Published October 25, 2012
By Jeff Cobb
In medieval days alchemists sought to turn ordinary metals to gold – an element so alluring and valuable that it has been a most prized possession, and even started wars. Today, gold is still with us as is a dwindling world supply of petroleum – which some would contend ranks equally high if not higher in economic importance.
As the world contemplates electrified and other alternatives to its 100-plus-year love affair with fossil fuels, longingly looking back to good-old-days that are still playing out, people keep trying to replace gasoline and diesel with other fuels to burn, including bio-sourced, and other synthetic fuels. Now, like those practicing modern day alchemy, scientists at a UK company called Air Fuel Synthesis say they can create petrol from thin air.
And while our opener is a goad to the skeptics to say “yeah I’ll believe it when I see it” – and rightfully so – the UK researchers have been inundated with media requests for its AFS process using a technique it calls “air capture” technology to synthesize fuel from carbon dioxide extracted from the atmosphere.
The fuel is said to be carbon neutral when electricity used to produce it comes from renewable sources. It works in existing internal combustion engines, and – encouraged by an initial five liters produced in less than three months by a small apparatus – the company is expanding on a $1.1-million GB pound ($1.8 million) project that it says has demonstrated its concept.
This month, the AFS process was shown off at an engineering conference in London, and next up are reportedly plans to produce a ton of the fuel per day within two years, and a complete refinery churning out much greater quantities within 15 years.
How it works
In brief, the AFS process mixes sodium hydroxide with carbon dioxide before subjecting the sodium carbonate produced in this swirl to electricity. The result is pure carbon dioxide.
Meanwhile hydrogen is produced by electrolyzing water vapor that is captured by a dehumidifier.
Next, the process uses the carbon dioxide and hydrogen to produce methanol and this is then passed through a gasoline fuel reactor, and out comes petrol.
Air Fuel Synthesis says it knows the process appears “too good to be true,” but is stone cold sober as it describes in finer detail its process of extracting fuel from the air we breathe:
i) Air is blown up into a tower and meets a mist of a sodium hydroxide solution. The carbon dioxide in the air is absorbed by reaction with some of the sodium hydroxide to form sodium carbonate. Whilst there are advances in CO2 capture technology, sodium hydroxide has been chosen as it is proven and market ready.
ii) The sodium hydroxide/carbonate solution that results from Step 1 is pumped into an electrolysis cell through which an electric current is passed. The electricity results in the release of the carbon dioxide which is collected and stored for subsequent reaction.
iii) Optionally, a dehumidifier condenses the water out of the air that is being passed into the sodium hydroxide spray tower. The condensed water is passed into an electrolyser where an electric current splits the water into hydrogen and oxygen. Water might be obtained from any source so long as it is or can be made pure enough to be placed in the electrolyser.
iv) The carbon dioxide and hydrogen are reacted together to make a hydrocarbon mixture, the reaction conditions being varied depending on the type of fuel that is required.
v) There are a number of reaction paths already in existence and well known in industrial chemistry that may be used to make the fuels.
(1) Thus a reverse-water-gas shift reaction may be used to convert a carbon dioxide/water mixture to a carbon monoxide/hydrogen mixture called Syn Gas. The Syn Gas mixture can then be further reacted to form the desired fuels using the Fisher-Tropsch (FT) reaction.
(2) Alternatively, the Syn Gas may be reacted to form methanol and the methanol used to make fuels via the Mobil methanol-to gasoline reaction (MTG).
(3) For the future, it is highly likely that reactions can be developed whereby carbon dioxide and hydrogen can be directly reacted to fuels.
vi) The AFD product will require the addition of the same additives used in current fuels to ease starting, burn cleanly and avoid corrosion problems, to turn the raw fuel into a full marketable product. However as a product it can be blended directly with gasoline, diesel and aviation fuel.
Synthetic fuels in time for post-peak oil?
Has a replacement in time to stave off economic collapse and oil wars been originated at the epicenter of a former world empire, and present-day center of finance in this civilization?
That question is beyond the scope of this overview, and really, while it is being suggested this is the case, no one knows until AFS has the chance to be further proven, but the company is touting its advantages, as one would expect.
It says synthetic fuels can be made “to spec” eliminating a step in traditional refining that requires removing impurities from a petroleum product.
The AFS process, says the company, can deliver the chemistry needed to produce any material presently made from crude-oil.
“This includes methanol, gasoline, diesel, lubricants and waxes as well as plastics and building materials, some of which have other substitutes, but few as useful and versatile as a hydrocarbon base,” says the company. “The first commercial AFS plants will produce high-spec fuels for blending into motorsport applications where demand for carbon-reduction and quality is particularly strong.”
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Advantages mentioned include also that unlike other synthetic fuels, the AFS process is not fossil-fuel based as are those utilizing coal or natural gas, nor does it require land or compete with food production, as can biofuels.
As have efforts to replace fuels with electrification, this effort has been called “the future” by politicians and media. The company outlines its business plan that starts with cashflow generated by sale of motorsports fuels, and says it is moving forward to mass market fuels that are carbon-neutral, secure, offer consistent quality and price-predictability.
More info can be found at the Air Fuel Synthesis Web site, including other news reports it is collecting for what on first blush could certainly appear to be practically alchemy.