THE TREATMENT OF NONINTEGER EXPONENTS IN REACTION-RATE EXPRESSIONS

The modelling of chemical reactions relies upon expressions being supp lied which give the rate of reaction as a function of local temperatur e and local concentrations. When power law rate expressions are used w ith concentrations to integer powers, the analysis and numerical solut ion of these equations is made easier. In this note the numerical diff iculties that arise when the order is non-integer are described and on e method is proposed which overcomes them in a differential-algebraic equation model of a catalytic monolith reactor.