In The Netherlands, 180.000 tons of toilet paper is flushed on a yearly basis and burned as waste. Using a special technique, KNN cellulose filters cellulose from the drain and processes it into Recell. Recell is currently applied in constructions, agriculture and chemical industries – as additive, raw material or end product. Omlab 3D-prints with a paste composed of the circular residues cellulose, Kaumera and calcite.
Transforming sewage water into printed stone
The printing material is made of:
- 60% calcium carbonate from water softening treatment by Aquaminerals
- 5% cellulose is screened during sewage treatment process
- 5% kaumera obtained during the Nereda sewage treatment process
- 30% water

Production process of the building elements
- The raw materials are mixed into a firm, clay-like paste, which is 3d-printed using an extrusion printhead.
- For printing the paste, it needs to be mixed and homogenized, this takes half an hour per half liter batch.
- The material is then printed (half an hour per liter).
- The material can receive post-treatment with calciumchlorate (5 minutes).
- Forced drying of the material, to harden the object, takes 1-2 days.
- The result is a breathing material that feels like stone or ceramic.

Applied
In the Exploded View during the Dutch Design Week 2020

Environmental impact
- No nature-unfriendly materials
- Completely made out of residual flows from water treatment that were previously largely burned
- The material is not baked, and therefore regenerable
Health
The material is breathable and has a positive impact on the indoor climate. The printed shape allows extra ventilation.
Growth opportunities
This product is still being developed and awaiting test results. For large-scale production, more people, (companies that operate) larger printers and co-investors are needed.
Physical building qualities
Curious about more detailed information? -> https://www.biobasedbouwen.nl/