• Journal of the Korean Applied Science and Technology
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• v.24 no.1
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• pp.86-91
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• 2007

Gasohol, which is combined solution of gasoline and ethanol, is difficult to apply to the field, because it usually brings phase separation by mingling of water. We investigated phase separation by adding different concentrations of "Ethanol", anhydrous and fermentative, to "Gasolines", gasoline, gasoline base and naphtha, Placing ethanol itself open to the air, the concentrations of water are increased in length of time. The phase separation temperatures of the gasolines-ethanol solutions have dropped in the following order : gasoline, gasoline base and naphtha. When adding water to the solutions of gasolines and anhydrous ethanol, the temperatures of phase separation is higher when the concentration of water increases more. Thus, it is obvious that the water is sensitive in phase separation.

• Membrane Journal
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• v.1 no.1
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• pp.34-43
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• 1991

The relationships between affinity of membranes and optimum operation conditions were investigated in the pervaporation of water(1)/ethanol(2) mixture through cellulose acetate(CA) membranes having more affinity to water and silicone rubber(SR) membranes having more affinity to ethanol. CA and SR membranes were prepared and amount of sorption, sorption selectivity, pervaporation separation factor and pervaporation rate in both of membranes were determined and compared. The effects of downstream pressure were analyzed using Thompson diagram and the sorption and pervaporation characteristics with composition of feed and operation temperature were examined in terms of affinity, activity coefficient, plasticizing effect and activation energy of individual species. In the separation of water through CA membranes, high performance of both pervaporation separation factor (water to ethanol, $[\alpha^2_1]_{PV}$) and pervaporation rate was obtained in the conditions of low downstream pressure, middle range of feed concentration and high temperature. In the separation of ethanol through SR membranes, pervaporation separation factor(ethanol to water, $[\alpha^2_1]_{PV}$) increased with downstream pressure and decreased with concentration of ethanol in feed and operation temperature, while pervaporation rate showed opposite trends to those of ($[\alpha^2_1]_{PV}$).

• Korean Chemical Engineering Research
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• v.43 no.2
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• pp.243-248
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• 2005

Membrane pervaporation processes could have advantages over distillation for separation of water/organics mixtures: a low energy demand and the ability to separate azeotropic mixtures or isomers. Zeolite membranes might show better thermal, mechanical and chemical stabilities than polymer membranes. Water could be effectively separated from water/organic mixtures using the NaA zeolite membrane because of its high hydrophilicity. In this study, water was separated by pervaporation using the NaA zeolite membrane from water/ethanol mixtures. As a mole fraction of ethanol increased, the total permeation flux and the water flux decreased while the separation factor increased, reached a maximum point, and decreased. As an experimental temperature increased, the total permeation flux increased while the separation factor increased at the lower mole fraction of ethanol than 0.8 and it decreased at the higher mole fraction of ethanol than 0.8. The total permeation flux and the separation factor could be maintained constant during the long term experiment longer than 160 hours. It was found that the NaA zeolite membrane synthesized in our study showed better performance on water/ethanol separation than that of a distillation process or PVA polymeric pervaporation membranes.

• Journal of the Korean Applied Science and Technology
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• v.25 no.2
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• pp.252-256
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• 2008

We investigated phase separation by adding different concentrations of MTBE, to the mixtures of naphtha, ethanol and water. The phase separation temperatures of the Naphtha-Ethanol-Water solutions have dropped when the concentration of MTBE increases more. When adding IPA and IBA to the solutions of Gasoline-Ethanol and Gasoline base-Ethanol individually, IBA shows lower temperatures of phase separation than IPA, and it shows synergistic effect when mixtures of IPA and IBA is applied.

• KSBB Journal
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• v.25 no.5
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• pp.466-470
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• 2010

In this study, we developed simple process for ethanol concentration. We developed magnetically separable polyanilline nanofiber (PAMP) for selective ethanol adsorption. PAMP can adsorbed 80% of ethanol in the solution. After adsorption, the ethanol was recovered with simple magnetic separation and centrifugation process. After 10 times recycle of PAMP, the ethanol adsorption maintained 92% of its initial adsorption capacity. Using ethanol concentration process, the ethanol concentration increased up to 197.6 g/L from 46 g/L which was 4.3 folds increase.

