Black is the new green

by Rebecca Priestley / 18 April, 2013
Turning waste biomass into carbon holds promise for tackling climate change.
A potato exploding in a microwave – a teenage cooking attempt – led Chris Turney to a discovery that could one day reduce carbon emissions. After 40 minutes in a microwave, Turney discovered, the potato is transformed into a piece of charcoal and the microwave is broken.

Photo/Thinkstock


Fast-forward two decades and Turney is a scientist and author (his 1912: The Year the World Discovered Antarctica was one of the Listener’s best books of 2012) and a technology based on his discovery is being commercialised by CarbonScape, a Marlborough clean-tech company led by Nick Gerritsen.

Turney’s climate research – he is climate change professor at the University of New South Wales – led him to wonder if microwaves could turn waste biomass into useful carbon-neutral carbon products. He approached Gerritsen through a family connection.

“When someone comes to me and says they almost blew something up and think they’ve invented something, it’s often a good indication there is novelty,” says Gerritsen. “We started to play around with microwave technology to see how we could turn low-value ubiquitous biomass like pine sawdust into high-value carbon products.”

In a pilot plant developed by CarbonScape, which Turney and Gerritsen co-founded with two colleagues, biomass is first fed into a dehydrator to remove volatile gases and bio-oils. A microwave cooks the dehydrated remains until it looks a little like Turney’s charcoaled potato. Gases and heat removed in the dehydration process are converted to electricity, making the plant self-sustaining.

“Our idea is not rocket science, in the sense that the whole idea is to speed up fossilisation,” says Gerritsen. These freshly “fossilised” products can then be used in place of fossil fuels, or put back into the ground as a way of storing, in an inert form, the carbon the plant extracted from the atmosphere during its growing life.

CarbonScape’s products so far include activated charcoal, a molecular sieve used in a variety of industrial and manufacturing processes, and biochar, a soil conditioning and carbon-sequestration product. The company is also confident it has produced graphene, a single-atom layer of carbon described by one of its 2010 Nobel Prize-winning discoverers as “the thinnest known material in the universe and the strongest ever measured”.

But it is green coke, a charcoal-like product comparable to coking coal, that is likely to be first to market. Late last year, CarbonScape’s green coke was named runner-up in a global clean-tech contest, and early this year, the company signed an agreement to supply the product to New Zealand Steel.

The green coke exceeds the steel-maker’s technical specifications and meets the market on price, says Gerritsen. It’s also a safer, more consistently high-quality product than coke derived from coal. So how is it going to reduce carbon emissions? Green coke is made from recycling atmospheric carbon through trees rather than withdrawing multimillion-year-old fossil carbon from the ground. Replacing fossil coke with green coke “reduces the overall carbon footprint of the steel facility by about 25%”, says Gerritsen.

But he doesn’t see green coke displacing coking coal in steel manufacturing anytime soon: to do so on a global scale would require about 20% of nature’s annual supply of waste biomass. The industry is so huge, though, that even becoming a significant niche player “is a mind-boggling business opportunity”.

CarbonScape now needs to raise $2 million to build a plant to provide the first test sample to New Zealand Steel. After that, the world awaits. l Green coke “reduces the overall carbon footprint of the steel facility by about 25%”.
MostReadArticlesCollectionWidget - Most Read - Used in articles
AdvertModule - Advert - M-Rec / Halfpage

Latest

The legacy of NZ’s departing environmental watchdog Jan Wright
81635 2017-10-18 00:00:00Z Environment

The legacy of NZ’s departing environmental watchdo…

by Rebecca Macfie

After 10 years as the country's environmental watchdog, Jan Wright is bowing out, having shaken up a lot of our complacency about being clean & green.

Read more
How Amazon's Australasian invasion will change the way we shop
81604 2017-10-17 00:00:00Z Business

How Amazon's Australasian invasion will change the…

by Mark Broatch

The global online sales giant is preparing to set up down under, and life for shoppers and retailers is about to change big-time.

Read more
Bird song or squawk? Why some birds sound flocking awful
81489 2017-10-17 00:00:00Z Life in NZ

Bird song or squawk? Why some birds sound flocking…

by Margo White

There's a bit of difference between a tui or kokako's call, compared to a mollymawk or shearwater. Just ask RNZ's Morning Report fans.

Read more
I came, I sawed, I conquered
81613 2017-10-16 16:51:07Z Life in NZ

I came, I sawed, I conquered

by Greg Dixon

Tree down! It’s time to pull on the fluorescent orange and crank up the chainsaw – one page at a time.

Read more
White Trash: The 400-Year Untold History of Class in America – book review
81586 2017-10-16 13:30:02Z Books

White Trash: The 400-Year Untold History of Class …

by Linda Herrick

The ultimate meritocracy was class-ridden from the get-go and Donald Trump exploited the fact.

Read more
NZME-Stuff media merger saga goes to court
81581 2017-10-16 12:54:33Z Business

NZME-Stuff media merger saga goes to court

by Colin Peacock

New Zealand's two biggest publishers of news go to court today to try to overturn the competition watchdog's refusal to green-light a merger.

Read more
The living hell experienced by Rohingya Muslims
81556 2017-10-16 11:02:05Z World

The living hell experienced by Rohingya Muslims

by Kate White

Kate White, a co-ordinator with Médecins Sans Frontières, describes daily life for Rohingya who have fled to Bangladesh - and how you can help.

Read more
Why some people get wheezy when peeling potatoes
81550 2017-10-16 10:31:13Z Nutrition

Why some people get wheezy when peeling potatoes

by Jennifer Bowden

As if living with hay fever isn’t enough, many people with oral allergy syndrome also react to certain foods.

Read more