Payment mechanism for
Technology Management
Payment mechanism for
(inter)national biochar carbon trade
Based upon established protocols within the framework of IPCC and Kyoto agreement-Master thesis, Technology
Management-University of Groningen
Author: T.F. Bouwkamp student number 1733427
Supervisors: Prof.dr.ir. R.J.F. van Haren Prof.dr.mr. C.J. Jepma
September, 2009
Preface
This thesis is part of the Master of Science (MSc) program Technology Management at the University of Groningen and serves as a final document before graduation. The study Technology Management includes the relation between technology and management. Since technology plays an important role in our society, firms and organizations need to focus on the use of new product and process technology in order to meet customer needs. This thesis will elaborate further on such a promising technique/innovation: Biochar.
With regard to the development of this thesis I want to express my appreciations to the following persons which all contributed to the development of this thesis:
Many thanks to prof.dr.ir. R.J.F. van Haren for his commitment, the discussions, his time, the insights, the possibility to conduct research with regard to such an interesting subject and for being my first supervisor. Furthermore, I want to thank Productschap Akkerbouw and Kiemkracht for the ability to conduct this research. Besides, I want to thank prof.dr.mr. C.J. Jepma for his knowledge concerning CCS strategies, the idea to compare different CCS strategies with biochar and for being my second supervisor. Moreover, my thanks goes to Mr. J. Coszijnsen for meeting me in Utrecht where we started a brainstorm concerning the developed payment mechanism and for verifying the information given within the chapter international trade. Finally, I want to thank Ms. I. van Maanen for supporting me during the development of this thesis.
Leeuwarden, September 2009
I
Summary
Biochar offers the opportunity to create a triple-win scenario for simultaneously sequestering carbon, while increasing crop yields by improving soil and water quality of (sandy) soils and producing bio-energy. It is the carbon-rich product obtained when biomass, such as wood, (chicken) manure or leaves, is heated in a closed container with little or no available air. With no oxygen present, the biomass cannot burn or gasify. This process is called pyrolysis which converts trees, grasses, crop residues or other organic material into biochar, with twofold higher carbon content than ordinary biomass.
In sum, biochar additions to agricultural fields are beneficial since: bio-energy is produced in a sustainable way, bio-waste is managed effectively, fertility on (sandy) soils is improved, crop yield might increase, machinability of clayey soils improved, CO2is being sequestered and a time buffer is created which enables scientists to come up with innovations with regard to renewable energy sources such as solar, wind and/or wave power.
Therefore, the use of biochar seems promising when mixed into agricultural soils. However, despite all benefits, many NGOs still are sceptical.
Indeed, some critiques make sense and considerable uncertainties remain about the applicability of biochar to different soils and crops and about how much biochar production is feasible with respect to constraints on economics, land availability and competing demands for biomass (including direct incorporation into the soil). Nonetheless, there is evidence that at least for some crop/soil combinations, addition of biochar may be beneficial.
II toxicity and employers safety. However, these conditions are not final. On the contrary, the given conditions are flexible and can differ per chosen scenario.
Based upon these conditions, a payment mechanism is developed which enables agriculturalists to maximize the adoption of biochar in the Netherlands.
CO2 storage B Production function € C3 C4 C5 Purchasing function Trustee Sales function Other overhead Bio-energy customers A D C Soil €2 CO2 customers € €2 € C5 C1 € € €1 €1 € C2 Crop yield €1 Compliance market Voluntary market
Figure 1: Scheme for possible payment interventions C1= Biomass, C2= GHG emissions, C3and C4= Bio fuels, C5= Biochar,
€ = Money, €1= Incentives, €2= Carbon Credits, moment to monitor.
Subsequently, this research investigates whether the developed payment mechanism can be generalized, i.e., can each country have the same payment mechanism? Since every country has different interests and rules and legislations, the developed payment mechanism cannot be generalized. Two extremes with regard to a payment mechanism abroad can be distinguished and allocated in the following matrix:
III In sum, the most favorable situation from an agriculturalist perspective to adopt biochar is one in which a highly positive government complements rules to adopt biochar, i.e. high promoting interests which heterogeneous rules and legislation. Least favorable is the situation in which a government wants to counterwork on the adoption of biochar whereby it can complement its own restrictions.
Finally, a business case is developed after which the following can be concluded:
It seems economically more viable to obtain biochar by means of a large-scale fast pyrolysis unit instead of a small-scale slow pyrolysis unit. Moreover, the cost of the biochar strategy is in range with other CCS reducing strategies.
IV
Glossary
BAP Biochar Adoption Platform.
Biochar The carbon-rich product obtained after pyrolysis of biomass. In this
thesis also known as: black carbon, char, and charcoal.
Biological carbon cycle The biogeochemical cycle by which carbon is exchanged among the
biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of the Earth.
Biomass Trees, saw dust, wood chips, vegetables, (chicken) manure, fruit,
grasses, sludge, crop residues and/or other organic materials.
Bio-oil The condensable vapor obtained after pyrolysis of biomass.
Carbon credit Equivalent to 1 ton reduced CO2. It can be traded on the CO2market.
Also known as emission rights or emission allowances.
CCS Carbon Capture and Storage.
CDM The Clean Development Mechanism enables industrialized countries to reduce GHG emissions abroad after which carbon credits can compensate on national emissions.
CO2 Carbon dioxide.
Compliance market The compliance CO2 market is the market on which companies are
required to trade in emission rights or carbon credits. I.e., companies within the NAP, which have a pre-determined emission cap.
Emission cap/ceiling The pre-determined amount of CO2which a country and/or companies
may emit. I.e. the allocated emission rights.
EU ETS European Union Greenhouse Gas Emission Trading System is the CO2
trading system within the European Union based on agreements under the Kyoto protocol.
GHG Greenhouse gasses.
IPCC The Intergovernmental Panel of Climate Change is the leading body for the assessment of climate change, established by the United Nations Environment Program (UNEP) and the World Meteorological Organization (WMO) to provide the world with a clear scientific view on the current state of climate change and its potential environmental and socio-economic consequences.
V
Kyoto protocol The Kyoto protocol is an international agreement linked to the United
Nations Framework Convention on Climate Change (UNFCCC). The major feature of the Kyoto Protocol is that it sets binding targets for 37 industrialized countries and the European community for reducing greenhouse gas (GHG) emissions.
MNS content The concentration Mineral, Nitrogen and Sulphur in biomass.
Moisture content The percentage moisture in biomass.
National Allocation Plan The National Allocation Plan (NAP) determines which methods will
be used to allocate emission rights, the number of rights which are being allocated and the institutions which will receive them.
NGO Nongovernmental Organization, i.e. stakeholders.
Oxy-fuel combustion See pre-combustion.
pH Acidity.
Photosynthesis The transformation from CO2and H2O to C6H12O6(Glucose) and O2.
Pre- and post combustion A method to capture CO2.
Pyrolysis Thermal degradation of biomass in the absence of oxygen to produce
condensable vapors, gases, and charcoal. In some instances a small amount of air may be admitted to promote this endothermic process .
