Daniela Thran, Marlies Hardtlein and Martin Kaltschmitt

11.1. THE NEED FOR A SOLID BIOFUEL STANDARDIZATION

There is a significant potential for an increased use of biomass all over the European Union. Solid biofuels can contribute significantly to reach the political goals of the European Commission and national governments to increase the share of renewable energy and reduce CO2 emissions from anthropogenic sources. For various reasons, however, this is not happening easily. In many cases, the costs of energy provision are higher for biofuels than for fossil fuels so that additional development programs are urgently needed if this potential is to be rationally explored.

Table 11.1 shows the current use of biomass resources for electricity and heat generation in the EU and the estimated potential from different sources in each country. Large differences can be observed both in the amount and the type of resources being exploited in each country. It can be noted, for instance, that while some countries such as Denmark, the Netherlands and Austria have already exploited 40 to 50 per cent of their potential, Germany is only using 10 per cent of its total potential.

Differences can also be observed in the conversion forms through which biomass resources are being exploited. The use of biomass for district heating has reached quite significant levels in a few countries such as Austria, Finland and Sweden, where mainly fuelwood and wood residues from forestry and wood-processing industries are being utilized. In Germany, woody residues have been used at a more or less steady level in the last ten years for domestic heating purposes, while other biomass resources have not yet been much explored. There is, for example, a significant amount of herbaceous residues, mainly straw, which can be used with technologies that are readily available.

To develop a more widespread use of the solid biofuel resources, the costs of production, provision and use of biomass fuels have to be reduced significantly so that they can compete with fossil fuels economically. With this in mind, it is necessary to consider the possibilities of cost reduction all along the supply chain of

153 Bioenergy — Realizing the Potential

© 2005 Dr Semida Silveira Published by Elsevier Ltd. All rights reserved.

Table 11.1. Use and potential of biomass in the EU

solid biofuels. This includes the agricultural production of biofuels, their preparation and provision, their use in the generation of energy and in the recycling of ashes. Additionally, noneconomical and nontechnical barriers that slow down a widespread use of solid biofuels need to be addressed.

Compared to other renewable energy sources, solid biofuels are characterized by a wide range of fuel types. They differ in origin, physical and mechanical properties (e. g. moisture content, particle size and particle size distribution) and chemical composition (e. g. content of sulfur, nitrogen and chlorine). In fact, lack of clearly defined biofuel properties as well as clear supply conditions are seen as major nontechnical barriers for biofuels (Kaltschmitt et al., 2001).

Thus standardization of biofuel properties and their measurement is one of the tools that needs to be developed to improve biofuel markets. Standardization is expected to improve markets in the following ways:

• Producers of solid biofuels get more concrete instructions for the production of solid biofuels. They are then able to optimize their production processes with regard to the properties demanded of the fuels and can reduce costs through a more efficient production.

• Having a solid specification available, one that is well adapted to practical needs, the development of a solid biofuel market is more promising. The properties of the trade product solid biofuel are clearly defined and well known just as it is, for example, for different liquid fuels such as gasoline or fuel oil. Prices will then reflect specific categories and qualities of the fuels, these also being well defined and well known. This makes the markets more transparent, favoring cost reduction and volume increase.

• Energy provision systems and conversion technologies can be better designed and optimized to operate more efficiently and environment-friendly if fuel qual­ity is defined within a narrow range. This refers primarily to the requirements concerning conveyor problems, emissions control or corrosion phenomena.

There is a general agreement on the need for European standards in the field of solid biofuels. European standards are seen as a good tool to develop business oppor­tunities and acceptance in the area of biomass. In particular, countries with a high potential share of solid biofuels regard standardization as an important step in promoting the use of biomass as energy source.

To demonstrate and verify our method in more detail, we apply it to a small region well known to us. In the first step, we determine the theoretical potential, that is, the overall heat demand and its geographic location, continuing with the distribution of the total heat demand of different building types and their geographic location. In the second step, we estimate the practical potential, searching out the small geographic clusters, e. g. 500 x 500 m2, where the heat demand exceeds for example 0.5 GWh. Those clusters can be the starting points for small-scale district heating and CHPs.

The 36 x 48 km2 region is located in the middle of the county of Kalmar, southeast Sweden. It is a rural district with 8000 inhabitants, thus only 5 inhabitants per km2. There are 2000 people living in the largest urban agglomeration, and seven villages with populations between 300 and 600 inhabitants. This small region is mostly forested with an abundant supply of wood waste. In addition, there is a small agricultural district around the largest center and some of the other villages, which can provide biomass in the form of agricultural residues. There are ten hydropower stations in the two main rivers of the region, producing approximately 25 GWh annually. Solar and wind energy is very marginal. There is one new, small district­heating system of 0.8 GWh using wood pellets.

