solid-phase sorption method showed excellent recovery and reproducibility while the sampling was less labor intensive and less time consuming than the solvent impinge method. Following the laboratory tests, the solid-phase sorption technique was successfully applied to sampling biogas from a field site. This study shows that the activated carbon-based solid-phase sorption can be a reliable and less time-consuming option for the sampling and collection of siloxanes under various different landfill conditions.