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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal DOI :
The Korean Society of Clean Technology
Editor in Chief :
Volume & Issues
Volume 15, Issue 4 - Dec 2009
Volume 15, Issue 3 - Sep 2009
Volume 15, Issue 2 - Jun 2009
Volume 15, Issue 1 - Mar 2009
Selecting the target year
Benefit Analysis of CNG as an Automobile Fuel
Cho, Haeng-Muk ; Mahmud, Md. Iqbal ;
Clean Technology, volume 15, issue 1, 2009, Pages 1~8
The adoption of compressed natural gas (CNG) as a vehicle fuel is a common phenomenon as it is accelerating worldwide. Increasing number of CNG driven vehicles around the world has jumped up from one million in 1996 to five million in 2006. CNG as a vehicle fuel is very popular to the end users because of its clean-burning properties and cost effective solution compared to other alternative fuels like diesel and gasoline. The use of CNG as a fuel reduces vehicular emission that is consisted of carbon monoxide (CO), hydrocarbons (HC), oxides of nitrogen (
), carbon dioxide (
) etc. This research highlights the characteristics of CNG vehicles, CNG arrangement in the vehicles, CNG fueling procedures and most importantly the environmental and economic factors that are highly considered as cost effective solution for the flexibility of using CNG in the automobiles.
Detoxification of PCBs Containing Transformer Oil by Catalytic Hydrodechlorination in Supercritical Fluids
Choi, Hye-Min ; Kim, Jae-Hoon ; Kim, Jae-Duck ; Kang, Jeong-Won ;
Clean Technology, volume 15, issue 1, 2009, Pages 9~15
Catalytic hydrodechlorination of PCBs (polychlorinated biphenyls) included in the transformer oil was carried out to detoxify PCBs and to recycle the treated oil. Catalysts such as 0.98 wt% Pt and 0.79 wt% Pd on
) support, 12.8 wt% Ni on
, and 57.6 wt% Ni on silica-alumina (
) support were used for the catalytic hydrodechlorination. Various supercritical fluids such as carbon dioxide, propane and isobutane were used as reaction media. The effects of reaction temperature, reaction time, catalysts, and supercritical fluids on the catalytic hydrodechlorination were examined in detail. The detoxification degree increased in the order of Ni > Pd > Pt. This is possibly due to higher metal loading and larger metal size of the Ni catalyst. Below
was found as the most effective reaction media for the catalytic hydrodechlorination of PCBs included in the transformer oil.
Development of Glass Fiber Composite Material to Extend the Life of Fly Ash Transport Pipe: Wear Test
Jeong, Gyu-Sang ; Chang, Yoon-Sang ;
Clean Technology, volume 15, issue 1, 2009, Pages 16~22
In this study, a fiber reinforced plastic (FRP) pipe with superior wear resistance was developed to replace the fly ash pipe of cast iron. Wear test was performed with various combinations of SiC filler and resin materials of unsaturated polyester, vinylester, epoxy, and phenol. Test results of ASTM D4060 showed the optimal combinations of resin, filler size, and resin/filler ratios. Test results of comparison between FRP and cast iron showed the possibility to replace cast iron pipe with the FRP pipe. Field test executed to compare the wear resistance between cast iron pipe and developed FRP pipe showed the superiority of the FRP pipe.
A Study on the Standard Method to Calculate Recyclability Rate of Electrical and Electronic Equipments
Yi, Hwa-Cho ; Kang, Hong-Yun ; Shim, Kang-Sik ; Kim, Jin-Han ; Sim, Jae-Sul ;
Clean Technology, volume 15, issue 1, 2009, Pages 23~30
European directive DIRECTIVE 2002/96/EC requires the minimum recycling & recovery rate on the waste electrical and electronic equipments (WEEE). But, they do not have guidelines on the calculation methods for recycling and recovery rate. A standard method to calculate recyclability and recoverability rate of products in the designing stage is necessary for the manufacturers so that they can reflect the calculated result to the improvement of product design. In this work, we investigated the existing calculation methods for the recycling and recovery rates of WEEE and the recyclability and recoverability rates of electrical and electronic equipments (EEE). A method for the calculation of recyclability and recoverability rates for the EEE products in the development stage was developed. The newly-developed calculation method was applied to some EEE products and the calculated results were evaluated.
