Updated: Feb 22, 2022
We were standing in the shade of a large maple at a neighbour’s backyard party a couple of summers ago. Their daughter Emily was tossing one of those florescent green tennis balls from hand to hand when she stopped and said, “did you know that if Earth was the size of this ball, its atmosphere would only be as deep as the fuzz?”
Climate scientists agree that rapidly implementing technologies capable of capturing carbon dioxide out of the atmosphere may be a useful strategy for helping to protect the planet from the increasing effects of climate change.
Here’s some good news for Emily’s tennis ball.
Gravitas Carbotura, an environmentally focused start-up based in Florida has embarked upon an ambitious, if somewhat speculative project to turn massive quantities of hydroponically grown hemp into high-value commodities like graphene and industrial-grade diamonds.
Each of Carbotura’s so-called high-density bio-factories is projected to house up to 38 million plants and capture and sequester in the range of 100-350 tons of carbon per day.
Picture huge multi-storied warehouse factories stacked with hydroponic trays seeded with hemp. As the plants grow and photosynthesize, carbon dioxide is pulled out of the air in a process Carbotura is calling Direct Air Carbon Sequestration.
Additionally, a proposed irrigation system would use hazardous wastewater from nearby phosphate mines to greatly accelerate the hemp’s growth rate by cycling hundreds of litres of water through the system every few hours. After about a week, the previously contaminated water would be clean enough to return to local waterways.
About 600,000 plants are expected to be harvested every day. In a closed-loop, zero-waste process, the carbon-rich biomass gets fed into a hi-tech industrial furnace called a microwave plasma pyrolysis system. At the rate of a thousand kilograms an hour, the hemp is converted into fuel used to power the operation.
At the end of the combustion cycle, a product called biochar remains. Biochar can be processed into Bio-Graphene, which Carbotura claims, will be the highest purity and lowest cost graphene available. Graphene, a recently discovered wonder material at just one atom thick is 200 times stronger than steel and an excellent conductor of heat and electricity.
A second potential biochar conversion process would create industrial grade diamonds. The process involves subjecting microscopic fragments of diamond to a high-pressure carbon-rich atmosphere. Layer by layer, carbon gradually accretes onto the fragments resulting in industrial-grade diamonds suitable for use in a wide range of applications.
Carbotura’s longer range plan is to develop other microwave plasma pyrolysis systems for processing waste materials like garbage and plastic and turning these into high-value products as well.
With an unlimited supply of hemp and waste materials to feed these closed-loop systems, it is expected there will be little negative impact on neighbouring ecosystems.
The Direct Carbon Sequestration System has won Selected Project status with the US Department of Energy, and Carbotura is in the process of securing funding for the first round of construction in South-West Florida. To learn more about the world's first carbon-negative green bond, visit the company’s LinkedIn page.
Emily looks at a tennis ball and sees a planet in crisis. She is aware in a way her parents never were that she’s living in a very narrow space under the sky. Yet as ambitious as Carbotura’s carbon sequestration plans are, they remain tiny relative to the size of the challenge the planet faces. Nevertheless, big ideas like this will be needed on a global scale if the work of removing billions of tons of carbon dioxide from the atmosphere can succeed.
Just Have a Think
Hemp conversion to graphene and diamond. Smart carbon capture?
Direct Air Carbon Sequestration From the "Hot Planet Repair Team"