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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Korean Chemical Engineering Research
Journal Basic Information
Journal DOI :
The Korean Institute of Chemical Engineers
Editor in Chief :
KIM JAE JEONG
Volume & Issues
Volume 45, Issue 6 - Dec 2007
Volume 45, Issue 5 - Oct 2007
Volume 45, Issue 4 - Aug 2007
Volume 45, Issue 3 - Jun 2007
Volume 45, Issue 2 - Apr 2007
Volume 45, Issue 1 - Feb 2007
Selecting the target year
Systems Biology Studies and Metabolic Modification of Metabolites Producing Bacteria
Hong, Soon-Ho ;
Korean Chemical Engineering Research, volume 45, issue 6, 2007, Pages 529~535
Recently, an attempt to analyze and modify metabolic networks of living organisms in global level emerged with the benefit of development of high-throughput techniques, and it is generally called systems biology. Various systems biology studies have been carried out for the development of enhanced metabolite production systems. By modification of metabolic characteristics of microorganisms, metabolite productivities and yields obtained with metabolically engineered bacteria increased significantly compare with that obtained with wild type bacteria.
Preparation of Nanoparticles by Gas Phase Processes
Kim, Dong-Joo ; Kim, Kyo-Seon ;
Korean Chemical Engineering Research, volume 45, issue 6, 2007, Pages 536~546
The nanoparticles have several interesting properties which cannot be shown in their bulk materials because of their high ratio of surface area to volume. They can be used to manufacture the nanostructured materials, the industrial materials, or the catalyst materials etc.. We can prepare nanoparticles of various sizes with high degree of monodispersity by gas phase processes and those particles can be used as raw materials for various advanced functional materials. In this paper, we introduced the aerosol reactors to synthesize nanoparticles by gas phase processes and also analyzed several features of those aerosol reactors and tried to introduce the recent interesting studies on nanoparticle synthesis by gas phase processes
The Effect of Pore Structure of Zeolites on their Product Distribution and Deactivation in the Catalytic Cracking of n-Octane
Min, Byung-Goo ; Lee, Jae-Youl ; Song, Yo-Soon ; Seo, Gon ;
Korean Chemical Engineering Research, volume 45, issue 6, 2007, Pages 547~553
The catalytic cracking of n-octane over FER, MFI, MOR and BEA zeolites was studied by the protolytic cracking mechanism in order to understand the effect of pore structure of zeolites on their product composition and deactivation. The selectivities for C3 and C3= were high over the zeolites with medium pores due to additional cracking, while those for C4 and C4=, the initial products, were high over the zeolites with large pores. MFI zeolite showed slow deactivation due to small carbon deposit, while FER zeolite with small pores deactivated rapidly with severe carbon deposit. The deactivation of BEA zeolite was slow even with a large amount of carbon deposit, but MOR zeolite showed a rapid deactivation even with a small amount of carbon deposit. The conversion measured along with the time on stream on these zeolite catalysts was simulated by a mechanism based on the simplified reaction path of n-octane cracking and the deactivation related to the pore blockage by carbon deposit.
Effect of the Additives on Direct Dimethyl Carbonate Synthesis using Methanol and Carbon Dioxide over
Han, Gi-Bo ; Park, No-Kuk ; Yoon, Suk-Hoon ; Lee, Tae-Jin ;
Korean Chemical Engineering Research, volume 45, issue 6, 2007, Pages 554~559
본 연구에서는 메탄올과 이산화탄소를 이용한 디메틸카보네이트(dimethyl carbonate, 이하 DMC) 의 직접 합성에서 수율 증대를 위하여 주입된 다양한 첨가제의 영향을 살펴보았다. 그리고 첨가제의 주입과 동시에 반응조건을 달리하여 얻어진 반응특성을 살펴봄으로써 필요한 반응조건의 최적화를 살펴보았다. Citric complexation method에 의해 제조된 복합금속산화물 Ce1-xZrxO2 촉매들 가운데, 가장 높은 성능을 지니고 있는 Ce0.8Zr0.2O2 촉매가 DMC 합성에서 사용되었다. 황산염(sulfate) 계열, 질산염(nitrate) 계열, 인산염(phosphate) 계열 및 제올라이트 등의 다양한 첨가제가 사용된 가운데 DMC 생성량의 변화가 관찰되었다. 그 결과, -SO4를 지니는 황산염 계열의 K2SO4 및 Na2SO4 등의 첨가제가 Ce0.8Zr0.2O2 촉매와 함께 사용됨으로써 가장 높은 DMC 생성량을 얻었다. 기존의 첨가제 없이 Ce0.8Zr0.2O2 촉매가 사용된 경우, 약 0.6 mmol의 DMC 생성량을 얻을 수 있었으며, K2SO4 첨가제가 동시에 주입된 경우 가장 높은 0.91 mmol의 향상된 DMC 생성량을 얻었다.
