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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 19, Issue 4 - Dec 2013
Volume 19, Issue 3 - Sep 2013
Volume 19, Issue 2 - Jun 2013
Volume 19, Issue 1 - Mar 2013
Selecting the target year
Pre-treatment Technology of Wastewater Sludge for Enhanced Biogas Production in Anaerobic Digestion
Kim, Dong-Jin ;
Clean Technology, volume 19, issue 4, 2013, Pages 355~369
DOI : 10.7464/ksct.2013.19.4.355
Economic feasibility is one of the most important factors in energy production from regenerative biomass. From the aspect, biogas from anaerobic digestion of wastewater sludge is regarded as the most economical because of its cheap substrate and additional income from the disposal of waste sludge. Sludge hydrolysis has been regarded as the rate limiting step of anaerobic digestion and many sludge pre-treatment technologies have been developed to accelerate anaerobic sludge digestion for enhanced biogas production. Various sludge pre-treatment technologies including biological, thermo hydrolysis, ultrasonic, and mechanical methods have been applied to full-scale systems. Sludge pre-treatment increased the efficiency of anaerobic digestion by enhancing hydrolysis, reducing residual soilds, and increasing biogas production. This paper introduces the characteristics of various sludge pre-treatment technologies and the energy balance and economic feasibility of each technology were compared to prepare a guideline for the selection of feasible pre-treatment technology. It was estimated that thermophilic digestion and thermal hydrolysis were most economical technology followed by Cell rupture
, and ultrasound. The cost for waste sludge disposal shares the biggest portion in the economic analysis, therefore, water content of the waste sludge was the most important factor to be controlled.
Capability of CO
on Metal-Organic Frameworks-Based Porous Adsorbents and Their Challenges to Pressure Swing Adsorption Applications
Kim, Moon Hyeon ; Choi, Sang Ok ; Choo, Soo Tae ;
Clean Technology, volume 19, issue 4, 2013, Pages 370~378
DOI : 10.7464/ksct.2013.19.4.370
This review has shown the capability of MOFs and ZIFs materials to adsorb
under typical PSA temperatures and pressures. The usual operating conditions are adsorption temperatures of
and adsorption pressures of 4~6 bar based on numerous PSA processes which are widely employed in gases industry for adsorptive separation of
. The extent of
adsorption on the microporous materials depends on the metal species and organic linkers existing in the frameworks. The pore size and the surface area, and the process variables are the key parameters to be associated with the efficiency of the adsorbents, particularly adsorption pressures if other variables are comparable each other. The MOFs and ZIFs materials require high pressures greater than 15 bar to yield significant
uptakes. They possess a
adsorption capacity which is very similar to or less than that of conventional benchmark adsorbents such as zeolites and activated carbons. Consequently, those materials have been much less cost-effective for adsorptive
separation to date because of very high production price and the absence of commercially-proven PSA processes using such new adsorbents.
Ethanol Steam Reforming Reaction for a Clean Hydrogen Production and its Application in a Membrane Reactor
Lim, Hankwon ;
Clean Technology, volume 19, issue 4, 2013, Pages 379~387
DOI : 10.7464/ksct.2013.19.4.379
Ethanol steam reforming reaction considered as a clean hydrogen production method is introduced in this paper. Reactivity and reaction rate equation of ethanol steam reforming reaction using various catalysts, reaction temperature, and molar ratio of ethanol and water will be discussed. In addition to introducing a membrane reactor combining a reactor and a separator, the effect of the use of a membrane reactor on an ethanol conversion and hydrogen yield will be compared to those from a conventional packed-bed reactor.
