Multiplicity of solutions in the optimization of a bifunctional catalyst blend in a tubular reactor

The reaction scheme for the isomerization and hydrogenation of methylcyclopentane using bifunctional catalyst is considered in a tubular reactor. The aim is to maximize the concentration of benzene at the outlet of the reactor by choosing the optimal blend of the catalyst along the reactor. When the problem was attempted by nonlinear programming employing sequential quadratic programming, twenty‐five local optima were obtained from 100 random starting conditions. By using iterative dynamic programming in addition to the best two local optima obtained by nonlinear programming, the global optimum was also obtained.