• Resources Recycling
• /
• v.8 no.3
• /
• pp.31-36
• /
• 1999

In the process of manufacturing acrylonitrile, azeotrope of water-acetonitrile is formed as by-product. To1uene-ethylacetate mixture was selected as solvent to determine the liquid-liquid equilibria for to1uene(l)-water(2)-acetomtrile(3)-ethyjacetate(4) system. The experimental he-line data were correlated with the UNIFAC model. The distribution and selectivity for quaternary system was also studied.

• 한국신재생에너지학회:학술대회논문집
• /
• 2009.11a
• /
• pp.518-519
• /
• 2009

투과증발은 저 에너지 분리기술로서 공비혼합물의 분리 및 유기화화물을 선택적으로 분리하는 공정에 활용되고 있다. 투과증발공정을 위한 막으로 쓰이는 대표적인 고분자 재료인 친수성 고분자 PVA(Poly(vinyl alcohol)는 하이드로실 그룹을 포함하고 있어 물에 대한 선택도가 뛰어난 장점을 가지고 있다. 그러나 PVA는 물에 대한 친화력이 높아 투과증발막으로 적용하기 위해서는 내수성을 향상시키기 위하여 가교시킨후 투과증발막으로 사용가능하다. 본 연구에서는 PVA 분리막을 투과증발막으로 적용하기 위하여 PVA를 전기방사에 의해 나노섬유로 제조하고 제조된 나노섬유가 수용액에서 내수성을 갖게 하기 위해 10-70%의 KOH수용액에 가교화 하여 특성을 알아보았다.

• Journal of the Korean Society of Industry Convergence
• /
• v.8 no.1
• /
• pp.37-45
• /
• 2005

Adsorption equilibrium data of pure solvent vapors (n-Hexane, Toluene, MEK) as well as their binary mixtures on activated carbon (sorbonorit $B_4$) were experimentally determined in the range of 293.2~323.2 K and beyond saturated vapor pressure corresponding to experimental temperature. Langmuir, Freundlich, LRC, W-VSM, FH-VSM were estimated for the predication of single component as well as binary mixtuer systems. The isosteric heat of adsorption at infinite dilution of pure n-hexane, toluene, MEK on activated carbon were 45.18, 25.85, 34.62 Kcal/mol, respectively, also, n-hexane-toluene binary adsorption of activated carbon formed an azeotrope at 293.2 K and total pressure 5.1~10.3 mmHg.

• Proceedings of the Membrane Society of Korea Conference
• /
• 2003.07a
• /
• pp.77-80
• /
• 2003

Hydrocarbon-hydrocarbon separations are one of the most important processes in petroleum refining. Distillation process has been used for separating hydrocarbons, but this conventional process is very energy consuming. Pervaporation separation through polymeric membranes is an emerging process alternative to distillation because of energy savings, compact system installation, reduced capital investment, and other performance attributes. In hydrocarbon separations, polymeric membranes are easily swollen by hydrocarbons and can lose mechanical strength. Chemically robust membranes are needed for the separation of hydrocarbons. In this study, the blend membrane was applied to separate benzene and cyclohexane. This is a model system for aliphatic and aromatic separation. Cyclohexane is also physically very similar to benzene and as a result of the very closing boiling points (0.6$^{\circ}C$), benzene and cyclohexane form an azetrope. Thus the system provides a good model for azeotrope breaking by pervaporation. The semi-quantitative thermodynamic model predicts that the calculated selectivity increases with increasing Hydrin contents in the blend membranes. Pervaporation experiments utilizing various operating temperatures and feed concentrations with different blend membranes are compared with the result from semi-quantitative thermodynamic calculations.

• Membrane Journal
• /
• v.17 no.1
• /
• pp.1-13
• /
• 2007

Pervaporation process using membrane is newly emerging energy saying and cost effect process instead of distillation process. Especially, in pertrochemical industry, pervaporation process is a strong candidate to substitute the conventional energy consuming processes because that petrochemical industry has much energy consuming separation processes, many azeotrope mixtures to separate and needs to compact space to install new process units. Aromatic/aliphatic separation including benzene/cyclohexane mixture, olefin/paraffin separation, xylene isomer separation, reactive monomer recovery and sulfur compound removal from gasoline have been inversitigated for the application of pervaporation membrane process by many researchers and are under commercializing.