Evaluations of Life Cycle Assessment on Indium-Tin-Oxide Electrochemical Recycling Process
Kim, Raymund K.I. ; Lee, Na-Ri ; Lee, Soo-Sun ; Lee, Young-Sang ; Hong, Sung-Jei ; Son, Young-Keun ; Hong, Tae-Whan ;
Clean Technology, volume 19, issue 4, 2013, Pages 388~392
DOI : 10.7464/ksct.2013.19.4.388
Iindium-tin-oxide (ITO) material was had to use in display application as transparent electrode. However it would be problems comes up, the depletion of indium, tin and energy consumption of production process. Therefore recently trend was demanded alternative ITO material and recycling/reused ITO. In this conditions, the environmental impact have to express correct value about recycling/reused ITO process. The life cycle assessment was valuable method in this process. Thus first step was carried out separating in/out put (material) sources and then, exactive data base (DB) was applied. The result of environment impact was calculated by affect categories and recycling rate was set to 34% (This value was measured in previous project). The rate (g) of ITO material was calculated by chemical equivalent. In result, environmental impact were revealed acidification potential and abiotic depletion and if do not recycle/reuse ITO, $ 476 per 1 ton waste in land.
A Study on Synthesis and Hydrolysis of the Maleated Polyethylene Wax
Yu, Si-Won ; Choi, Joong-So ; Na, Jae-Sik ;
Clean Technology, volume 19, issue 4, 2013, Pages 393~400
DOI : 10.7464/ksct.2013.19.4.393
In this study, Polyethylene wax, which was produced in manufacturing process of high density polyethylene was grafted with maleic anhydride (MAH). The influences of reaction parameters on the graft polymerization as well as the effect of hydrolysis of the anhydride functions were investigated. The results show that the grafting degree increased and conversion of maleic anhydride decreased with an increase in MAH monomer content. This means the highest grafting efficiency for the reaction can be met when MAH monomer content is about 15 wt%. DCP (dicumyl peroxide) and DTBP (di-tert-butyl peroxide) have been used as the initiator and the highest yield of grafting was obtained when the initiator content is about 0.5 wt%. However, It can be seen that the gel content values of this polyethylene wax grafted MAH were below 2%. It was also observed that the grafting degree increased with an increase in reaction temperature and the maximum value was reached 2 hours later. Although MAH functions grafted onto polyethylene wax were mainly in the carboxylic acid forms, some anhydride form of MAH appeared in over 5% of grafting degree. As a result of hydrolysis reaction, it was observed that the conversion of anhydride group into carboxylic acid group was reached up to 10%.
A Study on Morphology and Mechanical Properties of Biodegradable Polymer Nanocomposites
Jang, Sang Hee ;
Clean Technology, volume 19, issue 4, 2013, Pages 401~409
DOI : 10.7464/ksct.2013.19.4.401
BBiodegradable polymers have attracted great attention because of the increased environmental pollution by waste plastics. In this study, PLA (polylactic acid)/Clay-20 (Cloisite 20) and PLA (polylactic acid)/PBS (poly(butylene succinate)/Clay-20 (Cloisite 20) nanocomposites were manufactured in a twin-screw extruder. Specimens for mechanical properties of PLA/Clay-20 and PLA/PBS (90/10)/Clay-20 nanocomposites were prepared by injection molding. Thermal, mechanical, morphological and raman spectral properties of two nanocomposites were investigated by differential scanning calorimetry (DSC), tensile tester, scanning electron microscopy (SEM) and raman-microscope spectrophotometer, respectively. In addition, hydrolytic degradation properties of two nanocomposites were investigated by hydrolytic degradation test. It was confirmed that the crystallinity of PLA/Clay-20 and PLA/PBS/Clay-20 nanocomposite was increased with increasing Clay-20 content and the Clay-20 is miscible with PLA and PLA/PBS resin from DSC and SEM results. Tensile strength of two nanocomposites was decreased, but thier elongation, impact strength, tensile modulus and flexural modulus were increased with an increase of Clay-20 content. The impact strength of PLA/Clay-20 and PLA/PBS/Clay-20 nanocomposites with 5 wt% of Clay-20 content was increased above twice than that of pure PLA and PLA/PBS (90/10). The hydrolytic degradation rate of PLA/Clay-20 nanocomposite with 3 wt% of Clay-20 content was accelerated about twice than that of pure PLA. The reason is that degradation may occur in the PLA and Clay-20 interface easily because of hydrophilic property of organic Clay-20. It was confirmed that a proper amount of Clay-20 can improve the mechanical properties of PLA and can control biodegradable property of PLA.
