A simple method was presented for obtaining good approximate solutions of diffusionreaction boundary value problems in immobilized enzyme.Based on approximate solutions for diffusionreaction problems,the mathematical expressions for calculating effectiveness factor of immobilized enzyme were proposed.Calculations of effectiveness factor were made with MichaelisMenten kinetic expression for spherical immobilized enzyme pellet.The results show that the agreement of approximate solution of effectiveness factor with numerical solution obtained by numerical method is satisfactory in a wider parameter range.The presented method for calculatin effectiveness factor of immobilized enzyme is simple and the calculation is fast.
The residence time distribution for laminar flow of non Newtonian Casson fluids in a tubular reactor was analysed theoretically,and the analysis expressions were derived for the residence time distribution density function in the Casson laminar flow reactor Based on the residence time distribution density function derived, equations to calculate the product distribution for simple series reactions in an isothermal tubular reactor were presented The conditions which must be satisfied for maximizing intermediate product yield were derived Computation of optimal Dahmk hler number, optimal conversion and maximum possible yield of intermediate product was carried out By using these calculated results, design charts which show quantitatively how the reaction rate constant ratio and the parameter of Casson laminar flow model affect optimal product distribution and optimal Dahmkhler number were obtained Also,correlated diagrams and correlations which show the influence of parameter of Casson laminar flow model on optimal feed rate and optimal reactor volume were given These diagrams and correlations are useful for engineering