The theoretical heat demand potential found for this region is 102 GWh, based on estimates for every single building, and implying an average heat demand per inhabitant near the national average lOMWh. Figure 8.3 shows the geographic distribution of the theoretical potential in the region, where relevant concentration is found in less than ten places. Obviously, there is a strong correlation between the distribution of population and activities performed in the region and what is observed in this figure.

Of the total 102GWh, 77GWh is the demand of one — and two-family houses, 7 GWh from multidwellings, 13 GWh from industrial, 2 GWh from commercial and 3GWh from public buildings. This distribution was anticipated as small houses dominate in rural districts. Thus 75 per cent of the theoretical potential comes from single dwellings. Multidwellings are found in only eight places with at least 300 inhabitants, and industrial and public buildings are more scattered. As much as 25 per cent of the heat demand is found in the larger buildings, which facilitates the search for starting points for the district-heating grids.

Stepping from the theoretical to the practical potential, we focus our interest on small geographic clusters where the heat demand exceeds a certain limit. We have used a quadratic shape, the four cluster sizes 250 x 250 m2,500 x 500 m2,750 x 750 m2 and 1000 x 1000 m2, and a minimum heat demand of 0.5 GWh. Table 8.1 shows the number of clusters found for each range of heat demand. Obviously, when the cluster area increases, more clusters reach the minimum stipulated limit of 0.5 GWh. At the same time, adjacent clusters merge.

Focusing on single dwellings, the share of the heat consumption included in the clusters in relation to the total 77 GWh increases as the clusters are enlarged, going from 16 per cent for the 250 x 250 m2 clusters to 65 per cent for the 1000 x 1000 m2 clusters. Consequently, the average heat consumption per cluster increases from 0.6 GWh in the smallest cluster size to 1.6 for the largest cluster size. At the same

time, the average heat consumption per km2 in a cluster decreases from 9.9 GWh per km2 in the 250×250 m2 clusters to 1.6 in the 1000 x 1000 m2 clusters (see also Figure 8.4).

Before leaving our small region, we will also summarize the heat demand for all building types. We limit the analysis to 500 x 500 m2 clusters and a minimum heat demand of 0.5 GWh per cluster. In this case, we arrive at 53 clusters, which together account for 64 of the total 102 GWh heat demand in this small region. Table 8.1 indicates the number of clusters found for each range of heat demand and allows an easy comparison with the case where only single houses are considered. The inclusion of all building types results in a larger number of clusters with enough heat demand to justify combined heat and power already today. Moreover, the nonresidential buildings with their larger average heat demand can serve as crystallization points for the heat grid. Many of them also have production facilities that can be of some

use. Figure 8.5 shows the distribution of the clusters found, and their heat demand in more detail.

A good half of the heat demand from single houses in the area, and some 85 per cent of all heat demand from other buildings are captured in the clusters found. Continued technical development and increased taxation of external costs of nonsustainable energy sources can make more clusters rapidly ready for CHP, while also attracting investors to build the necessary infrastructure.

We have previously pointed out the need to involve developing countries more directly in climate change mitigation measures. Energy demand in developing countries is expected to at least double in the next 20 years which shall result in significant increase in greenhouse gas emissions (Nakicenovick et al., 1998). The dynamics of well-established industries and fuel markets shall strongly influence the evolution of energy generation and its use in developing countries in the medium term, leading to an overall increase in the utilization of fossil fuels and, consequently, more emissions from these countries.

However, there are opportunities for developing countries to take a different direction. Already today, medium-income countries are moving towards larger energy efficiency and increased utilization of combustible renewables and waste (Sun, 2003; Miketa, 2001). Liberalization of energy markets and various national policies have already led to significant savings of emissions in fast-growing develop­ing countries such as Brazil, India and China. These countries already constitute important markets for clean technologies. Therefore, it is important that, as new investments are made in the expansion of energy supply infrastructure in developing countries, renewable systems be given high priority and sustainability criteria be observed. In this context, CDM can contribute as a channel to attract capital aimed at clean technologies that contribute to socioeconomic development, thus meeting both global environmental interests and development priority needs.

The CDM can provide a bridge for increased collaboration between industria­lized and developing countries to shift energy systems towards sustainable and renewable systems. The mechanism can be used to promote renewable energy technologies and energy efficiency, reducing costs and risks and channeling investments to developing countries. To make that possible, public and private efforts have to be made jointly. The support of civil society at large is, obviously, also a prerequisite for succeeding. Therefore, stakeholder dialogs have to take place along the whole project cycle (Baumert and Petkova, 2000).

