Making charcoal for the gasifier
Post date: Jan 28, 2013 11:24:28 PM
The gasifier will run on dried wood chips but for testing purposes I wanted a fuel that wouldn't make tar and foul up the engine before we got the set up all figure out. Charcoal has the stuff that makes char cooked out of it. Making charcoal can be a pretty wasteful process where a barrel of wood chunks are heated up by an external source. The chunks get hot in an oxygen poor environment and give off gas. The lack of oxygen keeps the wood from being completely burned to ash and leaves charcoal behind. The charcoal burn hot and clean which works well for cooking, smelting bronze and in gasifiers. I've been making charcoal this winter in my Finish style masonry stove. The fire that heats my home warms up the wood chunks. The gas given off get blown into the flames of the fire and helps to heat the house. I get clean charcoal and heat without waste.
The gas given off is flammable and poisonous. It can contain carbon monoxide. Pressure can develop in the can if the vent holes get plugged or if they are too small. You don't want it to explode in your fireplace or poison your family. After removing the can from the fire make sure it is cooled well below 400 degrees F all the way to the core before the can is opened. If the charcoal is exposed to oxygen before it has cooled down it will start to burn or smolder. Dump the finished charcoal in a metal bucket until your are 100% sure it is cool. Once cooled down I have been storing the charcoal in a large plastic bag inside a 30 gallon plastic barrel.
I have made charcoal in very small batches in a one quart metal paint cans. It has a couple of small holes drilled in the lid. I have used it many times but the last time the holes must have gotten plugged and the top popped off. The lid is a nice safety feature. With the added oxygen the top layer of the wood chunks burned to ash but some charcoal remained in the bottom of the can. A one gallon metal paint can would also work if you could find one.