反应工程课件ppt.ppt

2.3.2 The Quasi-equilibrium approximation 2.3.2 The Quasi-equilibrium approximation 2.3.2 The Quasi-equilibrium approximation 2 . 3 Reaction order For overall reactions the rate often cannot be written as a simple power law. In this case orders will generally assume non-integral values that are only valid within a narrow range of conditions. This is often satisfactory for the description of an industrial process in terms of a power-rate law. The chemical engineer in industry uses it to predict how the reactor behaves within a limited range of temperatures and pressures. * 催化反应工程 Catalytic Reaction Engineering 李翔 西部校区化工实验楼B325 Xiang Li B-325, Chemical Engineering Laboratory, Western Campus Tel： E-mail: lixiang@dlut.edu.cn 教材和讲义 王安杰，周裕之，赵蓓. 化学反应工程学. 化学工业出版社 O. Levenspiel Chemical Reaction Engineering. John Wiley Sons, Inc. 1999. 3. I. Chorkendorff, J.W. Niemantsverdriet. Concepts of Modern Catalysis and Kinetics. WILEY-VCH Verlag GmbH Co. KGaA, Weinheim, 2003. 2. Chemical Reaction Kinetics 2.1 Conversion and Molar Fraction 2.2 Rate equation 2.3 The reaction order 2.4 Temperature Dependence of Reaction Rate 2.5 Kinetic theory 2.6 Autocatalytic Reactions Reaction rate 2 . 1 Conversion and Molar Fraction Conversion In the Batch Reactor In the Steady-State Flow Reactor Molar Fraction 2 . 1. 1 Conversion 1. In the Batch Reactor Suppose that nA0 is the initial amount of A in the reactor at time t=0, and that nA is the amount of A at time t . Then the conversion of A in constant volume system is given by (2.1) (2.2) (2.3) (2.4) (2.5) 2 . 1. 1 Conversion Suppose that I is an inert, then ： nt0 is the initial amount of A in the reactor at time zero, nt is the amount of all components at time t : (2.6) (2.7) (2.8) Expansion Factor： (2.9) (2.10) Expansion Ratio： 2 . 1. 1 Conversion The Steady-State Flow Reactor Since the composition in steady-state reactor is uniform throughout, the conversion is given by： (2.11) (2.12) 2 . 1. 2 Mola