DIY Biogas

By Paul Scheckel

A Practical Manual for Making and Using Renewable Natural Gas

 

Make your own homemade natural gas from food scraps, garden trimmings, and animal waste!

Understand how to craft a recipe to make your own renewable energy substitute for natural gas and propane.
DIY Biogas contains complete plans and parts lists to build two different biogas generators that help you learn, understand, and grow your biogas operation. With this hands-on, minds-on guide, you'll gain the knowledge and experience you need to convert waste into energy. Whether you're looking for a unique science project or want to cook meals with your own backyard biogas, this book is the most practical place to start.
With fuel prices and scarcity on the rise, it's time to re-learn how to meet our own energy needs. Start today and harvest your own local, renewable energy resource!

Professional renewable energy consultant and hands-on-off-grid homesteader, Paul Scheckel, has been promoting the use of homemade biogas since 2013 through workshops and publications. The information presented in this book is based on science and real-life experience. Betty Crocker tested all her recipes, and so do I!

Additional material and interaction: https://www.youtube.com/c/HandsOnOffGrid

 

• Language: English
• Publisher: Parsec Energy Consulting
• Release date: Sep 26, 2022
• ISBN: 9781736290248

Paul Scheckel

PaulScheckel is an energy auditor and consultant who has visited more than 3,000 homes, educating people about energy efficiency, cost-effective improvements, and indoor air quality. His articles have appeared in such publications as Mother Earth News, Home Power, and Vermont Life, and he contributes a monthly energy and environment column to two state-wide newspapers. A frequent radio guest, Scheckel has also appeared as a guest expert on the acclaimed television show “Ask this Old House”. He lives off-grid in northern Vermont with his family in a solar- and wind-powered house.

Book preview

DIY Biogas

Make and Use Your Own Renewable Natural Gas

By Paul Scheckel

First published by Paul Scheckel, 2022

Parsec Energy Consulting

Copyright © 2022 by Paul Scheckel

ISBN: 978-1-7362902-4-8

All rights reserved. No part of this publication may be reproduced, stored or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning, or otherwise without written permission from the publisher. It is illegal to copy this book, post it to a website, or distribute it by any other means without permission. The author has no responsibility for the persistence or accuracy of URLs for external or third-party Internet Websites referred to in this publication and does not guarantee that any content on such Websites is, or will remain, accurate or appropriate.

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This book is for entertainment purposes only. It is not intended to be a comprehensive text on all the intricacies involved in successfully managing the information contained herein. Adequate skills and knowledge in multiple disciplines are required in order to safely approach the subject matter presented. If you do not have the appropriate level of knowledge and skills, seek training, or enlist a competent professional.

The author cannot be held liable or accountable for how the information in this book is used. Following the advice in this book can lead to fire, personal injury, and damage to property. You alone are responsible for how you use the information presented, and you assume any and all liability for damage to people or equipment that may result. It is your responsibility to determine the suitability of any project, parts, assembly, and any and all results or outcomes, to be used for any purpose whether presented in this book or not. It is up to you to use tools and equipment properly and to take proper precautions with chemicals, mechanical equipment, electrical service, combustible gas handling, associated materials, and procedures. You alone are responsible for injuries to yourself or others or for damage to equipment or property.

Have fun, be safe!

Table of Contents

Introduction: What is Biogas?

The Basics of Producing Biogas

Challenges

Keep it Simple

How it Works

Production Rate

Variables

Biogas Recipe

The Carbon to Nitrogen (C:N) Ratio

Calculating C:N Ratio in a Recipe

Recipe Example

Table 1: Recipe Evaluation C:N ratio

Solids and Liquids

VS and Gas Production

Digester Care and Feeding

Inoculation

Starting Up

Temperature

Retention Time

Loading Rate

Where to Start

Loading Rate and pH

Avoid Indigestion

Mixing

So, how much gas can you make?

Table 2: Recipe Evaluation VS and Gas Production

Ok, but how much gas can you make, really?

Types of Digesters

Batch

Continuous Flow

Materials

What to do with the Effluent

Using Biogas

Safe Handling

Maintain Positive Pressure

Flame Arrestors

Respect the Hazards!

Storing Biogas

Gas Burners

Orifice Size

Table 3: Orifice Diameter Multiplier for Gas Appliances

Airflow

Gas Pressure

Engines

Purifying Biogas

Environmental care

Make and Use a Biogas Generator

Make a 5-Gallon Batch Digester

5-Gallon Parts List

Make a 55-Gallon Hybrid Digester

55-Gallon Parts List

Assembly Illustrations

Non-Energy Benefits

Cow Manure and Gas Generation; a special case

Appendix A: Characteristics of Raw Materials

Appendix B: Biogas Resources

Appendix C: Quick Unit Conversions

Introduction: What is Biogas?

Biogas is a mixture of gases formed anywhere organic material decomposes in the absence of oxygen. Underwater, deep in a landfill, bubbling out of municipal solid waste, or in the guts of animals (including you), biogas (aka swamp gas) is produced through the biological and chemical processes of anaerobic digestion (AD). All that is a long-winded way to describe a fart. Yes, your farts – and your dog’s – are biogas, and they will burn. How much flame is produced depends on what you (or your dog) eat and how efficient your digestive system is at dealing with your diet. This decomposition of organic matter happens without any outside help, but we can assist nature by providing the ideal environment to maximize gas production.

Anaerobic digestion is the decomposition (digestion) of carbohydrates in an oxygen-free (anaerobic) environment. It begins with a process similar to the fermentation of alcohol, but without oxygen AD continues past fermentation. In fact, oxygen is toxic to the process in that it inhibits the growth of methane-producing microbes, known as methanogens, which are ultimately what we want to encourage in order to produce combustible biogas.

The main ingredient of biogas produced in this controlled environment is methane. Methane is a hydrocarbon made up of one molecule of carbon and four molecules of hydrogen (CH4). Methane is the primary component of natural gas commonly used for cooking and heating, although biogas is not as energy dense as natural gas. The methane content of the biogas you make will probably range from 50 to 80 percent, compared to about 70 to over 90 percent with utility-supplied natural gas. Natural gas also contains other combustible gases such as butane, propane, and ethane, while biogas does not.

The exact makeup of biogas depends in part on