Syngas The gas obtained after pyrolysis of biomass.
Terra Preta Portuguese for black soil, i.e. carbon-rich soil.
Voluntary market The voluntary CO2 market enables companies to trade in CO2 on a
voluntary basis. Since trade is on a voluntary basis, the monitoring process is relatively easy compared to the monitoring process in the compliance CO2market. Indeed, the price of an emission allowance is
VI
Table of content
Introduction... 1
1. Carbon Capture and Storage ... 6
1.1. Introduction to CCS... 6
1.2. CCS strategies ... 7
1.3. Rethinking CCS... 8
2. Introduction to Biochar ...11
2.1. The objectives of biochar ...11
2.2. How is biochar produced? ...12
2.2.1. Slow pyrolysis ...13
2.3. Carbon negative fuels...14
2.4. Feedstock for pyrolysis ...16
2.4.1. Organic waste management and biochar ...16
2.5. Soil fertility and biochar...17
2.6. The influence of biochar on soil structure ...18
2.7. Stability of biochar in the soil ...19
2.8. Rethinking biochar ...21
3. Critiques with regard to Biochar ...25
3.1. Biochar, a big new threat to people, land and ecosystems ...25
3.2. Biochar for climate change mitigation: fact or fiction?...30
4. Criteria for a valid biochar strategy? ...36
4.1. Criteria for feedstocks ...36
4.2. Criteria for biochar application in soils ...37
5. What position can Biochar take in (inter)national carbon trade and post Kyoto climate agenda? ...38
5.1. Kyoto Protocol ...39
5.1.1. Clean development mechanism...40
5.1.2. Joint implementation ...40
5.1.3. International emission trading ...41
VII
5.3. European Union Greenhouse Gas Emission Trading System ...42
5.4. Compliance market...43
5.4.1. Cap-and-trade ...43
5.4.2. Credit against baseline ...43
5.5. Voluntary market...44
5.6. Framework development ...45
6. What payment mechanism is suitable for those (agriculturalists) who adopt and use biochar? ...47
6.1. Prerequisites with regard to the price of biochar ...47
6.2. Prerequisites with regard to a suitable payment mechanism within the Netherlands ...48
6.3. Payment mechanism for the Netherlands ...49
6.3.1. CO2market and revenues per carbon credit ...52
6.4. Generalized payment mechanism...53
6.5. Business case scenario...56
6.5.1. Cost per ton biochar compared to other GHG reducing technologies ...58
6.6. Conclusions with regard to the developed payment mechanism ...59
7. Conclusion...61
8. Future research ...66
References...68
Introduction
As a result of the world’s industrialization and the increased economic welfare, global warming has become a major issue in today’s political agenda. The concentration of carbon dioxide (CO2) in the atmosphere has increased by more than 30 percent over the last 250 years, largely due to human activity[1]. This figure will increase in the nearby future since China now is building about two coal power stations every week[2]. Therefore, according to research, more CO2 is emitted in the atmosphere (coal emits 978 gram CO2 per kWh compared to oil (891 gram CO2per Kwh), natural gas (883 gram CO2per Kwh) and wind energy (3-22 gram CO2 per Kwh)[3]). CO2is an important greenhouse gas (GHG) which affects the climate1. Figure 28 in appendix 1 depicts the effects of CO2in the atmosphere. “Note that the average Earth surface temperature correlates well with the amount of CO2 in the atmosphere”[4]. Hence, since CO2 levels in the atmosphere have increased, surface temperature has gone up simultaneously. This illustrates the worrisome conditions regarding CO2emissions. Moreover, considering that “fossil fuels supply over 85% of all primary energy, and nuclear power, hydroelectricity, and renewable energy (commercial biomass, geothermal, wind, and solar energy) supply the remaining 15%”[5], it is likely that this figure will increase the coming decades. Furthermore, it is not safe to assume that the huge investments made nowadays bring significant results in the nearby future. Therefore, reducing GHG, in order to meet the Kyoto protocol2, is necessary. Moreover, “with global human population already at 6.8 billion[6]and growing and with a total ecological footprint already 1.3 times the world’s carrying capacity[7], productive land is a scarce resource, and is set to become more so”[8].
1
Common greenhouse gases in the Earth's atmosphere include Carbon dioxide (CO2), Methane (CH4), Nitrous oxide (N2O), Hydrofluorocarbons (HFCs), Perfluorocarbons (PFCs), Sulphurhexafluoride (SF6)[9].
2 The Kyoto Protocol is an international agreement linked to the United Nations Framework Convention on
In order to emphasize further on the relevance of this thesis I refer to appendix 63in which a policy brief of the Food and Agriculture Organization (FAO) of the United Nations is included. In sum, this policy brief provides several proposals with regard to climate change mitigation and on how it might be addressed in an agricultural setting: “Parties shall cooperate in R&D of mitigation technologies for the agriculture sector, recognizing the necessity for international cooperative action to enhance and provide incentives for mitigation of GHG emissions from agriculture, in particular developing countries”[80].
Agriculture is under pressure to produce more to meet increased food demands associated with a growing population, giving rise to pressures for land conversion to agriculture and land degradation that generate increased emissions. Moreover, nationally appropriate mitigation action in the agriculture sector will vary across countries and will need to be in tune with country circumstances and capacities. Therefore it is necessary to develop new financing mechanisms with broader, more flexible approaches, integrating different funding sources and innovative payment/incentive/delivery schemes to reach producers, including smallholders. Since the objectives within this thesis are in line with the proposals provided within the policy brief of the FAO this thesis hopes to contribute to certain transitions in the FAO policy making process.
Hence, the underlying problem can be formulated in twofold: (1) humanity (including agriculture) is emitting to much CO2and (2) humanity (including agriculture) is exhausting the Earth.
Consequently, in order to reduce CO2 levels, scientists propose several geological storage solutions[5], as has been described in appendix 2. Indeed, for many alternative Carbon Capture and Storage (CCS) methods CO2is only stored away, and is not locked up permanently.
Beside these CCS possibilities, a relatively new product called biochar4provides more benefits. “Simply put, biochar is the carbon-rich product obtained when biomass, such as wood, manure or leaves, is heated in a closed container with little or no available air”[11]. With no oxygen present, the biomass cannot burn or gasify. This process is called pyrolysis which converts trees, grasses, crop residues or other organic material into biochar, with about twofold higher
3The policy brief from the FAO is received about one week before the deadline of this thesis. This indicates that what will be developed in this thesis is highly relevant and can serve as an input for transitions with regard to FAO policy making.
carbon content than ordinary biomass. Pyrolysis and the carbonization of biomass can play a role in the fight against global warming since biochar locks up rapidly decomposing carbon in plant biomass in a much more durable form.
A further discussion with regard to biochar provided a number of questions, namely: What benefits provides the use of biochar, from which perspective?
Are there any critiques with regard to biochar?
What is the potential for biochar in terms of carbon trade?