Fabrication of Supercapacitors using Silver Nano Paste and Gel Electrolyte
Yoon, Seong Man ; Jang, Hyunjung ; Kim, Dae Won ; Jang, Yunseok ; Jo, Jeongdai ; Go, Jeung Sang ;
Clean Technology, volume 19, issue 4, 2013, Pages 410~415
DOI : 10.7464/ksct.2013.19.4.410
The supercapacitors were fabricated using silver (Ag) nano paste and activated carbon paste on the polyimide (PI) film and 5% potassium polyacrylate (PAAK) was used for gel electrolyte. In this paper, the current collector film and the electrode film were fabricated using screen printing. The thickness of printed silver paste was
and the sheet resistance has the range of
. An activated carbon with a surface area of
, an electronic conducting agent (SUPER P, TIMCAL) and poly (4-vinylphenol) were mixed in 2-(2-buthoxyethoxy) ethyl acetate (BCA) with a ratio of 7:1:3 to fabricate the electrode paste. To analyze electrochemical characteristics, cyclic voltammetry was performed to evaluate the stability of the devices under the voltage range of -0.5-0.5 V. The calculated specific capacitances were 44.04 and 8.62 F/g for 10 and 500 mV/s scan rates, respectively.
Glycerol Carbonate Synthesis by Glycerol Oxidative Carbonylation over Copper Catalysts
Choi, Jae Hyung ; Lee, Sang Deuk ; Woo, Hee Chul ;
Clean Technology, volume 19, issue 4, 2013, Pages 416~422
DOI : 10.7464/ksct.2013.19.4.416
In environmental friendly aspects, the synthesis of glycerol carbonate from glycerol using carbon monoxide and oxygen gases which were produced in petrochemical plants was studied. The oxidative carbonylation of glycerol under batch reaction system was performed on parameter conditions such as effect of various metals (Cu, Pd, Fe, Sn, Zn, Cr), oxidizing agents, mole ratio of carbon monoxide to oxygen, catalyst amount, solvent types, reaction temperature and time and dehydrating agents. In particular copper chloride catalysts showed the excellent activities, and the glycerol carbonate yields over CuCl and
catalysts were the maximum of 44% and 64%, respectively at the following reaction conditions: solvent as nitrobenzene, mole ratio of 1:3:0.15 (glycerol:carbon monoxide:catalyst), mole ratio of 2:1 (carbon monoxide:oxygen), the total pressure of 30 bar at 413 K for 4 hr. It was found that reactivity were significantly different depending on the oxidation number of Cu catalysts, and oxygen plays an important role as oxidizing agents in producing H2O during oxidation reaction after carbonylation of glycerol.
Development of Flowable Backfill Material Using Waste Oyster Shell, Coal Ash, and Surplus Soil
Kim, Min-Jin ; Wang, Xue ; Lee, Je Joo ; Lee, Sang Ho ; Kim, Sung Bae ; Kim, Chang-Joon ;
Clean Technology, volume 19, issue 4, 2013, Pages 423~429
DOI : 10.7464/ksct.2013.19.4.423
This study aimed to develop flowable backfill material using oyster shell, coal ash, and surplus soil. The high temperature (>
) reaction was required to convert
to CaO. The solid specimens formed by pozzlanic reaction between CaO and coal ash showed low unconfined compressive strength. The effect of kaolin and blast furnace slag was also examined. It was found that CaO and coal ash could not be utilized due to high cost and low performance. The use of oyster shell without calcination (
) was evaluated. The specimens composing of oyster shell and cement showed the higher unconfined compressive strength than that composing of coal ash and cement. However, use of oyster shell is limited in mortar due to the presence of salt. Addition of soil into oyster shell-coal ash-cement mixture satisfied the specification of flowable backfill material by optimizing their ratio.