A Study on the Development of Activated Carbons from Sewage Sludge
Lee, Taek-Ryong ; Chung, Chan-Kyo ; Joe, Young-Cheon ;
Clean Technology, volume 15, issue 1, 2009, Pages 31~37
This study deals with the production process of activated carbons from the sewage sludge char by chemical activation reaction. KOH and NaOH were used as activating agents, which react well with carbon. From the experiments, it was found that activated carbons made with KOH treatment had better physicochemical properties in terms of iodine number and BET value than those made with NaOH treatment. It was also found that the optimal deposition ratio of an activating agent to the sewage sludge char was 75 wt% of KOH and 50 wt% of NaOH. Activated carbons were washed out by distilled water after neutralization with 5 M hydrochloric acid solution. The activated carbons that were produced from a sewage sludge char at this optimal conditions have BET surface areas of approximately
Leaching of Iron and Aluminum from Red Mud and Preparation of Coagulants
Lee, Jae-Rok ; Hwang, In-Gook ; Bae, Jae-Heum ;
Clean Technology, volume 15, issue 1, 2009, Pages 38~41
Red mud is generated as a waste byproduct during the production of aluminum hydroxide/alumina from bauxite ore in the Bayer process. In this study coagulants for wastewater treatment were prepared by leaching iron and aluminum from red mud with hydrochloric acid. The removal efficiency of heavy metal ions by the red mud coagulant increased with increasing the adjusted pH value of the synthetic wastewater. When the red mud coagulant was prepared, the leaching efficiency of Fe decreased with increasing the weight of red mud, while the pH value of the red mud coagulant increased. The solution of the red mud coagulant mixed with water was reacted again with red mud to produce the leached solution, which had higher concentrations of Fe and Al and a higher pH value than the red mud coagulant. Also, its pH value was comparable to that of other coagulants:
Direct Preparation of Dichloropropanol from Glycerol over Acetin Catalyst
Song, Sun-Ho ; Park, Dong-Ryul ; Woo, Sung-Yul ; Song, Won-Seob ; Kwon, Myong-Suk ; Song, In-Kyu ;
Clean Technology, volume 15, issue 1, 2009, Pages 42~46
Solvent-free direct preparation of dichloropropanol (DCP) from glycerol (by-product of bio-diesel production) and hydrochloric acid gas was carried out over acetin catalyst in a gas-liquid batch reactor. For this purpose, acetin mixture and triacetin were used as a homogeneous acetin catalyst. Performance in the acetin-catalyzed reaction was compared to that in the non-catalytic reaction under the same reaction conditions (
, 3 bar, 3 h). Conversion of glycerol in the acetin-catalyzed reactions was ca. 3% higher than that in the non-catalytic reaction, and selectivity for dichloropropanol in the acetin-catalyzed reactions was ca. 50% higher than that in the non-catalytic reaction. It was also revealed that the catalytic performance of triacetin was ca. 2% higher than that of acetic mixture.
Hydrogen Production by Steam Reforming of Liquefied Natural Gas (LNG) over Nickel Catalyst Supported on Surfactant-templated Mesoporous Alumina
Seo, Jeong-Gil ; Youn, Min-Hye ; Song, In-Kyu ;
Clean Technology, volume 15, issue 1, 2009, Pages 47~53
Mesoporous aluminas (A-C, A-A, and A-N) were prepared by a templating method using cationic(C), anionic(A), and non-ionic(N) surfactant as a structure-directing agent, respectively. Nickel catalysts supported on mesoporous alumina (Ni/A-C, Ni/A-A, and Ni/A-N) were then prepared by an impregnation method, and were applied to hydrogen production by steam reforming of liquefied natural gas (LNG). Regardless of surfactant type, nickel species were finely dispersed on the surface of mesoporous alumina in the calcined catalysts. It was revealed that interaction between nickel species and support in the reduced catalysts was strongly dependent on the identity of surfactant. LNG conversion and
composition in dry gas increased in the order of Ni/A-C < Ni/A-A < Ni/A-N. It was found that catalytic performance increased with increasing nickel surface area in the reduced catalyst. Among the catalyst tested, Ni/A-N catalyst with the highest nickel surface area showed the best catalytic performance.
Characteristics of Separation of Water/Bitumen Emulsion by Chemical Demulsifier
Park, Kuny-Ik ; Han, Sam-Duck ; Noh, Soon-Young ; Bae, Wi-Sup ; Rhee, Young-Woo ;
Clean Technology, volume 15, issue 1, 2009, Pages 54~59
In this study, the separation of water/bitumen emulsion was investigated by chemical demulsification method. Motor oils (GS Caltex Deluxe Gold V 7.5W/30, Hyundai gear oil 85W/140) and asphalt (AP-5, KS M 2201, Dongnam Petrochemical MFG. Co.) were used as model oils in the preliminary experiments to effectively remove water from water/bitumen emulsion. The bitumen extracted from Canadian oilsands was used in this study. The water/oil emulsion was not separated without demulsifiers, and Hyundai motor oil showed higher efficiency of water separation at a low concentration of demulsifier compared with that for GS Caltex motor oil. However, as the concentration increased, the efficiency did not rapidly increase compared with that of GS Caltex motor oil. It was highly speculated that the water phase of Hyundai motor oil was not dispersed well compared with that of GS Caltex motor oil because the viscosity of Hyundai motor oil was much higher than that of GS Caltex motor oil. The demulsifier of higher HLB (hydrophilic - lipophilic balance) value had high separation efficiencies in water/oil emulsion. The TWEEN 20 (polyoxyethylene sorbitan monolaurate solution) showed better separation efficiency than other demulsifiers.
Adsorptive Removal of TBM and THT Using Ion-exchanged NaY Zeolites
Jung, Gap-Soon ; Lee, Seok-Hee ; Cheon, Jae-Kee ; Choe, Jae-Wook ; Woo, Hee-Chul ;
Clean Technology, volume 15, issue 1, 2009, Pages 60~66
Adsorptive removal of tetrahydrothiophene (THT) and tert-butylmercaptan (TBM) that were widely used sulfur odorants in pipeline natural gas was studied using various ion-exchanged NaY zeolites at ambient temperature and atmospheric pressure. In order to improve the adsorption ability, ion exchange was performed on NaY zeolites with alkali metal cations of
and transition metal cations of
. Among the adsorbents tested, Cu-NaY and Ag-NaY showed good adsorption capacities for THT and TBM. These good behaviors of removal of sulfur compound for Cu-NaY and Ag-NaY zeolites probably was influenced by their acidity. The adsorption capacity for THT and TBM on the best adsorbent Cu-NaY-0.5, which was ion exchanged with 0.5 M copper nitrate solution, was 1.85 and 0.78 mmol-S/g at breakthrough, respectively. It was the best sulfur capacity so far in removing organic sulfur compounds from fuel gas by adsorption on zeolites. While the desorption activation energy of TBM on the Cu-NaY-0.5 was higher than NaY zeolite, the difference of THT desorption activation energy between two zeolites was comparatively small.