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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Iranian Journal of Chemical Engineering(IJChE)
- نوع مقاله: Journal Article
- کلمات کلیدی: Mass transfer,RSM,heat transfer,Nano-particles,Liquid desiccant,Dehumidification
- چکیده:
- چکیده انگلیسی: This study introduces an experimental and theoretical investigation of the performance of a proposed air dehumidification system using a nanofluid of γ-alumina nano-particles in LiBr/H2O as a desiccant. Comparative experiments organized using a central composite design were carried out to evaluate the effects of six numerical factors (air velocity, desiccant flow rate, air humidity ratio, desiccant solution concentration, air temperature, desiccant temperature) and one categorical factor (adding nano-particles) on outlet air humidity ratio and outlet air temperature as responses. Reduced quadratic models were derived for each response. The results revealed that the concentration of LiBr/H2O solution and air temperature had the largest effect on outlet air humidity ratio and outlet air temperature, respectively. It was found that the average increase in mass transfer rate was 12.23% and heat transfer rate was 13.22% when γ-alumina nano-particles (0.02% wt) were added to the LiBr/H2O solution. The average increase in mass transfer coefficient was 22.73% and heat transfer coefficient was 26.51%.
- انتشار مقاله: 31-01-1395
- نویسندگان: Leila Omidvar Langroudi,Hassan Pahlavanzadeh,Sara Nanvakenari
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Chemistry and Chemical Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: liquid-liquid extraction,2,Oleyl alcohol,Extractive fermentation,3-Butanediol
- چکیده:
- چکیده انگلیسی: Recovery of metabolites from fermentation broth by solvent extraction can be used to optimize fermentation processes. End-product reutilization, low product concentration, large volumes of fermentation broth and the requirements for large bioreactors, in addition to the high cost largely contributed to the decline in fermentative 2, 3-butanediol production. Extraction can successfully be used for in-situ alcohol recovery in 2, 3-butanediol fermentations to increase the substrate conversion.In the present work organic extraction of 2, 3-butanediol produced by Klebsiella pneumoniae fermentation was studied to detect solvent effect on 2, 3-butanediol production and determination of efficient volume of solvent. The aim of this research was liquid-liquid extractive fermentation systems evaluation as an alternative to overcome the end product effect and to increase of 2, 3-butanediol production by K. pneumoniae because conventional fermentative production of 2, 3-butanediol by K. pneumoniae hasthe disadvantage of product reutilization by the organism. The highest 2, 3-butanediol production (23.01 g/L) achieved when 20% oleyl alcohol was used.
- انتشار مقاله: 13-07-1389
- نویسندگان: Hassan Pahlavanzadeh,Gholam Khayati,Nasser Ghaemi,Ebrahim Vasheghani-Farahani
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Chemistry and Chemical Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Mass transfer,mathematical model,heat transfer,Desiccant wheel,Explicit program
- چکیده:
- چکیده انگلیسی: This paper describes the theoretical and experimental investigations of the key components and also the performance analysis of a rotary wheel for using as a solid desiccant dehumidifier and also indirect evaporator cooling system. Solid desiccants have long been used in dehumidification and cooling systems for energy efficiency or reduce electricity. Although many mathematical models on the rotary desiccant wheel have been proposed, the effect of air speed on wheel performance as a momentum equation combined with heat and mass transfer has not been studied. In this study, for the first time the two dimensional mathematical modeling of a desiccant wheel and its numerical simulation using an explicit method considering momentum equation and Ackermann correction factor were described. The results indicated that Ackermann correction factor had a significant effect on performance efficiency. Air stream velocity was one of the most effective parameter on performance and dehumidification rate of wheel. The performance was increased when process air stream velocity decreased. The model suggested the optimum air stream velocity and rotational speed of wheel as 1.86 m s-1 and 10 rad h-1, respectively, obtaining maximum efficiency
- انتشار مقاله: 29-01-1388
- نویسندگان: Sayed Amir Hossein Zamzamian,Hassan Pahlavanzadeh
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Chemistry and Chemical Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: liquid-liquid extraction,2, 3-Butanediol,Oleyl alcohol,Solvent selection
- چکیده:
- چکیده انگلیسی: Recovery of metabolites from fermentation broth by solvent extraction can be used to optimize fermentation processes. End-product reutilization, low product concentration and large volumes of fermentation broth and the requirements for large bioreactors, in addition to the high cost largely contributed to the decline in fermentative 2,3-butanediol production. Extraction can successfully be used for in-situ alcohol recovery in 2,3-butanediol fermentations to increase the substrate conversion. In the present work organic extraction of 2,3-butanediol produced by Klebsiella pneumoniae fermentation was studied to determine solvent effect on 2,3-butanediol production. The aim of this project was liquid-liquid extractive fermentation systems evaluation as an alternative to overcome the end product effect and to increase of 2,3-butanediol production by K.pneumoniae because Conventional fermentative production of 2,3-butanediol by K. pneumoniae has the disadvantage of product reutilization by the organism. Alternatives to overcome this problem have met with limited success. Extractive fermentation has been shown to solve this problem. An effort has been made in this study to use for the extractive fermentation of 2,3-butanediol using oleyl alcohol as extract-ant. Eighteen organic solvents were examined to determine their biocompatibility for in situ extraction of fermentation products from cultures of the K. pneumoniae. From 18 tested solvents, 13 of which were non-toxic to K.pneumoniae. The highest 2,3-butanediol production (23.01 g l-1) was achieved when oleyl alcohol was used. In situ removal of end products from K.pneumoniae resulted in increased productivity. In conclusion 2,3-butanediol productivity increased from 0.5 g l-1h-1 to 0.66 g l-1h-1 in extractive fermentation using oleyl alcohol as the extraction solvent.
- انتشار مقاله: 30-02-1387
- نویسندگان: Hassan Pahlavanzadeh,Gholam Khayati,Ebrahim Vasheghani Farahani,Nasser Ghaemi
- مشاهده
- جایگاه : پژوهشی
- مجله: Advances in Environmental Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: Adsorption Isotherm,chicken feather,keratin nanoparticle,biosorbent,Cu(II) removal
- چکیده:
- چکیده انگلیسی: A straightforward procedure to synthesize keratin nanoparticles (KNP) from chicken feathers was introduced. The characterization of the synthesized nanoparticles was done using Fourier transform infrared (FTIR) spectroscopy, dynamic light scattering (DLS), X-ray diffraction (XRD) patterns and transmission electron microscopy (TEM). The FTIR analysis revealed no significant chemical change after the nanoparticle synthesis. TEM imaging indicated the synthesis of KNPs with a spherical morphology and mean size of 42 nm. The DLS results indicated that the synthesized KNPs were stable in aqueous media by having a zetapotential of lower than -30 mV. The produced KNPs were then evaluated for the biosorption of Cu (II) from aqueous solutions. The analyzed adsorption isotherm data revealed the change from a Redlich-Peterson isotherm to a Langmuir one by increasing the biosorbent dosage, which could be attributed to the more prepared adsorption sites. The experiments of the effect of the biosorbent dosage suggested the best removal at a KNP dose of 3.0 g/L. At this dosage, the maximum Cu (II) adsorption capacity and Langmuir constant were 50 mg/g and 10.8×10-3 L/mg, respectively; the adsorption kinetic followed the pseudo-second order model.
- انتشار مقاله: 16-03-1397
- نویسندگان: Seyedeh Zahra Mousavi,Mehrdad Manteghian,Seyed Abbas Shojaosadati,Hassan Pahlavanzadeh
- مشاهده