A Study on the Adsorption Characteristics of Benzene Using Activated Carbon from Waste Timber
Kim, Jong-Moon ; Chung, Chan-Kyo ; Min, Byong-Hun ;
Clean Technology, volume 19, issue 4, 2013, Pages 430~436
DOI : 10.7464/ksct.2013.19.4.430
In this study, experiments on the static adsorption of benzene were carried out using activated carbon made from Pinus koraiensis which is normally discarded waste timber in South Korea. The experiment were performed at 303.15 K, 318.15 K and 333.15 K under the pressure up to 7.999 kPa. Isothermal adsorption curves were obtained using Langmuir isotherm, Freundlich isotherm and Toth isotherm for comparison. Based on the fitting, the adsorption quantity of Benzene (q), the isothermal adsorption curves obtained from Langmuir isotherm and Toth isotherm showed the higher accuracy. Although there was little difference in accuracy between result from Langmuir isotherm and that from Toth isotherm, the adsorption quantity of Benzene (q) was expressed in terms of Langmuir isotherm because less parameters were required for Langmuir isotherm than for Toth isotherm. Moreover SEM images of the activated carbon from Pinus koraiensis and the commercial activated carbon were taken to observe the pore size development. The results showed that the perforation development of activated carbon from Pinus koraiensis (waste timber) was better than that of commercial activated carbon (DARCO A.C., SPG-100 A.C.). Adsorption quantity of benzene on activated carbon from Pinus koraiensis was confirmed to be higher than that on commercial activated carbon. Therefore, we may conclude that it is feasible to commercialize the process to manufacturing activated carbon from waste timber.
Hydrodynamic Characteristics of Absorbent and Catalyst for Pre-combustion CO
Ryu, Ho-Jung ; Yoon, Joo-Young ; Lee, Dong-Ho ; Shun, Dowon ; Park, Jaehyeon ; Park, Yeong-Seong ;
Clean Technology, volume 19, issue 4, 2013, Pages 437~445
DOI : 10.7464/ksct.2013.19.4.437
To develop SEWGS (sorption enhanced water gas shift) system using dry
absorbent for pre-combustion
capture, hydrodynamic characteristics of
absorbents were measured and investigated. The minimum fluidization velocity of
absorbent was measured and the effects of the operating conditions were investigated to operate the system at bubbling fluidized bed condition. The minimum fluidization velocity decreased as pressure and temperature increased. Moreover, the minimum fluidization velocity decreased as column diameter increased. The effects of operating conditions on the solid circulation rate were measured and investigated to select appropriate operating conditions for continuous
capture and regeneration. The measured solid circulation rates were ranged between 10 and 65 kg/h and increased as the solid injection velocity, gas velocity in the regeneration reactor, and solid height increased.
Synthesis of Lithium Manganese Oxide by Wet Mixing and its Removal Characteristic of Lithium Ion
You, Hae-Na ; Lee, Dong-Hwan ; Lee, Min-Gyn ;
Clean Technology, volume 19, issue 4, 2013, Pages 446~452
DOI : 10.7464/ksct.2013.19.4.446
In this paper, the wet mixing method was introduced to prepare spinel lithium manganese oxide (LMO) with
. The physical properties of the resulting lithium manganese oxide were characterized by the XRD and SEM. The adsorption properties of LMO for
were investigated by batch methods. The maximum adsorption capacity of lithium was calculated from Langmuir isotherm and found to be 27.25 mg/g. The LMO are found to have a remarkable lithium ion-sieve property with distribution coefficients (
) in the order of
, which is promising in the lithium extraction from seawater.
