Gasifiers Wood Gasification & Off Grid Power

By George Eccleston

What is a Gasifier?

How does it work?

How do you build one?

What parts do you need?

What type of fan do you need?

What does the fan do?

Where does the fan go?

Building a gasifier seems to be one never ending stream of questions for the beginner. Wouldn't it be nice if there was a book that answered these questions for you? Well there is and this is it!

All the basic details needed for you to understand how gasifiers work without the technical jargon that confuses most beginners. There is a multitude of diagrams & simple explanations detailing the different designs and the chemical processes that occur inside the gasifier itself.

Written especially for the beginner this book holds all the necessary information that you will need to get started in wood gasification.

• Language: English
• Publisher: George Eccleston
• Release date: May 10, 2018
• ISBN: 9781386376972

Book preview

Copyright©2018 George Eccleston

Produced in the United Kingdom

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise without written permission of the author or publisher.

Disclaimer

Although the author and publisher have made every effort to ensure that the information in this book was correct at press time, the author and publisher do not assume and hereby disclaim any liability to any party for any loss, illness, damage, or disruption caused by errors or omissions, whether such errors or omissions result from negligence, accident, or any other cause.

Beginning warning

Before you read or use any information from this book please be aware that gasifiers are dangerous devices. They contain very high temperature areas which can cause burns & fires. They also expel poisonous and explosive gases. These gases can be colourless, odourless and deadly to humans and animals even in small amounts. Always use gasifiers outdoors where there is plenty of ventilation. Always have a quick read carbon monoxide meter near the gasifier as an early warning of any leaks that may have occurred on your system.

This book documents the information that I have learnt about building and using gasifiers. Whilst this book has a wealth of information inside it on this topic, it should not be taken as a definitive guide on the matter. This book documents the actions that I have taken and the knowledge that I have built up on gasifier construction and use. If you decide to emulate any designs or use any information that is contained within this book it is entirely at your own risk and the author shall not be held responsible or liable for any damage, injury or loss that occurs because of this. If you are happy to agree to these terms then continue reading this book as it should contain all the information that you need to get started in wood gasification and producing your own off-grid power.

Contents

Chapter 1 An introduction to Gasifiers

Chapter 2 Types of Gasifiers

Chapter 3 In the beginning

Chapter 4 The FEMA gasifier

Chapter 5 The Imbert gasifier

Chapter 6 The four main steps of gasification

Chapter 7 Cracking the gases

Chapter 8 The fuel of choice

Chapter 9 The basic anatomy of a gasifier

Chapter 10 Gasifiers suck

Chapter 11 Cleaning the gases

Chapter 12 Cooling the gases

Chapter 13 Filtering the gases

Chapter 14 Using valves

Chapter 15 Pipes

Chapter 16 Designing your gasifier

Chapter 17 Lighting your gasifier

Chapter 18 Powering an engine

Chapter 19 Dangers of wood gas

Chapter 20 Getting started

Chapter 21 More books by this author

Chapter 1

An introduction to Gasifiers

Wood has been burnt for thousands of years by civilisations throughout the world for cooking and heating. The earliest recorded history of using wood & coal gas in a commercial way was around 1795 in both France and England. This process was used extensively until the discovery of natural gas and Petroleum which was cheap and plentiful.

Wood gas production fell out of favour and was largely forgotten about for a very long time. It was only the advent of the Second World War when oil was scarce and rationed that people started to use wood gas again to power their vehicles. If it wasn’t for the use of wood gas powered vehicles and farm equipment during this time the results of this war would have turned out very different  and many thousands more people would have perished.

Where does wood gas come from?

Inside organic (biomass) material there are gases that we can use such as Methane, carbon dioxide, carbon monoxide & hydrogen gas. Some of these gases are very useful to us while others are just waste products. If we use a bit of knowledge and machinery it is possible to literally rip the wood apart and take out the useful substances that this burnable matter contains and discard the parts that we don’t need.

This wood gas is also called Syngas or Producer gas and the gasifier can also be referred to as a gas reactor depending on who you are discussing it with.

It may come as a surprise to most people to find out that wood itself doesn’t burn. It is actually the gases that are stored within the wood itself that burns. If you light a match and look at the flame then you will see that the wood itself isn’t burning. In fact there is a shield of different gases that flow around the wood itself. The matchstick itself simply shrinks as the gases escape from it, changing it from wood into charcoal (carbon) in front of your eyes.

If you look at the picture of the match the part that is actually burning is the gas above the match, the yellow section. The blue gas at the bottom is new gas coming out of the match itself. The flame is not actually touching the wood itself because wood doesn’t burn it is the gas that wood releases that actually burns. And this gas only burns when it comes into contact with the air (oxygen) above the match itself (yellow flame).

If you heat wood without a flame i.e. for example baking it in and electric oven (definitely not recommended - DON’T DO THIS!), then the gasses inside the wood can literally float out of the wood itself. This would be a very dangerous thing to do because as soon as these gases come into contact with oxygen there is likely to be an explosion or a massive flame. Any gases that are extracted from wood must be kept separate from oxygen (air) until you are ready to burn it.

All biomass contains carbon (charcoal), hydrogen gas, oxygen and an array of other gases & compounds. Once all the gases are removed then the only thing left is the carbon (charcoal). Only when all these gases are removed does the carbon itself start to burn and only then if there is oxygen present.

In an ordinary campfire we will only ever get around one third of the possible energy out of this wood. The rest is wasted in the form of smoke, which is just another name for wasted energy. This wasted energy is literally thrown up into the sky to pollute people’s lungs. We waste two thirds of all the possible heating energy when biomass is burnt like this. This wasted energy can be reduced by using modern stoves that use baffles and primary and secondary heated air supplies. But this still only gives us heat we are still unable to use the wood gas for our own needs.

Gasification is a very efficient process and is much less wasteful than a standard fire. It will give you heat, cooking capabilities and fuel to run your generators and vehicles.

A very basic way to get wood gas

There is a safer way to extract gases from wood than using an electric oven and it is a relatively simple thing to do. This is the way most people get started in their experiments with extracting wood gas.

You simply heat the wood in a sealed (except for one small outlet pipe) metal container and literally bake it over a camp fire or on a BBQ. A metal paint tin is good for this. The heat will dry the wood out and allow the gases inside the wood to escape from it. If air was allowed to get into this metal container the gas will burst into flames (or explode) and burn up all the wood at the same time. The wood gases are being pushed from the wood by the intense heat so the air is unable to get into the metal container. The gases can only move in one direction which is out of the can along the outlet pipe. When this gas leaves the exit pipe and it mixes with the air it becomes flammable. Without air the wood gas will not burn, it is only when the two are mixed together that there is the possibility of fire.

This is a very basic way of getting wood gas out of biomass. It is however