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Turn over a new leaf for using CO2

Carbon dioxide is bad. That’s the common thread in public discourse. We’re constantly told of the need to reduce the amount of CO2 in the atmosphere and that it’s destroying the planet.

Of course the reality is that carbon dioxide is a key part of the natural cycle of energy and vital to the survival of all life on this planet. It also has a wide range of commercial uses. So should we see CO2 as more of a resource than a problem?

Our supplies of the gas are set to increase massively as carbon-capture power plants become a reality, and scientists and industry are increasingly looking for new ways to use and hopefully monetise it.

Carbon dioxide is already used in food preparation and preservation, in drug and chemical processing, in water treatment, welding and pneumatics. None of these applications will soak up all the CO2 we’re going to produce in the next fifty years, though at least CCS power stations could become more cost-effective if they sell the gas on.

But what if we could develop a use for carbon dioxides that actually helped the climate change cause and made a big impact on greenhouse gas emissions?

Injecting CO2 into oil wells as they dry up keeps it out of the atmosphere but also helps get more oil out, meaning we have more fossil fuels to burn and even more CO2 to deal with.

A different idea, as highlighted in our recent feature, is to mineralise CO2 to create products for use in the construction and food industries. If we can make it economical and energy efficient, we could even take the waste materials of existing cement-making processes – ash and carbon dioxide – and combine them to make a stronger form of cement.

Nature, as so often is the case, could also provide a solution ­– photosynthesis. It gives plants their own wonderful use for CO2, but unless we literally go back to living in forests by covering the whole world in trees, there’s really only so much they can do for us.

Instead, some scientists are hoping to deliver an artificial version of photosynthesis that effectively turns carbon dioxide into an energy storage medium. If we can efficiently use sunlight to power the reaction, we can transform the pesky gas (and water) into usable fuels.

Of course, we are already turning plants into fuel with serious consequences for food prices. Around 40 per cent of corn grown in the US is now used to make ethanol instead of feeding humans and animals, according to the Department of Agriculture.

Photosynthesising algae could provide one alternative to this. Another idea is to do the energy conversion ourselves. Scientists at MIT have already developed a ‘practical artificial leaf’ that uses solar energy and inexpensive catalysts to produce hydrogen from water with efficiencies much greater than those of real leaves.

Find a way of efficiently adding carbon dioxide to this artificial process and we could create biofuels to use in our existing fuel infrastructure without the need to rely on growing plants (and impacting food production).

Though all these ideas are still at the laboratory stage, the business world is taking notice. Spanish research institute MATGAS, which is majority-owned by industrial gas company Air Products, is coming to the end of a €26m project examining these very ideas.

Speaking this week at MATGAS’s tenth anniversary conference, institute director Dr Lourdes Vega said the challenge was now to move the concepts to market and the biggest areas of potential were increased use of water pH treatment, new materials and bio-energy.

Alongside the technology issue, however, cost remains a major problem. Some fear that without a global carbon pricing system or a major rise in oil prices, using CO2 to produce fuels won’t be economically attractive for most companies.

Vega admitted that the size of the market for carbon dioxide still wasn’t clear, and that industrial uses wouldn’t provide an alternative to reducing emissions or storing them in large quantities.

‘The amount of CO2 emitted two to three years ago was 25 gigatonnes and the amount used for all industrial applications was 125 megatonnes,’ she said.

‘But there is room for everything. If you use different sources of energy you will have less CO2 in the atmosphere. If you find ways to use CO2 you are converting a residue into a resource with added value.’

Readers' comments (8)

  • CO2 is also very useful as the coolant in Magnox and AGR nuclear power plants.

    That's what I call killing two birds with one stone - a method of power generation that not only emits no CO2 but also uses it in the process!

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  • What we need to be clear about here is that it is only permanent sequestration of CO2 that will be effective in limiting CO2 in the atmoshpere. Making things out of it would be OK from a financial viewpoint but it is what happens to the carbon in the long term that is the important point, surely.

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  • I met the MD of Carbon Sequestration Ltd recently - they are doing this already The TSB funded work on this over the last year and this is not new at all to the UK.

    The UK need this approach working alongside Carbon Capture, Transport and Storage - CCTS as it really should be called!

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  • And what of methane, N2O, and ozone? Much of what is being done to curb CO2, ends up increasing methane and N2O emissions. Methane is 28X worse than CO2 as a GW gas, and N20 is 296X worse. 3% of the fertilizer used to grow corn for ethanol is emitted as N2O. Ethanol significantly increases ozone emissions. Methane and coal are the most used to run the ethanol processing.

    While you focus on the good gas, the other gases are getting out of control.

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  • Has anyone checked the cost/benefits of watering the worlds deserts before we spend billions on dodgy carbon capture schemes, and billions in aid to the people living in these areas.

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  • I agree with randydutton, I think that focussing on CO2 takes the focus off methane, NOx, and chlorine which is believed to survive in the atmosphere for over 300 years. Where's strong government when you need it? Yes, there's a lot of fancy talk, but not a lot of real action, just targets. Stop landfilling food waste and other putrescibles, drastically improve public transport and cease production of PVC and bleaching paper and we are half way there!

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  • A Brief History of Agricultural Time

    Our farming for over 10,000 years has been responsible for 2/3rds of our excess greenhouse gases. This soil carbon, converted to carbon dioxide, methane and nitrous oxide began a slow stable warming that now accelerates with burning of fossil fuel. The unintended consequence has been the flowering of our civilization. Our science has now realized the consequences and developed a more encompassing wisdom.

    Modern Agriculture has evolved in the ability to remove the limitations to plant growth, from burning forest for ash fertilizers, to bison bones, to Guano islands, then in 1913, to crafty Germans figuring out how to suck nitrogen from the air to now with natural gas derived fertilizers. These chemical fertilizers have over come nutrient limits to growth for 100 years.

    NPK and the "Green Revolution" in genetics have brought us to where we are, all made possible by basically mining soil carbon stocks. So we have now hit a carbon limit in two distinct ways. The first is continued loss of soil carbon content, the second is fossil carbon energy cost. The present farming system spends ten cents of fossil energy delivering one cent of food energy.

    We can not go back, but we can go forward with our newly acquired wisdom. Wise land management, Conservation Agriculture and afforestation can build back our soil carbon, Biochar allows the soil food web to build much more recalcitrant organic carbon, (living biomass & Glomalins) in addition to the carbon in the biochar.

    We can rectify the carbon cycle, and beyond that, biochar systems serve the same healing function for the nitrogen and phosphorous cycles, toxicity in soils and sediments and as a feed additive cut the carbon foot print of livestock by 50%.

    Recent NATURE STUDY;
    Sustainable bio char to mitigate global climate change

    Proceedings of the National Academy of Sciences
    Reducing abrupt climate change risk using
    the Montreal Protocol and other regulatory
    actions to complement cuts in CO2 emissions

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  • We first proposed CO2 Energy Storage in the Conoco Phillips Energy Prize competition in 2008. As the inventor of CO2 Energy Storage and recovery their are several comments that apply in the article. Energy storage is most likely the very best and most economical use of sequestered CO2 because it will pay for the associated expense and empower renewable energy sources. Energy Storage delivers massive long term benefits as follows
    :: serving as an "electricity reserve" much like the Petroleum Reserve in the US.
    :: stabilizing electricity markets
    :: stabilizing the transmission and distribution grid
    :: enabling more efficient use of existing generation assets
    :: most importantly, making renewable energy economically viable, and capable of energy on demand operation.

    We do take issue with the idea that civilization is an accident, despite appearances to the contrary. If we can not clean the Coal power plants up then we must shut them down.

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