کد مقاله کد نشریه سال انتشار مقاله انگلیسی ترجمه فارسی نسخه تمام متن
38690 45787 2016 7 صفحه PDF ندارد دانلود رایگان
عنوان انگلیسی مقاله
Pd-Ag/Al2O3 catalyst: Stages of deactivation in tail-end acetylene selective hydrogenation
ترجمه فارسی عنوان
کاتالیزور Pd-Ag/Al2O3: مراحل غیرفعال کردن در هیدروژناسیون انتخابی استیلن قسمت انتهایی
کلمات کلیدی
هیدروژناسیون استیلن؛ Pd-Ag/Al2O3؛ غیرفعال کردن کاتالیست؛ تشکیل کک
Acetylene hydrogenation; Pd-Ag/α-Al2O3; Catalyst deactivation; Coke formation
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی کاتالیزور
چکیده انگلیسی


• Differential analysis of acetylene selective hydrogenation data was performed.
• Two distinct stages of activity loss was observed in long-term runs.
• From Stage I to II, rate constants (k and kd) were decreased one order of magnitude.
• Characterization of used catalyst showed formation of soft coke after about 100 h.

The deactivation of a Pd-Ag/α-Al2O3 catalyst (2.5 mm in diameter, containing 0.03 wt.% Pd and 0.18 wt.% Ag) with egg-shell distribution was studied for acetylene selective hydrogenation. The reaction was performed in a fixed bed reactor using C2H2/C2H4/H2 feed mixture (1:67.5:1.5 molar ratio). The long-term deactivation behaviour of the catalyst was studied by differential method of analysis using appropriate power law kinetics for the main reaction and catalyst decay. Based on the analysis of model results, it was proposed that the catalyst deactivation proceeded in two stages. The initial stage (Stage I) was relatively short (<20 h) and characterized by rapid catalyst deactivation, followed by second stage (Stage II) of much slower deactivation rate exhibiting a deactivation rate constant one order of magnitude smaller than Stage I. It was attributed to the dual role of carbonaceous deposits on catalyst that exhibited sequential activation and deactivation effects. The TG and FT-IR analysis of the spent catalyst revealed formation of aliphatic (soft) coke after about 100 h on stream.

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ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Applied Catalysis A: General - Volume 525, 5 September 2016, Pages 197–203
نویسندگان
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