Preparation of Copper Fine Particles from Waste Copper by Chemical Reduction Method
Kim, Yoon-Do ; Song, Ki-Chang ; Song, Jong-Hyeok ;
Korean Chemical Engineering Research, volume 45, issue 6, 2007, Pages 560~565
Copper fine particles, ranging from 0.11 μm to 0.64 μm in average size, were prepared by a chemical reduction method using hydrazine (N2H4) as a reduction agent in waste copper solutions. The effect of the amount of hydrazine addition was investigated on the properties of the obtained powders. Also, the effect of the addition of dispersing agents [Polyvinyl alcohol (PVA), polyvinyl pyrrolidone (PVP)] during particle synthesis was studied. The powders, obtained from 1 M waste copper solutions, showed the mixtures of Cu and Cu2O crystals at low hydrazine addition amounts of 0.8 mol and 1.0 mol, while those exhibited pure Cu crystals at adequate hydrazine addition amount of 0.12mol. The average size of the Cu powders decreased with increasing the concentrations of hydrazine and dispersing agents. The addition of PVA to the solutions as a dispersing agent was more effective than that of PVP in preventing the aggregation of particles.
Preparation and Reactivity of Cu-Zn-Al Based Hybrid Catalysts for Direct Synthesis of Dimethyl Ether by Physical Mixing and Precipitation Methods
Bang, Byoung-Man ; Park, No-Kuk ; Han, Gi-Bo ; Yoon, Suk-Hoon ; Lee, Tae-Jin ;
Korean Chemical Engineering Research, volume 45, issue 6, 2007, Pages 566~572
Two hybrid catalysts for the direct synthesis of DME were prepared and the catalytic activity of these catalysts were investigated. The hybrid catalyst for the direct synthesis of DME was composed as the catalytic active components of methanol synthesis and dehydration. The methanol synthesis catalyst was formed from the precursor contained Cu and Zn, the methanol dehydration catalyst was used γ-Al2O3. As PM-CZ+D and CP-CZA/D, Two hybrid catalysts were prepared by physical mixing method (PM-CZ+D) and precipitation method (CP-CZA/D), respectively. PM-CZ+D was prepared by physically mixing methanol synthesis catalyst and methanol dehydration catalyst, CP-CZA/D was prepared by depositing Cu-Zn or Cu-Zn-Al components on γ-Al2O3. The crystallinity and the surface morphology of synthesized catalyst were analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM) to investigate the physical property of prepared catalyst. And BET surface area by N2 adsorption and the surface area of Cu by N2O chemisorption were investigated about the hybrid catalysts. In addition, catalytic activity of these hybrid catalysts was examined with varying reaction conditions. At that time, the reaction temperature of 250~290 ℃, the reaction pressure of 50~70 atm, the [H2]/[CO] mole ratio of 0.5~2.0 and the space velocity of 1,500~6,000 h-1 were investigated the catalytic activity. From these results, it was confirmed that the reactivity of CP-CZA/D was higher than that of PMCZ+D. When the conditions of reaction temperature, pressure, [H2]/[CO] ratio and space velocity were 260 ℃, 50 atm and 1.0, 3,000 h-1 respectively, CO conversion using CP-CZA/D hybrid catalyst was 72% and the CO conversion of CP-CZA/D was more than 20% compared with the CO conversion of PM-CZ+D. It was known that Cu surface area of CP-CZA/D hybrid catalyst was higher than that of hybrid PM-CZ+D catalyst using N2O chemisorption. It was assumed that the catalytic activity was improved because Cu particle of hybrid catalyst prepared by precipitation method was well dispersed.
