• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.10 no.11
• /
• pp.3246-3252
• /
• 2009

The interest on the recovery of thermal energy using the waste has been rising to solve the problems of continuous increase of waste generation and the depletion of the fossil fuel recently. The incineration has been used most popularly as a treatment process of the waste for the energy recovery. However, it is expected that incineration and design cost will increase in the treatment of air contaminant emitted from incinerator. This research has simulated the actual incinerator and the flue gas treatment system using the Aspen plus which is the software to simulate the chemical process. The incineration process is composed of the 1st and 2nd combustor to burn the waste, SNCR process to reduce the $NO_x$ using the urea, and the steam generation process to save the energy during incineration. The $Ca(OH)_2$ slurry was used as an acid gas (HCl, $SO_2$) treatment materials and the removal efficiency for the products from the neutralization of acid gas in SDA and combustion ash was simulated at the bag filter. The simulation result has been corresponded with the treatment efficiency of emitted gas from the actual industrial waste incinerator and it is presumed to be used to forecast the efficiencies of flue gas treatment system in the future.

• Korean Chemical Engineering Research
• /
• v.57 no.2
• /
• pp.244-252
• /
• 2019

This study investigated the effect of addition of aromatics such as Toluene/LCO/resin on the coke depression and asphaltene conversion. The experiment was carried out with vacuum residue as a feedstock with Molybdenum dispersed catalysts under the slurry-phase hydrocracking condition (Temp. of $425^{\circ}C$, $H_2$ pressure of 80 bar at $80^{\circ}C$, reaction time of 4 hr, Mo-concentration of 500 ppm). As results, the coke reduction was shown to be similar irrespective of types of aromatics, while asphaltene was more converted to gas and maltene when LCO and resin with higher dipole moment were added. The addition of aromatics with change of reaction time showed no difference in terms of depression of coke formation. But the addition of LCO rather increased the coke yield after 2 hr. And it was found that asphaltene in liquid phase had the higher aromaticity index so that asphaltene is difficult to disperse in oil phase.

• Korean Chemical Engineering Research
• /
• v.49 no.6
• /
• pp.786-789
• /
• 2011

In order to estimate the possibility of applying electrolytes generally used in solid oxide fuel cells(SOFCs) to direct carbon fuel cells(DCFCs), properties of YSZ(yttria stabilized zirconia) electrolyte were evaluated. In this study, vacuum slurry coating method was adapted to coat thin layer on anode support substrate. After sintering the electrolyte at $1400^{\circ}C$ for 5hrs, microstructure was analyzed by using SEM image. Also, gas permeability and ionic conductivity were measured to find out the potential possibility of electrolyte for DCFCs. The YSZ electrolyte represented dense coating layer and low gas permeability value. The ionic conductivity of YSZ electrolyte was high over $800^{\circ}C$. After measurement of the electrolyte properties, direct carbon fuel cell was fabricated and its performance was measured at $800^{\circ}C$.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.33 no.4
• /
• pp.257-262
• /
• 2013

This study investigates the effect of fermentable carbohydrate on the concentration of odorous compounds in pig slurry. Four types of pig diet were studied: control, peanut hull (crude fiber 29.87, NDF 44.02%), golden fiber (crude fiber 48.77, NDF 65.88%), and almond hull (crude fiber 44.30, NDF 64.44%). Pigs (average BW 37.0 kg) were fed diets that met the Korean Feeding Standard (2012) and their excreta samples were collected from the slurry pits. Levels of volatile organic compounds (phenols and indoles) and volatile fatty acids were analyzed by gas chromatography. Phenol level was the lowest (p<0.05) in golden fiber (33.26 ppm) group and the highest in control (97.29 ppm). The concentration of indoles in the peanut hull (1.27 ppm), almond hull (1.20 ppm), and golden fiber (1.02 ppm) groups was lower (p < 0.05) than that of control (1.79 ppm). Levels of short chain fatty acid (SCFA) were lower (p < 0.05) in golden fiber (1,319 ppm) and almond hull (1,433 ppm) groups than in control (1,893 ppm). Concentration of branched chain fatty acid (BCFA) in the golden fiber group (74 ppm) was lower (p < 0.05) than that of control (98 ppm). Taken together, the concentration levels of phenols, indoles, and VFAs decreased on addition of peanut hull, golden fiber or almond hull to the diet, suggesting that fermentable carbohydrate may contribute to reducing odorous compounds in pig slurry.

• Journal of the Korean Ceramic Society
• /
• v.42 no.12 s.283
• /
• pp.827-832
• /
• 2005

In this study, thin electrolyte layer was prepared by 8YSZ ($8mol\%$ Yttria-Stabilized Zirconia) slurry dip and sol coating onto the porous anode support in order to reduce ohmic resistance. 8YSZ polymeric sol was prepared from inorganic salt of nitrate and XRF results of xerogel powder exhibited similar results $(99.2\pm1wt\%)$ compared with standard sample (TZ-8YS, Tosoh Co.). The dense and thin YSZ film with $1{\mu}m$ thickness was synthesized by coating of 0.7M YSZ sol followed by heat-treatment at $600^{\circ}C$ for 1 h. Thin film electrolyte sintered at $1400^{\circ}C$ showed no gas leakage at the differential pressure condition of 3 atm.

