• Title, Summary, Keyword: Thermodynamic parameters

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Pridiction of Adsorption Equilibrium for Binary Gas Mixtures on Cation Exchanged Forms of ZSM-5

  • Going Yim;Chai Suck Yim
    • The Journal of Engineering Research
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    • v.6 no.2
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    • pp.85-98
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    • 2004
  • The adsorption equilibrium data for the binary gas mixture system from the pure gas adsorption data of carbon dioxide and ethylene on ZSM-5 prepared were predicted. The binary gas mixture adsorption data have been examined against predicted values by two models-the vacancy solution model(VSM) and the statistical thermodynamic model(STM), using parameters obtained from the single component isotherm. The binary gas mixture data for the carbon dioxide-ethylene system were obtained for cation exchanged forms of ZSM-5 for the gas phase carbon dioxide mole fraction of 0.752 at $37^{\circ}C$ and 1 atm. The experimental adsorption phase diagrams were obtained for carbon dioxide-ethylene on sodium form ZSM-5 synthesized. The single component adsorption isotherms for carbon dioxide and ethylene were also obtained for this zeolite. The single component data were used to obtain parameters derived in two models. These parameters were, in turn, used to predict the binary mixture isotherms for this zeolite. Both the vacancy solution and the statistical thermodynamic models give satisfactory predictions of adsorption phase diagrams for the binary gas mixtures of carbon dioxide and ethylene on sodium exchanged ZSM-5. Also the correlation between the experimental data and the predicted values is generally in good agreement. The system appears to show ideal behavior with a relatively constant separation factor. The slight increase in adsorption capacity with an increase in ionic radius is due, in part, to the higher polarizability associated with larger cations.

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The Theory of Significant Structure of Liquids : A New Method of Fixing Parameters (액체의 구조에 관하여 -새로운 Parameter 결정법-)

  • Hyungsuk Park;Seihun Chang
    • Journal of the Korean Chemical Society
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    • v.7 no.2
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    • pp.174-178
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    • 1963
  • The new method to determine the parameters in the liquid partition function of H. Eyring and co-workers is proposed, in which method the equilibrium condition of the three phases and the boundary condition of the liquid partition function at the triple point are used. The calculated thermodynamic properties using the new determined parameters are agreed well with the observed values.

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Inhibition Effect of Nevirapine an Antiretroviral on the Corrosion of Mild Steel Under Acidic Condition

  • Bhat, J. Ishwara;Alva, Vijaya D.P.
    • Journal of the Korean Chemical Society
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    • v.55 no.5
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    • pp.835-841
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    • 2011
  • Corrosion inhibition of mild steel by nevirapine, an antiretroviral has been investigated using potentiodynamic polarization, electrochemical impedance spectroscopy technique and weight loss methods. The experimental results suggested, nevirapine is a good corrosion inhibitor for mild steel in 1M hydrochloric acid medium and the inhibition efficiency increased with increase in inhibitor concentration. The kinetic parameters for corrosion process and thermodynamic parameters for adsorption process were calculated and discussed. The adsorption of the inhibitor on the surface of mild steel followed Langmuir adsorption isotherm.

Determinationof Optimal Cutting Condition for High Quality Cutting Surface (표면품질 향상을 위한 레이저 절단조건)

  • 황경현
    • Proceedings of the Optical Society of Korea Conference
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    • pp.37-41
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    • 1990
  • The quality of cutting surface such as surface roughness, heat affected zone, serf width can be improved by controlling the parameters of cuting process. These parameters includes cutting velocity, laser beam power, material depth and assistant gas. Thermodynamic analysis and systematical experiments are attempted to pedict and determine the optimal cutting condition. There exists the optimal cutting condition to ensure high quality surface. Under this operation, the minimum surface roughness of the mild steel, the stainless steel and the titanium becomes 3.8${\mu}{\textrm}{m}$ 13${\mu}{\textrm}{m}$ and 10${\mu}{\textrm}{m}$ respectively.