Removal using MEA (monoethanolamine) Impregnated Mesoporous Materials
Park, Ye-Won ; Baek, Il-Hyun ; Park, Sang-Do ; Lee, Jae-Wook ; Park, So-Jin ;
Korean Chemical Engineering Research, volume 45, issue 6, 2007, Pages 573~581
The present study deals with removal of CO2 using various mesoporous materials impregnated with MEA (monoethanolamine). The mesoporous materials such as MCM-41, MCM-48 and SBA-15 were synthesised and then impregnated with 30, 50 and 70 wt% of MEA, respectively. XRD, FT-IR and SEM were used to evaluate the characterization of those. From the adsorption/desorption experiments for various materials, the adsorption capacity of these materials were found in the order of MCM-41> MCM-48> SBA-15. MCM-41 impregnated with 50 wt% of MEA showed the maximum adsorption capacity of 57.1 mg-CO2/gr-sorbent at 40 ℃. It is nearly 8 times higher than MCM-41 without impregnation of MEA. In the multiple cycle test of 20 times, MCM-41 impregnated with 50 wt% of MEA showed a constant adsorption capacity
Multiscale Modeling and Simulation of Water Gas Shift Reactor
Lee, Uk-June ; Kim, Ki-Hyun ; Oh, Min ;
Korean Chemical Engineering Research, volume 45, issue 6, 2007, Pages 582~590
In view of the analysis of the phenomena and the prediction of the performance, mathematical modelling and simulation of a high temperature pilot reactor for water gas shift reaction (WGSR) has been carried out. Multiscale simulation incorporated computational fluid dynamics (CFD) technique, which has the capability to deal with the reactor shape, fluid and energy transport with extensive degree of accuracy, and process modeling technique, which, in turn is responsible for reaction kinetics and mass transport. This research employed multiscale simulation and the results were compared with those from process simulation. From multiscale simulation, the maximum conversion of was predicted approximately 0.85 and the maximum temperature at the reactor was calculated 720 K, resulting from the heat of reaction. Dynamic simulation was also performed for the time transient profile of temperature, conversion, etc. Considering the results, it is concluded that multiscale simulation is a safe and accurate technique to predict reactor behaviors, and consequently will be available for the design of commercial size chemical reactors as well as other commercial unit operations.
Development of Membrane Filter with Nanostructured Porous Layer by Coating Metal Nanoparticles onto a Micor-Filter
Lee, Dong-Geun ; Park, Seok-Joo ; Park, Young-Ok ; Ryu, Jeong-In ;
Korean Chemical Engineering Research, volume 45, issue 6, 2007, Pages 591~595
The membrane filter coated with nanostructured porous surface layer was made by heat treatment after depositing nanoparticles onto a conventional micron-fibrous metal filter as a substrate filter. The nanostructured porous layer membrane filter (NSPL-MF), whose the filtration performance was improved compared with the conventional metal membrane filters, was developed by coating the nanoparticle agglomerates of dendrite structure onto the micronfibrous metal filter. Pressure drop of nanostructured porous layer membrane filter decreased with increasing the heat treatment temperature to make the nanostructured porous layer adhered on the filter surface because the nanoparticle agglomerates shrank, but filtration efficiency did not decrease clearly.
The Technology for On-line Measurement of Coal Properties by using Near-Infrared
Kim, Dong-Won ; Lee, Jong-Min ; Kim, Jae-Sung ; Kim, Hak-Jong ;
Korean Chemical Engineering Research, volume 45, issue 6, 2007, Pages 596~603
Rapid or on-line coal analysis is of great interest in coal industry as it would allow efficient plant operation. Multivariate analysis has been applied to near-infrared(NIR) spectra coal for investigating the relationship between coal properties(%) (moisture, ash, volatile matter, fixed carbon, carbon, hydrogen, nitrogen, oxygen, sulfur), heating value(kcal/kg) and corresponding near-infrared spectral data. The quantitative analysis was carried out by applying PLS(partial least squares regression) to determine a methodology able to establish a relationship between coal properties and NIR spectral data being applied mathematical pre-treatments for minimizing the physical features of the samples. As a results of the analysis, this technique is able to classify the species of coals and to predict the all coal properties except ash, nitrogen and sulfur. The efficient operation of coal fired power plant is expected owing to real time on-line coal analysis of moisture and heating value.
