Automation & Control Consulting

Increasing plant efficiency through control process optimisation

Chemical plants can benefit in many ways from optimising their controls. I offer this activity as a service.

What can control engineering help to do process optimisation?

By optimising the control technology, the variability of important process parameters can be significantly reduced. This in itself can be a great gain, e.g. if the process parameter is a quality criterion and as a result less waste is produced. Often there is also the possibility to operate the process closer to its limits with a profit. Possible results can be:

1. Increase in plant throughput

In many cases, chemical processes consist of a series of individual process steps. This chain is as strong as its weakest link. If one of these links can be strengthened through improvements in process control, thus eliminating the bottleneck in the plant, a considerable increase in profitability can be achieved with little effort. Since the fixed cost of the plant remain constant and only the variable cost depends on throughput, the overall site profit is significantly improved with an increase in throughput.

2. Increase in energy efficiency

An increase in energy efficiency is synonymous with a reduction in energy consumption and thus a reduction in CO2 emissions. This goal can be achieved through many control optimisations, e.g. by precisely maintaining the required product quality (avoiding overprocessing). In practice, for example while operating a distillation column, a reduction of the reflux flow and consequently a reduction of the heating energy to be used in the column sump. In other situations, energy can be saved and throughput can be increased by avoiding or reducing recycly streams.

3. Increase in process efficiency

If process efficiency is improved, both raw material and energy can be saved, improving profitability and reducing environmental impact. Precise temperature and pressure control in reactors improves the selectivity of many reaction processes. Similarly, in crystallisers, for example, the grain size can be better controlled as a decisive quality criterion.

4. Increase in availability

Poorly controlled processes are sensitive to changes in production conditions. Unobserved disturbances can have a surprising effect on the process. and cause critical process values to get so out of control that scrap is produced as a result or the plant even has to be shut down and restarted, which can lead to considerable financial losses. This can be prevented by optimising the controls through improved tuning, disturbance variable switching or other measures.

5. Increased degree of automation

With functioning process control through reliable controllers, chemical plants can be operated with significantly less manual intervention. This reduces the workload of the plant operators, Furthermore, the plant operation becomes more reproducible. Ideally, the plant operator becomes a plant supervisor and fault manager. This approach makes optimal use of the advantages of computers and humans. Computers can tirelessly monitor measurements every second, twenty-four hours a day, and can and perform control interventions for hundreds of process parameters simultaneously, which no human can do. Humans, on the other hand, are intuitive, not limited by their programming, and can arrive at meaningful results even with incomplete information, which, outside of a limited parameter range, computer controls are usually unable to do. Therefore, the division of tasks proposed above is mandatory in the long term. In power plant technology, this form of task distribution has been standard for a long time.

How can control engineering optimize your process ?

It is crucial for optimised process control that important process parameters can be brought as close as possible to their design parameters. This is the central task of control engineering. However, there are many reasons why this task is not optimally fulfilled:

Often these deficits are not even noticed. There are publications in the technical literature on the use of PID controllers in which insufficient quality is regularly found. Typically, about 1/3 of the controllers work suboptimally, 1/3 are not used at all and only 1/3 work sufficiently well. In the case of unused controllers, the causes range from defective hardware to unfavourable design to unsuitable control behaviour, so that the plant operator prefers manual operation over the utilisation of the control loop.

The optimisation of control technology is a promising method that can be applied with little effort:

Here is a selection of the services I offer for process optimisation:

Can't find the right one? Contact me and we will discuss the solution you need.