Actual hydrogen plant data consisting of temperatures and partial pressures of inlet and outlet gases of the reformer were collected over a five-year period. Subsequently a one-dimensional pseudohomogeneous reactor model comprising the Langmuir-Hinshelwood-Hougen-Watson reaction kinetic has been developed. Established intrinsic kinetic parameters from literature were used and the effect of intraparticle gradients was accounted for by incorporation of effectiveness factor. The validated model was used to predict the actual plant conversions and temperature profiles in the reformer tube. The steady-state one-dimensional pseudohomogeneous model was then extended to include the temporal variation of heat and mass transfer phenomena and then the dynamic response of the reformer under sudden disturbances in the feed conditions were studied.