CIESC Journal

• 化工学报 • 上一篇    下一篇

钼系多组分催化剂上的丁烯-2氧化脱氢动力学

陈曙,俞启全,金韵,庞礼,林波,章贵德,宋文,张苏华   

  1. 北京大学化学系 ,北京大学化学系 ,北京大学化学系 ,北京大学化学系 ,北京大学化学系 ,北京大学化学系 ,北京大学化学系 ,北京大学化学系
  • 出版日期:1982-03-25 发布日期:1982-03-25

Kinetics of Oxidative Dehydrogenation of Butene-2 on Multicomponent Molybdates Catalyst

Chen Shu, Yu Qiquan, Jin Yun, Pan Li, Lin Po, Zhang Quide, Song Wen and Zhang Suhua Chemistry Department of Beijing University   

  • Online:1982-03-25 Published:1982-03-25

摘要: 用玻璃流动循环反应器研究了Bi_(1.5)Fe_(3.0)Ni_(4.5)Co_1Cr_(0.5)Mo_(12)K_(0.3)(原子比)氧化物催化剂(SiO_2载体)上的丁烯-2氧化脱氢动力学,发现丁烯转化速度对丁烯及氧的反应级数m及n与温度及反应物浓度有关,而且m+n≈1。 根据Redox稳态机理可认为: ①催化剂被丁烯还原的速度与还原态催化剂再氧化的速度达到稳态。 ②丁二烯在催化剂的氧化态表面部分上可逆吸附起了阻碍丁烯转化的作用,并导出速度方程为: 计算出催化剂还原步骤的活化能E_1=4.53kcal/g-mol,催化剂再氧化步骤的活化能E_2=21kcal/g-mol(>400℃)及60kcal/g-mol(<400℃),E_2在400℃附近转折。当丁二烯阻碍作用不显著时(相对于丁烯,丁二烯分压较小,或反应温度较高)方程可以简化为 本文还对常见的钼系催化剂的丁烯转化的活化能发生转折的原因进行了讨论。

Abstract: The kinetics of oxidative dehydrogenation of butene-2 to butadiene on the multiconponent molybdates catalyst, Mo12Bi1.5Fe3Co1Ni4.5Cr0.5K0.3/SiO2 (atomic ratio), has been investigated in a flow-recirculation glass reactor. It was found that the butene conversion was m-order with respect to butene and n-order with respect to oxygen, m and n depended on the reaction temperature and concentration, m increased and n decreased with the rise of reaction temperature, and m+n=1. According to the steady state Redox mechanism: 1 ) The reduction of catalyst by butene and the reoxidation of reduced catalyst by oxygen were in steady state; 2 ) Butadiene reversibly adsorbed on the fraction of sites of the oxidized catalyst inhibited the butene conversion, the rate equation, was derived. The activation energy of catalyst reduction step E1 was 4.53 kcal/g-mole, the activation energies of catalyst reoxidation E2 were 21 kcal/ g-mole (>400℃) and 60 kcal/g-mole (<400℃). The Arrhenius figure of k2 appeared a broken-line and the turning point was at about 400℃.Under the condition of insignificant inhibition of butadiene, i. e. small partial pressure of butadiene or higher temperature, the above equation could simplify as: