Jin-Do Chung

Rapid sonochemical synthesis of novel PbSe–graphene–TiO2 composite sonocatalysts with enhanced on decolorization performance and generation of ROS

Nanostructured PbSe-graphene-TiO2 composites have been successfully synthesized via a facile ethylene glycol assisted-sonochemical synthesis approach in an aqueous solution. The as-prepared PbSe-graphene-TiO2 composites possessed enhanced decolorization of rhodamine B (Rh.B) and industrial dyes such as Texbrite BA-L (TBA), extended light absorption range, and efficient charge separation properties simultaneously. And the generation of reactive oxygen species (ROS) was detected through the oxidation reaction from 1,5-diphenyl carbazide (DPCI) to 1,5-diphenyl carbazone (DPCO). The sono-catalytic reaction mechanism was investigated by analyzing the date obtained. The coated PbSe and TiO2 nanoparticles with small and good dispersion station could be related to the sonochemical assisted synthesis route, it is wished that this paper might offer some important subjects for broadening the applications of sonocatalytic technologies.

Filtration and Dust Cake Experiment by Ceramic Candle Filter in High Temperature Conditions

Particulate collection at high temperature and high pressure (HTHP) is important in an advanced coal power generation system not only to improve the thermal efficiency of the system, but also to prevent the gas turbine from erosion and to meet the emission limits of the effluent gas. The specifications for particulate collection in those systems such as Integrated Gasification Combined Cycle (IGCC) and Pressurized Fluidized Bed Combustion (PFBC) require absolutely high collection efficiency and reliability. Advanced cyclone, granular bed filter, electrostatic precipitator, and ceramic filter have been developed for particulate collection in the advanced coal power generation system. However, rigid ceramic filters and granular bed filters among them show the best potential. The problems experienced of these systems on performance, materials, and mechanical design were investigated. Ceramic candle filters have the best potential for IGCC at this moment because they have nearly the highest efficiency compared with other filtering systems and have accumulated many reliable design data from many field experiences. The purpose of this study was to investigate the efficiency of ceramic filters and stability of material against high temperature and longterm operation condition by applying fly ash on the surface of the filter and relation of pressure drop and dust cake thickness. Experimental conditions were 50 hours at 450 °C, 650 °C and 850 °C.

Impact of Yellow Dust Transport from Gobi Desert on Fractional Ratio and Correlations of Temporal PM 10 , PM 2.5 , PM 1 at Gangneung City in Fall

Hourly concentrations of , and , were investigated at Gangneung city in the Korean east coast on 0000LST October 26~1800LST October 29, 2003. Before the intrusion of Yellow dust from Gobi Desert, (, ) concentration was generally low, more or less than 20 (10, 5) , and higher PM concentration was found at 0900LST at the beginning time of office hour and their maximum ones at 1700LST around its ending time. As correlation coefficient of and ( and , and and ) was very high with 0.90(0.99, 0.84), and fractional ratios of were 1.37~3.39(0.23~0.54), respectively. It implied that local concentration could be greatly affected by particulate matters of sizes larger than , and concentration could be by particulate matters of sizes smaller than . During the dust intrusion, maximum concentration of (, ) reached 154.57(93.19, 76.05) with 3.8(3.4, 14.1) times higher concentration than before the dust intrusion. As correlation coefficient of and (vice verse, , ) was almost perfect high with 0.98(1.00, 0.97) and fractional ratios of were 0.48~1.25(0.16~0.37), local concentration could be major affected by particulates smaller than both and (fine particulate), opposite to ones before the dust intrusion. After the ending of dust intrusion, as its coefficient of 0.23(0.81, - 0.36) was very low, except the case of and and were 1.13~1.91(0.29~1.90), concentrations of coarse particulates larger than greatly contributed to concentration, again. For a whole period, as the correlation coefficients of , , were very high with 0.94, 1.00 and 0.92, reliable regression equations among PM concentrations were suggested.

A Study in The Efficiency Improvement of Thermal Plasma Gas Processor Through Fluid Dynamics Analysis of Reaction Zone

This study explores the numerical analysis method of fluid dynamics in the reaction section to improve the gas processing efficiency in the hazardous gas removal by atmospheric thermal plasma. This study also intends to contribute in technology advance to improve the processing efficiency and make the process more stable. Numerical analysis of temperature distribution in the reaction section dependent on the change in flow velocity of Ar and plasma temperature change, which are major control variables in the cracking process of HFC-23 using arc plasma, was done. The characteristic of incoming oxygen by temperature suggested that when temperature increased to 1600K, 1700K, 1800K respectively, the range of cracking temperature 1500K increased to 75.0%, 83.3%, 90.2% respectively. The temperature change of Ar by velocity change was widest in the area higher than 1500K when the velocity was 2.5m/s; however, since there was no big difference when the velocity was 2m/s, it is believed that 2 m/s would be most proper.

A Study on the Development of Equation from Calculation about Emissions of Greenhouse Gases in Glass Manufacturing Industries

The aim of this study is investigated greenhouse gas emissions of glass industry, and when calculates greenhouse gas emission, using formula(Tier 3) advising in IPCC(Intergovernmental Panel on Climate Change) and using self designed formula(Tier 3+) authors of this study. Studied to propose calculation formula that can compare these two calculation results and apply to domestic. Formula of Tier 3 calculated to theoretical composition of carbonate material, And Formula of Tier 3+ calculated on the basis of chemical substance formation table that get from glass manufacture company(The S company). As a result, Dolomite, Soda ash, Limestone, Industrial Barium carbonate is calculated value of Tier 3+ lower than value of Tier 3, And Industrial Potassium carbonate, Industrial Strontium carbonate was calculated value of Tier 3 lower than value of Tier 3. This study finding, formula of Tier 3+ has higher confidence than formula of Tier 3 when consider revision about purity of injection raw material. And hereafter, When calculate greenhouse gas emissions about nonmetallic mineral industry, use of Tier 3+ is considered that should be encouraged.

Numerical simulation of fluid flow in porous filters for a particulate removal facility

In order to simulate the fluid flow in a porous filter in a dust removal facility, gas velocity and pressure distributions in the filter element at T = 673 K and Pc = 20 atm were calculated numerically for both steady and non-steady states. The effects of the diameter and length of the filter element on those distributions were also studied. The size of a porous filter had influence on the baseline pressure loss and the distribution of flow in the filter during filtration and cleaning. Filter size was, however, restricted by cleaning performance because a large amount of cleaning gas had to be flushed into the internal filter. As the length of the filter increases and the diameter decreases, total pressure and the inlet velocity of the cleaning gas increases rapidly. It can produce an insufficient cleaning effect, forming cleaning velocity distributions within filter. In an analysis of the transient region from filtration to cleaning, the flow in the filter approached steady state in 50 ms after injecting pulse jets. Initially after injecting pulse jets, the pressure was relatively high at the inlet regime of filter.