- -Outputs of Biomass Pyrolysis (FAO.org)
"Pyrolysis is thermal degradation either in the complete absence of oxidizing agent, or with such a limited supply that gasification does not occur to an appreciable extent or may be described as partial gasification. Relatively low temperature are employed of 500 to 800 °C, compared to 800 to 1000 °C in gasification. Three products are usually produced: gas, pyrolysis oil and charcoal, the relative proportions of which depend very much on the pyrolysis method, the characteristics of the biomass and the reaction parameters."
Editor's Note: The article needs some editing for grammar. 03-14
- A Nepali Villager's Tradition of Making Biochar (Biochar-International.org)
"In March 2012, a team from Australia, the Philippines, and Nepal visited the Dhand Chaur village in the mountainous Dholakha District of Nepal and found a farmer there had been producing and utilizing biochar for at least two generations as part of her regular farming routine."
"To create the biochar, she digs up soil in an area greater than 5 sq meters. Straw and grass is then laid on top of the soil and smoldering dried cow/buffalo dung cakes mixed with straw are then laid on top of the residue. More twigs and leaves are placed on top of the dung, which is then covered by soil, steadily creating a mound."
"The dung slowly smolders for three days, transforming the biomass to biochar, and changing the dark brown soil to a lighter reddish color. She then works the charred material into the ground and then leaves it for three weeks before planting millet seeds." 11-12
- Biochar Methods (Wikipedia.org)
"Pyrolysis produces biochar, liquids and gases from biomass by heating the biomass in a low/no oxygen environment. The absence of oxygen prevents combustion. The relative yield of products from pyrolysis varies with temperature. Temperatures of 400–500 °C (752–932 °F) produce more char, while temperatures above 700 °C (1,292 °F) favor the yield of liquid and gas fuel components. Pyrolysis occurs more quickly at the higher temperatures, typically requiring seconds instead of hours. High temperature pyrolysis is also known as gasification, and produces primarily syngas. Typical yields are 60% bio-oil, 20% biochar, and 20% syngas. By comparison, slow pyrolysis can produce substantially more char (~50%). Once initialized, both processes produce net energy. For typical inputs, the energy required to run a 'fast' pyrolyzer is approximately 15% of the energy that it outputs. Modern pyrolysis plants can use the syngas created by the pyrolysis process and output 3–9 times the amount of energy required to run." 11-12
- Field Guide for Biochar Application (InternationalBiocharInitiative.org)
"This guide provides an overview of current biochar knowledge pertinent to its application to soil, and gives ideas for using biochar in a variety of soil management systems. Very little data is currently available on practical aspects of working with biochar, including labor requirements, economic feasibility and efficacy. This guide summarizes what is known so far and is intended as a practical guide for farmers and others engaged in biochar field trials."
"A best management practice to greatly reduce such wind losses is to moisten biochar, however adding water increases the weight of the material and this can increase transport costs. While water is usually added to biochar immediately after exiting the pyrolysis unit in order to quench it, more water could be applied to reduce dustiness prior to field application. Moisture content must always be taken into consideration when determining application rate, whether or not the end user adds water themselves. Biochar that is seemingly dry can contain a high percentage of moisture, and application rates can be overestimated."
"In the published literature, several studies have reported positive effects of biochar application on crop yields with rates of 5-50 tonnes of biochar per hectare, with appropriate nutrient management. This is a large range, but often when several rates are used, the plots with the higher biochar application rate show better results (Chan et al., 2007, 2008; Major et al., 2010b)." 11-12
- Goals for Biochar Production (InternationalBiocharInitiative.org)
"IBI is focusing presently on the feasibility of one “wedge,” which equals one gigaton of carbon per year. The term 'wedge' comes from an often-quoted analysis (Pacala and Socolow, 2004) showing a need to have seven gigatons of carbon per year (seven wedges) of reduced carbon emissions by 2054 just to keep emissions at the2004 level." Uses technical language; it was not written for non-scientists.11-12
- Guide for the Production of Biochar (InternationalBiocharInitiative.org)
"This document was produced to assist in the development and testing of small pyrolysis plants and provides advice on equipment design and testing as well as the specification and testing of the biochar product."
Includes diagrams of biochar processes. 11-12
- Misconceptions and Myths About Biochar (InternationalBiocharInitiative.org)
"IBI has prepared this document in response to various press releases and reports issued by the groups EcoNexus and Biofuels Watch, including a report titled: Agriculture and climate change: Real problems, false solutions." Uses technical language; it was not written for non-scientists. 11-12