Automated pH analysis boosts process efficiency at Evonik

pH is a critical parameter in many chemical production processes. At Evonik Antwerp, the optimisation of pH measurements through automatic cleaning and calibration not only resulted in more reliable results but also led to a significant reduction in maintenance, lower sensor consumption, and improved safety. In this case study, you will discover how smart process analytics using the Knick cCare system truly makes the difference.

Evonik, a global player in the chemical industry

Evonik Antwerp NV is one of the largest production sites within the Evonik Industries AG group, strategically located in the port of Antwerp. The site specialises in producing high-quality products such as the amino acid methionine and the silica product Aerosil, which are used among others in animal nutrition, coatings, and consumer applications.

The Antwerp site employs approximately 960 people and places great emphasis on safety, environmental responsibility, and sustainable business practices. Thanks to investments in sustainability, the site actively contributes to the energy transition.

Sustainable partnership

The collaboration between Evonik and Elscolab dates back to the early years of the latter. Over time, this relationship has evolved into a structural partnership covering applications in pH measurement, conductivity, gas measurement, turbidity, and colour measurement.

Critical pH measurement optimised through automation

A concrete example of this collaboration is the implementation of the Knick cCare system for automated cleaning and calibration of pH measurements. On an amino acid production line, pH was a critical parameter: it indicated when the product had reached its final stage before transitioning to the next phase.

Challenges in the process

Initially, measurements were taken via a bypass with two different types of electrodes. Significant deviations occurred—sometimes up to 3 pH units—between the two measurements. Causes included temperature fluctuations (from 95°C hot down to ambient), rinsing with acidic and basic products, and the presence of slurry that could clog the diaphragm. As a result, measurements were inaccurate, manual maintenance was frequent, and sensor consumption was high (usually 2 to 3 per week, sometimes even multiple per day).

Reliable measurements through automatic cleaning and calibration

Evonik switched to a uniform setup with two identical electrodes in a single line, connected to the Knick cCare system. This concept includes:
•    Ceramat: the retractable sensor holder
•    Unical: the automatic cleaning and calibration module
•    Protos: the transmitter

Thanks to automatic flushing (with diluted NaOH) and adjustment/calibration, measurement quality improved significantly. Electrode lifespan increased from multiple replacements per day to just one every 3 to 6 months. Maintenance dropped drastically, the number of lost batches decreased, and operational costs were reduced.

Application in new process environments

Although the original installation is now decommissioned, the system remains operational on a test skid to test further optimisations at a smaller scale. This allows Evonik to apply the cCare concept in other challenging processes as well.

Another scenario involves a facility for substances with specific safety requirements. Here, the focus is less on measurement complexity and more on minimising human contact with the product. Automating the analysis increases workplace safety.

I can also say that we have fully standardised on Elscolab for our pH measurements, which speaks volumes.

Andrew Brands

Process Analytical Technology (PAT) Manager, Evonik Antwerp

Impact in practice

The application of the Knick cCare system at Evonik Antwerp clearly demonstrates how automated process analytics contributes to:
•    higher measurement reliability
•    longer sensor lifespan
•    reduced maintenance and interventions
•    increased process efficiency and product quality
•    improved safety in hazardous environments
•    lower operating costs thanks to reduced consumption and maintenance

In addition, with ISM Core software, electrodes are continuously monitored, enabling targeted maintenance exactly when needed. The cooperation between Evonik and Elscolab exemplifies how innovative technologies and sustainable partnerships create tangible added value in industrial processes.

Why work with ELSCOLAB?

"I can always count on pleasant interactions with highly knowledgeable people. When there's a problem, I can call directly, which is very convenient. Also, high-quality training sessions are offered both at Elscolab and on-site, adding real value.

Moreover, it’s a big advantage that Elscolab is located nearby—they're a local partner who can respond quickly.

I can also say that we have fully standardised on Elscolab for our pH measurements, which speaks volumes.” – Andrew Brands, Process Analytical Technology (PAT) Manager, Evonik Antwerp

Looking ahead: process analytics as a catalyst for innovation

PAT (Process Analytical Technology) is booming and making a clear impact on operations. Process optimisation, sustainability, and digitalisation in process analytics are seen as key developments shaping the future.

We look back on a successful long-term partnership spanning 40 years, but this is by no means the end. The partnership continues to evolve, tackling future measurement challenges and applications. We look forward to continuing this pleasant and productive collaboration.