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Linear Relationships between Thermodynamic Parameters. Part 6 Solvent Effect on Chloride Exchanges in Benzyl Chloride (열역학함수간의 직선관계 (제6보) 염화벤질의 염소교환에 미치는 용매효과)

  • Lee, Ik-Choon;Park, Yong-Ja
    • Journal of the Korean Chemical Society
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    • v.12 no.4
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    • pp.160-162
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    • 1968
  • Rate constants and activation parameters have been petermined for the chloride exchanges of benzyl chloride in 60, 70, 80 and 90 vol.% ethanol-water solutions. Results showed a good linearity when appiled to our general equation. The significance of this linear fit has been discussed in conjunction with the Dewar's relation which was derived from the PMO method.

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Thermodynamic Studies on Complexes for Dibenzo-16-crown-5 Sulfur Lariat Ether with Metal Ions (Dibenzo-16-crown-5 Lariat Ether와 금속이온과의 착물형성에 관한 연구)

  • Cho, Moon Hwan;Lee, Sang Chul;Cho, Jae Hoon;Kim, Eung Tae;Rhee, Chang Hwan;Choi, Young Sup;Lee, Jong Chan
    • Journal of the Korean Chemical Society
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    • v.42 no.4
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    • pp.443-448
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    • 1998
  • The thermodynamic parameters for the interaction of metal ions with dibenzo-16-crown-5 and its derivatives have been determined by solution calorimetry in methanol at 25$^{\circ}C$. Thermodynamic properties of log K, ${\Delta}H$, and $T{\Delta}S$ have been determined for the complexation of metal cations by dibenzo-16-crown-5 and its derivatives. Dibenzo-16-crown-5 and its derivatives have been studied as metal cations carrier in bulk liquid membrane (BLM) and supported liquid membrane (SLM) system. $Ag^+$ has been much more transported using dibenzo-16-crown-5 derivatives as carriers and several other metal cations have been small transported using carrier in BLM and SLM system. Ligand structure, the length of side arm, donor atom, stability constant, and carrier concentration are also important parameters in the transport of cations.

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Thermodynamic Study on the Mixed Micellization of Cationic Surfactants DPC and TTAB (양이온 계면활성제인 DPC와 TTAB의 혼합마이셀화에 대한 열역학적 고찰)

  • Lee, Byung Hwan
    • Journal of the Korean Chemical Society
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    • v.43 no.6
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    • pp.614-620
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    • 1999
  • The critical micelle concentration (CMC) and the counterion binding constant (${\beta}$) at the CMC of the mixtures of Dodecylpyridinium chloride (DPC) and Tetradecyltrimethylammonium bromide (TTAB) have been determined from the concentration dependence of electrical conductance at various temperatures from $4^{\circ}C$ to $36^{\circ}C$. Thermodynamic parameters (${\Delta}C_p$, ${\Delta}G^o_m$, ${\Delta}H^o_m$ and ${\Delta}S^o_m$), associated with the micelle formation of DPC/TTAB mixtures, have been estimated from the temperature dependence of CMC and ${\beta}$values. The measured values of ${\Delta}C_p$ and ${\Delta}G^o_m$ are negative but the values of ${\Delta}S^o_m$ are positive in the whole measured temperature region. The values of ${\Delta}H^o_m$ are positive at low temperature region and negative at high temperature region. The results show that all of the thermodynamic parameters are dependent on temperature and mole fraction of DPC(${\alpha}_DPC$).

