Can spent yeast from beer brewing be used to replace fossil-based raw material in adhesives? This is being investigated in the Reflows project, which uses waste yeast from breweries to produce adhesives adapted for wood and paper applications in a circular way.
To reduce climate impact and the depletion of the Earth's resources, we need to switch to more sustainable materials. Material transition is about replacing resource-intensive materials with more sustainable alternatives. It can be about the raw materials, moving from using a finite resource, such as oil, to a renewable raw material, such as wood. It can also be about switching to circular production processes, i.e. we try to reuse and recycle the materials already in circulation as raw materials for new materials and products. The construction sector uses a lot of glued wood products, such as chipboard, plywood, glulam beams and cross-laminated timber. The glues used today are almost exclusively fossil-based. The smaller of the two Swedish chipboard factories currently uses around 4,000 tons of fossil-based glue per year.
Protein glue, a new idea
Glued wood products were manufactured long before crude oil was available. Often with protein-based adhesives that had very good properties. One example is the glulam beams that support the roof of Stockholm Central Station, which were manufactured almost 100 years ago and still serve their purpose today. They are glued with casein glue, an adhesive produced from milk protein. Another bio-based alternative available on the market today is starch-based adhesives, which are used in the manufacture of corrugated cardboard, for example. Starch-based adhesives have also started to be used in the production of chipboard. Since starch can also be used as food for humans and animals, it is relevant to also look at other alternatives. Starting from an available resource, such as spent yeast, saves both energy and fossil-based raw materials without using additional land and water resources. For some time, RISE has been exploring the potential of using yeast protein from spent yeast as a raw material and has seen promising results both for glued wood products, such as plywood and chipboard, but also for corrugated cardboard. This is now being further developed in the Reflows project where spent yeast is used for the first time in a value chain for the production of new bio-based products.
- Spent yeast is a protein-rich waste stream that is continuously generated in our beer brewing process. It has traditionally gone to farmers where it has been used as pig feed or as a soil improver, but in this research project we are investigating whether there are also other uses. In the best case, we can link an entire value chain where glue is created from our yeast, which can then be used for our packaging," says Raimo Liikamaa, operations manager for the beer process at Spendrups Brewery in Grängesberg.
Yeast raw material is also generated from other fermentation processes, such as in wine production and in biorefineries. The amount of yeast raw material available in the world is thus very large and the potential for large-scale production of bio-based adhesives and other products is therefore good.
- Being able to use an existing residual product as a raw material to produce new products in demand seems urgent. We therefore want to develop an alternative to today's fossil-based and more resource-intensive adhesives based on spent yeast. The project is a first step, but in an extension it is also interesting to look at how the water in the residual stream can be utilized and whether the extracted protein can be suitable as feed. This is an extremely exciting project," says Marielle Henriksson, project manager and researcher at RISE.
It seems that the time is now ripe and the wood panel industry is ready to explore the possibilities of yeast protein. - Byggelit has always used wood raw material from Norrland forests, which we know is of high quality and as pure as possible. The development of the entire board industry has been at a standstill for several years and Byggelit sees the project as part of the new growth journey. We want to drive innovative solutions with the environment in the driver's seat where we see the customer benefit in the short and long term, says Kent Ögren, environmental / quality manager at Byggelit.
This is an article from our magazine Trävärden, view it here! (Link)
ABOUT THE PROJECT
The Reflows project connects for the first time research on the extraction of end-of-life yeast and bio-based adhesives at RISE with residual stream producers and need owners such as recycling companies, adhesive manufacturers and the packaging and wood processing industry, to strengthen the resilience of the value network. Participants in the project are Spendrups, Ragn-Sells, Akzo Nobel Adhesives, Byggelit Sweden, DS Smith Packaging Sweden and RISE Research Institutes of Sweden. The work has been carried out within the Strategic Innovation Program BioInnovation - a joint effort by Vinnova, Formas and the Swedish Energy Agency.
