Yokogawa & Nouryon Co-Innovation Leads to New pH-Analyzer

Trust and openness are two indispensable factors of collaboration that are essential to developing the right product solution. Over the past four years, Yokogawa worked with Nouryon on a pH analyzer that is considered a significant step forward by engineers, technicians, operators, and the chemical company’s management. The Nouryon Industrial Chemicals Rotterdam MEB plant is active in the chlor-alkali industry.

The chlor-alkali industry produces chlorine with its co-products sodium/potassium hydroxide (also called caustic soda/potash) and hydrogen by electrolysis of brine. Chlorine is largely used in the synthesis of chlorinated organic compounds e.g. PVC and isocyanates. The main areas of application of sodium hydroxide are water treatment (acidity control), the synthesis of organic/inorganic compounds, pulp and paper, textile, soaps/surfactants and metallurgy. In several of Nouryon’s process steps it is essential to measure the acidity and to ensure that these measurements are accurate for process optimization. Due to the high salt concentrations in this process, it is challenging to measure the acidity accurately with a conventional pH sensor. Thanks to the close cooperation between Yokogawa and Nouryon, a new pH-sensor was born to monitor the acidity in this challenging process accurately.

High maintenance costs and malfunctions 
Around four years ago, Martijn Dane, a process technician at Nouryon, started to acquaint himself better with pH analyzers. “The maintenance of our previous pH analyzers was very time-consuming and costly. We encountered frequent breakdowns causing the staff much work overtime. Furthermore, the sensors weren’t user-friendly, and we had the impression the measurement results could be further improved”.

Hearing complaints such as this is considered a severe problem because chemical dosing is controlled based on the pH measurements. If these pH measurements are inaccurate, the dosage of chemicals will be incorrect, which dramatically affects the process efficiency. One day, a brochure caught Martijn’s eye – it presented a measurement suitable for brine applications. “After getting in touch with Yokogawa, it became evident that they were the perfect party to provide the right solution.” Jorrit Walgien, account manager at Yokogawa Netherlands, remembers those first conversations. “These are challenges that drive us. When we presented a solution that could solve the challenge, we grasp the nettle and put our best foot forward”.

Teamwork makes the dreamwork
With the slogan ‘Co-innovating tomorrow’, we aim to combine good citizenship with the courage to innovate. This project is related to the slogan in every respect,” says Erik Visser, sales and marketing manager at Yokogawa Netherlands. The term symbolizes the drive to develop new solutions that add value in a long-term business relationship and close cooperation with customers. “It is more than selling a product. We showed that we are persistent and that we continue to communicate. The same goes for Nouryon. We have cooperated fully on both sides and shared insights and results openly. This approach has enabled us to make a great product that would never have been so successful without Nouryon’s input. That is what we call co-innovation!” 
Yet, the right solution was not realized overnight. Martijn says: “Major change projects take time. Sometimes it took longer because of our busy schedules, and at other times Yokogawa needed more time. Thanks to openness and good communication, we understood that quality comes before speed”.

In search for the best solution
Krystian Pietrzyk is a senior technician of instrumentation and quality measurements at Nouryon. “I cannot recall how many phone calls me and my colleagues in the I/KM department have had about pH measurements. That is why when I joined the company, I spent a lot of time looking for the best solution. I carried out tests, studied and compared reports, and then discussed with Yokogawa how the sensors could be further improved”. Initially, an existing Yokogawa sensor, the SC24, was installed. Krystian says: “Previously, a flowing reference system was used, but this was poisoned by our process. That is why we started to focus on a closed reference system. The SC24 was a good step forward and under close cooperation, this sensor was eventually further developed into the FU-20 MTS with a salt sensitive sensor”. As the production process continued at Nouryon, prototypes were tested in addition to a familiar measurement, so testing would never at the expense of the production process. What's more, the results could be compared so easily. Yokogawa thought along in this area as well.

The birth of a new sensor
This process has therefore led to the development of an entire new sensor that is suitable for measuring the acidity in a brine solution. Erik Visser: “The measurement consists of one electronica and a glass sensor. When water with salt flows past it, the glass can wear out, and eventually break”. The salt also affects the measurement. The glass sensor reacts to hydrogen, but it needs a reference, a zero line. However, because of the salt, that zero line is hard to define. Thus, if you make another glass which is sensitive to salt, you can make a zero-line based on the salt percentage. From that zero line you can then measure the pH,” Erik explains. This special ball of salt-sensitive glass is created with high precision. At the Yokogawa factory in Amersfoort there are glass blowers who blow these sensor parts manually. This salt-sensitive glass requires a special blowing technique because the sphere must be able to be attached to normal glass again. This is an extremely difficult and intensive procedure. In the old SC24 there were several glass welds. The FU20 MTS only has one glass weld left. 
There has been more plastic involved for the housing so that the sensor is less vulnerable. The right seal with the connection of the glass to the plastic also required intensive care. The seal must also be suitable for the chlorine alkali process.

Specific Application for a Specific Customer
In order to create the ultimate pH meter, both parties put a lot of time and effort into the project. Martijn: “I had to convince the management that this long development process would eventually prove itself. In the meantime, Krystian had to ask his colleagues in the production MEB department for their trust and patience. He was a real supporter in ensuring that this new system could win a chance”. Jorrit confirms this: “From Yokogawa, we sent our service engineers to Nouryon in the beginning”. Krystian joined them to identify areas for improvement. In the end, Krystian wrote an entire procedure plan for Nouryon employees. Krystian adds: “Fortunately, I could count on the full support of my colleagues and my supervisor. On the other hand, Erik and Jorrit also encountered challenges within Yokogawa”. Erik explains: “Our factory produces for customers worldwide. We had to make it clear that developing this sensor for this specific customer, for this specific application, would be worthwhile”. Martijn: “We really appreciate that Yokogawa gave us the opportunity to think with us and they really listened to us. I'm sure that has not always been easy, but we developed an outstanding new product thanks to good cooperation”. 

Positive results
The basis for this co-innovation is trust and perseverance. Thanks to the open communication and personal touchpoints, all those involved knew that this would result in a new, unique technology. In addition to the technology, it is also important to maintain the correct usage. For this reason, Yokogawa organized a special training day to allow engineers to learn how to handle the equipment. “That went very well. In the field of corrective maintenance, we made a huge step forward. Reduced maintenance costs, smoother processes and satisfied operators. Since we have been using the new sensors, I have not been called once regarding pH measurements. That is very different compared to the past,” says Krystian. Martijn is also satisfied in many ways. “I can show positive results to the management. The costs of the preventive and corrective maintenance of the pH measurements have reduced enormously. Furthermore, we are now performing much better in the pH range and the measurements are more accurate. We see that we use fewer chemicals and this fits in well with Nouryon's sustainability goals. Another dot on the horizon for Nouryon is the full automation of all systems. We can now better map out what this pH measurement does, meaning we are more in control of dosing, calibration and maintenance”.

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