These questions triggered the need to find a suitable perspective wherein the research should be conducted. Chosen is to conduct the research from an agriculturalists perspective since biochar has the potential to increase crop yield and improve soil stability and therefore can be seen as a fertilizer. Subsequently, Productschap Akkerbouw5 is approached to conduct the research for after which the following main research question was developed:
What is the function of biochar in Carbon Capture and Storage strategies, and what characteristics should a payment mechanism have in order to allocate indirect revenues, obtained by reducing the carbon concentration of the atmosphere, to enable that agriculturalists adopt biochar and to improve future progress in the process to biochar.
The main question is based upon established protocols within the framework of Intergovernmental Panel on Climate Change (IPCC)6 and Kyoto agreement and can be distinguished in two targets:
In essence, the first target is set to control whether the use of biochar is a suitable CO2reducing and soil improving strategy. Subsequently, when biochar looks promising, the target will shift towards the development of a payment mechanism which enables agriculturalists to maximize the use of biochar.
The main question can be divided into several sub questions, namely: 1. What is meant with Carbon Capture and Storage?
2. What is biochar?
5Productschap Akkerbouw is a cooperation between growers, producers, manufacturing, bakers and retail traders and has as its objective to bring interests and activities for entrepreneurs and employees together.
3. Are there possible critiques with regard to biochar?
4. What criteria have to be taken into account to for a valid biochar strategy?
5. Which position can biochar take in (inter)national carbon trade and post Kyoto climate agenda?
6. Which payment mechanism is suitable for agriculturalists who adopt and use biochar? 7. Can each country have the same payment mechanism?
The first question clarifies what is meant with CCS. Therefore, several strategies will be mentioned in order to develop understanding. The second question is formulated in order to conclude whether biochar fits the topic ‘CCS strategies’. Possible issues involved are:
What are the characteristics of biochar? How is biochar obtained?
What are the advantages, from agriculturalists perspective, when biochar is used?
Thirdly, critiques are mentioned. Several scientists and nongovernmental organizations (NGOs) address possible critiques with regard to biochar. Doubts concerning soil stability, carbon storage and more have been mentioned. Main goal while comparing supporters and opponents of biochar is to find out whether critiques are reasonable and which conditions should be included within a possible payment mechanism. Moreover, these critiques will clarify where possible future projects should focus on. Hence, when critiques are plausible, the possibility for prerequisites increases (e.g. only small-scale production of biochar). The answer of the third question automatically leads to the fourth question. Question four develops understanding in possible prerequisites, based on critiques and literature. Once the first target of the research is achieved –define biochar as a suitable CO2reducing technique- I can determine what position biochar can take in (inter)national carbon trade. Subsequently, a suitable payment mechanism can be developed which enables both agriculturalists and producers to maximize the use of biochar and which does right to the critiques mentioned by NGOs.
Figure 3: Conceptual model
Main goal is to reduce CO2 levels in the atmosphere in order to cope with global warming. Therefore, I have studied CCS strategies, biochar, and (inter)national agreements. Subsequently, I can develop a payment mechanism which -if biochar looks promising- enables that agriculturalists can maximize the use of biochar.
Or in terms of sequence:
Figure 4: Structure of the thesis Before going on, I want to emphasize that all recommendations made during this research are
1.
Carbon Capture and Storage
Within this chapter greater understanding with regard to carbon capture and storage (CCS) strategies will be developed. First, CCS is explained briefly after which several CCS categories can be distinguished.
1.1. Introduction to CCS
In recent decades, there is increasing attention to global warming. Although there is a natural greenhouse effect, the warming of the Earth is intensified by the production of carbon dioxide (CO2).
CO2is a main greenhouse gas. In essence, the gas is a harmless gas which occurs naturally in the atmosphere. CO2 takes part in the natural cycle of photosynthesis, i.e. the transformation from CO2and H2O to C6H12O6 (Glucose) and O2. Eventually almost all life on Earth depends on photosynthesis. When this natural cycle is in balance, no problems occur. However, if the CO2 concentration in the atmosphere is too high or too low, ecosystems will become unbalanced. Since the levels of CO2have increased by more than 30 percent over the last 250 years[1], the CO2 concentration in the atmosphere is too high which results in unbalanced ecosystems.
per produced kWh, which is much higher than for example oil (891 gram CO2 per Kwh), natural gas (883 gram CO2per Kwh) and/or wind energy (3-22 gram CO2per Kwh)[3]. “By far the largest potential sources of CO2 today are fossil-fueled power production plants. Power plants emit more than one-third of the CO2 emissions worldwide”[5]. Since China now is building about two coal power stations every week[2], the CO2concentration in the atmosphere will increase further. Moreover, since 85% of all primary energy is supplied by fossil fuels[5] and expects believe that this number only decreases to 70-80% in 2020[13], it is likely that the percentage of CO2in the atmosphere will increase in the (nearby) future.
In line with the European Unions agreed objective which states that global average temperature increase should not exceed 2°C above pre-industrial level, it is necessary to reduce CO2 emissions with 60-80%[13]. Hence, it is necessary to find suitable solutions which cope with the GHG problem, and especially the CO2issue involved. Strategies which are developed to extract CO2from the atmosphere are known as Carbon Capture and Storage (CCS) strategies or carbon sequestration. “Carbon sequestration can be defined as the capture and secure storage of carbon that would otherwise be emitted to, or remain, in the atmosphere. The rationale for carbon capture and storage is to enable the use of fossil fuels while reducing the emissions of CO2into the atmosphere, and thereby mitigating global climate change”[5].
1.2. CCS strategies
As elaborated in appendix 2, different CCS strategies already have been developed, such as the sequestration of CO2in depleted oil and gas fields, ocean storage and deep saline formations. These CCS strategies can be distinguished into two categories: category 1 and category 2. The CCS strategies in category 1 actually capture CO2 from the atmosphere by means of pre-combustion, post-combustion and/or oxy-fuel combustion7.
Figure 6: CCS strategies, category 1
Category 2 strategies are based on the transformation of CO2by using organisms which apply photosynthesis in order to obtain glucose (C6H12O6). One possibility is forestation. By increasing the amount of forests, CO2levels in the atmosphere can be compensated. Another possibility is the use of algae. Just like trees, algae need CO2to grow. Hence, by increasing the amount of algae, more CO2is being captured. Furthermore, from algae, bio-oil can be obtained.
Figure 7: CCS strategies, category 2 With regard to biochar. Strictly, biochar does not capture CO2from the atmosphere since the carbon already is embedded into the biomass. Instead of capturing CO2 (by pre-combustion, post-combustion or oxy-fuel combustion) biochar offers the possibility to change the rapid decomposing biomass into a much more durable form by means of carbonization. Therefore, when considering CCS as a means to reduce CO2from the atmosphere it is possible to include biochar in category 2 of the CCS strategies.
‘Tangible’ CO2which can be stored
CO2is stored in organisms (photosynthesis) Category 1
Category 2 ForestationAlgae
Biochar
Figure 8: The CCS categories. Biochar is a category 2 CCS strategy since it converts CO2from the rapid biological carbon cycle to a much more
slower CO2cycle by means of carbonization.