• Clean Technology
• /
• v.18 no.1
• /
• pp.22-30
• /
• 2012

Separation of $SO_2$ from the flue gases of fossil fuel power plants are important issue because of its strong environmental impact. Industrially, $SO_2$ is being removed with a slurry of limestone, lime or aqueous caustic soda. However, these scrubbing processes possess several drawbacks such as the generation of huge amount of wastewater and the production of metal salts. Recently, ionic liquids have gained increasing interest as an absorbent for acid gas, $CO_2$ and $SO_2$. In this review, we have introduced the recent progress of ionic liquids as a $SO_2$ absorbent.

• Journal of the Korean Ceramic Society
• /
• v.40 no.9
• /
• pp.891-896
• /
• 2003

Novel fabrication technique was developed for high strength Reaction-Bonded SiC (RBSC) hot gas filter for use in IGCC (Integrated Gasification Combined Cycle) system. The room and high temperature fracture strengths for Si-melt infiltrated reaction-bonded SiC were 50-123, and 60-66 MPa, respectively. The average pore size was 60-70 $\mu\textrm{m}$ and the porosity was about 34 vol％. RBSC infiltrated with molten silicon showed improved fracture strength at high temperature, as compared to that of clay-bonded SiC, due to SiC/Si phase present within SiC phase. The thickness for SiC/Si phase was increased with increasing powder particle size of SiC from 10 to 34 $\mu\textrm{m}$. Pressure drop with dust particles showed similar response as compared to that for Schumacher type 20 filter. The filter fabricated in the present study showed good performance in that the filtered powder size was reduced drastically to below 1 $\mu\textrm{m}$ within 4 min.

• Korean Journal of Materials Research
• /
• v.9 no.7
• /
• pp.675-679
• /
• 1999

An investigation was performed to prepare spherical cobalt powder with about particle size of 400nm from aqueous cobalt hydroxide slurry under hydrothermal reduction conditions using palladium chloride as a catalyst. The reduction kinetics was in good agreement with a surface reaction core model equation. and the activation energy obtained from Arrhenius plots was 55.6 KJ/mol at the temperature range of $145~195^{\circ}C$. Additionally, the study showed that the cobalt reduction rate is proportional to the initial hydrogen pressure with a reaction order of n=0.63. which corresponds to the gas chemisorption reaction type.

• Korean Journal of Materials Research
• /
• v.14 no.5
• /
• pp.368-373
• /
• 2004

To improve the conventional cathode-supported tubular solid oxide fuel cell (SOFC) from the viewpoint of low cell power density, expensive fabrication process and high operation temperature, the anode-supported tubular solid oxide fuel cell was investigated. The anode tube of Ni-8mol% $Y_2$O$_3$-stabilized $ZrO_2$ (8YSZ) was manufactured by extrusion process, and, the electrolyte of 8YSZ and the multi-layered cathode of $LaSrMnO_3$(LSM)ILSM-YSZ composite/$LaSrCoFeO_3$ were coated on the surface of the anode tube by slurry dip coating process, subsequently. Their cell performances were examined under gases of humidified hydrogen with 3% water and air. In the thermal cycle condition of heating and cooling rates with $3.33^{\circ}C$/min, the anode-supported tubular cell showed an excellent resistance as compared with the electrolyte-supported planar cell. The optimum hydrogen flow rate was evaluated and the air preheating increased the cell performance due to the increased gas temperature inside the cell. In long-term stability test, the single cell indicated a stable performance of 300 mA/$\textrm{cm}^2$ at 0.85 V for 255 hr.

• Journal of the Korean Ceramic Society
• /
• v.29 no.8
• /
• pp.587-592
• /
• 1992

Sheets of SiC-SiC whisker maxed matrix were prepared from the mixed slurry of SiC whisker and SiC matrix by the rolling method. With the increase of SiC whisker, the pore size, the porosity and the phosphoric acid absorbency of the matrix were increased, while the bubble pressure was decreased. The activation energy for the transfer of H+ ion was decreased with the increase of mixing ratio of SiC whisker to the SiC matrix from the measurement of hydrogen ion conductivity. The activation energy was evaluated as 0.25 eV when the mixing ratio of SiC whisker to the SiC matrix was 1 : 2 and the activation energy was 0.16 eV for the 2 : 1 matrix. It means that SiC whisker matrix contributes to attain a better microstructure for the diffusion of hydrogen ion. From the measurement of single cell performance of matrix with various mixing ratio, it is concluded that if SiC-SiC whisker maxed matrix has a sufficient bubble pressure to prevent the crossover of H2 gas, the current density of a fuel cell is increased with the increase of acid absorbency of the matrix. Current density was improved from 140 mA/$\textrm{cm}^2$ for 0.25 mm thickness of matrix to 170 mA/$\textrm{cm}^2$ for the 0.20 mm one at 700 mV.