Case study: Guaranteed product quality and cost savings through inline refractometry and pH measurement

Bayer Agriculture, global leader in crop protection products and seeds

Bayer is an international company striving for innovations in healthcare and agriculture. The organization consists of 3 divisions, namely Pharmaceuticals, Consumer Health & Crop Science.

Bayer Agriculture, situated in the port of Antwerp, falls under the Crop Science division. By cleverly combining biology, chemistry and digital tools, they create innovation in agriculture.

They have been producing chemicals at this site since 1966, including crop protection products for the European, African and Asian markets. With their innovative products, they aim to approach farmers as sustainably as possible.

What is it about?

Glyphosate is made at the Antwerp site. Before it becomes a usable product, the glyphosate must be further concentrated. This is done in an important first step with a classic crystallization process. The end result is a pure glyphosate crystal. By default, they aim for 20 to 25% solids concentration at the crystallizer. And it is precisely this parameter that process operators want to control as well as possible.

Refractometry to reliably control the process and also save costs

If the solids concentration is too high, then the crystallizers and heat exchangers will foul. This causes the steam to no longer be used optimally, which in itself has major cost implications (natural gas and CO₂). If they can keep the solids concentration on point, we are talking about clear cost savings, which makes it a sustainability project for Bayer.

Historically, monitoring of solids concentration was done using online density measurements. However, this brought limitations. For example, the concentration obtained from the density measurement was affected by impurities in the liquid. Bayer went in search of a measurement technique that could measure the total sum of impurities in the liquid phase. Refractometry is precisely the technique for measuring the total dissolved solids in a liquid. Without the influence of particles, color or gas bubbles. Inline refractometry is used to correct density for impurities. As a result, the correct solids concentration is now measured inline in real time.

When implementing the Vaisala K-Patents refractometers, they built in correlation. By doing different sampling over one month on the three crystallizers, you got a clear variation in the solids concentration. In this way, the solids concentration could be linked to the density measurement and the Refractive Index (RI) measurement. This is how a relationship was finally established with statistical tools, where a comparison came out and that comparison was plugged into the DCS systems.

When the measurements were introduced, a control system was also immediately implemented, with the obvious result being a huge reduction in the variation in solids concentration. In addition, the use of steam 3 to 4% became more efficient, which ultimately resulted in less maintenance of the heat exchanger. A nice cost savings overall!

Read the full case study and find out how Bayer Agriculture is using refractometry even more as a check for quality and product identification.