• Journal of Energy Engineering
• /
• v.2 no.3
• /
• pp.308-314
• /
• 1993

Both Vapor-liquid equilibrium data and boiling temperature have been measured for ternary and each corresponding binaries of n.dodecane-1.decanol-1.dodecanol mixture under constant pressure of 15 mbar. Measured vapor-liquid equilibrium data were correlated with the conventional g$\^$E/ model ; Margules, van Laar, Wilson, NRTL and UNIQUAC equations. Binary equilibrium data were thermodynamically tested by Redlich-Kister integral method and ternary data were also qualitatively checked by two point consistency test, suggested by McDermott-Ellis. Among the binary VLE data, only the system n.dodecane-1.decanol has minimum boiling azeotrope.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.14 no.4
• /
• pp.332-340
• /
• 2002

In these days, environmental concerns have been increased throughout the industry and community worldwide. To prevent the ozone depletion, ozone depletion potential of a refrigerant must be zero. Simultaneously, a refrigerant with low GWP (global warming potential) is very demanding to induce green house effect. Chlorine-free HFC-l34a is a refrigerant widely used for automotive air-conditioning system because its destruction potential is ecologically zero. Although HFC-l34a has no ozone depletion potential, its global warming potential is so high that it is not considered as a perfect alternative refrigerant that is acceptable for long-term use. In this paper, experimental measurement has been carried out to analyze the performance characteristics of automotive air-conditioning system using HFC-152a, which has low GWP and zero ODP. Also mixed refrigerant that is composed of HFC-152a and $CF_3$ was applied to investigate an alternative possibility for the automotive airconditioning system. As a result of this study, we could draw following conclusions; With respect to the variation of the rotational speed of compressor, outside air temperature and flow rate, the heat amount of evaporator and compressor and performance coefficient was varied.

• Solar Energy
• /
• v.18 no.1
• /
• pp.69-79
• /
• 1998

This paper is concerned about the performance of HCFC22 alternative refrigerants used in heat pumps and industrial chillers. A water-to-water breadboard heat pump with counter-current heat exchangers and a hermetic compressor was built to carry out the experiments with various refrigerants. For each test, more than 40 temperatures, 4 pressures, power input, mass flow rates of the heat transfer fluids were measured. Refrigerants tested were HCFC22, R290(Propane), an azeotrope of 45%Propane/55%R134a mixture, and a nonazeotropic mixture of Calor 50. All tests were conducted under ARI test A condition. It is found that the COP and capacity of propane were 18% and 2.5% higher than those of HCFC22 while the COP and capacity of 45%Propane/55%R134a mixture were 3.5% and 5.3% higher than those of HCFC22 respectively. Also the COP and capacity of Calor 50 were 17% and 7.8% higher than those of HCFC22. Compressor discharge temperatures of alternative refrigerants were roughly $35^{\circ}C$ lower than that of HCFC22 indicating that these refrigerants are good from the view point of compressor reliability. The charging amounts for the alternative refrigerants were reduced by 40-60% as compared to that of HCFC22. Overall, it can be said that hydrocarbon containing alternative refrigerants are excellent in thermodynamic performance but should be used with considerable care due to their flammability.

• Journal of Energy Engineering
• /
• v.2 no.2
• /
• pp.225-230
• /
• 1993

Isothermal vapor-liquid equilibrium data have been measured for binary systems n-dodecane-1-defanol, n-doderane-1-dodecanol, and 1-decanoi-1-dodecanol at 140$^{\circ}C$ by using head space gas chromatography (H.S.G.C) as a static method. The activity coefficients, calculated taking into acount the nonideality of the liquid phase, were correlated with the conventional g$\^$E/ model, Margules, van Laar, Wilson, NRTL equations. These equilibrium data were thermodynamically consistent by Rrdlich- kister test, among these data, system n-dodecane-1-detanoi has minimum azeotrope.

• Membrane and Water Treatment
• /
• v.8 no.5
• /
• pp.483-498
• /
• 2017

Novel mixed matrix membranes of Sodium Alginate (NaAlg) were developed by the incorporation ofunmodified, modified Phosphomolybdic acid (PMA) then cross-linked with glutaraldehyde externally. These membranes were prepared by the solution casting technique. Pervaporation (PV) experiments have been performed with pure NaAlg, unmodified NaAlg-PMA5, NaAlg-PMA10, modified NaAlg-mPMA5, and NaAlg-mPMA10 (wt. % of PMA 5 and 10) at 30, 40 and $50^{\circ}C$, to separate water-isopropanol feed mixtures containing 10-30 wt. % of water. Pervaporation results of NaAlg-mPMA10 produced a highest separation factor of 9028 with a flux of $0.269kg/m^2.h$ for 10 wt. % of water containing feed mixture. Both separation factor and flux for water increased significantly with increasing content of mPMA into NaAlg; a significant improvement in PV performance was observed for NaAlg-mPMA5 and NaAlg-mPMA10 membranes when compared to pure NaAlg& PMA-5, PMA-10 membrane.