Next they learned to grind up the coal into smaller pieces, so it burned better.

After that was drying the coal. People don’t think of it, but lots of coal has quite a bit of water in it. This is especially useful if we want to turn brown coal into fuel, as we do here in Victoria – brown coal has heaps of water and sulphur in it.

After grinding up and drying out the coal, all you can do to make it emit less is turn it into a gas. What you do is to heat the coal with water, you get carbon monoxide and hydrogen. You remove the impurities (the sulphur, mercury, etc), burn the carbon monoxide and hydrogen with oxygen, and get carbon dioxide and water again.

It’s not a new process, the USA has had a couple of plants doing it for some years, and long before that people were gasifying coal so they could get useful chemicals like ammonia. See the quite good wikipedia article on coal gasification.

While you get less carbon dioxide emissions with a coal gasification plant, you get a lot more acids, ammonia, mercury and so on. That’s the disadvantage to the thorough burning of the carbon in the coal – not only do you bring out each carbon atom, but lots of others, too.

And in the end, the efficiency of burning coal doesn’t matter. What matters is the total amount of carbon dioxide we put into the atmosphere. Whether the 1,000 tonnes of CO2 generated 1,000,000 kWh, 200,000kWh, 150,000,000kWh or however many doesn’t really matter – it’s 1,000 tonnes of CO2.

Projects to capture and bury the carbon dioxide continue at the Western world’s most polluting power plant, Hazelwood. US$1,000/t to deal with the CO2 seems a bit pricey. Even solar panels are cheaper than that, in terms of CO2 emissions avoided. And they’re only managing 25 tonnes a day, not terribly impressive. Someone could probably plug a hole in a leaking steam pipe at Hazelwood and get the same emissions reductions.

In the end, we are going to have to accept the fact that one day we’ll have to get along without burning stuff.