Biochar for environmental management: science and technology

Citation preview

Biochar for Environmental Management

Biochar for Environmental Management Science and Technology

Edited by Johannes Lehmann and Stephen Joseph

London • Sterling,VA

First published by Earthscan in the UK and USA in 2009 Copyright © Johannes Lehmann and Stephen Joseph, 2009 All rights reserved ISBN:

978-1-84407-658-1

Typeset by MapSet Ltd, Gateshead, UK Cover design by Susanne Harris For a full list of publications please contact: Earthscan Dunstan House 14a St Cross Street London, EC1N 8XA, UK Tel: +44 (0)20 7841 1930 Fax: +44 (0)20 7242 1474 Email: [email protected] Web: www.earthscan.co.uk 22883 Quicksilver Drive, Sterling,VA 20166-2012, USA Earthscan publishes in association with the International Institute for Environment and Development A catalogue record for this book is available from the British Library Library of Congress Cataloging-in-Publication Data Biochar for environmental management : science and technology / edited by Johannes Lehmann and Stephen Joseph. p. cm. Includes bibliographical references and index. ISBN 978-1-84407-658-1 (hardback) 1. Charcoal. 2. Soil amendments. 3. Environmental management. I. Lehmann, Johannes, Dr. II. Joseph, Stephen, 1950TP331.B56 2009 631.4'22—dc22 2008040656 At Earthscan we strive to minimize our environmental impacts and carbon footprint through reducing waste, recycling and offsetting our CO2 emissions, including those created through publication of this book. For more details of our environmental policy, see www.earthscan.co.uk. This book was printed in the UK by MPG Books, an ISO 14001 accredited company.The paper used is FSC certified and the inks are vegetable based.

Contents

List of figures, tables and boxes List of contributors Preface Foreword by Tim Flannery List of abbreviations 1

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Biochar for Environmental Management: An Introduction Johannes Lehmann and Stephen Joseph What is biochar? Biochar terminology The origin of biochar management and research The big picture Adoption of biochar for environmental management Physical Properties of Biochar Adriana Downie, Alan Crosky and Paul Munroe Introduction Biochars: Old and new Relevance of extended literature Caution on comparing data Origin of biochar structure Influence of molecular structure on biochar morphology Loss of structural complexity during pyrolysis Industrial processes for altering the physical structure of biochar Soil surface areas and biochar Biochar nanoporosity Biochar macroporosity Particle-size distribution Biochar density Mechanical strength Future research Characteristics of Biochar: Microchemical Properties James E. Amonette and Stephen Joseph Introduction and scope Formation and bulk composition Surface chemistry

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BIOCHAR FOR ENVIRONMENTAL MANAGEMENT

Characteristics of Biochar: Organo-chemical Properties Evelyn S. Krull, Jeff A. Baldock, Jan O. Skjemstad and Ronald J. Smernik Introduction Elemental ratios 13C-nuclear magnetic resonance (NMR) spectroscopy Oulook Biochar: Nutrient Properties and Their Enhancement K. Yin Chan and Zhihong Xu Introduction Nutrient properties of biochars and crop production responses Factors controlling nutrient properties of biochar Improving the nutrient value of biochars: Research opportunities and challenges Conclusions Characteristics of Biochar: Biological Properties Janice E.Thies and Matthias C. Rillig Introduction Biochar as a habitat for soil microorganisms Biochar as a substrate for the soil biota Methodological issues Effects of biochar on the activity of the soil biota Diversity of organisms interacting with biochar Conclusions Developing a Biochar Classification and Test Methods Stephen Joseph, Cordner Peacocke, Johannes Lehmann and Paul Munroe Why do we need a classification system? Existing definitions and classification systems for charcoal, activated carbon and coal Proposed classification system for biochar Biochar Production Technology Robert Brown Introduction History of charcoal-making Mechanisms of biochar production from biomass substrates Opportunities for advanced biochar production Biochar Systems Johannes Lehmann and Stephen Joseph Introduction Motivation for biochar soil management Components of biochar systems Biochar systems Outlook

53 53 54 58 63 67 67 68 74 79 81 85 85 86 89 91 92 95 102 107 107 108 112 127 127 128 133 139 147 147 148 149 154 164

CONTENTS

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Changes of Biochar in Soil Karen Hammes and Michael W. I. Schmidt Introduction Mechanisms of incorporation and movement of biochar in soil Physical changes of biochar in soil Chemical changes of biochar in soil Biotic changes of biochar in soil Conclusions Stability of Biochar in Soil Johannes Lehmann, Claudia Czimczik, David Laird and Saran Sohi Introduction Extent of biochar decay Biochar properties and decay Mechanisms of biochar decay Stabilization of biochar in soil Environmental conditions affecting biochar stability and decay A biochar stability framework Biochar Application to Soil Paul Blackwell, Glen Riethmuller and Mike Collins Introduction Purpose of biochar application Biochar properties and application methods Methods of application and incorporation: Specific examples Comparison of methods and outlook Biochar and Emissions of Non-CO2 Greenhouse Gases from Soil Lukas Van Zwieten, Bhupinderpal Singh, Stephen Joseph, Stephen Kimber, Annette Cowie and K. Yin Chan Introduction Evidence for reduced soil greenhouse gas (GHG) emissions using biochar Biological mechanisms for reduced GHG emissions following biochar application Abiotic mechanisms influencing GHG emissions using biochar Conclusions Biochar Effects on Soil Nutrient Transformations Thomas H. DeLuca, M. Derek MacKenzie and Michael J. Gundale Introduction Nutrient content of biochar Potential mechanisms for how biochar modifies nutrient transformations Direct and indirect influences of biochar on soil nutrient transformations Conclusions

