An empirical rate expression was obtained for the photolysis of tetrachloroplantinic acid (TCPA). The data used to evaluate the parameters of the rate expression were obtained in an elliptical photoreactor operated at high recycle rates in order to maintain a uniform reactant concentration within the photoreactor. A low-pressure mercury lamp provided light at a wavelength of 2,537Å. The light was assumed to enter the reactor radially and uniformly with respect to both the axial and angular directions.

This rate expression was incorporated in a reactant conservation equation which was solved to obtain the predicted conversion of TCPA in an elliptical photoreactor operating in the laminar regime. Solutions of the conservation equation were obtained for photoreactors of two different diameters and for three different lengths.

Experimentally observed conversions of TCPA in the laminar regime agreed well with the theoretical solutions except at conversions above 55%, where a solid precipitate apparently caused the lack of agreement.