Forced Periodic Reactor Operation Applied to Methanol Synthesis

Abstract Focus of this paper is the experimental demonstration of forced periodic operation applied to the synthesis of methanol. A theoretical analysis using the nonlinear frequency response (NFR) method and rigorous mathematical optimization provide a general guideline for analyzing simultaneously carried modulations of inlet composition and total volumetric flow rate. Influences of the forcing parameters (amplitudes, frequencies, phase differences, and shapes of forcing functions) were studied for well‐mixed reactors (CSTR) and theoretically for tubular reactors. Predictions of promising operating conditions were made exploiting a kinetic model developed and validated for an industrial Cu/ZnO/Al 2 O 3 catalyst. Confirming the trends of the theoretical results, in an experimental study using a laboratory CSTR, higher time‐averaged product amounts and improved yields were achieved compared to conventional steady state operation applying the optimized phase‐shift. Hereby, square wave modulations of the inputs outperformed sinusoidal modulations. A severe and unsolved problem concerns the deactivation of the catalyst observed in the course of the three months experimental campaign, which caused performance reductions for both steady state and periodic operation.