The derivation and applicability of reduced-order models for selection and assessment of plantwide control structures is studied. The paper demonstrates the advantage of exploiting the intrinsic structure of a chemical plant, which mirrors the decentralization of the control problem. The recommended procedure is to apply model reduction to individual units, followed by coupling these reduced-or...

With the goal of demonstrating the advantages of supercomputer simulations for process design and operations, Bayer AG recently teamed up with Cray Research to perform plantwide dynamic simulations of an entire Bayer production facility in Leverkusen. This paper presents project results and benefits from both a computational standpoint and a Bayer company perspective. Regarding computational as...

In part I of this study, control structures were proposed for different operational regions of a postcombustion CO2 capturing process using the top-down steady-state economic part of the plantwide procedure. In the current study, the bottom-up part of the complete procedure is considered. For this purpose, dynamic simulation is used to validate the proposed control structures. Different control...

The paper studies the problem of nonlinear feedback control design of non-isothermal Continuously Stirred Tank Reactors (CSTR). The objective is to construct a feedback controller such that a desired equilibrium of the closed-loop dynamic is asymptotically stable and such that the closed-loop vector field is a conservative vector field of a particular type, i.e., a gradient system. Properties o...

Plant-wide control system design for economically optimum operation of a recycle process with side reaction is studied. The process consists of a liquid phase CSTR followed by two simple distillation columns. The exothermic irreversible reactions A + B → C (main reaction) and C + B → D (side reaction) occur in the CSTR. The reactor effluent is distilled in the recycle column to recycle the ligh...

The plant design and control tasks are usually carried out sequentially. Initially the plant is designed and then the control structure is determined as a function of the design. Such a formulation neglects the coupling between design and control. This may lead to processes where a suitable control scheme cannot be synthesized for a given design. Even if a control scheme can be generated, it ha...

Background: Despite progress in developing technologies for health promotion and disease treatment, mental disorders remain highly prevalent. In light of the associated personal and societal burden, primary prevention of new onset disorder can be seen as a primary challenge for health care systems and society. Internetand mobile-based interventions (IMIs) are a promising approach to scale up pr...