HYDRODESULFURIZATION OF THIOPHENE OVER MILDLY DEACTIVATED COAL-LIQUID HYDROTREATMENT CATALYST: EFFECT OF TEMPERATURE
作者:
A.P. RAJE,
D.B. DADYBURJOR,
期刊:
Chemical Engineering Communications
(Taylor Available online 1993)
卷期:
Volume 126,
issue 1
页码: 59-78
ISSN:0098-6445
年代: 1993
DOI:10.1080/00986449308936210
出版商: Taylor & Francis Group
关键词: Catalyst Deactivation;Hydrotreatment;Hydrodesulfurization Mechanism
数据来源: Taylor
摘要:
The hydrodesulfurization (HDS) of thiophene was carried out over mildly deactivated NiMo/ahimina catalysts used for the hydrotreatment of coal-derived liquids. Arrhenius plots were obtained covering a wide temperature range, 180-54O°C. The observed rate constant is found to level off at the highest temperatures. This phenomenon cannot be explained by further catalyst deactivation, catalyst desulfiding, external mass transfer control, formation of an inert external shell or thermodynamic equilibrium for the HDS of thiophene. A modified two-step reaction mechanism is suggested to explain these results. Step 2 has a higher activation energy and controls the reaction rate at lower temperatures. Step 1 has a low activation energy and controls the rate at the highest temperatures. The proposed mechanism successfully predicts the experimental observations. Increasing deactivation affects the effective diffusivity to a greater extent than it does the intrinsic reaction rate constants.
点击下载:
PDF (564KB)
返 回