Reaction Characteristics of Elemental and Oxidized Mercury with Fly Ash Components
Lee, Sang-Sup ; Kim, Kwang-Yul ; Oh, Kwang-Joong ; Jeon, Jun-Min ; Kang, Dong-Chang ;
Clean Technology, volume 19, issue 4, 2013, Pages 453~458
DOI : 10.7464/ksct.2013.19.4.453
Fly ash has capacity to oxidize or adsorb mercury in a flue gas. Mercury oxidation and adsorption efficiencies of fly ash vary depending on the properties of fly ash. This study was designed to understand reaction characteristics of mercury with fly ash components. The fly ash components were tested to determine their oxidation and adsorption capabilities for elemental mercury and oxidized mercury. A sample was synthesized with fly ash components and tested. The test results were compared with those of the fly ash sample obtained from a coal-fired power plant.
, CuO and carbon black showed higher oxidation or adsorption efficiency for elemental mercury while CaO, MgO, CuO and carbon black showed higher adsorption efficiency for mercury chloride. In addition, the synthesized sample showed comparable mercury oxidation and adsorption efficiencies to the fly ash sample.
Importance-Performance Analysis for Nano-Safety Researches
Kim, Younghun ;
Clean Technology, volume 19, issue 4, 2013, Pages 459~463
DOI : 10.7464/ksct.2013.19.4.459
Recent rapidly growth in nanotechnolgies is promised novel benefits through the exploitation of their unique industrial and biomedical applications. In addition, these nanomaterials and nano-consumer products have increased in quantity per year, and thus their uncontrolled release into the environment is anticipated to grow dramatically in future. Many papers for cytotoxicity of nanomaterials have been already reported, and thus government supports has funded to various research topics for nanosafety. Herein, we analyzed the importance and performance of nanosafety researches and tried to show the research direction where we have to go.
Characteristics of Coal Water Fuel by Various Drying Coals, Surfactants and Particle Size Distribution Using Low Rank Coal
Kim, Tae Joo ; Kim, Sang Do ; Lim, Jeong Hwan ; Rhee, Young Woo ; Lee, Si Hyun ;
Clean Technology, volume 19, issue 4, 2013, Pages 464~468
DOI : 10.7464/ksct.2013.19.4.464
In this study, in order to increase solid content of coal water fuel (CWF), various experimental parameters (i.e., coal type, additive, particle size distribution, drying method) were evaluated. To investigate the drying method, specimen is compared to using flash dry, fluidized bed dry and oil deposit stabilized coal. Difference of the solid content between low rank coal and high rank coal in this case indicate that high rank coal exhibits more higher than 20% of the solid cotent. And specimen for dispersibility was prepared by using dispersing agent of 4 types. As a result, using the dispersing agent was shown 5% higher in sold content than the case of not using the dispersing agent. Efficiency of CWF was improved by using fine coal of 80% in the particle size distribution of coal. Result of CWF using drying methods of 3 types, oil deposit stabilized (ODS) coal dried and stabilized was effective 12% higher in sold content than raw coal.
Stabilization Characteristics of Upgraded Coal Using Palm Oil Residues
Park, In Su ; Chun, Dong Hyuk ; Jo, Wan Taek ; You, Ji Ho ; Lee, Si Hyun ; Rhee, Young Woo ;
Clean Technology, volume 19, issue 4, 2013, Pages 469~475
DOI : 10.7464/ksct.2013.19.4.469
In this research, the stabilization characteristics of upgraded coal using palm oil residues were investigated. The Eco coal, which is the Indonesian low-rank coal, was used as a raw material. The low-rank coal was mixed with palm fatty acid distillate (PFAD), and then dried in a nitrogen atmosphere at
. The trend of spontaneous combustion of upgraded coal was studied by measuring of crossing-point temperature (CPT), low temperature oxidation and moisture readsorption. The results of the CPT measuring and low temperature oxidation showed that the propensity of spontaneous combustion of the upgraded coal was improved compared to the dried coal. The moisture readsorption characteristics of the upgraded coal was also improved. The upgraded coal was stabilized through the surface coating with PFAD, and stability of upgraded coal was proportional to the content of PFAD.
