The nonlinear frequency response (NFR) method, which is an analytical, fast, and easy method for evaluating the performance of forced periodically operated chemical reactors, was used to investigate possible improvements to a nonisothermal continuous stirred‐tank reactor (CSTR) when inlet concentration and/or flow rate are periodically modulated. The product yield was used for evaluating the performance improvements. Part I of this paper considered the general nonisothermal case. In this part, the results are applied to an adiabatic CSTR. A laboratory‐scale adiabatic CSTR was analyzed by applying kinetic parameters for the hydrolysis of acetic anhydride. It is shown that improvement can be obtained for simultaneous modulation of the two inputs with appropriately chosen forcing parameters.

Traditionally, methanol is produced in large amounts from synthesis gas with heterogeneous Cu/ZnO/Al2O3 catalysts under steady state conditions. In this paper, the potential of alternative forced periodic operation modes is studied using numerical optimization. The focus is a well-mixed isothermal reactor with two periodic inputs, namely, CO concentration in the feed and total feed flow rate. Exploiting a detailed kinetic model which also describes the dynamics of the catalyst, a sequential NLP optimization approach is applied to compare optimal steady state solutions with optimal periodic regimes. Periodic solutions are calculated using dynamic optimization with a periodicity constraint. The NLP optimization is embedded in a multi-objective optimization framework to optimize the process with respect to two objective functions and generate the corresponding Pareto fronts. The first objective is the methanol outlet flow rate. The second objective is the methanol yield based on the total carbon in the feed. Additional constraints arising from the complex methanol reaction and the practical limitations are introduced step by step. The results show that significant improvements for both objective functions are possible through periodic forcing of the two inputs considered here.

The analysis of the potential to improve performance of a methanol synthesis reactor through forced periodical operations by Nonlinear Frequency Response method is presented. The methanol synthesis in an isothermal and isobaric lab-scale CSTR is considered. First, the analysis was performed for single input modulations (in Part I), which showed that significant improvements can't be achieved. Here, the study is extended to analysis of simultaneous modulations of two inputs. All possible input combinations (6 cases) are analysed and the optimal forcing parameters, maximizing the time-average methanol production, were determined. For all combinations the improvement is possible, but for some cases it is not significant. The highest improvement is predicted for simultaneous modulation of the inlet partial pressure of CO and the inlet volumetric flow rate. This case, for which it is possible to achieve up to 33.51 % of methanol production, is analysed it detail and optimized using multiobjective optimization.

In this two-part paper a comprehensive study of the potential to improve performance criteria of a methanol synthesis reactor through forced periodical operations is presented. The study uses the Nonlinear Frequency Response method, a powerful analytical and approximate tool which gives an answer whether and under which conditions certain periodic operation would lead to improvement of process performance. To demonstrate the method, isothermal and isobaric methanol synthesis in a lab-scale CSTR is considered. In Part I, the analysis is performed for single input modulations. Partial pressures of each reactant in the feed stream and the total inlet volumetric flow-rate are considered as possible modulated inputs. The results show that modulations of single inputs essentially do not provide potential for significant improvements. In Part II, the study will be extended to analysis of periodic operations with simultaneous modulations of two inputs and conditions offering significant performance enhancements will be identified.

The reaction network of the ethene-to-propene (ETP) reaction over Ni/AlMCM-41 catalysts was studied. This reaction consists of the dimerization of ethene, the isomerization of 1-butene, and the metathesis of ethene and 2-butene to propene. This work focused on the latter. ETP experiments followed by in situ diffuse reflectance infrared Fourier transform spectroscopy were carried out. Metathesis activities were evaluated by the isomerization of butenes, the metathesis of ethene and 2-butene, and the retro-metathesis of propene. Metathesis activities of Ni/AlMCM-41 catalysts were not observed. Thus, a conjunct polymerization of ethene to propene is proposed.