Characteristics of Steam Gasification and Combustion of Naphtha Tar Pitch
Kim, Uk-Yeong ; Son, Sung-Mo ; Kang, Suk-Hwan ; Kang, Yong ; Kim, Sang-Done ; Jung, Heon ;
Korean Chemical Engineering Research, volume 45, issue 6, 2007, Pages 604~610
Characteristics of steam gasification and combustion of naphtha tar pitch, which is the bottom product of naphtha cracking process, were investigated by using the thermo gravimetric analyzer to develop the technology for obtaining syngas by using the naphtha tar pitch as a carbon source. Friedman’s and Ozawa-Flynn-Wall method were used to calculate activation energy, reaction order and frequency factor of reaction rate constant for both of steam gasification and combustion. The activation energy of combustion of naphtha tar pitch based on the fractional conversion by Friedman’s method was in the range of 41.58 ~ 68.14 kJ/g-mol when the fractional conversion level was in the range of 0.2~0.6, but 183.07~191.17 kJ/g-mol when the conversion level was 0.9~1.0, respectively. In case of steam gasification of naphtha tar pitch, the activation energy was in the range of 31.87~44.87 kJ/g-mol in the relatively lower conversion level (0.2~0.6), but 70.63~87.79 kJ/g-mol in the relatively higher conversion level (0.8~0.95), respectively. Those results exhibited that the steam gasification as well as combustion would occur by means of two steps such as devolitilization followed by combustion or gasification.
Fabrication of Hollow Micro-particles with Nonspherical Shapes by Surface Sol-gel Reaction
Cho, Young-Sang ; Jeon, Seog-Jin ; Yi, Gi-Ra ;
Korean Chemical Engineering Research, volume 45, issue 6, 2007, Pages 611~618
We demonstrate the sol-gel coating technique of colloidal clusters for producing hollow micro-particles with complex morphologies. Cross-linked amidine polystyrene (PS) microspheres were synthesized by emulsifier-free emulsion copolymerization of styrene and divinylbenzene. The amidine PS particles were self-organized inside toluene-inwater emulsion droplets to produce large quantities of colloidally stable clusters. These clusters were coated with thin silica shell by sol-gel reaction of tetraethylorthosilicate (TEOS) and ammonia, and the organic polystyrene cores were removed by calcination at high temperature to generate nonspherical hollow micro-particles with complex morphologies. This process can be used to prepare hollow particles with shapes such as doublets, tetrahedra, icosahedra, and others.
Predictive Thermodynamic Model for Gas Permeability of Gas Separation Membrane
Kim, Jong-Hwan ; Hong, Sung-Kyu ; Park, Sang-Jin ;
Korean Chemical Engineering Research, volume 45, issue 6, 2007, Pages 619~626
It is of special interest in our membrane separation technology due to its low energy consumption and cost, relatively simple equipment, low investment and operation cost, et al. Full scale utilization of such processes can be widely utilized to the various fields. Using the difference of permeability of gas molecules between the filter layers, it is able to separate effectually pure gases from the mixed gases. In this paper, the membranes of PDMS, γ-radiated PDMS, PTFE, PTFE-X are chosen to develop the predictive model for the separation of pure gases such as oxygen, nitrogen, hydrogen, and other gases from mixed gases. By utilizing the thermodynamic gas properties(σ, ε/k) and experimental data of gas transport characteristics for different polymer membranes, it is able to develop the predictive model equation under the influence of temperature, pressure and polymer characteristics. Predictive model developed in this research showed good agreement with experimental data of gas permeability characteristics for develop four different polymer membranes. The proposed model can also be extended to the general equation for predicting the separation of gases based on the properties of polymeric membranes.
Distribution Characteristics of Radionuclies
During the Melting of Radioactive Metal Waste
Min, Byung-Youn ; Choi, Wang-Kyu ; Oh, Won-Zin ; Jung, Chong-Hun ; Kang, Yong ;
Korean Chemical Engineering Research, volume 45, issue 6, 2007, Pages 627~632
A fundamental study on the melt decontamination of metal wastes generated by dismantling the nuclear facility, the melting of metal wastes such as stainless steel and carbon steel have been carried out to investigate the distribution phenomena of the radioisotopes such as 60Co and 137Cs into the ingot, slag and dust phases by using the various slag types, slag concentration and basicity in an arc furnace. The 60Co remained homogeneously in the ingot phase above 90 % and it was barely present in the slag below 10 %. The effect of the slag composition on the distribution for Co-60 was not considerable, but a basic slag former with high fluidity showed effective. 137Cs was completely eliminated from the melt of the stainless steel as well as the carbon steel and distributed to the slag and the dust phase.