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Biochar Effects on Nutrient Leaching Julie Major, Christoph Steiner, Adriana Downie and Johannes Lehmann Introduction Evidence for relevant characteristics of biochar Magnitude and temporal dynamics of biochar effects on nutrient leaching Conclusions and research needs

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Biochar and Sorption of Organic Compounds Ronald J. Smernik Introduction Sorption properties of ‘pure’ biochars Influence of biochar on the sorption properties of soils Effects on sorption of adding biochar to soil Direct identification of organic molecules sorbed to biochar Conclusions and directions for future research Test Procedures for Determining the Quantity of Biochar within Soils David A. C. Manning and Elisa Lopez-Capel Introduction Biochar quantification methods Routine quantification of biochar in soils Conclusions Biochar, Greenhouse Gas Accounting and Emissions Trading John Gaunt and Annette Cowie The climate change context Greenhouse gas emissions trading How biochar contributes to climate change mitigation What mitigation benefits are tradable in a pyrolysis for biochar and bioenergy project? Greenhouse gas balance of example biochar systems Issues for emissions trading based on pyrolysis for bioenergy and biochar Conclusions Economics of Biochar Production, Utilization and Greenhouse Gas Offsets Bruce A. McCarl, Cordner Peacocke, Ray Chrisman, Chih-Chun Kung and Ronald D. Sands Introduction Pyrolysis and biochar Examination of a biomass to pyrolysis feedstock prospect Sensitivity analysis Omitted factors Conclusions

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CONTENTS

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Index

Socio-economic Assessment and Implementation of Small-scale Biochar Projects Stephen Joseph Introduction Developing a methodology Model scenario of a hypothetical village-level biochar project Conclusions Taking Biochar to Market: Some Essential Concepts for Commercial Success Mark Glover Introduction Biochar’s positioning in the sustainability and climate change agendas The sustainability context for biomass generally Inherent characteristics of the biomass resource Lessons from the first-generation liquid biofuels sector Biochar commercialization framework Commercial factors and business modelling Policy to Address the Threat of Dangerous Climate Change: A Leading Role for Biochar Peter Read The tipping point threat Beyond emissions reductions Carbon removals The economics of biosphere C stock management (BCSM) and biochar A policy framework for carbon removals:The leaky bucket Food versus fuel and biochar Conclusions

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List of Figures,Tables and Boxes

Figures 1.1 1.2 1.3 1.4

Structure of graphite as proven for the first time by J. D. Bernal in 1924 Advertisement for biochar to be used as a soil amendment in turf greens Motivation for applying biochar technology The global carbon cycle of net primary productivity and release to the atmosphere from soil in comparison to total amounts of carbon in soil, plant and atmosphere, and anthropogenic carbon emissions 2.1 Ideal biochar structure development with highest treatment temperature (HTT) 2.2 Relationship between biochar surface area and micropore volume 2.3 Biochar surface area plotted against highest treatment temperature (HTT) 2.4 Scanning electron microscope (SEM) image showing macroporosity of a wood-derived biochar produced by ‘slow’ pyrolysis 2.5 SEM image showing macroporosity in biochar produced from poultry manure using slow pyrolysis 2.6 Influence of biomass pre-treatment and HTT on the particle-size distribution of different biochars 2.7 Helium-based solid densities of biochars with HTT 2.8 Bulk density of wood biochar, plotted against that of its feedstock 3.1 Biochar yields for wood feedstock under different pyrolysis conditions 3.2 Selected small-angle X-ray scattering (SAXS) profiles from normal wood 3.3 Transmission electron microscopy (TEM) images of modern biochar samples 3.4 Schematics demonstrating the concepts of the quasi-percolation model of Kercher and Nagle (2003) 3.5 Scanning electron microscopy (SEM) micrographs of different mineral phases in chicken manure biochar and their energy-dispersive X-ray spectroscopy (EDS) spectra 3.6 Distribution of non-C elements on the surface of wood biochar determined by microprobe analysis 3.7 SEM micrographs and associated EDS spectra for mineral phases in maize-cob biochar prepared by flash pyrolysis 3.8 SEM micrographs and associated EDS spectra for mineral phases in white oak biochar prepared by fast pyrolysis 3.9 SEM micrographs and associated EDS spectra for mineral phases in poplar wood biochar from a combustion facility 3.10 Heteroatoms and functional groups commonly found in activated carbons

