Advanced Process Control How Intelligent Technology Squeezes Maximum Profit from the Plant

Author / Editor: Norbert Meierhoefer / Anke Geipel-Kern

Modern process plants are becoming more complex. With commercial pressures to optimise product quality and maximise profits, refineries and chemical companies face on-going operational problems. Protecting assets is vital in ensuring that capital hardware investments are safeguarded, production runs smoothly and engineering time is used effectively.

The Author Norbert Meierhoefer is Business Support Director by AspenTech.
The Author Norbert Meierhoefer is Business Support Director by AspenTech.
(Bild: Aspentech)

In the process industries Advanced process control (APC) delivers the perfect combination. It maximises operational performance and process profitability enabling companies to get much more from their assets. In the past, if you selected APC there was a heavy reliance on highly experienced specialists to perform time-consuming tasks to maintain and utilise the technology.

Also, those same engineers spent a lot of time with less sophisticated tools trying to improve the control of plant behaviour, which was not optimal because of the lack of leading-edge software. With APC today, process manufacturers can now independently maintain the running of their plants in an optimal way using intuitive and highly advanced software.


No dollars left on the table

It is mission critical to operate a plant safely and prevent disruptions to production, but at the same time to optimise operations to stay competitive and maximise profit. Change occurs every minute as feedstock composition and ambient conditions alter.

Each change that occurs has an effect and the aim is to control and manage the variables to achieve the quality and the amount of product that is required. Only if you know the predictive behaviour of the plant can you counteract on time to keep the plant at the optimal target.

The plant operator is not in a position to manually react to such changes and conduct corrective actions on a minute-by-minute basis and in an optimal way. APC gives manufacturers the solution to solve these issues providing far-reaching operational, financial and time-management benefits.

The software automatically improves operational efficiency, maximises process profitability and business competitiveness. It reduces cost, maintenance time and disruption through real-time asset optimisation, delivering improved visibility and decision support.

How Advanced Control helps

Capitalising on the full potential of modern control techniques is vital to maximising production and remaining competitive. Any industry with complex processes can gain tremendous benefits, including refineries, ethylene and chemical plants and processes where there is change (i.e. feedstock, temperature change, operational target changes).

APC can be applied to any process where outputs can be optimised on-line and in real-time and anywhere that has a Distributed Control System (DCS) or Programmable Logical Circuit (PLC) in place and where you can model the dynamic predictive behaviour of the plant.

In addition, the software improves process safety and reduces environmental emissions. Benefits from implementing APC can range from 2% to 6% of operating costs and by reducing process variability plants will be operated to their designed capacity.

Profitable gains from implementing APC include:

• Reduce energy costs between 3 – 5 %

• Increase throughput up to 5%

• Minimise erosion of benefits

• Return controllers to service faster after turnarounds

• Reduce controller maintenance costs by 25%

• Increase benefits by continually improving performance

• 10% - 20% increase in total APC benefits

Adaptive Process Control - The smart technology differentiator

APC applications deliver large benefits to the operation immediately after commissioning, but plant performance degradation will occur over time. This is mainly due to the constant changing conditions within the plant itself, as opposed to problems with the technology.

Recent innovations in APC deliver game changing improvements to both controller sustainability and initial application development. Hence, today there is an intelligent technology differentiator that delivers continuous APC sustainability.

Adaptive Process Control developed by AspenTech is a revolutionary breakthrough technology that eliminates the need to approach APC maintenance as a project and creates a continuous process of assessing model quality, collecting current data and generating new models as the behaviour of the plant changes over time. This smart software can detect, isolate and correct problems without increasing the burden on engineering staff.

There is a crucial difference between the traditional approach to controller maintenance (sustained value) and Adaptive Process Control. With sustained value, revamping the controller is typically carried out as part of a lengthy and costly project. Under Adaptive Process Control, however, the clever controller is modified over time in more of a continuous process.

The update of the model occurs without the need to take the controller off-line and enables a company to reap the benefits of control and optimisation while the model is under maintenance. Model quality analysis, which continually runs and assesses the accuracy of the model, can detect when performance degradation occurs. It can pinpoint a specific part of a controller, thereby helping engineers to determine the underlying cause of the degradation.

Over a long period of time, companies lose substantial profits because the plant conditions change. The additional benefit of Adaptive Process Control is the ability to squeeze every possible cent from the asset on a continuous basis. Today, with Adaptive Process Control, non-expert engineers can do everything required to update the models without the need to turn off the controller. Crucially, the software permits the engineer to always make decisions when new models replace existing ones in on-line applications. This advanced technology dramatically changes the way in which new APC application are created, gaining benefits immediately and eliminating any inconvenience related to a disruptive plant test in order to regain a good model.

The key advantages of Adaptive Process Control over traditional sustained value approaches include:

• The controller model is continually analysed for accuracy

• Poorly performing areas of the model are identified

• Non-disruptive background testing collects new process data while the unit is being optimised

• New data are monitored in real time and bad data are automatically identified and removed

Time to change

Many refineries and chemical companies struggle to improve their margins. Notwithstanding capital cost investments that may provide a medium to long-term return, executive decision-makers seek quicker return on investment and reduced cost investments. Even today many manufacturing facilities are still operated by unsophisticated or primitive control schemes. Fortunately, the process industries have witnessed significant technological changes in recent years, which have yielded tremendous business benefits. Adaptive Process Control, in particular, improves long-term profitability by reducing process variability and allows plants to be operated optimally. Refiners and chemical companies have seen great value returns in product yield improvement and minimised energy costs with financial pay-back within short time periods.

For key decision-makers across the enterprise, the software is becoming more accessible to non-experts as the inclusion of knowledge, best practices and workflow automation within the software enables smoother APC deployments in organisations where in previous years it was costly and a drain on specialist resources. Another important factor is that APC is now affordable for smaller plants.

Overall, APC software is intelligent technology that delivers sustainable, measurable benefits and allows companies to operate their facilities with greater autonomy, cost-effectiveness, reliability and compliance with environmental regulations. Adaptive Process Control has raised the game in production standards and is enabling manufacturers to compete far more effectively in a dynamic marketplace.

* The Author is Business Support Director, AspenTech