In Silico SE Blog
Chemical process plants, completely designed in an In Silico environment
May 19, 2022
By: Pablo Hernández Arango
All the stages associated with the processes of physicochemical transformation, which can be traditional, electrochemical, or biological, can be designed in a virtual environment that allows their optimization with better precision and at a lower cost.
Most chemical processes contain steps of purification, catalysis, reactions to extreme conditions, and separation. Defining each of these stages is an essential task in the design of chemical processes. However, selecting and adjusting features can be very tedious and costly. Thus, In Silico design methods are highly desirable to describe the behavior of the process, and thus minimize experimental effort and cost. It is helpful to outline the qualities of advanced simulation software such as COMSOL Multiphysics® for In Silico design of chemical processes.
Contour of flow lines in the simulation of a water purification process.
(A. Foley, COMSOL Blog. 8.03.2013)
PURIFICATION
In the purification stages, the raw materials that feed the chemical processes are subjected to physical or chemical treatments that reduce the presence of contaminants or excipients, which could subsequently inhibit the reactive processes or reduce the quality of the finished products.
In the case of chemical purification processes, special attention should go to the possible formation of by-products or the permanence of purifying agents in the raw material, which can act as impurities in the later stages of the process. An example is the formation of Bromates or the accumulation of Chlorine or Ozone in the purification of water used in food processes or drug manufacturing processes. In this sense, the definition of residence times and minimum quantities of purifying agents is a goal of the In Silico design of the purification stages since these determinations come from the application of transport phenomena and the chemical mechanisms associated with the process.
CATALYSIS AND EXTREME REACTION CONDITIONS
Reaction steps are the most important in the chemical industry. In traditional chemical, electrochemical, and biochemical processes; catalytic and noncatalytic, researchers and engineers must define the physicochemical properties of solids, gases, and liquids and their interaction at the interfaces they form. These interactions are limited and are described by either chemical kinetics or mass transfer. In turn, these limitations are variable according to the conditions of pressure, temperature, and composition of the reactive media. Of course, the description of the spatial change (gradients) of these parameters is essential for the design of efficient reactors from different points of view: chemical, energetic, and environmental.
Velocity field (flow lines) and concentration contour in a catalytic process.
(E. Dickinson, COMSOL Blog. 13.07.2017)
The Multiphysics simulation of a reactive process must consider at least the following components: i). Associated chemical mechanisms, ii). Transport of species in the reactive medium, iii). Physicochemical interaction between phases and iv). Momentum transport in the reactor.
In practice, the only economically feasible ways to describe these interactions and to observe the effect of the variations of the process conditions on them, are the In Silico design and experimentation, otherwise, using physical studies, is not possible. It is possible to incur many tests that reasonably describe all interactions without incurring high capital and operating costs.
SEPARATION
Finally, every chemical process has one or several stages of separation of by-products, or in other words, purification to obtain final products. These stages are usually based on multiphase systems, in which changes in the concentration of the species are used, at specific conditions of pressure and temperature, to enrich a specific phase (solid, liquid, or gas) in a chemical species (product or by-product). Gas-liquid unit operations are an example of technologies widely used for this purpose.
To favor the separation of the species, the geometry of the associated equipment and the evaluation of the operating conditions are fundamental (for example in the formation of bubbles). In this sense, the multiple existing heuristics, although adequate, do not favor design optimization, and the implementation of physical prototypes is notably expensive. In such a situation, the simulation of processes using In Silico tools favors design and engineering exercises, granting them efficiency in terms of costs and time.
Movement and growth of a bubble in an unit of gas-liquid separation
(E. Fontes, COMSOL Blog. 26.03.2020)
IN SILICO SE SAS SOLUTIONS
Through the professional use of COMSOL Multiphysics® and our Simulation-Driven Innovation services, In Silico SE SAS can:
- Analyze process stages in which the conditions of mixing and efficient consumption of the raw materials are necessary.
- Establish physicochemical models from laboratory or plant conditions that can be extrapolated to other process conditions without the need to carry out physical tests on them.
- Carry out the detailed design of reactors both from the geometric point of view and from the chemical kinetics and transport phenomena.
- Carry out the design of separation processes through advanced simulation of physical and chemical phenomena that interact in the same process operations.
Additionally, in our portfolio of services, we include STEM training. We use a dynamic methodology to help COMSOL Multiphysics®, Python™ or GNU Octave users get out the best of the software on the way to fulfilling their academic, research, or chemical process development goals.
Also, you can access to our own Courses Platform to learn about simulation with our training offer.
About the author: Pablo Hernández Arango
Pablo is a Chemical Engineer, and has Master in Sciences and PhD titles in the same area at the TU Darmstadt in Germany. He has developed his academic and work activity in the simulation and design of processes in different areas of the productive industry.