In order to obtain greater understanding with regard to CCS strategies, I refer to appendix 2 in which the capturing strategies, the techniques behind these strategies, and the different phases of the CCS process will be elaborated upon briefly.
1.3. Rethinking CCS
fields and other CCS strategies, as described in appendix 2, are only a few of the alternatives developed in recent years. However, scientists alone cannot fight global warming effectively. Other parties involved, such as society and governments should also create great awareness with regard to CO2reduction and especially their own energy usage. Figure 9 indicates how global CO2emissions can be reduced by 71 percent in 2050 compared to emissions today[14].
Figure 9: November 2007, strategy to reduce CO2[14]. Based upon calculations, figure 9 indicates how global emissions can be reduced with 71 percent in 2050
compared to emissions today.
With regard to figure 9, it shows how the combination of enhanced energy efficiency, more renewable energy, and full deployment of CCS can lead to sufficient reduction in global CO2 emissions[14]. CCS is an important means when attempting to reduce global CO2 emissions. “The potential for reducing CO2emissions by enhanced energy efficiency and more renewable energy production is limited in this time period. Therefore, other options are required to complement energy efficiency and renewable energy in the strategy to reduce global CO2 emissions[14].
Besides the storage of CO2 in reservoirs, other relevant CCS strategies, as described in appendix 2, still are in development. For now, understanding is developed with regard to CCS, its purpose and the possibilities it offers. However, these topics -although interesting- fall outside the scope of this research. Instead the focus is on another CO2 reducing strategy: Biochar.
bio-energy, sequestering carbon, while increasing crop yields by improving soil and water quality.
Figure 10 shows a biological carbon cycle in which carbon is extracted by means of carbonization of biomass. Subsequently, the carbonized biomass can be sequestered into the soil. Besides, the figure also depictures CCS categories 1 and 2 in which carbon actually is captured from the atmosphere by means of Pre-, Post-, Oxy-fuel combustion or photosynthesis.
Figure 10: From the fast carbon cycle to the slow carbon cycle Category 1 CCS strategies actually capture CO2after which the CO2is being stored in the slow(er) carbon cycle.
By means of category 2 CCS strategies, the amount of forests in the fast carbon cycle can be increased. Furthermore, released CO2from extracted bio fuels can be captured by means of a category 1 CCS strategy. Finally, biomass in the fast carbon cycle (e.g. organic waste) can be stored away into the slow(er) carbon cycle by
means of carbonization.
With regard to carbonization. During the fast carbon cycle, where biomass adsorbs CO2from the atmosphere to synthesize tissue, it accumulates carbon. However, during decomposition of the biomass the carbon is released again as CO2. In undisturbed ecosystems the accumulation and release of CO2 is balanced. However, due to human activities, far more CO2is produced than processed. Consequently, the ecosystem is not in equilibrium. By means of a carbonization technique, the embedded CO2can be locked in and sequestered into the soil. Subsequently, the CO2concentration of the atmosphere decreases.
2.
Introduction to Biochar
This chapter will elaborate further on biochar as a CO2 reducing strategy and aims on developing a greater understanding with regard to biochar, the characteristics and the prerequisites.
2.1. The objectives of biochar
Biochar is a by-product of some biomass-to-energy processing systems. The biochar strategy has as its objective to create awareness, to build confidence in biochar as a way to store carbon and to increase soil quality and stability in order to make the soil climate change resilient. Biochar improves soil stability, soil quality, soil fertility and it increases water holding capacity. Biochar also increases soil biodiversity and hence increases soil resilience to soil borne diseases. Furthermore, biochar has positive agronomic effects and increases in a sustainable way crop yields. It remains stable in soils for centuries and makes soils resilient to the effects of climate change, especially the effects of weather extremes. Finally, biochar has the ability to remediate poor or contaminated soils[11].
This chapter will elaborate further on the characteristics of biochar, its purpose and the possibilities it offers. Figure 11 shows the four objectives of biochar[11].
Mitigation of climate change Energy production Soil improvement Waste management
2.2. How is biochar produced?
To obtain biochar, “biomass is heated in a closed container with little or no available air”[11]. This burning process is called pyrolysis, whereby biomass, such as trees, grasses, crop residues and/or other organic materials are transferred into charcoal, bio-oil and gas[11][15]. scientiests explain pyrolysis as “thermal degradation of biomass in the absence of oxygen to produce condensable vapors, gases, and charcoal; in some instances a small amount of air may be admitted to promote this endothermic process”[16]. The released energy during pyrolysis is approximately 7 times higher than what is needed to maintain the pyrolysis process[17]. Furthermore, a distinction among slow pyrolysis, conventional pyrolysis, and the recently redefined fast pyrolysis can be made[16].
“Pyrolysis involves trade-offs between the production of biochar, bio-oil and gas, and the process can be calibrated to maximize the output of different products, depending on economic factors”[16]. The temperature, time for heating and other variables determine whether the pyrolysis action produces predominately charcoal solids (typically via slow processes) or bio-oil liquids (typically via fast pyrolysis). Table 1 provides us with an idea concerning the outputs of the different types of pyrolysis.
2.2.1. Slow pyrolysis
Slow pyrolysis converts biomass into a liquid, solid and gaseous form. “The process involves slower heating to less than 400°C. The biomass is typically in the reactor for at least thirty minutes and possibly several hours”[11]. “Slow pyrolysis has been used for centuries to produce charcoal, tars, alcohols such as ethanol and methanol and other solvents”[19]. Furthermore, “It is well-known that both the yield of char and its properties, including size, morphology, composition, and reactivity depend strongly on the pyrolysis conditions in which the char is formed”[24]. Different variables have an influence on the output of the process. One is the moisture content of the biomass. Research points out that “the yield of bio-oil and char increased, while the yield of gas decreased accordingly with microwave drying of the biomass input”[25]. Scientists also conclude that microwave drying can be used together with heating air drying from the heat waste of the pyrolysis process to decrease the moisture content of biomass before processing in a pyrolysis unit[25].
Another process variable is the heating rate. This rate has to be minimal, for an optimal char output. Table 2 shows that slow heating rates should go alongside temperatures below 400ºC. Research points out that slow pyrolysis couples slow heating rates (typically 5ºC – 80ºC minimum) with moderate temperature (typically 300ºC – 600ºC), in order to maximize char yield[26]. Furthermore, large particles give an increase in char yield, which is related to the slower heating rate inside the particles. Finally, long gas residence time increases the char yield via secondary coking[26].
With regard to table 2 it can be concluded that while the carbon content of the produced char increases with increasing temperature, the carbon yield8of the pyrolysis process decreases (e.g. wood, 400 ºC contains 79.8% carbon and carbon yield is 51.5%).
Table 2: The carbon yield for different input materials[26]. RCG is a type of grass with a wide distribution in Europe, Asia, northern Africa and North America. RDF
represents pre-processed municipal solid waste which is usually distributed in pellets.
Raw biomass has a carbon yield of 100%. However, this cannot be stored into the soils since it decomposes and therefore stays in the fast carbon cycle. Hence, slow pyrolysis offers the possibility to lock in the embedded CO2. It transfers the CO2 in biomass from the rapid biological carbon cycle to the much slower biochar cycle, as is depicted in figure 12.
