Gasification- If you see Sid , tell him.

There are a number of features which set modern wood burning (MWB) boilers apart from their more traditional stove or furnace counterparts.

One key aspect of all MWB boilers is gasification, a clever way of burning waste gasses from wood making it about 70% more efficient and a cracking word to remember for Scrabble.

Gasification is, in its simplest form a means of converting the heat energy stored in wood into a gas which can then be burnt. The technology is not new. During World War II, Million’s of vehicles (over 1million in Europe alone) ran on wood. I knew nothing about this before I started today’s blog and I hope you will forgive me if I diverge from boilers to cars for a moment

Wood gasification is a pretty efficient way to power vehicles. Modern research is showing figures of around one pound of wood (say an average sized bit of firewood) per mile. Limiting factors are wood tank size and the need to reload the boiler. Efficiency levels with modern wood fuelled cars are easily comparable to electric cars and in some cases, petrol ones.

It seems crazy, given the sustainability of forest cycles and wood (and the fact that we cannot eat it), that in Brazil vital rainforests are being cleared to plant a food crop (sugar cane) for conversion to Ethanol when wood could do the same thing so very simply.

Land that functions as the planets lungs is cleared to grow food that is then turned into fuel. The soil is nutrient poor in cleared rainforest land so will only grow the crop for a short time, hence more rainforest destruction etc- (a cycle of destruction).

This Ethanol business is, by the way being seen as an example of sustainable fuel production.(cue – silent scream and deep breath)

You can go around the world with a saw and an axe (John Dutch)

(John has presumably not passed through a UK airport recently)

This diagram shows how gasification works in MWB’s

To quote from GWI fact-sheet 2

"When wood is burnt with a natural (upwards) flame, the wood burns quite fast and waste gases from it go up the chimney, as is the case with an open fire. An open fire is about 30 % efficient so about 70 % of potential heat is wasted".

Wood gasification uses a downward burning flame and a tightly controlled air flow to smoulder the wood. The waste gases produced, (about 70% of the total heat values of the fuel) are then burnt. This has numerous advantages in terms of fuel efficiency (often 90%+) less emissions and ash, a long life for the firebox and longer re-fuelling periods”. Creosote build up on flues and sooting  of glass panels is also much reduced.

In short if you want to burn wood- gasify it. If you do anything else, you are just blowing hot gas out of your chimney!