It's all in the mix!

In the spirit of a circular economy, large parts of a new window should ideally be made of recycled material. In order to make window profiles even more sustainable, GEALAN is now taking a new approach: Together with its development partner Ragn-Sells from Estonia, the goal is to increase the proportion of CO2-reduced raw material. This would mean that emissions for the window would continue to fall and GEALAN would become less dependent on primary raw materials. Ideally, GEALAN profiles will consist of a combination of recycled material and CO2-optimised PVC formulations in the future. 

Reduce the CO2 footprint of the profiles

One component of PVC profiles is chalk (calcium carbonate). In cooperation with Ragn-Sells, GEALAN is researching a substitute material - and has found what it is looking for: In the future, the chalk will be extracted from the ashes of oil shale. The big advantage is that it binds and stores CO2 from industry and later from the atmosphere - and thus has a negative CO2 balance in a positive sense. The chalk from oil shale ash is to be produced in such a way that it will have the same quality as the raw material currently used in the future – and at the same time save emissions. 

Opportunities and challenges of development 

The initial situation: GEALAN needs around 10,000 tonnes of chalk for the production of 100,000 tonnes of plastic profiles. Normal chalk is a mineral and therefore has a low CO2 value, but is not neutral due to the manufacturing process and is based on a primary raw material. The use of recycled oil shale ash in combination with more sustainable production results in a climate-optimized product. 

To put this into perspective: For every ton of calcium carbonate that has been used so far and which is replaced by synthetic chalk, about one ton of CO2 is saved in the production process!  

Currently, a total of around 600 million tonnes of this oil shale ash are available - in Estonia a waste product from oil shale combustion for energy production. This additive does not produce any additional CO2, on the contrary: the industrial CO2 is recycled and GEALAN products are used as CO2 storage, so to speak.  

The big challenges: On the one hand, the ash brings impurities with it. On the other hand, the particles of the synthetic chalk must be just the right size to fit perfectly into the plastic mixture and thus ensure high quality for resilient, durable profiles.  

Project with Ragn-Sells 

GEALAN is a cooperation partner of Ragn-Sells throughout the entire process up to a possible market maturity – i.e. from conception to development, construction and industrialisation. The company has set itself the task of producing new raw materials from waste. Specifically, in this case, Ragn-Sells plans to produce CO2-negative chalk on an industrial scale. A first contact between GEALAN and the Estonian company was established back in 2019/2020.  

After an initial laboratory phase, the so-called pilot phase of the development process has begun: Here, the ash must be treated and dissolved so that the synthetic chalk is formed. In initial tests, quantities of around 100kg were used. At the same time, the work continues in the laboratory in cooperation with Münster University of Applied Sciences. The end result should be a recipe that proves to be of the best quality.   

Once this has been achieved, GEALAN buys larger quantities of the chalk produced from ash and continues to develop it with ragn-sells until the best raw material mix is available. The first prototypes with a new formulation will then be developed on demo systems. These prototypes are needed to test the mechanical properties, thermostability, colour properties and, above all, the weathering properties of the new synthetic chalk profiles. Such a demo plant is used for the development of the production plant and for small industrial quantities. Later on, much larger systems will be used here. Finally, once everything has been coordinated, the synthetic chalk is used for production.