Figure 12: From the fast carbon cycle to the slower biochar cycle Therefore, it can be concluded that slow pyrolysis, burning biomass with little or no available air at low temperature is a promising technique to lock in CO2. However, remember that other pyrolysis variants could satisfy in a given situation as well.
Since “char, viscous tarry liquid (bio-oil) and gases (syngas) are formed in approximately equal mass proportions due to the slow degradation of the biomass and extensive secondary intra particle and gas/vapor phase reactions”[19], the by-products of the pyrolysis process (liquid and gas) can be used to meet the energy requirements of the process or eventually to produce surplus energy. The following paragraph will elaborate further on what to do with this surplus in energy.
2.3. Carbon negative fuels
“Biomass has been identified as a promising resource because it is abundantly available and in principle CO2 neutral”[20]. “Biomass consumes the same amount of CO2from the atmosphere during growth as is released during combustion. Therefore, blending coal with biomass fuels can reduce fossil-based CO2emissions”[21].
Bio-oil is a complex liquid produced as part of biomass pyrolysis. It has only 42% of the energy content of fuel oil on a weight basis and 61% on a volumetric basis. The presence of water in bio-oil lowers its heating value but improves its flow characteristics, which is beneficial for combustion (pumping and atomization). Bio-oil can be used as a basis for higher-value extracts and by-products, for example acetic acid, resins, food flavorings, agrichemicals, fertilizers, and emission-control agents[15].
Syngas is a non-condensable gas product containing CO, CO2, H2, CH4 and higher hydrocarbons[22]. It can be used for heat or power and it can be converted into liquid fuels by the Fischer-Tropsch process or to industrial chemicals. Part of the syngas will be retraced to the pyrolysis unit, to the drying process.
Although oil and syngas can be used in several industries, this paragraph will focus on bio-oil and syngas as a replacement for current fossil fuels (e.g. diesel and LPG) since “bio-bio-oil and syngas can displace fossil energy sources”[22]. However, bio-oil could only replace diesel as transport fuel if it is upgraded[15]. Therefore, future research with regard to this topic is needed. However, possibilities for CO2negative fuels exist.
Figure 13: Carbon negative fuels by means of pyrolysis of biomass and the sequestration of biochar. With regard to figure 13. By collecting biomass, and conducting pyrolysis with for example wood; biochar, bio-oil and syngas are obtained. The biochar is used to sequester CO2into the soil and to improve the productivity of the soil. The surplus of energy of the other two outputs, bio-oil and syngas, can be used to replace current fossil fuels. These bio fuels contain CO2, which is captured from the atmosphere and therefore are called carbon neutral. Hence, you will be reducing carbon emissions per kilometer[23], instead of emitting CO2 per kilometer. This only is the case if bio fuels are combined with the sequestration of biochar.
The next paragraphs will elaborate further on biomass, which is needed to conduct pyrolysis.
2.4. Feedstock for pyrolysis
Based upon process variables, most biochar is obtained by conducting slow pyrolysis with large particles biomass containing a low moisture content[25][26]. Furthermore, it is necessary to select a biomass type with a high carbon content[11].
Remember, the elaborated examples within this paragraph serve as an input to develop greater understanding with regard to (future) possibilities and cannot been seen as dedicated recommendations since each scenario has its own optimization.
“In general, any organic fuel can be considered as a biomass fuel. For the context of this discussion, biomass is used to describe organic waste products and dedicated energy crops. Waste products include wood waste material (e.g. saw dust, wood chips, etc), crop residues (e.g. corn husks, wheat chaff, etc.), and organic municipal, animal and organic industrial waste (e.g. (sewage) sludge, (chicken) manure, etc.). Dedicated energy crops, including short-rotation woody crops like hard wood trees and herbaceous crops like switch grass, are agricultural crops that are solely grown for use as biomass fuels. These crops have very fast growth rates and can therefore be used as a regular supply for fuel”[21].
2.4.1. Organic waste management and biochar
Since pyrolysis depends on organic waste and this research is focusing on biochar as a tool in waste management, it is not recommended to obtain biomass by means deforestation. Instead, other sources of biomass will be considered in this paragraph.
Table 3 shows a part of the amount of organic waste which is collected in the Netherlands on an annual scale.
Collected waste by municipalities in the Netherlands (× 1.000 ton) 2003 2004 2005 2006 2007 Total amount waste (different kinds) 8.891 9.120 9.158 9.166 9.303 Waste from vegetables, fruit and garden 1.406 1.340 1.362 1.296 1.317
Coarse garden waste 377 397 406 407 452
Wood 283 310 318 341 348
be used in pyrolysis. This is because moisture content will have an impact on char yield as explained before. Wood generally has a lower moisture content than grass and therefore requires a smaller amount of feedstock material for the same amount of char production. “After the economical analysis was linked to the technical analysis the results showed a lower char price for wood”[87]. Furthermore, wood is widely available and is also cheaper which results in a more viable scenario[87].
Beside low moisture content, the size of particles is affecting the pyrolysis process significantly. Therefore, wood offers great advantages compared to vegetables, fruit and garden wastes since it generally has a lower moisture content and can be shaped in large particles. Figure 14 shows that wood has a high biochar yield at low temperature which makes it a suitable input to obtain biochar, bio-oil and syngas from biomass.
Figure 14: Biochar yield for wood feedstock under different pyrolysis conditions[22]
2.5. Soil fertility and biochar
Indeed, wood can be seen as a suitable feedstock for pyrolysis since smaller amounts are needed for the same amount of char production, compared to grass. However, “most biochars derived from wood and nut shells contain less than 5 percent total mineral, nitrogen and sulphur (MNS content)”[22]. Since the MNS content is important to soil fertility, it is recommended to add sewage sludge9and animal manures to the biochar since, “sludge and animals manure have a MNS range of between 20 and 70 per cent”[22]. Based on research[30][31], as elaborated in appendix 4, chicken manure amendments resulted in the highest cumulative crop yield over four seasons. Most importantly, surface soil pH, phosphorus (P), calcium (Ca), and magnesium (Mg) were significantly enhanced by chicken manure. Therefore, chicken manure proved to be the most effective treatment within the experiment[30].
The high carbon yield using wood and the high MNS content using chicken manure results in a stable form of biochar which increases soil fertility and sequesters CO2.
Figure 15: Production of chicken manure biochar The relatively high char yield of wood combined with the fertilizer capabilities of chicken manure results in a type
of biochar which increases the fertility of the soil and sequesters CO2. The percentages within the figure are chosen arbitrary.
However, biochar additions (without chicken manure) can also improve the fertility of the soil. This can be derived from figure 16 where additions of biochar increased maize yield. The biochar was produced locally from wood of mango trees using traditional methods[88].
2003 2004 2005 2006 Control
8 t * ha-1
20 t * ha-1
Year Maize grain yield
10 8 6 4 2 0
Figure 16: Maize yield with biochar additions (after[32]) Beside the selection of biomass, the structure of the soil may influence the characteristics of biochar as well. The following paragraph will elaborate further on the differences between the soil types clay and sand.
