By Don Harfield (President & CEO, CharTerra)

The Biochar Handbook by Kelpie Wilson is a practical guide to making biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More on a farm or acreage and applying it to enhance the productivity of soils. Biochar is a carefully produced type of charcoal suitable for adding to soils, and Kelpie is a passionate authority on how to make biochar at home.

Kelpie Wilson lives in Oregon and has devoted 15 years of full time work to the field of biochar, including five years as a project developer of the first set of biochar standards and testing guidelines with the International Biochar Initiative. She started as a consultant in 2012 and pioneered the development of the flame-cap kiln biochar technology and sells the Ring of Fire Biochar Kiln through her company Wilson Biochar, LLC.

Kelpie explains early in the book that her passion for home-based biochar started when she first heard of terra pretaTerra preta, meaning “black earth” in Portuguese, is a type of highly fertile soil found in the Amazon Basin. It is characterized by its high biochar content, which contributes to its long-term fertility and ability to support productive agriculture More in the black soils of the Amazon back in 2006. She describes the long history of the application of charcoalCharcoal is a black, brittle, and porous material produced by heating wood or other organic substances in a low-oxygen environment. It is primarily used as a fuel source for cooking and heating.   More in fields around the world including China, Japan, Europe, and South America.

Defining Biochar

Kelpie explains how biochar can play a major role in enhancing soil carbon which invigorates and sustains living soils resulting in healthier plants and gardens. She reminds us that there are two types of carbon: organic and inorganic carbon. Organic carbon is essentially living and decomposing bodies of bacteria, fungi, insects, and worms found within plant debris and manure. Biochar is a type of organic carbon which is chemically stable and is known to last hundreds of years. Inorganic carbons, on the other hand, are carbonates associated with calcium and dolomitic minerals and salts. Our soils need organic carbon and biochar is a healthy way to make our soils more productive and resilient in drier climate conditions.

Making Biochar

Kelpie explains that biochar is produced through a process called pyrolysisPyrolysis is a thermochemical process that converts waste biomass into bio-char, bio-oil, and pyro-gas. It offers significant advantages in waste valorization, turning low-value materials into economically valuable resources. Its versatility allows for tailored products based on operational conditions, presenting itself as a cost-effective and efficient More which is basically cooking wood in the absence or limited availability of oxygen. Burning wood produces heat and ashAsh is the non-combustible inorganic residue that remains after organic matter, like wood or biomass, is completely burned. It consists mainly of minerals and is different from biochar, which is produced through incomplete combustion.   Ash Ash is the residue that remains after the complete More and leaves little or no biochar behind. The book explains the basic burn science behind the intentional production of biochar.

The book advocates the production of biochar from open kilns, which are simple to use. And it describes several designs including the Kon-tiki, the Maxham, the Ring of Fire, and the Utah Big Box kilns. Other systems can capture the liquids including wood vinegar which can be very beneficial as a soil conditioner. Other designs include the TLUD (top lit updraft design gasifier).

The book explains that sometimes the best kiln is no kiln at all and can be constructed on the ground as a “conservation burn.” Safety throughout this process is essential for the workers and to ensure that the fire does not get out of hand. 

Standards and Safety

As a help to the reader to understand biochar standards and testing, Kelpie refers to the guidelines published by International Biochar Initiative (IBI). Something that the reader should note, however, is that these guidelines were last updated in November 2015 and the jurisdictions from the US, UK, EU, Canada, and Australia were used to construct the range of values for acceptability. Caution should be exercised in solely using these guidelines and you should consult with local regulations to ensure that your biochar is in compliance with your jurisdiction.

The review of lab test results is very helpful to understand how key parameters such as moisture, bulk density, organic carbon, and electrical conductivity impact the quality of biochars. Importantly, the book explains the concern for toxins in biochars and there are several ways to confirm that your homemade biochar is safe to use. Contaminated biomassBiomass is a complex biological organic or non-organic solid product derived from living or recently living organism and available naturally. Various types of wastes such as animal manure, waste paper, sludge and many industrial wastes are also treated as biomass because like natural biomass these More feedstockFeedstock refers to the raw organic material used to produce biochar. This can include a wide range of materials, such as wood chips, agricultural residues, and animal manure. More can contribute to PCBs (man-made organic chemicals consisting of carbon, hydrogen and chlorine atoms that are known to cause a variety of health issues) included in the biochar. And salt (NaCl) can contribute to dioxins, which are known to cause various immune, endocrine, and nervous system conditions. High temperatures can also contribute to PAHs (polyaromatic hydrocarbons linked to tumor development). The book recommends that a germination test and a worm avoidance test are useful to figure out if you have a problem with toxic compounds.

There is a chapter on building soil  starting with humus and how to use biochar in compost for application to soils. Biochar helps build soil, which is the whole point of making biochar for your garden or farm land. Raw biochar needs to be conditioned before direct application for planting and there are several recipes for doing that.  

The Biochar Handbook is an excellent resource and starting point for anyone looking to dig deeper into the making and use of biochar. The illustrations and photographs make the book an easy and informative read, and there are references at the back of the book should you want to explore topics further.

The book is available for pre-order now and is set to be published on June 27, 2024.

Don Harfield is President and CEO of CharTerra, a biochar consulting firm serving Western Canada. Don is a seasoned executive, professional engineer, project manager, production operations & facilities optimizer, and researcher with over 40 years experience in waste management, oil & gas production, and the pulp & paper industry. He was also the technical lead for the Alberta Biochar Initiative. He applies his comprehensive knowledge to help clients navigate their way to success.