• Korean Chemical Engineering Research
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• v.59 no.3
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• pp.467-479
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• 2021

Abstract: A kinetic model was developed for the dehydration of ethanol to ethylene based on two parallel reaction pathways. Kinetic parameters were estimated by fitting experimental data of powder catalysts in a lab-scale test, and the effectiveness factor was determined using data from pellet-type catalysts in bench-scale experiments. The developed model was used to design a multitubular fixed-bed reactor (MTR) and an adiabatic reactor (AR) at a 10 ton per day scale. The two different reactor types resulted in different process configurations: the MTR consumed the ethanol completely and did not produce the reaction intermediate, diethyl ether (DEE), resulting in simple separation trains at the expense of high equipment cost for the reactor, whereas the AR required azeotropic distillation and cryogenic distillation to recycle the unreacted ethanol and to separate the undesired DEE, respectively. Quantitative analysis based on the equipment and annual energy costs showed that, despite high equipment cost of the reactor, the MTR process had the advantages of high productivity and simple separation trains, whereas the use of additional separation trains in the AR process increased both the total equipment cost and the annual energy cost per unit production rate.

• Food Science and Biotechnology
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• v.15 no.2
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• pp.189-195
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• 2006

A study was conducted to develop optimal conditions for a large-scale, sequential separation method for value-added components from egg yolk. Starting with liquid egg yolk, immunoglobulin Y (IgY), phospholipids, and neutral lipids were extracted sequentially using water, ethanol, and n-hexane. The remainder was yolk proteins. Adjusting the pH of diluted egg yolk to pH 5.0-5.2 decreased phospholipids content in the supernatant after centrifugation, which was very important for preventing clogging problem of ultrafiltration filters during the subsequent concentration step for IgY separation. Extraction of precipitants after centrifugation with four volumes of 100% ethanol once removed most of the phospholipids and the purity of phospholipids was more than 85% (wt.) after drying. The subsequent extraction of precipitant from ethanol extraction with four volumes of hexane 3 times removed neutral lipids almost completely and resulted in a high protein product with minimal lipids. The sequential separation method is considered to be advantageous for large-scale separations of many valuable components from egg yolk.

• Korean Journal of Food Science and Technology
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• v.15 no.1
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• pp.70-76
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• 1983

Separation of fructose from glucose-fructose mixture was studied by utilizing the solubility differences of both sugars in the mixed solvents of water and alcohols with or without the presence of NaCl and $CaCl_2$. Better separation of fructose was obtained in ethanol-water solvent than other solvent-water systems. The addition of NaCl to the ethanol-water solvent system improved the separation factor based on the relative composition of two sugars in the supernatant by twice. The change in feed composition from 50-50 mixture of glucose and fructose resulted in a worse separation factor. It was found in the present studies that the best separation of fructose (fructose 75%, glucose 25%) was achieved when NaCl and ethanol was slowly added to the solution containing 20% water, 40% fructose and 40% glucose to make up the final solution with the parts of ethanol 36 ml, water 4 ml, glucose 8 gm, fructose 8 gm and NaCl 0.25gm.

• Journal of the Korean Applied Science and Technology
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• v.28 no.3
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• pp.374-378
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• 2011

The studied results of the gasohol, which is the mixture of gasoline and ethanol, were investigated for the promotion of applications on commercially by gasoline vehicle referring to octane number, minimum water contents be involved, and separation inhibitors for protecting phase separation etc. especially for the E10 and E20. The results showed that octane number will be revised by higher value as the ethanol is added more, and it's more effect in case of be added as a mixture than individually when inhibition agents is added for the inhibition of separation. and it's reasonable for the water contents of less than 1% by comparing with experimental results and in view of regulations of various countries.

• Applied Chemistry for Engineering
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• v.4 no.4
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• pp.791-797
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• 1993

The application of the pervaporation process in biotechnology is rapidly growing. A two stage pervaporation process can be applied to the downstream processing of ethanol fermentation. In this paper, the second stage process in which the water-ethanol composition was 50:50 wt.% was investigated in more detail by using Nylon 4 and its blended membranes containing poly(vinyl alcohol) (PVA) and poly(acrylic acid) (PAA). Nylon 4 membranes were tested for compositions at 25, 30, and $35^{\circ}C$. Nylon 4 membranes had a separation factor of 4.18 with a permeability of $0.69kg/m^2hr$ at water-ethanol composition of 50:50 wt.%, while nylon 4-PVA blended membranes crosslinked by 5 Mrad gamma-ray irradiation showed a higher separation factor of 10.56 with permeability $0.55kg/m^2hr$ at the same composition. Nylon 4 also showed a high separation factor 27.8 at the ethanol-water azeotropic composition among the homopolymer membranes.