Electroless Plating of Co-Alloy Thin Films using Alkali-Free Chemicals
Kim, Tae-Ho ; Yun, Hyeong-Jin ; Kim, Chang-Koo ;
Korean Chemical Engineering Research, volume 45, issue 6, 2007, Pages 633~637
Electroless plating of Co-alloy thin films as capping layers for Cu interconnection has been investigated using alkali-free precursors such as (NH4)2Co(SO4)2·6H2O, (NH4)2WO4, (NH4)H2PO4, etc. The characteristics of the Co-alloy thin films were discussed by analyses of the effects of pH, Co-precursor concentration, and deposition temperature on the thickness and surface morphology of the films. The thickness of the Co-alloy thin films increased with increasing pH, Co-precursor concentration, and deposition temperature, similarly to the results of electroless plating of Co-alloy thin films using alkali-containing chemicals. The SEM images of the surface of the Co-alloy thin films showed that the proper ranges of pH and deposition temperature were 8.5~9.5 and 75~85 ℃, respectively. This work found a feasibility that Co-alloy thin films as capping layers for Cu interconnection could be electroless plated using alkali-free chemicals.
The Development of Evaluation Chart for the Applicability of
Flooding in Oil Reservoirs and Its Applications
Kwon, Sun-Il ; Cho, Hyun-Jin ; Ha, Se-Hun ; Lee, Won-Kyu ; Yang, Sung-Oh ; Sung, Won-Mo ;
Korean Chemical Engineering Research, volume 45, issue 6, 2007, Pages 638~647
In this study, we present the evaluation chart for assessing the applicability of CO2 flooding method to oil reservoirs. The evaluation chart consists of four categories as source availability, miscibility, applicability and injecting method of miscible flooding. The applicability of reservoir and oil in the chart has basic items of the properties such as oil gravity, viscosity, oil saturation, reservoir temperature and permeability, and these are quantitatively graded. Meanwhile, for additional items of CO2 purity, reservoir thickness and formation dip, they are graded as “highmediumlow”. In the case of evaluating the injection method of either continuous injection or WAG (CO2), the qualitative decision will be made according to formation dip, vertical permeability, reservoir thickness, etc. The recommended score in the chart was assigned by utilizing 51 oil producing fields which CO2 flooding is successfully being applied. The evaluation chart developed in this work has been applied to the Captain oil producing field located in Scotland as well as to the Onado oil field of Venezuela, which Korean oil companies have participated in. For the Captain field, the reservoir quality in terms of permeability and porosity is considered to be very excellent to flow the oil. The oil in captain field contains heavier component of C21+ as 54%. Therefore, this heavy oil could be immiscibly displaced, hence the evaluating result with the basis of immiscible criteria shows that CO2 immiscible flooding in this field could be properly applied. In the case of Onado oil producing field, since the estimated minimum miscibility pressure is lower than the reservoir pressure, it was assessed that the Onado field would be efficiently conducted for CO2 miscible flooding.
Advanced Oxidation Process for the Treatment of Terephthalic Acid Wastewater using UV,
: Organic and Color Removal Studies
Kwon, Tae-Ouk ; Park, Bo-Bae ; Moon, Il-Shik ;
Korean Chemical Engineering Research, volume 45, issue 6, 2007, Pages 648~655
/H2O2, O3, O3/H2O2, UV/H2O2/O3 processes were tested for the removal of COD and color from terephthalic acid wastewater. COD removal efficiencies were 10, 48, 56, 63% in the UV/H2O2, O3, O3/H2O2, UV/H2O2/O3 process respectively. Color removal efficiency of UV/H2O2 process was 80% and O3, O3/H2O2, UV/H2O2/O3 processes were almost more than 99%. Terephthalic acid, isophthalic acid and benzoic acid were completely destructed in terephthalic wastewater within 120 min by UV/H2O2/O3 process and shows high COD and color removal efficiencies. The optimum concentration of H2O2 dosage was found to be 0.5 M, 25 mM and 5 mM for UV/H2O2, O3/H2O2 and UV/H2O2/O3 processes respectively, Organic destruction efficiency was enhanced and also reducing the consumption of H2O2 dosage by combining UV, H2O2 and O3 process.
