摘要
在Ｐｔ／Ａｌ２Ｏ３催化剂上，用外循环无梯度反应器研究了异丁醇内扩散对异丁醇完全氧化动力学的影响。用０．４５～０．６０ｍｍ催化剂，反应在动力学区域进行，异丁醇完全氧化的动力学用－０．６级速度方程描述。当催化剂颗粒增大到４ｍｍ时，反应受内扩散控制，在内扩散区域异丁醇反应级数变为－０．０１级。测定了催化剂有效因子η，其值在０．２１～０．６１之间。它表明孔扩散阻力严重。在温度恒定时，ηｅｘｐ值随异丁醇分压的升高而增加。在异丁醇分压固定时，ηｅｘｐ值随反应温度升高而下降。反应在动力学区域时，异丁醇完全氧化的活化能为２６．０ｋＪ／ｍｏｌ，而在内扩散区域时，反应活化能为２３．７ｋＪ／ｍｏｌ。
The effect of internal diffusion on the kinetics of the complete oxidation of isobutyl alcohol over Pt/Al 2O 3 catalyst has been investigated by the external circulation gradientless reactor. The complete oxidation of isobutyl alcohol occurred in the kinetic region with 0.45-0.60 mm catalyst. It's kinetics was described by the rate equation with -0.6 order. When the particle size of catalyst was increased to 4 mm, the reaction occurred in the internal diffusion region. The effectiveness factors η , ranging from 0.21 to 0.61, indicating that the reaction was strongly retarded by internal diffusion. The value of η increased with the raise of partial pressure of isobutyl alcohol at a constant temperature, and η decreased with the raise of reaction temperature at a constant partial pressure for isobutyl alcohol. The apparent activation energies of the complete oxidation of isobutyl alcohol was 26.0 kJ/mol in the kinetic region and 23.7 kJ/mol in the internal diffusion region.
出处
《北京大学学报（自然科学版）》
CAS
CSCD
北大核心
1996年第4期417-424,共8页
Acta Scientiarum Naturalium Universitatis Pekinensis
基金
国家自然科学基金
