A black error

Regular readers will know that I do not care for the activities of the chain saw volunteers on Epsom Common and that I would much prefer a much lower level of intervention. See, for example, references 1 and 2. And apart from chain saws and cows, another activity on the Common of which I disapprove is the making of charcoal, on the grounds that cooking wood to make charcoal releases all kinds of stuff into the atmosphere which would be better left in the wood. And, furthermore, that it would trap much more carbon if the trees chopped down to make the charcoal were left to live out their natural lives.

The sack

The missive

So not best pleased this afternoon to find these small sacks of Common produced charcoal lined up outside the Manor Green Road butcher, with a choice of hazel or oak.

However, I was moved to check. Had I got hold of the right end of the stick?

Perhaps I should not have been surprised that it was all a lot more complicated than I had realised. 

According to Bing, charcoal was important from a saving the planet point of view, but mainly because large amounts of forest were being chopped down in the tropics, in a very unsustainable way, to make charcoal for cooking. And very inefficient making it was too, puffing a lot more gases into the atmosphere than carbon under cooking pots. A situation made worse by the export of lots of charcoal from the tropics to feed the barbecues of the west.

There was also a suggestion that making charcoal properly, in what sounded like a sort of pressure cooker, was not, in itself too polluting. Nearly all the carbon got converted either into heat to drive the process or into the charcoal product. Yes, some carbon was getting back into the atmosphere, but as carbon dioxide and not in the form of smoke, soot and unpleasant hydrocarbons.

Trying to dig a bit deeper, reference 3 looked promising but required more payment than I was prepared to proffer. Reference 4, however, was available for download without payment, and I have started to take a look. I offer a few titbits.

The raw material of charcoal

Nowadays we get a lot of energy from coal and oil, both derivatives of the remains of life, both laid down for present purposes over very long periods of time, more the 50 million years ago. With coal forming in a window of opportunity before the right sort of wood eating bacteria had been invented. We are burning up energy which was harvested from the sun over a very long period of time.

But for perhaps 50 thousand years we have been burning charcoal, a good quality fuel which, in geological terms, can be made more or less instantaneously from trees. A fuel which was also important - and remains important - in the extraction of metals from ores and oxides. Norway, for example, uses lots of the stuff today (at least it did twenty years ago) in the manufacture of that very important metal called silicon.

Now trees contain a lot of cellulose, a carbohydrate which might be thought of as being made up of a mixture of carbon and water, that is to say carbon, hydrogen and oxygen. The trick is to strip the water out of the cellulose, leaving the fine honeycomb structure of carbon which we know as charcoal. And without producing all kinds of other, gaseous or liquid carbon products in the process, like carbon monoxide, carbon dioxide and tar. Not to mention stuff like soot and smoke.

Other products which, for a hundred years or so, were important in their own right, with a large chemical industry being founded on their extraction. The idea then was to maximise their production and to minimise that of charcoal.

But as far as the manufacture of charcoal is concerned, there are two important issues. The first is to extract the raw wood from woods and forests in a sustainable way. This the Epsom ecovols claim to be doing. The second is to cook up the wood in such a way as to maximise the production of charcoal and to minimise the emission of all the other carbon products which are potentially available into our already overloaded atmosphere.

So while I continue to dislike, to disapprove of cooking charcoal on the Common, perhaps I had better keep my disapproval to myself until I get around to being better informed.

Reference 1: https://psmv4.blogspot.com/2020/06/horton-lane-clockwise.html. 

Reference 2: http://pumpkinstrokemarrow.blogspot.com/search?q=chain+saw+volunteers.

Reference 3: Traditional charcoal making: an important source of atmospheric pollution in the African Tropics - J.-P.Lacaux, D.Brocard, C.Lacaux, R.Delmas, A.Brou, V.Yoboué, M.Koffi - 1994.

Reference 4: The Art, Science, and Technology of Charcoal Production - Michael Jerry Antal, Morten Grønli - 2003.

Reference 5: https://en.wikipedia.org/wiki/Cellulose. The source of the third snap above.