Study on Hydrogen Production and CO Oxidation Reaction using Plasma Reforming System with PEMFC
Hong, Suck-Joo ; Lim, Mun-Sup ; Chun, Young-Nam ;
Korean Chemical Engineering Research, volume 45, issue 6, 2007, Pages 656~662
Fuel reformer using plasma and shift reactor for CO oxidation were designed and manufactured as H2 supply device to operate a polymer electrolyte membrane fuel cell (PEMFC). H2 selectivity was increased by non-thermal plasma reformer using GlidArc discharge with Ni catalyst simultaneously. Shift reactor was consisted of steam generator, low temperature shifter, high temperature shifter and preferential oxidation reactor. Parametric screening studies of fuel reformer were conducted, in which there were the variations of the catalyst temperature, gas component ratio, total gas ratio and input power. and parametric screening studies of shift reactor were conducted, in which there were the variations of the air flow rate, stema flow rate and temperature. When the O2/C ratio was 0.64, total gas flow rate was 14.2 l/min, catalytic reactor temperature was 672 ℃ and input power 1.1 kJ/L, the production of H2 was maximized 41.1%. And CH4 conversion rate, H2 yield and reformer energy density were 88.7%, 54% and 35.2% respectively. When the O2/C ratio was 0.3 in the PrOx reactor, steam flow ratio was 2.8 in the HTS, and temperature were 475, 314, 260, 235 ℃ in the HTS, LTS, PrOx, the conversion of CO was optimized conditions of shift reactor using simulated reformate gas. Preheat time of the reactor using plasma was 30 min, component of reformed gas from shift reactor were H2 38%, CO<10 ppm, N2 36%, CO2 21% and CH4 4%.
Autothermal Reforming of Methane using Metallic Monolith Catalyst Coated Ni/
Lee, Tae-Jun ; Cho, Kyung-Tae ; Lee, Jong-Dae ;
Korean Chemical Engineering Research, volume 45, issue 6, 2007, Pages 663~668
The autothermal reforming reaction of methane was investigated to produce hydrogen with Ni/CeO2-ZrO2 catalysts. Alumina-coated honeycomb monolith was applied in order to obtain high catalytic activity and stability in autothermal reforming of methane. Metallic monolithic catalyst showed better methane conversion than that of powder type at high reaction temperature. It was confirmed that H2O/CH4/O2 ratio was important factor in autothermal reforming reaction. H2 yield was increased as H2O/CH4 ratio increased. Methane conversion was improved as O2/CH4 ratio was increased, whereas, the yield of H2 was decreased. The catalytic activity for Ni/CeO2-ZrO2 catalyst with 0.5 wt% Ru loading was improved at low reaction temperature.
Effect of Organic Melecular Weight and Functional Group on Membrane Fouling
Jung, Chul-Woo ; Son, Hee-Jong ; Shin, Hyun-Sool ; Sohn, In-Shik ;
Korean Chemical Engineering Research, volume 45, issue 6, 2007, Pages 669~676
The raw water was fractionated into hydrophobic (HPO), transphilic (TPI), and hydrophilic portions (HPI) using XAD resins. The raw water DOC contains 39% of hydrophilics, 43% of hydrophobics, and 18% of transphilics. When fractionated NOM (natural organic matter) was passed through hydrophilic membrane with 100 kDa, hydrophobic portion (HPO) caused the most fouling and hydrophilic portion (HPI) caused the least fouling. This could be related to size and adsorption capability of organics. Small sized organics would pass through membrane pores, but large sized organics would be attracted to either membrane pores or surface, which led to the fouling. An effect of membrane pore size on membrane fouling is related to the availability of organics at membrane pores. As the pore size became larger, the more organics were transported into the membrane pore. Some organics caused pore blocking, and others caused pore adsorption, which resulted in membrane fouling. Membrane material is also important for membrane fouling. More fouling occurred at hydrophobic membrane than hydrophilic membrane regardless of its pore size. Hydrophobic interaction caused more fouling at hydrophobic membrane.
Dry Synthesis of Nearly Monodisperse Spherical Silica
Park, Hoey-Kyung ; Park, Kyun-Young ;
Korean Chemical Engineering Research, volume 45, issue 6, 2007, Pages 677~679
Nearly monodisperse spherical silica particles, 200~300 nm in diameter, were produced via a dry route for the first time through a two-stage hydrolysis of SiCl4 vapor. In the first stage, the SiCl4 was partially hydrolyzed in a batch reactor at 150 ℃ to form nearly monodisperse silicon oxychloride particles. In the second stage, the oxychlorides were hydrolyzed further in a tubular reactor to have produced silica with the morphology and size nearly conserved.