Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal Basic Information
Journal DOI :
The Korean Society of Clean Technology
Editor in Chief :
Volume & Issues
Volume 14, Issue 4 - Dec 2008
Volume 14, Issue 3 - Sep 2008
Volume 14, Issue 2 - Jun 2008
Volume 14, Issue 1 - Mar 2008
Selecting the target year
Value-added Chemicals Derived from Propane Using Heterogeneous Catalysts
Yoon, Ji-Sun ; Suh, Dong-Jin ; Park, Tae-Jin ; Cho, Young-Sang ; Suh, Young-Woong ;
Clean Technology, volume 14, issue 2, 2008, Pages 71~86
In this review we discussed the effective ways to catalytically derive value-added chemicals from propane which has been utilized only as an energy source so far. Among various propane-derived products, the most valuable chemicals such as propylene and acrylonitrile were mainly focused herein. Propylene could be manufactured through oxidative dehydrogenation of propane using
, etc. as an oxidant for the purpose of overcoming thermodynamic limitations of propane dehydrogenation. On the other hand, propane ammoxidation would be an alternative to propylene ammoxidation for producing acrylonitrile since propane is much cheaper than propylene as a starting material. Although effective
catalysts have been developed fur propane ammoxidation in recent years, more detailed studies should be thoroughly performed. In carrying out both oxidative dehydrogenation and ammoxidation of propane fur a long period, the most critical issue is definitely considered to find out the most active and selective catalysts, which makes it possible to commercialize both reactions into economically viable processes.
Amination of Ethanol over Large Pore Zeolites
Jeon, Hee-Young ; Jeon, Seong-Hee ; Lee, Cheon-Jae ; Shin, Chae-Ho ;
Clean Technology, volume 14, issue 2, 2008, Pages 87~94
The catalytic properties of large pore zeolite (mordenite, beta, and Y) with 12-membered rings were comparatively evaluated in the synthesis of diethylamines from ethanol amination. The number of strong acid sites, which obviously promoted the formation of mono- and diethylamines, was decreased with the increase of Si/Al ratio of the zeolites that were used. H-beta and H-Y zeolites with multidimensional pore channels favorably formed diethylether by the dimerization of ethanol, due to their large cage volumes and low acid strength. On the other hand, H-mordenite which has one dimensional straight channel was shown to be suitable for the formation of mono- and diethylamine which are well known as the useful intermediates of fine chemicals.
A Study on the Evaluation of Cleaning Ability Using Optically Stimulated Electron Emission Method
Min, Hye-Jin ; Shin, Jin-Ho ; Bae, Jae-Heum ;
Clean Technology, volume 14, issue 2, 2008, Pages 95~102
In order to choose alternative environmental-friendly cleaning agents, it is very important in the present point that the systematic selection procedures should be introduced and applied to the industry through the evaluation of their cleaning ability, environmental characteristics, and economical factors, and that the objective and effective evaluation methods of cleanliness should be established for the industry. Thus, a novel cleaning evaluation method utilizing optically stimulated electron emission (OSEE) among various methods of cleaning ability was studied in this study. The contaminants used in this cleaning experiments were flux, solder, grease, cutting oil, and mixed soil of 35% grease and 65% cutting oil. The cleaning agents developed or prepared in our laboratory were employed and their cleaning ability were comparatively evaluated by the OSEE, gravimetry and contact angle methods. The experimental results in this work showed that flux cleaning efficiency measured by the OSEE method was similar to that of the gravimetric method, but that the OSEE method could not be compared with gravimetric method for the case of solder or grease cleaning because the contaminants radiate or absorb ultra-violet light. In case of cutting oil cleaning, the gravimetric method indicated its limitation of cleaning efficiency of cutting oil since it showed cleaning efficiency of 100%, even though residual soil remaining on the substrate surface a little after its cleaning. The comparative experimental results of cleaning ability evaluated by the OSEE- and contact angle measurement methods showed that they were similar in case of cleaning of flux, mixed soil and cutting oil. It was judged that the contact angle measurement method could evaluate the cleaning ability more precisely than the OSEE method for cleaning solder and grease.
A Study on the Evaluation Methods of Residual Flux Cleaning Ability by Alternative Semi-Aqueous Cleaners Using Metal Test Tools After Soldering with Solder Paste
Lee, Dong-Kee ;
Clean Technology, volume 14, issue 2, 2008, Pages 103~109
In this study, in order to develop evaluation method of the cleaning efficiency of residual flux which remains on the surface after soldering with solder paste, a specially designed metal tool is used to reduce spread uncertainty of flux while soldering. Using this tool, the measurement of cleaning efficiency of flux after soldering for some typical alternative semi-aqueous cleaners and 1,1,1-TCE by weighing method was conducted. As the test result of cleaning efficiency for each cleaner at several different cleaning times, the precision of the data is confirmed to within about 4% relative standard deviation (RSD) range. So, it is considered that this would be a good evaluation method for evaluating the cleaning efficiency of the residual flux which remains after solder paste soldering in the alternative cleaning. The results of this test method shows that the cleaning efficiency of ST 100SX and Neozal 750H in the cleaning of residual flux was better than other semi-aqueous cleaners, but its cleaning efficiency was clearly inferior to 1,1,1-TCE.
