Different processes often have similarities. For instance, in grain production the segregation and blending of different truck deliveries is essential to improve the overall protein content of the grain in the silo.
It is the same for feed products made from animal rendering processes. The protein content of final products will always vary, but with effective segregation, batches can be made to match customers’ exact need for protein content. The trick is to be flexible and fast enough to get it right every time.
It is a challenge that Frank Hölscher, Production Manager, at the Ten Kate production plant in Sögel Germany is familiar with. His customers at the other end of the telephone are petfood companies around the globe. Among many quality parameters, there is one that they are especially interested in – protein. And they are not shy about voicing complaints if the protein content is not spot-on. “Our customers are looking for high protein content so that they do not need to add from other sources,” he says.
Until a year ago, Hölscher and his team used a near infrared instrument in the plant’s laboratory to give an indication of protein in rendered products. The instrument gave reliable results, but the time and work involved in using the instrument left gaps in their knowledge about what was going on in the process.
The ProFoss unit and sensor installed in the process.
From Lab to process
The rendering process is conducted at high temperatures and the samples taken for the laboratory instrument were typically about 90 -100 Centigrade. These needed to be cooled down slowly to at least 37 Centigrade for testing in the laboratory NIR instrument.
“With the Lab NIR it was very labour intensive to take samples out of the process every 15 minutes, cool down the sample, make a measurement and go back to the factory,” explains Hölscher. “It took too long to make a change, to adjust the raw material and so on.”
With this challenge in sight, the plant invested in the in-line NIR analysis ProFoss system in 2014. Instead of taking samples for testing in the lab, the NIR analysis is now integrated into the process with an NIR sensor positioned to measure final products just before storage. The sensor is positioned in a pipe with a specially designed glass plate interface that allows the infrared light to measure product material as it passes by. Tests are made every few minutes and the results are conveniently displayed on a computer screen.
The continuous flow of results allows operators to decide how to store the products in different silos according to customer orders. In addition to protein, the ProFoss also measures, fat, moisture and ash which gives the operators extra information to help control machinery to get the best protein result. That said, this ability to make adjustments is quite limited due to the nature of the rendering process. Unlike some processes where adjustments can be made quite quickly by adjusting a tap or hopper, the rendering process is more difficult to manoeuvre. In this respect, the main impact of the in-line NIR has been to make deliveries to customers more stable by allowing more effective segregation of final products.
“With the ProFoss, we can show our customers that we have a system to guarantee a consistent protein level. It is much more stable than before and they are very interested in it,” says Hölscher. “We can produce a good product continuously.”
The NIR instrument in the laboratory is still used for final checks on products and also to check on the results from the ProFoss which has shown a good correlation over the year that it has been installed.
“We are very satisfied,” says Hölscher. Judging by the lack of calls from petfood producers, it appears that customers are too. “We don’t have so many complaints and we do not need to pay back money and so on,” he says. “There have been no complaints for the last six months.”
Ten Kate produce high-quality animal fats and proteins for the food and animal feed industries and for manufacturers of technical products.
The ProFoss in-line NIR system is installed at a large production site in Sögel, Germany, which produces fats and proteins for petfood.