2.6. The influence of biochar on soil structure
This chapter investigates the potential for introducing biochar in the agricultural industry, i.e. how agriculturalists can maximize productivity.
Sandy soils have lower water holding capacity than finer textured soils (e.g. clayey soils). Moreover, the organic matter in clayey soils is high than in sandy soils. Therefore, additions of organic matter may improve sandy soils to a greater extent[8] since “biochar additions at the most degraded sites doubled maize yield (equaling responses to green manure additions in some instances), which was not fully explained by nutrient availability, suggesting improvement of factors other than plant nutrition”[31].
In sum, adding biochar to sandy soils offers the most benefits since organic matter, water and nutrient holding capacity increases. Therefore, it is likely that crop yield will increase as a consequence. Adding biochar to clayey soils offers less benefits. Water and nutrient holding capacity and the organic matter of the soil decreases[64]. However, since porosity increases, soils are easier to cultivate. Based upon the above, the following table can be derived:
Current Biochar Current Biochar
Porosity high high low higher
Water holding capacity low higher high lower
Nutrient holding capacity low higher high lower
Soil organic matter low higher higher bit lower
Productivity low higher high bit lower
Machinability easy easy difficult easier
Sandy soils Clayey soils
Table 4: Consequences when using biochar per soil type In sum, the possibilities of biochar look promising. However, “the interactions between crop, soil type, local conditions, biochar feedstock, production method and application rate will have to be studied in far more detail before large scale deployment of biochar as a soil amendment can be contemplated”[8]. Nonetheless, there is evidence that at least for some crop/soil combinations, addition of charcoal may be beneficial. However, before going on, one important note has to be made. Literature indicates that the recommended maximum of biochar additions should not exceed 25% in sandy soils and 10% in clayey soils[17].
Now understanding is developed with regard to biochar and the influence on the fertility of the soil we can elaborate further on the stability of biochar. Is biochar stable in the biochar cycle? And how long does it lock up carbon?
2.7. Stability of biochar in the soil
in soils. Therefore, this paragraph has as its main objective to conclude whether biochar is stable.
“The longevity of bio-char in ecosystems is an important question since only a long half life will ensure a relevant sequestration”[45]. “Although black carbon (BC) in general is presumably very stable, research reported a significant oxidation of graphite (the most stable form of BC by microorganisms. Therefore, decomposition also of bio-chars can be expected”[45]. However, several scientists found that transforming biomass into biochar results in diverting carbon into a biochar cycle, which decomposes and diverts carbon much slower than in the rapid biological cycle[46]. This is endorsed by several scientists who argue that biochar is stable for at least thousands of years[47][48][49][50][51][52][53]: “BC is regarded as a chemically and biologically very stable carbon pool and can persist in nature for long periods of time”[35][54][55][56[[57]. However, “the long-term persistence of BC does not mean that the properties of BC remain unchanged after its deposition”[54]. Scientists reported “rapid oxidation of BC in short-term incubations, whereby BC properties were altered through the formation of oxygen-containing functional groups”[54][58][59]. After comparing new obtained BC with historical BC results showed that the historical BC samples were substantially oxidized after 130 years[54]. One major alternation by natural oxidation of BC included: “changes in elemental composition with increases in oxygen from 7.2% in new BC to 24.8% in historical BC and decreases in carbon from 90.8% to 70.5%”[54].
Since 20.3% of the carbon is replaced by either oxygen (from 7.2% to 24.8%) or hydrogen (1.7% to 4.5%) it can be concluded that the carbon is not sequestered permanently by means of biochar.
Figure 17: Elemental combustion of carbon, oxygen and hydrogen[54] New BC represents newly produced black carbon which is compared to BC-HA, BC30, BC70 and Historical BC. BC-HA represents the coating of new BC with humic acid for simulating short-term BC exposure in soils. BC30
The following indication can be derived from the research[54], biochar creates a carbon sink for at least 100 years since a minimal of 70.5% carbon is sequestered, compared to the average soil carbon content[60]. “Additionally, the decomposition of biochars is most likely reduced when it is transported down in the soil profile or buried in river, lake, or sea sediments”[45] since “biochar may be prone to erosion when it is not incorporated into the soil”[61].
For example, “the average age of BC buried in deep sea sediments, for example, was found to be up to 13,900 years greater than the age of other organic C such as humic substances”[45] which indicates “that in quantitative terms biochar is stable, with decomposition leading to subtle, and possibly important changes in the bio-chemical form of the material rather than to significant mass loss”[45].
Moreover, with regard to figure 18, it can be concluded that biochar is more stable than un-charred organic matter[45].
Figure 18: Biomass carbon remaining after decomposition of crop residues[45] This indicates that biochar is stable for >100 years. However, it should be noted that the feedstock, soil and pyrolysis process might differ per chosen scenario, which in turn affects the half-life time of biochar.
For now insight with regard to biomass, pyrolysis and biochar is developed. However, beside the earlier mentioned low risk and long term storage possibilities, biochar has more characteristics which will be summed up in the following paragraph.
2.8. Rethinking biochar
Furthermore, HTC10 looks promising, but this process is still in development and at this moment in its infancy. Therefore, since this research is focusing on biochar, I have chosen for slow pyrolysis since the char yield in this pyrolysis process is much higher than for the other options. The following variables influence the slow pyrolysis process of different types of biomass/waste (but are also still valid for pyrolysis in general):
char yield decreases with increasing moisture content,
char yield decreases with increasing temperatures and heating rates,
large particles give an increased char yield, which is related to the slower heating rate inside the particles, and
long gas residence time increases the char yield via secondary coking.
Furthermore, biochar can be mixed with (chicken) manure to increase the MSN concentration. The high carbon yield using wood and the high MNS content using chicken manure can result in a biochar which sequesters CO2-at least for 100 years- and increases soil fertility on (sandy) soils.
Besides, it is interesting to know how much CO2is sequestered by means of biochar. “1 ton of biochar is equivalent to nearly 3 tons of CO2”[32] and “1 ton of biochar is equal to approximately 2 tons of CO2”[62]. Furthermore, 1 ton biochar sequesters between 1.3 and 3 ton CO2 depending on the composition of biochar[17]. Indeed, as mentioned above, char yield depends on several factors.
Research shows “that the avoided emissions are between 2 and 5 times greater when biochar is applied to agricultural land (2–19 Mg CO2 ha-1 y-1) than when used solely for fossil energy offsets”. “41–64% of these emission reductions are related to the retention of C in biochar, the rest to offsetting fossil fuel use for energy, fertilizer savings, and avoided soil emissions other than CO2”[63]. Therefore, it can be concluded that biochar additions to the soil sequester between approximately 1 and 3 ton CO2depending on the composition of biochar by means of the conversion of 1 ton biomass.
In theory, the maximum amount of sequestered CO2 by means of biomass carbonization is 3.667 since 1 ton biochar is equivalent to 3.667 tons sequestered CO2if the C content within the biochar is 100%, i.e. the theoretical max, as has been depicted below.