Raman Spectroscopy and Molecular Modeling Study on the CH
Mixture Gas Hydrate Growth Behavior
Lim, Jun-Heok ; Lee, Ju Dong ; Park, Sung Soo ; Eom, Ki Heon ; Won, Yong Sun ;
Clean Technology, volume 19, issue 4, 2013, Pages 476~480
DOI : 10.7464/ksct.2013.19.4.476
The growth behavior of
mixture gas hydrate has been investigated by a combined approach of Raman spectroscopy and molecular modeling. Raman spectroscopy results presented that when
is used only,
guest molecule is inserted first into the large cavity of the host structure built by
molecules and then into the small cavity to stabilize the whole gas hydrate structure. In the other hand, when
is mixed together,
is favored over (or competing with)
in being inserted into the large cavity and the small cavity still prefers
insertion. The calculations of binding energies clearly supported this. While
has a binding energy of -26.9 kcal/mol a little lower than -24.2 kcal/mol of
in the large cavity,
has 1.2 kcal/mol and -22.0 kcal/mol, respectively, in the small cavity. It indicates that the sizable
is not preferred in the small cavity but has a relative energetic advantage over
in the large cavity.
Preparation and Characterization of Domestic Alkali-Surfactant-Polymer Solution for Enhanced Oil Recovery
Lee, Sang Heon ; Kim, Sang Kyum ; Park, Ji Yun ; Lee, Do Kyun ; Hwang, Soon Choel ; Bae, Wisup ; Kim, In Won ; Rhee, Young Woo ;
Clean Technology, volume 19, issue 4, 2013, Pages 481~486
DOI : 10.7464/ksct.2013.19.4.481
Alkali-surfactant-polymer (ASP) solution was manufactured by using the domestic surfactants for enhanced oil recovery. Domestic surfactants such as linear alkylbenzene sulfonic acid (LAS) and dioctyl sulfosiuccinate (DOSS) were used. This surfactants were purchased from AK chemtech Co., Ltd. (Korea). LAS and DOSS were blended and the ratio of LAS to DOSS are 1:1 and 2:1. Decane was used as a model compound of the crude oil. Surfactant solution and decane were blended to analyze microemulsion. Brine-oil-surfactant are mixed at varying concentration of brine from 0.8 to 3.6 wt.%. Increasing salinity causes the phase transition of microemulsion from water to middle to oil. Also, by measuring the surface tension and interfacial tension using pendent drop tensiometer and Huh`s equation optimal ratio of the ASP solution was determined.
Desorption Characteristics for Previously Adsorbed Gold and Copper-Cyanide Complexes onto Dowex21K XLT Resin Using Mixed Solvent with HCl and Acetone
Jeon, Choong ;
Clean Technology, volume 19, issue 4, 2013, Pages 487~491
DOI : 10.7464/ksct.2013.19.4.487
To efficiently desorb gold and copper-cyanide complexes adsorbed onto Dowex21K XLT resin, the mixed solvent with HCl and acetone which is a kind of dipolar aprotic solvent was used as a desorbing agent. The desorption efficiency for gold-cyanide complex was the highest as about 94% when the mixing ratio of HCl and acetone based on volume was the 7:3, however, the value decreased as the ratio of acetone increased. In the case of copper-cyanide complex, most of them was desorbed when the amount of HCl was relatively higher than that of acetone, however, desorption efficiency decreased as the ratio of acetone increased. The desorption efficiency for gold and copper-cyanide complexes was the 94 and 100%, respectively at the 0.6 M of HCl with the 7 (HCl) : 3 (Acetone) of mixing ratio and desorption efficiency for gold-cyanide complex not increased any more even though higher HCl concentration was used. And the desorption efficiency for gold and copper-cyanide complexes was about 100% at the S/L raio
whereas desorption efficiency for gold-cyanide complex was very low as about 20-29% at the S/L ratio > 1.0. Also, most of desorption process for gold and copper-cyanide complexes was completed within 120 min.