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Friday, 20 January 2012

Fuel out of Thin Air – Science Fiction or Carbon-Neutral Future?

An Old Lodger

Nowadays even toddlers know carbon dioxide (CO2). Open a newspaper and you can’t help falling over it. As an Earth dweller it has ancient rights. Scientists reckon it arrived here with comets and other celestial bodies that ploughed into our young planet.

It has had some bad press lately but to see it only in a negative light is unfair, dangerous even. CO2 has many uses. For a start it helped to stabilise a liveable atmosphere at a time when things were too toxic for anything but a few algae. Plants could not survive without it, and neither could anything that depends on them, which includes us. Dough rises because of CO2, it is used to decaffeinate coffee and can extinguish fires. It being a normal component of human blood, too low a concentration is even harmful.


Hold It

Of course, there is always too much of a good thing. Excessive indulgence leaves headaches and CO2 is no exception. According to the American National Oceanic and Atmospheric Administration the level in air has increased by 40% since the beginning of the Industrial Revolution. As it is a greenhouse gas and contributes to the warming of the Earth’s atmosphere this is serious.

Plants and oceans form a natural sponge that absorbs part of it but constant release of the gas by manmade processes exceeds their capacity. Carbon capture and the increased burning of fuels that store as much as they produce at the point of use are hailed, therefore, to be the way to go into an environmentally safer future.

So what if you could do all that with CO2 itself – take it out of the atmosphere, convert it to a resource, store it and reduce greenhouse gas levels or use it as a carbon-neutral fuel? Pulling something out of thin air sounds like a magic trick but is exactly what some scientists, businesses and entrepreneurs are proposing.

CO2 to Fuel – It’s Nothing New

The basis is a principle that has been around for about 3.5 billion years. Photosynthesis combines CO2 with hydrogen to make carriers of energy. These are hydrocarbons, an important term, as it is the same that covers the substances in crude oil, natural gas and fossil fuels. Only, whereas plants burn sugars it is petrol, diesel and kerosene that we have been using to satisfy our demands for power, mobility, comfort and affluence.

Once it was realised how harmful an increased concentration of that gas was, the question arose what to do? As David Biello quotes Andrew Bocarsly of Princeton University: “The dominant thinking 10 years ago was that we should bury the CO2. … If you could efficiently convert CO2 into something that was useful you wouldn’t have to spend all that money and energy to put it into the ground. You could sort of recycle it.” Imagine that, renewable petrol or carbon capture in form of reversed combustion with oil from exhaust gases stored back where it came from!

Tough Cookie

The only problem is CO2 and water are very stable. For most methods both need to be split to create carbon monoxide (CO) and hydrogen. This gobbles up large amounts of energy, which has been a problem until quite recently. It means that the gas-to-liquid process is often very inefficient and, consequently, expensive.

Many Recipes - Same Goal

The necessity of substantial energy input has not changed, of course, but science and engineering have moved on. Putting in large amounts of energy derived from fossil sources or nuclear fission would not make sense to those for whom carbon-neutral has to mean renewable as well. Increasing availability of power from solar installations, hydro-generation, wind and others makes a truly clean conversion of CO2 possible at last. One should not forget that for this purpose we won’t have to rely on the grid. Microgeneration will make it feasible for facilities to produce and control their own energy.

The best bit is that it is possible already to a degree to choose the kind of desired end result. Hydrocarbons come in many forms and are ultimately present in a wide variety from lubricants to jet fuel. The most successful approach will be to create drop-in products that can be used in different applications without much conversion.

Solar power

Several teams are working on the basis of harnessing the sun’s power. Among them are teams at the University of Messina, Italy; the University of Bath, Britain and Princeton University as well as Sandia Research Laboratories, America. All of them are saying that the large scale technologies needed to convert masses of CO2 are not yet available but progress is being made.

One area where efficiencies have been increased significantly are the collector panels and the ways in which they are deployed. In some cases they generate heat, which is then used directly to cause the required reactions. Other set-ups use photovoltaic installations, as electricity can be utilised for the same purpose.

So far the most successful outcomes have been methanol and butanol. These can then be used as fuels or basic building blocks for more complex hydrocarbons.


A different approach is to let those do the hard work that have become used to it over millions of years. At the University of California in Los Angeles research with genetically modified cyanobacteria was very positive. As these organisms use sunlight it would be a crafty way to employ solar power for making the desired substances. Other approaches include extremophiles that have been found near deep sea vents and need to achieve the same feat without the help of the sun, or bacteria that produce methane from CO2 as a pre-stage, which can then be turned into oil or fuel.

Carbon Sciences, in Santa Barbara, California, have developed a process to combine CO2 and methane (CH4). While their website talks of natural gas as a source, both are available in abundance because of microbial activity, for example, from landfill sites. The actual clever bit, so the company claims, are specially developed catalysts from common metals that allow the direct interaction between the two components.

The Entrepreneur’s Chemistry Set

Professor Tony Marmont is as unassuming as he is successful and energetic. I first heard him speak at the 2011 European Bioenergy Expo and Conference (EBEC) and it was he who stoked my interest in the idea of capturing a greenhouse gas and recycling it. A self-made millionaire who has set himself the goal of pushing renewable energy out of the recesses of laboratories into public awareness, he is chairman of Air Fuel Synthesis Ltd. (AFS), based in Darlington, Britain.

The company proposes another method, that of using sodium hydroxide. In a tower it is mixed with air, where it reacts with, and extracts, CO2 to form sodium carbonate. This is an interim stage from which CO2 can be released again using an electric current. Water (which could be obtained from the same air) is split to get hydrogen ions. Now the two elements can be combined into hydrocarbons.

CO2 + Sodium makes fuel

Professor Marmont sees one of the more promising uses in making aircraft fuels and stresses the independence from sources that are far away, in potentially politically unstable regions and require the materials to be transported over long distances. At this stage demonstrator units are about to be tested but hopes are high to achieve commercially viable cost-benefit ratios. With biofuels being only a partial solution to aviation's woes, CO2-to-fuel could be the answer.

A Long Way to Go

Capturing CO2 and using it in the ways described is one of the most exciting developments in renewable energy. It has a host of benefits:

  • Reducing greenhouse gases
  • Energy storage
  • Carbon-neutral fuels and base materials
  • Cheap basic components
  • Unlimited availability
  • Local or regional sourcing
    • with independence from potentially unreliable sources
    • no risk of being held to ransom
    • independence, affordable fuel and development potential for poor areas
  • Flexibility of use and further processing
  • No competition with food production over scarce land

I am sure I have forgotten some and we should not overlook that fossil oils are more than just the basis for fuel. They are used widely in pharmaceuticals, cosmetics and many other materials like plastics. Right now the consensus seems to be that the capacities and technologies are not ready for large-scale production of renewable oil as a substitute for its fossil equivalent. Often efficiencies, especially, are still way off the mark. The other question is, if we want to churn out these vast quantities, where can they be stored? Tony Marmont proposes to pump it back into old empty wells. It is an intriguing idea but no less fraught with potential environmental risks as pumping it out.

Nevertheless, it is not too good to be true but too good to be left struggling to get on its feet. We are talking about needless transport miles, greenhouse gases, fuel and food shortages, and pollution all the time. Here is a concept that can really solve several problems at once, among them political ones. It is time this receives broader recognition and support, and politicians should wise up double quick.

Why, then, should it concern us as end-users if it is so difficult even for the specialists? Because, if crude oil runs out, we will lose a lot more than just a can of petrol.

See you next week




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our next fuel will come from science fiction, think out side the box. but what do i know im a dreamer

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