C + O2 CO2
(12) (32) (44)
3.667
Element Atomic mass
Recalling the four objectives given in chapter 1, biochar has several advantages in the following four topics: (1) waste management, (2) soil amendment, (3) energy production, and (4) climate change mitigation. Each of these topics will be elaborated in the following section.
Waste management
Organic waste, such as wood, (chicken) manure, leaves, (sewage) sludge and other crop waste can serve as an input for biochar. Instead of decomposition of biomass into the fast carbon cycle, biomass is carbonized into biochar after which it is transferred to the biochar carbon cycle which is a much more durable process. I.e., the carbon in carbonized biomass is locked in temporarily (at least for 100 years).
Soil amendment
The use of biochar on (sandy) soils improves the organic matter of the soil, water and nutrient holding capacity[64]and leaching issues. Besides, “soil stability becomes extremely stable”[65], at least for 100 years. Furthermore, the acidity of the soil is lower and the soil becomes more stable. Moreover, biochar can fully restore soil productivity to levels observed before degradation started[31]. Hence, (sandy) soils mixed with biochar increases soil fertility which might result in an increase in crop yield. Beside the increase in crop yield, the advantages with regard to climate improvement and a more stable soil texture enables agriculturalists to use less fertilizer. Moreover, biochar additions to clayey soils lowers the density, which increases soil drainage, aeration and root penetration[64]. However, literature indicates that the recommended maximum of biochar additions should not exceed 25% in sandy soils and 10% in clayey soils[17].
Produce energy
Mitigate climate change
Finally, carbon sequestration by means of biochar locks carbon in the soil, at least for 100 years[54]. I.e., biomass is being transferred from the fast carbon cycle into a much slower carbon cycle by means of carbonization.
3.
Critiques with regard to Biochar
Previous chapters elaborated on biochar as a CO2 reducing strategy and already mentioned several critiques with regard to the use of biochar. Finally, conclusions with regard to the use of biochar were mainly positive. But is biochar not too good to be true? This chapter will elaborate further on critiques which have been addressed by scientists and have been undersigned by NGOs. Main goal while comparing opponents and advocates of biochar is to develop greater understanding with regard to biochar in order to clarify which conditions have to be taken into account after which an effective payment structure can be developed which enables agriculturalists to maximize the use of biochar.
3.1. Biochar, a big new threat to people, land and ecosystems
The document “Biochar, a big new threat to people, land and ecosystems”[27]is signed by over a hundred NGOs supporting several issues, which are:
“It is not yet known whether charcoal in soils represent a carbon sink”,
“The climate impacts of fossil fuel burning are irreversible, yet so-called 'soil carbon sinks' are highly uncertain and temporary”.
Indeed, carbon is not being sequestered permanently. However, research indicates that biochar creates a carbon sink for at least 100 years since a minimal of 70.5% carbon is sequestered after 130 years[54].
“Biochar advocates are promoting targets which would require the use of 500 million hectares or more of land to be used for producing charcoal plus energy”[27], and
“Large-scale production of charcoal would require many hundreds of millions of hectares of land for biomass production (primarily tree plantations)”. “Such large-scale production poses major threat to biodiversity, ecosystems and the livelihoods of many communities”[27].
grow. Indeed, deforestation has a major influence on biodiversity, ecosystems and the livelihoods of many communities. In order to cope with issues as deforestation, this research aims for obtaining biochar via organic waste (e.g. wood, which is collected by municipal waste collectors). Furthermore, it is not realistic to state that the use of biochar alone returns us to pre-industrial CO2level. Recalling figure 9, pp. 9, CCS strategies only provide a slight reduction of the current CO2 concentration in the atmosphere. Most CO2 can be reduced when society becomes aware of its own energy usage. I.e. when humanity starts reducing energy consumption.
“The 'biochar' initiative fails to address the root causes of climate change: Fossil fuel burning and ecosystem destruction, including deforestation and the destruction of healthy soils through industrial agriculture”.
If scientists only focus on the root cause of climate change: fossil fuel burning and ecosystem destructing, it is not likely that ecosystems become balanced again since the surplus CO2which is created in the previous decades is not dealt with. Consequently, global warming, although less rapidly, will continue, as is depicted in figure 19.
Figure 19: Balancing the climate Hence, Earth’s percentage carbon decreases faster when carbon negative options are adopted.
Only if the focus is on both, elimination of the root causes and the absorption of the already created surplus in CO2, ecosystems can become balanced again. Of course, CCS strategies alone cannot mitigate climate-change. Therefore, as is depicted in figure 9, this research aims on achieving two main objectives: (1) increase efficiency in energy usage, and (2) the development of new strategies which can help mitigating climate change.
changing social paradigms with regard to energy usage since it describes problems related to fossil fuel burning.
“There is a risk that biochar could in future be used to promote the development of genetically engineered tree varieties specifically engineered for biochar production or to try and extend the range of fast-growing trees”[27].
Indeed, it is possible to imagine that the development of genetically engineered trees are being promoted in order to create biomass. As a matter of fact, scientists already have “developed eucalyptus trees capable of ingesting up to three times more carbon dioxide than normal strains, indicating a new path to reducing greenhouse gases and global warming. Eucalyptus is a fast-growing tropical tree species used as a biomass source for bio-energy, and for pulp and paper manufacturing. Analyses show that there is a very large potential for the production of sustainable biomass from Eucalyptus in Central Africa and South America”[28]. Consequently, it is likely to assume that in the nearby future surfaces are being prepared in order to maximize sustainable biomass which can serve as an input for biochar.
However, this topic is highly complex and acceptation depends heavily on developed world views by stakeholders. Therefore it is recommended to conduct a future research on the impact of genetically engineered trees in the context of CO2reduction, from a social point of view. I.e. are modification techniques accepted and how can scientists increase public awareness?
“There is no consistent evidence that charcoal can be relied upon to make soil more fertile”.
However, based on research[30] as elaborated in appendix 4, (chicken) manure amendments results in the highest cumulative crop yield over four seasons. Since the MNS content is important to soil fertility, it is possible to add sludge and animal manures to the biochar. Hence, the high carbon yield using wood and the high MNS content using chicken manure results in a stable form of biochar which increases soil fertility and sequesters CO2, at least for 100 years.
“The combination of charcoal with fossil fuel-based fertilizers stimulates fossil fuel burning in the future”.
Indeed, if fertilizers are fossil fuel-based, it does. However, by means of the Haber-Bosch process, nitrogen fertilizer can be obtained without the use of fossil fuels. The Haber-Bosch process is the nitrogen fixation reaction of nitrogen gas and hydrogen gas, over an enriched iron catalyst, to produce ammonia[90].
“The process for making charcoal and energy (pyrolysis) can result in dangerous soil and air pollution”.
