Sunday, December 13, 2009

New uses for coal?

The following is an abridged version of an paper written by geologist and TTKD member Dr Lloyd Hamilton that first appeared in The Australian Geologist.
Since any discussion of coal usage can be somewhat controversial it is worth pointing out that, (intriguing as they may be), the views expressed below are solely those of Dr Hamilton.

A New Age of Coal Utilisation

Coal is essentially transformed sunlight and is surprisingly complex at the molecular level. This complexity continues to intrigue scientists and no chemist yet seems to know exactly what it is. Coal has a wonderful internal structure, with great molecular porosity. It may be a good reactor in nanotechnology. It can be used for a great many things but currently we mainly burn it for its heat energy or use it as a reductant for coke making. It is time to consider other ways of using coal.


It is true to say that the coal industry has made great changes and has reached a great level of efficiency but the changes associated with this have not been very radical and the changes have more or less been forced onto the industry by economic necessity. Generally there is much conservatism in the industry.

Conservatives resist change whether it is in approaches to industrial innovation or attitudes to preserving nature. Everything changes and if we do not adjust we become the ashes of history. When wood became too valuable to burn in England the Industrial Revolution began with coal as a substitute. Now it is time to move on beyond that. Some houses are being built out of plastics now.


It seems unreasonable to think the industry can keep going on in a straight line in a conservative manner. Alternative markets can open up or close down. Australia has only 8.3% of the world's coal whereas China has 11.6%. USA has the most coal with 25.4% of the world’s coal (World Energy Council, 2005. The figures quoted relate to total proven recoverable reserves for the end of 1999).

Australia has been the world’s largest exporter of hard coal since 1984. China is now the world’s fifth largest coal exporter. Will China keep buying coal from Australia when it has developed its own infrastructure? Or will Australia develop its infrastructure while China develops her infrastructure so that when they are both ready Australia’s extra infrastructure will be redundant?

Alternative sources of energy are emerging. Nuclear power has its problems but who knows when fusion power will sweep these aside? Hot rock exploration is well underway with three companies in Australia. Wind power and other forms of renewable power sources are now being taken seriously.

Sooner or later, the wholesale combustion of coal will have to be curtailed and reduced to levels lower than those of the 1990s -- especially as the Third World countries become more industrialised.


The industry can keep fighting this trend, but it seems inevitable that it will lose. So what is to be done? Plenty! Coal has a whole range of uses which can be employed. The first plastics were made of coal, and there are other avenues to be explored

Coal can probably be turned into food, and there should be a big market for that as the world population increases and food resources decrease. Coal is unstable and therefore a potential food source for microbes. Coal seldom forms outcrops, but degrades to a sooty soil-like substance. Microbes, including slime moulds, come in a vast array of varieties. Could some of these feed on coal and be used as a feedstock for lower plant forms or animals, which in turn, going up the food chain, could eventually be fed to chickens, pigs and rabbits, and then to us.

In may not be easy to find microbes that break coal down, especially without oxidising it, but there is a vast array to choose from. Microbes can live in temperatures ranging from freezing to boiling, and under a wide range of pressures and chemical environments. Some can live in environments that are particularly toxic to others. The utilisation of coal with microbes also has potential other than that as food stocks, giving a wide vista of exciting possibilities.

Coal might also be used directly for making carbon fibres. Currently, carbon fibres are made from special graphitizing carbon compounds, but it is probably quite possible to make carbon fibres directly from certain types of coal. In particular, I am thinking of coking coals of very high fluidity or thermoplasticity. Such coals could easily be made to produce fine fibres, and these would probably graphitize easily. When carbon fibres become cheaper imagine the uses expanding for them. They are already used in making golf clubs and tennis rackets and aeroplane propellers. They could replace steel in many applications.


“Coals aint coals” and different coals will have different uses. Brown coal may be best for most sorts of microbial transformations for food use. Bituminous coal may lend itself to quite different microbial effects. Carbon fibres will initially be made out of rather special coking coal of high fluidity. Anthracites are closer to graphite in molecular structure and would lend themselves to a different potential range of uses.

Different components in coals may have different uses. Currently, macerals are not separated from parent coals as this adds unnecessary expense but if valuable uses were found, then it would be possible to use macerals separately e.g. resinite for plastics and inks, sporinite for waxes, vitrinite for carbon fibres, and inertinite for activated carbon.


Ultimately, coal is too valuable to burn. Imagine the future when your great grandchild grows up to use coal in a whole lot of new ways. Will he say ” why didn't my ancestors see the great value in this wonderful material?” ” Why have they squandered our heritage and resources?” “Why did they burn it to give us greenhouse problems?” and ”Why did they sell our coal at a price lower than that of crushed road aggregate when it is so valuable for other uses?”

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