Industrial process models performance

The oxidative dehydrogenation of methanol to formaldehyde is a model reaction for performance evaluation of micro reactors (see description in [72]). In the corresponding industrial process, a methanol-air mixture of equimolecular ratio of methanol... 

The oxidative dehydrogenation of methanol to formaldehyde was choosen as model reaction by BASF for performance evaluation of micro reactors [1, 49-51, 108]. In the industrial process a methanol-air mixture of equimolecular ratio of methanol and oxygen is guided through a shallow catalyst bed of silver at 150 °C feed temperature, 600-650 °C exit temperature, atmospheric pressure and a contact time of 10 ms or less. Conversion amounts to 60-70% at a selectivity of about 90%. 

Off-line analysis, controller design, and optimization are now performed in the area of dynamics. The largest dynamic simulation has been about 100,000 differential algebraic equations (DAEs) for analysis of control systems. Simulations formulated with process models having over 10,000 DAEs are considered frequently. Also, detailed training simulators have models with over 10,000 DAEs. On-line model predictive control (MPC) and nonlinear MPC using first-principle models are seeing a number of industrial applications, particularly in polymeric reactions and processes. At this point, systems with over 100 DAEs have been implemented for on-line dynamic optimization and control. 

The design of a controller depends on a model of the process. If the controller is installed on a process whose parameters are not exactly the same as the model used to design the controller, what happens to its performance Is the system unstable Is it too underdamped or too slow These are very practical questions because the parameters of any industrial process always change somewhat due to nonlinearities, changes in operating conditions, etc. 

Since the advent of efficient and robust simulation and optimization solution engines" and flowsheeting software packages that allow for relatively easy configuration of complex models, numerous integrated, high fidelity, and multiscale process model applications have been deployed in industrial plants to monitor performance and to determine and capture improvements in operating profit. 

The organosilane modification of silica is of great importance in science and industry. Because of its widespread applications, there is a lot of interest in the underlying reaction mechanisms in the modification process. A fundamental understanding of these mechanisms can lead to an improvement of known applications and the development of new ones. Thus, fundamental knowledge supports industrial development. Mechanistic studies are performed on model systems with low complexity. Therefore organic solvent and vapour phase modification procedures are mostly used. Thus, the concentration of the reactants and the presence of water in the system may be easily controlled. From a careful description of the simple model systems, extrapolation towards large-scale industrial processes may be performed. 

The operation of the numerical model will be illustrated by means of three computer experiments, chosen more for their value in visualizing reactive flow than as detailed numerical simulations of real industrial processes. Simple fluid property models will be used in which material parameters such as viscosity and reaction order are not allowed to vary during the process, although real situations are often much more complicated than this. The numerical model does have the capability of performing... 

Summary The Direct Process discovered by Rochow and Muller around 1940 is the basic reaction used to produce methylchlorosilanes, which are the monomeric intermediates used for production of silicones. An understanding of the elementary reactions, the nature of active sites and the action of promotors does not nearly come close to the performance level of the industrial process and the economic importance. The silylene-mechanism is a useful model to understand the complex product mixture from the reaction of silicon with chloromethane. 

Even with these potential advantages, LMs have been only slowly developed as useful industrial vehicles. While many theoretical modelling studies of LMs as separation tools have been performed in the past decade, it has been only recently that industrial processes utilizing LM... 

The modeling procedure and the Process Ontology are planned to be further elaborated in a future project described in Sect. 7.3. The project aims at a generalization of the approach to cover different types of work processes in the chemical industries. It is performed in cooperation with four major players of the process industries, thus indicating the increasing importance that is attached to work process modeling by industrial users. 

---