Organic waste

Organic waste

OurCarbon

OurCarbon, a material produced by a San Francisco based company called Bioforcetech, is made of sewage sludge, known as biosolids, that have been transformed into a valuable carbon based pigment and material additive. This process starts by diverting organic material destined for landfill like food waste and biosolids from their unsustainable end of life. Had they gone to landfill, these organics would break down and form methane, a powerful greenhouse gas contributing to climate change.

Once diverted, the organics are directed to Bioforcetech’s technology where they are dried with help from thermophilic bacteria and put through a process where they are heated in the absence of oxygen, called pyrolysis. Working together, these two technologies generate the energy required to run them, making the whole process energy neutral. Now transformed into OurCarbon, the carbon molecules in the organics are bonded together, preventing them from breaking down and emitting for thousands of years.

The locked carbon material is utilised as a pigment to colour paints, 3d print filament, wood stains, and even screenprinting ink. In fact, OurCarbon has just been added to a new 80% bio based screen printing ink by Virus Inks that is already commercially available. Another new fashion application for OurCarbon is a beautiful grey textile dye, and when added to glass in a kiln the material leaves behind a coral-coloured iron oxide pigment. As a material additive, OurCarbon is featured in a bio based resin, concrete, and even porcelain.

Each of these applications are not just beautiful, they replace carbon intensive equivalents like carbon black pigment, mined and shipped concrete aggregates, harmful azo dyes used by the fashion industry, or synthetic fertilisers. For every ton of OurCarbon produced from biosolids that have been diverted from landfill, they prevent 10 tons of CO2e from entering our atmosphere (that's about the same as taking two cars off the road for an entire year). With each of Bioforcetech's installations producing over a ton of OurCarbon a day, this new supply chain has the potential to make a big impact.

Additional information

OurCarbon is transformed from biosolids into biochar in two steps, both which leverage the energy within the biosolids itself. Because biosolids are a very wet material, it must first be dried which can take a lot of energy. Normally this is done in a belt, drum, or paddle dryer that burns external fuel to create heat that dries the biosolids as small amounts of the material moves through the machine continuously. Water is not easy to evaporate, making this a really big energy load on waste treatment plants.

Bioforcetech's BioDryer takes a much more sustainable approach. Rather than use external energy like fossil fuels, we leverage bacteria to create heat. The BioDryer passes warm air through a batch of biosolids to cultivate thermophilic bacteria, bacteria that thrive in hot environments. As these bacteria grow and multiply, they release heat energy that evaporates the water around them, drying the biosolids. This works for almost the entire drying process. At the end, when there is not enough water for the bacteria to continue to flourish, we introduce heat energy from the second step of our process to finish the job. The process receives biosolids at only around 20% solids content, known to the biosolids industry as 'cake' for its cake batter or mud consistency. Despite being 80% water, the BioDryer can dry 8 tons of this biosolids 'cake' using little to no external energy per batch.

Now that the biosolids are dry, it can be transformed into OurCarbon. This is where the P-Series Pyrolysis process comes into play. Pyrolysis, the process that transforms organics into biochar, is the heating of an organic material in the complete absences of oxygen. Organics like biosolids are carbon based, which is why they normally break down and bond to oxygen, creating CO2 which in turn warms the planet. When you heat these organics without oxygen, something completely different happens. Almost all of the carbon cannot bond to anything in the reactor of the P-Series Pyrolysis, causing it to bond to itself in strong carbon bonds. These bonds are what form the black carbon colour in OurCarbon, and they cannot be broken for thousands of years. The other small amount of carbon molecules left bond to the hydrogen present in the reactor chamber, forming a burnable gas called 'syngas' that is utilised to power the system. By combusting the syngas right away and sending the heat to circulate around the chamber where biosolids are moving, the machine keeps the process going without having the flame ever actually hit the biosolids. This gives Bioforcetech a lot of control on the quality of the process and the OurCarbon that comes out of the machine. The specific temperature and residence time that the process uses also destroys 'forever chemicals' like PFAS and PFOA, pharmaceuticals, microplastics, and more, turning a notoriously 'dirty waste' into a valuable asset. The whole system can run on the energy it creates indefinitely, and any excess heat that the P-Series unit produces is sent back to the BioDryers to make them even more efficient. The only output is clean, carbon-fixed OurCarbon.

Ingredients

Organic waste material

Maker

OurCarbon

References

OurCarbon™ (Video)
bioforcetech reveals OurCarbon, a pigment made from sewage sludge (Article)
This is how OurCarbon turns sewage sludge into a carbon-negative material (Article)

Credits

Bioforcetech