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Study on Equilibrium, Kinetic and Thermodynamic for Adsorption of Coomassi Brilliant Blue G Using Activated Carbon (입상 활성탄에 의한 Coomassi Brilliant Blue G의 흡착에 대한 평형, 동력학 및 열역학에 관한 연구)

  • Lee, Jong-Jib
    • Clean Technology
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    • v.20 no.3
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    • pp.290-297
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    • 2014
  • Batch adsorption studies were carried out for equilibrium, kinetics and thermodynamic parameters for adsorption of coomassi brilliant blue G (CBBG) using activated carbon with varying the operating variables like initial concentration, contact time and temperature. Equilibrium adsorption data were fitted into Langmuir, Freundlich and Dubinin-Radushkevich isotherms. From estimated separation factor of Langmuir and Freundlich, this process could be employed as effective treatment for removal of CBBG. Also from Dubinin-Radushkevich isotherm model, adsorption energy (E) indicated adsorption process is physical adsorption. From kinetic experiments, the adsorption reaction was found to confirm to the pseudo second order model with good correlation. Intraparticle diffusion was rate controlling step. Thermodynamic parameters like change of free energy, enthalpy, and entropy were also calculated to predict the nature of adsorption. The change of enthalpy (406.12 kJ/mol) indicated endothermic nature of the adsorption process. The change of entropy (1.66 kJ/mol K) showed increasing disorder in process. The change of free energy found that the spontaneity of process increased with increasing adsorption temperature.

Equilibrium, Kinetic and Thermodynamic Parameter Studies on Adsorption of Acid Black 1 Using Coconut Shell-Based Granular Activated Carbon (야자각계 입상 활성탄의 Acid Black 1 염료 흡착에 대한 평형, 동역학 및 열역학 파라미터의 연구)

  • Lee, Dong-Chang;Lee, Jong-Jib
    • Applied Chemistry for Engineering
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    • v.27 no.6
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    • pp.590-598
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    • 2016
  • In this study, the adsorption behavior from aqueous solution as well as kinetic and thermodynamic parameters of Acid Black 1 were investigated through batch reaction using coconut shell based granular steam activated carbon. The effects of various adsorption parameters such as pH, initial concentration, contact time, temperature were studied. To confirm the effect of pH, pHpzc measurements were analyzed followed by measuring removal efficiencies of Acid Black 1 at the pH range from 3 to 11. Experimental equilibrium adsorption data were fitted using Langmuir, Freundlich, Temkin and Dubinin-Radushkevich adsorption isotherm. The conformity of adsorption reaction for pseudo first and second order model were evaluated through kinetic analysis. Values of enthalpy change and activation energy were also investigated through thermodynamic analysis and it was confirmed that the adsorption process was endothermic. The spontaneity of adsorption process was evaluated using the values of entropy and Gibbs free energy changes.

The Dyeing Properties of Poly(trimethylene terephthalate) by Disperse Dyes with Different Energy Level (Energy Level이 다른 분산염료를 이용한 Poly(trimethylene terephthalate)섬유의 염색성)

  • 백지연;김정렬;이난형;윤태희;김삼수
    • Textile Coloration and Finishing
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    • v.15 no.5
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    • pp.316-320
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    • 2003
  • In order to investigate the dyeing property of poly trimethylene terephthalate(PTT) fabric, the dyeing of PTT fabric was carried at under condition of different dyeing temperature by using several disperse dyes with different energy level. Particularly, this study discussed the PTT dyeing thermodynamically. Used disperse dyes were selected based on the their chemical structure and energy level. The obtained results were as followings; The dye adsorption of S type disperse dye such as C. I. Disperse Blue 79 increased with increasing dyeing temperature. In a exhaustion rate of PTT fabric with disperse dyes, C. I. Disperse Blue 56 showed higher values than that of C. I. Disperse Orange 29 and Blue 79. For the interpretation of thermodynamic dyeing behavior, the partition coefficient ( K ) and some several thermodynamic parameters such as standard affinity$(-\mu^\circ)$ and heat of dyeing$(\Delta{H}^\circ)$ calculated from the adsorption isotherm. From above results, as the energy level of disperse dye is small, the partition coefficient and standard affinity increased. But the heat of dyeing of PTT fabric with disperse dye showed high negative value in order of E type(C. I. Disperse Blue 56), SE type(C. I. Disperse Orange 29) and S type(C. I. Disperse 79).