Why "Clean Coal" Is an Oxymoron


The carbon dioxide produced when coal is burnt — mainly to generate electricity — is the single biggest contribution to climate change. "Clean coal" is an immediate contradiction.

Coal is a very dirty fuel for two fundamental reasons.

Firstly, because coal always contains a range of impurities, burning it produces a cocktail of gases, like oxides of sulphur and nitrogen, as well as soot, ash and heavy metals, even some radioactivity.

Secondly, coal is mostly carbon, so burning coal gives carbon dioxide, the most important greenhouse gas. Oil and natural gas contain significant amounts of hydrogen, which burns to produce water. As a result, those fuels produce less carbon dioxide per unit of energy.

Brown coal has a third problem: as it is mostly water, most of the energy produced by burning it is used to evaporate the water. It thus gives even less useful energy for every kilogram of carbon dioxide released.

So how can this dirty fuel be cleaned up? Kevin Rudd’s interest in so-called "clean coal" projects focuses on carbon capture and storage. This involves capturing the carbon dioxide from burning coal, compressing it into a liquid, and injecting that liquid into rock layers deep underground. Carbon capture does nothing to reduce other forms of pollution, so talk of "clean coal" is the height of chutzpah — and highly misleading.

Because air is nearly 80 per cent nitrogen and only about 20 per cent oxygen, carbon dioxide accounts for only a small fraction of the exhaust gases from a power station. Separating it from the other gases is a complex and expensive process which consumes large amounts of energy. Some propose burning coal in pure oxygen rather than air, so the exhaust stream would be mainly carbon dioxide. That would simplify separating tcarbon dioxide, but it would be expensive and energy-intensive to produce enough oxygen to burn bulk quantities of coal.

Compressing the gas into a liquid is technically feasible, but it also requires significant amounts of energy. The liquid carbon dioxide would then have to be transported to sites where the rocks are judged suitable for storage. The World Energy Council has estimated that the carbon dioxide from the world’s power stations would, if compressed to liquid for transport, be comparable in volume to the entire global oil and gas industry. While there are some sites that look suitable for long-term storage, it has not yet been shown that they will be secure for geological time; obviously, we cannot afford to have the gas leak out into the air. There may be some sites secure enough and close enough to power stations for a few demonstration projects, but it is moonshine to talk of applying this treatment to all future power stations.

Even if all the technical problems can be solved, the extra energy required for the process will mean that carbon dioxide released per unit of energy will only be reduced by about 70 per cent. We need to go much further than this by 2050 to stabilise the global climate, so it makes much more sense to invest in genuinely clean forms of energy like wind, solar and geothermal.

There are no credible estimates of the possible cost of carbon capture and storage, but industry sources talk openly about it adding 50 per cent to the price of coal-fired power. Studies of the prospective renewable supply systems indicate they can achieve greater reductions at lower cost — and much faster.

Even if everything were to work as well as the clean coal optimists hope, it will be many years before the technology is credible. The most that can be claimed is that "clean coal" will perhaps slow the growth of greenhouse pollution after 2020. Climate science is now saying we face an emergency and need to cut emissions significantly before then. Carbon capture is still an unproven technology and even if it can be made to work it will do too little, too slowly and at too high a cost.

So why is it being taken seriously?

There is no simple answer to this question. Coal companies want to stay in business, and have an obvious commercial interest in claims that allow them to keep burning coal.

At the 2020 Summit earlier this year, I argued that while there remain differences of opinion about the feasibility of "clean coal", surely we could all now agree that it is irresponsible to build old-fashioned coal fired power stations? A few delegates, mainly from the industry, objected and so Senator Penny Wong had to report that there was no consensus for the position I advocated. I was shocked to find that there are still people in the coal industry who think it acceptable to plan projects that will belch out millions of tonnes of carbon dioxide.

As well as those in business, some unionists representing coal workers — and some ALP politicians close to those unions — support "clean coal". The companies think it is only acceptable to keep the Earth habitable if profits are not reduced; the labour interests think it is be acceptable if no jobs are lost.

To be fair, jobs are at stake. The coal industry, domestic and export, employs more than 25,000 people. But that figure needs to be put into perspective. During John Howard’s tenure as PM 150,000 manufacturing jobs disappeared. Those workers were absorbed in other fields of employment. Expanding clean energy supply and efficient use will create far more jobs than the coal industry now provides. Training and other forms of assistance will help the workforce move into these new jobs.

Some technocrats hope for a big technical fix to the problem of climate change. So they are attracted to grand technical delusions like "clean coal" or nuclear power, rather than accepting the wisdom of applying simpler technologies like wind turbines, solar cells or improved efficiency.

The final challenge to formulating good energy policy is the level of political support required, including both public endorsements and huge allocations of funds. Even politicians who accept that climate change is a real and urgent problem are reluctant to propose the changes we need. They cling to the old myths: business can go on as usual, further growth is tolerable, some claim even that growth should be encouraged.

I criticised the Howard government for pursuing the ridiculous distraction of nuclear power, rather than responding to climate change. The equally bizarre notion of "clean coal" is now playing a similar role for the Rudd Government and State governments along the eastern seaboard: it is a simulated response, aimed at appeasing the public concern about climate change without antagonising business, unions or those troglodytes in Parliament who still can’t see the problem.

This is the real danger of the "clean coal" bandwagon. It is frittering away the time and resources that we should be using to re-structure our energy supply and use.

The Rudd Government should trust us and engage the community in developing a concerted response strategy, as was done in Sweden. We need that sort of participative process to produce a politically sustainable strategy to slow climate change. Unless we achieve that, we all face a very bleak future.

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