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3.11 Macroscopic representation of the features of C surface chemistry thought to be sufficient for understanding aqueous-phase sorption phenomena; microscopic representation of the functional groups thought to be sufficient for understanding aqueous-phase adsorption phenomena 4.1 Van Krevelen diagram of H/C and O/C ratios of biochars made under different temperature regimes between low-temperature biochars and those produced by high-temperature pyrolysis, as well as naturally occurring black C 4.2 Changes in elements with increasing temperature during the charring process of wood, as well as data from fast pyrolysis products and biochar 4.3 Changes in functional group chemistry obtained by nuclear magnetic resonance (NMR) spectroscopy with increasing temperature 4.4 Cross-polarization (CP) NMR spectra from biochar derived from wood (Eucalyptus camaldulensis) and pea straw (Pisum sativum) materials (biochar produced in the laboratory at 450°C in a muffle furnace for 1 hour) and vegetation fire residues from a natural fire 4.5 Changes in the proportions of O-alkyl, aryl and alkyl C from grass biochars produced at different temperatures 4.6 Comparison of the proportion of total signal intensity from CP 13C-NMR of biochars produced at unknown temperatures with those from known temperatures 5.1 Dry matter production of radish as a function of biochar application rate, either with or without N fertilizer application 5.2 Changes in total N, P and K concentrations in biochars produced from sewage sludge at different temperatures 5.3 Changes in K contents of rice straw biochar as a function of temperature during pyrolysis 5.4 Available P (bicarbonate extractable) as a percentage of total P of biochar as compared to biosolid and dried biosolid pellet 6.1 The porous structure of biochar invites microbial colonization 6.2 Arbuscular mycorrhiza fungal hyphae growing into biochar pores from a germinating spore 6.3 Time course of dissolved organic carbon (DOC) adsorption in slurries of soil with 30t biochar ha–1 added compared to unamended soil 6.4 Soil respiration rate decreases as the rate of biochar applied increases 6.5 Potential simultaneous adsorption of microbes, soil organic matter, extracellular enzymes and inorganic nutrients to biochar surfaces 6.6 Taxonomic cluster analysis of 16S rRNA gene sequences from Amazonian Dark Earths (ADE) and adjacent pristine forest soil based on oligonucleotide fingerprinting 6.7 Bacteria, fungi and fine roots readily colonize biochar surfaces 7.1 Classification of biochars as high, medium and low C-containing as a function of temperature for different feedstocks 7.2 Possible framework for classifying biochars 8.1 Large pit kiln 8.2 Mound kiln 8.3 Operation of a mound kiln showing the heavy smoke emitted during the carbonization process 8.4 Brick kiln

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LIST OF FIGURES, TABLES AND BOXES

8.5 8.6 8.7 8.8 8.9 8.10 8.11

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8.15 8.16 8.17 8.18 8.19 8.20 9.1 9.2 9.3 9.4 9.5 9.6 9.7 9.8 10.1

10.2 10.3 11.1 11.2 11.3

Transportable metal kiln,Tropical Products Institute (TPI) The Missouri-type charcoal kiln The continuous multiple hearth kiln for charcoal production Chemical structure of cellulose Structural formula for a common hemicellulose found in softwoods Monomers from which lignin is assembled Thermogravimetric analysis of the pyrolysis of cellulose, hemicellulose (xylan) and lignin at constant heating rate (10°C min–1) with N2 (99.9995 per cent) sweep gas at 120mL min–1 Reaction pathways for cellulose decomposition Chemical equilibrium products of cellulose pyrolysis: (a) effect of pressure at 400°C; (b) effects of temperature at 1MPa Carbon conversion for gasification of cellulose as a function of equivalence ratio (fraction of stoichiometric O requirement for theoretical complete combustion) calculated with STANJAN chemical equilibrium software Effect of pressure and purge gas flow rate on carbonization of cellulose Effect of pressure and purge gas flow rate on heat of pyrolysis for cellulose Screw pyrolyser with heat carrier Fluidized-bed fast pyrolysis reactor Different kinds of gasifiers suitable for co-production of producer gas and biochar Wood-gas stove Components of biochar systems Energy use in transportation of wood chips (Salix) as a percentage of energy delivered by the biomass Pyrolysis unit and adjacent poultry house,Wardensville,West Virginia Estimated annual production of the main biomass resources appropriate for biochar and bioenergy production of a 2.7ha farm in western Kenya Production of biochar using simple earthen mound kilns Highly diverse cropping system (maize, yam) with secondary forest in Ghana managed with rotational slash-and-char for 20 years Batch kiln for production of biochar without energy capture Case study from Sumatra, Indonesia A basic model of a complex biochar particle in the soil, containing two main distinguished structures of biochar: crystalline graphene-like sheets surrounded by randomly ordered amorphous aromatic structures and pores of various sizes Van Krevelen plot of the elemental composition change of five types of biochar with incubation and over time Scanning electron micrographs of biochar particles (a) in the clay fraction and (b) in the density fraction