|کد مقاله||کد نشریه||سال انتشار||مقاله انگلیسی||ترجمه فارسی||نسخه تمام متن|
|158299||457003||2008||10 صفحه PDF||سفارش دهید||دانلود رایگان|
A modified Amundson model was proposed to characterize breakthrough curves during gas phase desulfurization using fixed bed reactors. It contains two characteristic variables: saturation time (τ)(τ) and shape factor (lumped KK). The model has been verified experimentally at 400∘C. Combined with mass transfer correlations, the model was utilized to investigate kinetic influences due to using microfibrous entrapped sorbent (MFES) with high void volume fraction. Because of the utilization of nanosize ZnO grains supported on highly porous SiO2SiO2 particles (100–200μm), the intra-particle diffusion resistance of MFES was minimized resulting in a saturation capacity near the theoretical value. The microfibrous entrapment and the use of small sorbent particles enhanced the external mass transfer rate; the high void volume fraction reduced the capacity density resulting in increased overall lumped K. As a result, MFES demonstrated a longer breakthrough time, a sharper breakthrough curve, and higher ZnO utilization than ZnO extrudates tested at equivalent conditions. Moreover, MFES can be optimally used as a polishing layer at the downstream end of a packed bed to maximize the overall desulfurization performance.
Journal: Chemical Engineering Science - Volume 63, Issue 10, May 2008, Pages 2707–2716