STACKS

From potato starch to ecological building materials

From a lot of agricultural crops used in the food industry, considerable amounts of starchy residues still flow. In potato production, for example, about half of the potatoes grown do not reach consumers. Moreover, the processing of suitable potatoes inevitably produces a lot of starchy residues. These are often simply fermented. 

With the STACKS project, UC Leuven wants to investigate whether these residual flows are suitable for the development of building materials, in order to reuse them in a high-quality manner in the construction sector. 

Specifically, in this project we used starchy residue streams from Agristo and Dossche Mills to develop a new bio-ecological material with suitable physical and mechanical properties. We focused on how to manufacture building blocks and decorative wall tiles from that material. Product designer Nathan Vrebos also contributed, confirming the material's wide applicability by creating various interior items with it.

MOST IMPORTANT
RESULTS

1. We succeeded in making bio-ecological building blocks and wall tiles based on potato and grain residue streams. We developed a solid basic material, which can be further researched and optimised. 
2. Our robust, bio-ecological building bricks are workable and frost-resistant. The developed tiles have high impact strength and can therefore serve as decorative wall tiles. 
3. Over the course of the project, we significantly improved the water resistance of the material by applying an impregnating coating. 
4. In collaboration with product designer Nathan Vrebos, our new material was used to create several design interior objects. For example, a stool, table and panel were successfully created.

MOST IMPORTANT
LESSONS LEARNED

1. Over the course of the project, we designed a range of interesting base materials. Further development, scale-up and communication with relevant partners within the construction industry is still needed. The development of such products is a lengthy process. 
2. The maximum compressive strengths of our building blocks are almost identical to existing building materials. An important advantage is that our production process emits less CO2. However, to fully assess the commercial feasibility, we still lack additional analyses (economic analysis, LCA ...). 
3. It was not always obvious to reach the right partners or producers within the construction sector. We will put even more effort into this during the continuation of this project.

15 MPa maximum compressive strength

WHAT DOES
THE FUTURE HOLD?

This research will continue for another two years through a grant obtained from PWO (project-based scientific research). The production process is currently carried out at lab scale. With MEAM as a partner, we can look at how to scale up the process further. Furthermore, we want to make the production process even less energy-intensive. Additional tests on recycling, biodegradation and compostability are also included. 

Finally, we want to focus more on communication, so that the right partners and stakeholders from the building sector get to know our developed materials better. We will continue to valorise the expertise on circular economy and the development of circular materials in the university college.