Measurement of I-TEDA Removal Rate Using QCM in Supercritical Carbon Dioxide
Yoo, Jae-Ryong ; Koh, Moon-Sung ; Sung, Jin-Hyun ; Lee, Jeong-Ken ; Park, Kwang-Heon ;
Clean Technology, volume 14, issue 2, 2008, Pages 110~116
The radioactive wastes generated from the nuclear industry can be divided into the forms of solid, liquid, or gas. Radioactive methyl iodide, a gaseous radioactive waste, is absorbed by activated carbon with 5 wt% of Trietylenediamine (1,4-diazania-bicycle[2.2.2]octane, TEDA) impregnated on the surface. Methyl Iodide (
) is combined chemically with TEDA (the final product : I-TEDA). To recycle radioactive activated carbon, removal of I-TEDA from activated carbon is needed. A wet method for recycling impregnated active carbon was developed to remove radioactive I-TEDA using an acetonitrile solution, which produces lots of secondary wastes. We suggest the removal of I-TEDA by supercritical carbon dioxide with co-solvents. In this experiment, we used a quartz crystal microbalance (QCM) for measuring the removal rate of the I-TEDA. From the experimental results, methanol was found to be the optimum co-solvent, and the optimum conditions such as temperature, pressure, and co-solvent flow rate were obtained. Possibility of using supercritical fluid in the removal of I-TEDA from radioactive activated carbon was also discussed.
NOx Formation Characteristics of the Coal-derived Synthetic Gas Containing
Lee, Chan ;
Clean Technology, volume 14, issue 2, 2008, Pages 117~122
Theoretical analysis was conducted on the combustion and the NOx formation characteristics of the coal-derived synthetic gases with medium-BTU heating value. The synthetic gas was assumed to contain the major species of CO,
and the minor species of
. Through thermochemical analysis on the combustion of the synthetic gas, the flame temperature, major and minor species of exhaust gas, and thermal and fuel NOx emissions were computed. In addition, the effects of the
components in syngas fuel on combustion and NOx emission were investigated. Based on the computed results on the synthetic gases, basic direction and guidelines were provided fur the low NOx design of gas turbine combustor.
Separation of Nitric Acid and Acetic Acid from the Waste Acid in LCD Etching Process
Chun, Hee-Dong ; Roh, Yu-Mi ; Park, Sung-Kuk ; Kim, Ju-Han ; Shin, Chang-Hoon ; Kim, Ju-Yup ; Ahn, Jae-Woo ;
Clean Technology, volume 14, issue 2, 2008, Pages 123~128
The waste solution, which was discharged from the recovery process of LCD etching solution, consists of 15 wt% nitric acid and 20 wt% acetic acid. In this study, it was conducted to separate acid individually from the mixed acid by vacuum evaporation under -760 mmHg gauge and at
. We have investigated evaporation behavior of acid as a function of temperature. There have been problems that tiny amount of nitric acid were evaporated simultaneously above
. Thus, efforts were conducted to recover acetic acid by vacuum evaporation with adding
, waste mixed acid and 20 g/L NaOH for a curb on evaporation of nitric acid. By adding
, evaporation of nitric acid was reduced from 7% to 0.78%. However, it was reduced from 7% to 0.25% by adding mixed acid. In view of the results achieved so far, we may expect to separate the etching solution individually by controlling vacuum conditions.
A Study on the Water-Ethanol Separation by Membrane-Aided Distillation in Bio-Ethanol Process
Jung, Heon ; Choi, Young-Seok ; Yang, Dae-Rook ; Joo, Oh-Shim ; Jung, Kwang-Deog ;
Clean Technology, volume 14, issue 2, 2008, Pages 129~135
Nylon membrane was used to separate ethanol-water by a pervaporation method. Experimental equations were derived to use the simulation of membrane-aided distillation using nylon. The increases in permeation pressure resulted in the decrease in selectivity and energy consumption. The energy cost to enrich ethanol from 94 wt% to 99.5 wt% was calculated to be 53.3 won/kg of ethanol with extractive distillation and 18.9 won/kg of ethanol with a pervaporation method. The saving energy by the pervaporation method is consumed by recycling the permeate residue into the distillation column in the membrane-aided distillation column. Therefore, membrane with the high selectivity to minimize the permeate residue recycle is required to effectively enrich ethanol in the membrane-aided distillation method.
Simulation of Plume Length Induced by Orimulsion Combustion
Kwak, Byoung-Kyu ; Kim, Jong-Ho ; Joo, Ji-Bong ; Lee, Jeong-Jin ; Kim, Jin-Soo ; Kim, Young-Hun ; Yi, Jong-Heop ;
Clean Technology, volume 14, issue 2, 2008, Pages 136~143
The objective of this study is to investigate the visibility of plume at the Y power plant stack, which fires the orimulsion as a fuel. The plume contains numerous primary particles under
size and inorganic ions possibly inferred by the chemicals of secondary aerosol formation. We evaluated the visibility of the plume using the modified PLUVUE-II model. The monitoring data on the particle size distribution (PSD) and secondary aerosols of sulfate were applied to estimate and evaluate the main factors of plume opacity. The chemical reactions were applied to the model for the secondary aerosol formation of
. The maximum plume length was estimated by an optic method using threshold contrast. The results showed that the plume length was strongly dependent upon the PSD and
concentration of the plume emitted from the stack.
Comparisons of Environmental Characteristics between Diesel and Dimethyl Ether as Fuels
Han, Soon-Rye ; Chung, Yon-Soo ;
Clean Technology, volume 14, issue 2, 2008, Pages 144~151
Life cycle assessment was carried out to evaluate the environmental values of dimethylas a diesel alternative fuel with the assumption of dimethyl ether production from natural gas via synthesis gas. The whole life cycles from raw material acquisitions to the final usages of diesel and dimethyl ether were involved in the assessment. Inventory analysis showed that the most significant environmental impacts came from resource depletions and air emissions. Impact assessment revealed that dimethyl ether was environmentally better in the aspect of human health and ecosystem quality but worse in resource depletions compared with diesel fuel. Suggestions for environmental improvement of dimethyl ether as a diesel alternative fuel were prepared based on the assessment results.