“The nitrogen in coal, which mainly exists as XN (e.g. HCN, H3N, etc) readily oxidizes to form NOx (NO, NO2) at low temperatures (fuel NOx)”[21]. “Pollutant emissions are a growing concern and emission regulations are driving continuous development of new combustion technologies”[21]. Furthermore, “some feedstocks and conditions will generate phytotoxic and potentially cancerogenous organic materials”[34][35]. “Sub-optimal pyrolysis conditions can also result in negligible net sequestration from low carbon recovery[35]. “Therefore, an agriculturalist must be careful when choosing a particular pyrolysis system and when setting the operational conditions during pyrolysis”[36](e.g. in case of modified wood).
tool in waste management, more research should be conducted with regard to suitable inputs for pyrolysis.
“The Clean Development Mechanism (CDM) has perpetuated, rather than reduced fossil fuel burning by permitting industries to purchase ‘rights to pollute’ and further delaying the social and economic changes which are essential for addressing climate change“.
In contradiction to what is mentioned above “the CDM allows a country with an emission-reduction or emission-limitation commitment under the Kyoto protocol to implement an emission-reduction project in developing countries. Such projects can earn saleable certified emission reduction (CER) credits, each equivalent to one ton of CO2, which can be counted towards meeting Kyoto targets”[67]. ”The mechanism stimulates sustainable development and emission reductions, while giving industrialized countries some flexibility in how they meet their emission reduction or limitation targets”[67].
Therefore, the critique formulated here is not adequate. Instead of only purchasing ‘rights to pollute’, industrialized countries only can earn credits by initializing techniques which reduce emissions, as will be elaborated in chapter 5.
“Biochar companies and researchers have not been able to recreate Terra Preta”.
Thousands of years ago, Amazonian Indians enriched their infertile tropical soils with charcoal composted with manure, fish bones and plant residues. Even today, the resulting dark miracle soil retains high levels of nitrogen (N), phosphorus (P), organic matter (13-14%), calcium, zinc and manganese. And it anchors soil nutrients amazingly well. This Terra Preta (Portuguese for “black soil”) enabled large Amazon Indian societies to thrive on poor tropical soils. Biochar is based on Terra Preta and indeed, scientists have not been able to recreate such soils yet. Therefore, since the properties of biochar vary heavily, depending on the biomass used and on production conditions, it is recommended to investigate in crop, soil type, local conditions, feedstock and the production method before implementing biochar on agricultural sites.
Perversity with regard to biochar.
the soil. Strictly, such companies mitigate climate change by adopting biochar since the cumulative CO2 emissions decrease. Subsequently, opponents can argue that such companies should reduce their core activities, i.e. reduce the usage of stone coal. However, companies which obtain energy from coal are in turn triggered by human needs. I.e., their demand for energy. Hence, CCS strategies alone cannot solve the global warming problem. Instead, CCS strategies can serve as a tool in the battle against CO2 emissions. After all, humanity should adapt its energy usage to a level which does not affect the environment.
Furthermore, the document “Biochar for climate change mitigation: fact or fiction?” is criticizing biochar as well[43].
3.2. Biochar for climate change mitigation: fact or fiction?
The authors in the article contribute to the following:
“Unfortunately, like other such schemes to engineer biological systems, it is based on a dangerously reductionist view of natural world, which fails to recognize and accommodate ecological complexity and variation”.
Although more research is needed, the addition of biochar offers great possibilities. Beside CO2 sequestration, crop yield on (sandy) soils might increase. Indeed, adapting the structure of the soil (by implementing biochar) can make a chain reaction occur. However, since biochar is stable, it is difficult to imagine any incident or change in practice that would cause a sudden loss of stored carbon[46]. Indeed, small disturbances can also influence ecosystems. However, since biochar on (sandy) soils increases water and nutrient holding capacity and improves soil organic matter, it is relatively safe to assume that soils (and ecosystems) do not get degraded.
“Research on biochar is clearly indicating that there simply is no “one-size-fits-all” biochar solution, that many critically important issues remain poorly understood, and that there are likely to be serious and unpredictable negative impacts if this technology is adopted on a large scale”.
biochar on agricultural sites. However, there is evidence that at least for some crop/soil combinations, addition of charcoal may be beneficial.
“Carbon emitted during pyrolysis is supposedly offset by the carbon absorbed by new plant growth, and therefore ‘carbon-neutral’. During pyrolysis, a portion of the plant carbon is retained in the charcoal. If the carbon-rich charcoal is then tilled into soils, that portion, it is claimed, can be sequestered away, thus reducing CO2concentrations from the atmosphere. Unfortunately, this accounting completely ignores the numerous ecological and social impacts from land use changes that occur when massive demands for plant biomass are created.”
Indeed, if a massive demand for biochar (thus biomass) is satisfied by means of deforestation, ecological and social impacts can occur. Therefore, this research is emphasizing on biochar as a tool in waste management. Furthermore, it already is recommended to include suitable biodegradable wastes in a EU legislation proposal so that terminology and concepts relating to bio-wastes will be harmonized[86]. Moreover, if biochar is produced by means of organic waste, it can increase crop productivity, reduce soil erosion and reverse the desertification since water and nutrient holding capacity increases on (sandy) soils. Hence, it reduces the need for land use changes. Especially since biochar now is adopted by the UNCCD11which is “working towards the inclusion of carbon in soils and biochar under the UNFCCC12– Copenhagen agreement”[89].
“Proponents claim that charcoal can not only sequester carbon, on a globally significant scale, but also improve soil fertility, and thereby reduce demand for synthetic fertilizers and emissions of the powerful GHG N2O, and can conserve and purify water, prevent runoff of chemicals from farm lands, reduce emissions of black carbon from biomass cooking fires, reduce methane emissions from decomposing organic waste piles and more. Sound too good to be true?
Although more research is needed, the potential for biochar additions into (sandy) soils offers great opportunities. However, it still is recommended to study the interactions between crop,
11
United Nations Convention to Combat Desertification
soil type, local conditions, biochar feedstock, production method and application rate in far more detail before adopting biochar on a large scale.
With regard to Terra Preta soils: “can we replicate the success using industrial production?”
As has been mentioned in paragraph 3.1: ‘Biochar, a big new treat to people, land and ecosystems’, it is true that scientists not have been able to recreate Terra Preta yet. However, as can be concluded from chapter 2, the potential for CO2 sequestration and soil improvement exists.
“A recent field study near Manaus, Brazil found that charcoal mixed with synthetic fertilizer enhanced yield more than synthetic fertilizer alone, but the highest reported yields were obtained using solely chicken manure instead”.
Indeed, as has been elaborated in this research, the addition of chicken manure results in the highest yield. Therefore, it should be investigated whether it is more beneficial to mix biochar obtained from wood with (chicken) manure to put focus on both: soil fertility and CO2 sequestration. However, note that the performance will differ per soil type and the feedstock which is used.
“There are no longer-term field studies and so it is not known whether the increased plant growth sometimes observed with the addition of charcoal would be sustained over the longer term”.
Again, although the possibilities of biochar look promising, more research is needed. Indeed, especially with regard to longer-term effects.
“Biochar, like other bio-sequestration technologies does nothing to stem the flow of fossil carbon into the biosphere”.
