Could the humble sea urchin hold the key to carbon capture?

Feb 04, 2013

A chance discovery that sea urchins use Nickel ions to harness carbon dioxide from the sea to grow their exoskeleton could be the key to capturing tonnes of CO2 from the atmosphere.

Experts at Newcastle University, UK, have discovered that in the presence of a Nickel catalyst, CO2 can be converted rapidly and cheaply into the harmless, , calcium or magnesium carbonate. This discovery, which is published today in the academic journal Catalysis Science & Technology, has the potential to revolutionise the way we capture and store carbon enabling us to significantly reduce CO2 emissions – the key greenhouse gas responsible for climate change.

Dr Lidija Šiller, a physicist and Reader in Nanoscale Technology at Newcastle University, says the discovery was made completely by chance. "We had set out to understand in detail the carbonic acid reaction – which is what happens when CO2 reacts with water – and needed a catalyst to speed up the process," she explains.

"At the same time, I was looking at how organisms absorb CO2 into their skeletons and in particular the sea urchin which converts the CO2 to calcium carbonate. "When we analysed the surface of the urchin larvae we found a high concentration of Nickel on their . Taking Nickel nanoparticles which have a large surface area, we added them to our carbonic acid test and the result was the complete removal of CO2."

At the moment, pilot studies for Carbon Capture and Storage (CCS) systems propose the removal of CO2 by pumping it into holes deep underground. However, this is a costly and difficult process and carries with it a long term risk of the gas leaking back out - possibly many miles away from the original downward source.

An alternative solution is to convert the CO2 into calcium or magnesium carbonate. "One way to do this is to use an enzyme called carbonic anhydrase," explains Gaurav Bhaduri, lead author on the paper and a PhD student in the University's School of Chemical Engineering and Advanced Materials.

"However, the enzyme is inactive in acid conditions and since one of the products of the reaction is , this means the enzyme is only effective for a very short time and also makes the process very expensive. "The beauty of a is that it carries on working regardless of the pH and because of its magnetic properties it can be re-captured and re-used time and time again. It's also very cheap – 1,000 times cheaper than the enzyme. And the by-product – the carbonate – is useful and not damaging to the environment.

"What our discovery offers is a real opportunity for industries such as power stations and chemical processing plants to capture all their waste CO2 before it ever reaches the and store it as a safe, stable and useful product." Each year, humans emit on average 33.4 billion metric tons of CO2 - around 45% of which remains in the atmosphere. Typically, a petrol-driven car will produce a ton of CO2 every 4,000 miles.

Calcium carbonate, or chalk, makes up around 4% of the Earth's crust and acts as a carbon reservoir, estimated to be equivalent to 1.5 million billion metric tons of .

It is the main component of shells of marine organisms, snails, pearls, and eggshells and is a completely stable mineral, widely used in the building industry to make cement and other materials and also in hospitals to make plaster casts.

The process developed by the Newcastle team involves passing the waste gas directly from the chimney top, through a water column rich in Nickel nano-particles and recovering the solid calcium carbonate from the bottom.

Dr Šiller adds: "The capture and removal of CO2 from our atmosphere is one of the most pressing dilemmas of our time.

"Our process would not work in every situation – it couldn't be fitted to the back of a car, for example – but it is an effective, cheap solution that could be available world-wide to some of our most polluting industries and have a significant impact on the reduction of atmospheric ."

The team have patented the process and are now looking for an investor to take it forward.

Explore further: Marine pest provides advances in maritime anti-fouling and biomedicine

More information: "Nickel nanoparticles catalyse reversible hydration of carbon dioxide for mineralisation carbon capture and storage" Gaurav Bhaduri and Lidija Šiller. Catalysis Science & Technology, Royal Society of Chemistry. February 2013. DOI: 10.1039/c3cy20791a

Related Stories

New model suggests ocean pH falling more rapidly

Jun 15, 2012

(Phys.org) -- A new computer model developed in Switzerland shows that the pH of the ocean waters off the west coast of the US will fall over the next four decades faster than previously thought. The region ...

Pulverized rocks used to strip CO2 from large emitting plants

Dec 06, 2012

Researchers in Quebec are developing a process that would see steel, coal and cement plants as well as oil and gas facilities remove most of the carbon dioxide (CO2) from their emissions through chemical reactions with various ...

Red mud's carbon capture clue

Feb 29, 2012

(PhysOrg.com) -- An environmental disaster that occurred in Hungary in 2010 could lead to a new way of removing carbon dioxide emissions from the atmosphere.

Recommended for you

Nature inspires a greener way to make colorful plastics

19 hours ago

Long before humans figured out how to create colors, nature had already perfected the process—think stunning, bright butterfly wings of many different hues, for example. Now scientists are tapping into ...

New catalyst converts carbon dioxide to fuel

20 hours ago

Scientists from the University of Illinois at Chicago have synthesized a catalyst that improves their system for converting waste carbon dioxide into syngas, a precursor of gasoline and other energy-rich products, bringing ...

Building the ideal rest stop for protons

Jul 29, 2014

Where protons, or positive charges, decide to rest makes the difference between proceeding towards ammonia (NH3) production or not, according to scientists at Pacific Northwest National Laboratory (PNNL) and ...

Cagey material acts as alcohol factory

Jul 29, 2014

Some chemical conversions are harder than others. Refining natural gas into an easy-to-transport, easy-to-store liquid alcohol has so far been a logistic and economic challenge. But now, a new material, designed ...

User comments : 4

Adjust slider to filter visible comments by rank

Display comments: newest first

winthrom
5 / 5 (3) Feb 05, 2013
Where does the calcium come from?
JRi
not rated yet Feb 05, 2013
Calcium in water is in the form of Ca(OH)2 and CaSO4, in addition to Ca2 and CaOH , so at least the first one can release water if reacted with carbonic acid.
antialias_physorg
2.3 / 5 (3) Feb 05, 2013
At the moment, pilot studies for Carbon Capture and Storage (CCS) systems propose the removal of CO2 by pumping it into holes deep underground. However, this is a costly and difficult process and carries with it a long term risk of the gas leaking back out - possibly many miles away from the original downward source.

If I was in the 'carbon sequestering business' that's what I'd do: Pump it down, get paid by the cubic meter I 'sequester' and engineer a leak somewhere where it can escape undetected. Voila: infinite storage space (you can always 'blame' your increased storage space on carbon dissolving into rocks or groundwater or make up some PR babble about larger than expected compression ability...or just lie about your intial storage capacity. No one is going to check)
JRi
not rated yet Feb 05, 2013
PhysOrg seems to remove plus-signs from comments for some reason. Ca2 means Ca2plus and CaOH means CaOHplus