“…The case when the reaction mechanism should be taken into account in the film region is especially complex, since the component balance equations including simultaneous mass transfer and reaction in the film become non-linear (ordinary) differential equations of the second order which have to be solved in conjunction with all other model equations. This can be done either analytically, provided that some further assumptions with respect to the linearization of the diffusion and reaction terms are made (see Kenig, 2000;Kenig et al, 2000), or numerically (Noeres et al, 2003;Kenig et al, 2003Kenig et al, , 2004.…”