Ever heard of Betafib? Probably not, but it is a multifunctional ingredient that Cosun Beet Company-Biobased Experts (CBE) extracts from sugar beet pulp. The cellulosic solid therein has a number of specific and much sought after properties. The biobased microfibre is very effective in suspending particles and gas bubbles in water-based products. In facial creams, it helps to keep emulsions stable. In liquid detergent, it ensures that perfume capsules do not float despite the lower density. Added to latex, it prevents a layer of water from forming on top of the paint. The chance of sagging is much smaller during the drying of the paint. “This ingredient is the result of years of innovation,” says business development manager Francesco Staps of the Cosun Biobased Experts business unit via an online connection from the Cosun Innovation Center in Dinteloord (the Netherlands). “After the lab phase, our innovations are tested here on a pilot scale. Then we build a demo factory, intended to learn how to make a product and how we can produce significant market volumes, ”Staps explains. “Make no mistake about the word 'demo factory'. For us, this is a factory on a smaller scale, but it runs 24/7 production. The aim of such a demo factory is to develop a market for the product, but also to erase all the start-up problems from a process, because if you have to deal with that in a large factory, the costs are many times higher. ”
FROM BATCH TO CONTINUOUS
Since 2015 the demo factory for Betafib has been on the site of Sensus in Roosendaal (the Netherlands), a sister company of CBE. However, the production process of the popular ingredient was ready for the next phase. “There is a lot of interest in the market to use this product”, Staps continues. It is not only a good product, but also a green and circular alternative to existing fossil raw materials, such as polyacrylates or microplastics, which is much criticized now that they are not degradable in the environment. An important requirement for manufacturers is that we deliver a substantial volume. We used to run with a batch process. This resulted in a stable and excellent quality product to sell, but we wanted to move towards a continuous process, because it is much easier to scale-up and the process conditions can be controlled much better. To be able to switch from batch to continuous, we re-examined the process and returned to the pilot hall in Dinteloord. This was necessary in order to be able to test how we should organize and operate such a continuous process. We now have a very efficient process, with which we can achieve significant time savings and also quality benefits. ” The demo factory in Roosendaal was renovated at the end of 2019 and has been in use for more than a year.
The continuous production process resulted in a process line with a number of other types of equipment. The production process of Betafib consists roughly of two steps: separating the cellulose with other (unwanted) components and cracking the cellulose structure of this semi-finished product to achieve the desired functionality. The first step is done with an extraction process, the second with a technique that cannot be further specified by Cosun. Cosun has opted for decanter centrifuges for the continuous separation of the solid cellulose-containing ingredient from the other components that are made liquid for the extraction process. The extraction process of the ground sugar beet pulp takes place at relatively high temperatures and is done with a medium of high acidity. There are multiple extraction steps. The process line therefore has two decanters. “We set high standards for the separation process,” explains technical project manager Dees Lijmbach of Cosun R&D. “For example, we investigated a number of solid-liquid separations techniques and looked not only at decanters but also at other equipment, such as filters, that you can operate continuously. We ultimately opted for decanters because they have the advantage that they are easily adjustable and that you can properly operate and control the solid-liquid separation. This is necessary for the quality of the solid ingredient. Compared to the usually large filtration installations, the decanter is also a relatively small device with a small footprint that takes up fewer square meters. ”
TESTING AND SCALE-UP
Various suppliers were reviewed. The choice ultimately fell on Pieralisi. “We tried different decanters, all of which had their pluses and minuses,” says Lijmbach. “The advantage of this supplier was that we were able to get a device built to our R&D requirements and test it on a pilot scale for a longer period. As a researcher you are of course very happy with that. By testing again on a pilot scale, you get reliable data to further upscale the process to demo phase and further engineer it. By operating the decanter in a 2-stage inline set-up, we were able to fully simulate and master the process. ” The two by one meter and eighty centimeter wide "Baby" decanter, as Pieralisi calls the device, quickly delivered the desired product quality. After the positive tests in the pilot hall, the company succeeded in making the right translation to two larger decanters for the Cosun demo factory. “We now know that the decanters and other equipment can be scaled-up. Larger machines are available that fit perfectly with the next upscaling, ”says Lijmbach. “We can now prove to the market that we can make a fully developed product in a continuous process,” adds Staps. “We have provided proof in our own company that we can make the product cost-effective. This offers the potential to further scale-up the process. This is what we are investigating now. ”
With the Pieralisi decanter centrifuges, Cosun Beet Company-Biobased Experts (CBE) can better manage the quality of the product.
Thanks to the experiences with the small decanters in the pilot setting, the company was able to adapt the design of its larger decanters for the demo factory in Roosendaal. The originally Italian Pieralisi has a wide range of no less than nine series of decanters (from the 'Baby' series with decanters of 2 meters in length and a diameter of 0.3 meters to the 'Magnum' decanters of 6.5 meters in length and a diameter of 0.75 meters). In the design of his decanters, Pieralisi has, among other things, made adjustments to the pitch distance (the distance between two windings) of the scroll conveyor in the bowl of the decanter, which separates and discharges the solid. This is because each medium reacts differently in a decanter and that influences how the solid is conveyed out of the bowl. The decanter could be precisely tailored to the properties of the cellulosic product. Due to the correct height of the dam plates in the centrifuge bowl, the residence time of the product in the decanter could be adjusted to the flow rate of which Cosun wants to feed its product through the decanter. The decanters also had to comply the harsh conditions of the process. These are fairly extreme for decanter centrifuges, mainly because of the high temperature (close to boiling point) and the high acidity (2 to 9 pH) of the extraction medium. This has resulted in the decanter being made of stainless steel to prevent corrosion. Pieralisi has successfully passed all the trials so far. The result is that the larger decanters in Cosun's demo plant in Roosendaal function even better and deliver a higher quality product than the earlier 'Baby' decanter in the pilot installation in Cosun's Innovation Center in Dinteloord.