کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
209667 461679 2014 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Comparison of different molecular sieves for the liquid phase separation of linear and branched alkanes
ترجمه فارسی عنوان
مقایسه مقادیر مختلف مولکولی برای جداسازی فاز مایع آلکانهای خطی و شاخه ای
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی مهندسی شیمی (عمومی)
چکیده انگلیسی


• A PVDC-PVC based carbon molecular sieve (CMS) was prepared by a calcination process.
• A model quaternary mixture was used to test the CMS performance in liquid phase.
• The CMS was tested against ZSM-5, ZSM-22, ZSM-23, Silicalite-1 and Silicalite-2.
• CMS presented higher adsorption capacity for hydrocarbons than the other materials.
• Adsorption rate of all alkanes was slower in the CMS than in the other materials.

A carbon molecular sieve adsorbent (CMS-IMP12) obtained from the pyrolysis of a poly(vinylidene chloride-co-vinyl chloride) (PVDC-PVC, Saran™) material was tested and compared with other molecular sieve materials for the separation of a multi-component hydrocarbon mixture. Liquid phase experimental adsorption curves at 303 K were obtained in a stirred tank using a model mixture composed by n-heptane, 2-methylheptane, 2,5-dimethylhexane and 2,2,4-trimethylpentane, considering the last one as a non-adsorbing solvent. Materials compared against the CMS-IMP12 were zeolites ZSM-5 (Si/Al = 15), ZSM-5 (Si/Al = 140), ZSM-22, ZSM-23, Silicalite-1 and Silicalite-2. The CMS-IMP12 adsorbed at least three times the amount adsorbed by the other material tested (i.e. 206 versus 79 mg/gads for Silicalite-1) mainly because three components of the mixture (linear, methyl and non-geminal dimethyl alkanes) were adsorbed in higher proportions. None of the other tested materials adsorbed non-geminal dimethyl branched compounds. Regarding the kinetics of adsorption as represented by their second order rate constants, all the materials except the CMS-IMP12 adsorbed the methyl alkane molecule at the same rate as the n-alkane. The slower adsorption rate observed for 2-methylheptane as compared to n-heptane in the CMS-IMP12 may be due to the competition for adsorption sites between the two slow diffusing species: 2-methylheptane and 2,5-dimethylhexane.

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ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Fuel Processing Technology - Volume 124, August 2014, Pages 258–266
نویسندگان
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