Table 12.1 summarizes the main advantages and potential barriers that different actors may find when considering involvement in CDM projects. Why should they participate in CDM? What may cause them to refrain from doing it? We have defined the actors in broad groups, differentiating among governments in industrialized and developing countries because of their different position in terms of commit­ments within the Kyoto Protocol. We have also differentiated companies by size,

separating corporations from small- and medium-sized enterprises (SMEs). SMEs can be quite different in nature depending on size, sector, type of product or service provided and even geographic location so that the advantages and barriers indicated for this group should be seen as a very broad generalization.

When it comes to financial organizations, Chapter 13 presents particular insights that complement the list in Table 12.1. We have made a distinction among inter­national and national NGOs because of their different role in the context of CDM projects. International NGOs may have a particular impact on the development of methodologies and procedures for CDM implementation, making sure that the mechanism evolves into an effective way to facilitate the reduction of greenhouse gas emissions and to promote sustainable development. National NGOs play a role in following up the work at the local and national levels and making sure that CDM projects are really in line with the host country’s sustainable development strategies. A stronger link between national and international organizations is desir­able to enhance capacity building and favor resource allocation to ensure a moni­toring role at national and international levels throughout the implementation of projects.

Priyantha Wijayatunga, Upali Daranagama and K. P. Ariyadasa[11]

10.1. INTRODUCTION

Biomass accounts for 51 per cent of energy supply in Sri Lanka (see Figure 10.1). Most of this biomass-based energy use is traditionally confined to the domestic sector, where most of the rural and suburban households rely on fuelwood for cooking. Industrial and agricultural sectors also use wood fuel as well as other biomass-based material such as bagasse and rice husk, to generate heat or steam for agricultural processes and to drive small-scale industrial processes (Ceylon Electricity Board, 1998).

In recent times, biomass has attracted widespread interest as a primary energy source for electricity generation, due to its potential as a low cost, indigenous supply of energy as well as due to environmental benefits accompanying biomass-based generation technology. Conversion of biomass to electricity is considered as one option available to arrest CO2 emissions caused by fossil-fuel-based generation. In addition to this global benefit, there are local benefits mainly resulting from energy plantations accompanying biomass-based generation technology, such as reduced soil erosion, restoration of degraded lands, and amelioration of local impacts of fossil-fired power generation (e. g. SOx and NOx). Other advantages include social benefits such as creation of local employment and improved availability of fuelwood for household use.

From the energy point of view, the most important characteristics of a fuel are given by its composition, heating value and other properties related to the energy con­version technology where it will be used. Table 6.4 shows the results of an analysis conducted at the Alternative Fuels Laboratory at UNICAMP for eucalyptus, bagasse and trash from sugarcane. It turns out that the energy value of cane trash

was only 15 per cent lower than that of the bagasse at similar moisture content. Unfortunately, important characteristics such as the ash melting point, critical when a fuel is used in boilers, are not properly documented. Experiments on trash com­bustion are not reported either.

Wood from native forests has been historically used to provide useful energy through direct combustion. Also in Brazilian sugar mills, wood was and is still used to a limited extent to complement bagasse as energy source. Bagasse provides enough heat through direct combustion in steam boilers to meet the needs to crush the cane in the mills, to provide process heat in the factory operations and also to generate enough electricity by turbo-generators to drive all electric motors and meet other electricity requirements at the mill. Bagasse-based energy is not only enough to meet these needs but is also produced in excess in sugar mills and ethanol distilleries in Brazil. Many factories have to adjust their boilers to simply burn all excess bagasse because, otherwise, the material will deteriorate and pose risks.

Meanwhile, in the State of Sao Paulo, where most of Brazilian sugarcane is produced, fuel wood is used in the manufacture of bricks, in food industries, bakeries and restaurants. The wood is usually transported from distant locations using diesel trucks. It has become scarcer and more costly and is being gradually substituted for natural gas and even conventional burning oil.

There is a significant potential for bagasse to immediately substitute firing wood. The limiting factors are apparently associated with lack of entrepreneurship to disseminate a “bagasse culture” that helps promote a more diversified use of substitutes. One example of successful substitution is given by the Destilaria Rosa located in Boituva, Sao Paulo, where a small brick industry was installed just a few meters from the ethanol distillery. The excess bagasse, nearly 30 per cent of the total, is used to produce low cost bricks. Tests were conducted in their furnace to evaluate both efficiency and quality of the bricks (Aradas et al., 1998). In spite of good results, this example has not been emulated by other mills.

Bagasse is used in isolated cases in other industries, for example, in the vegetable oil industry. A more intensive use outside the sugar and ethanol sector has been observed in the orange juice industry, where bagasse boilers similar to those employed in the sugar mills are installed. The Brazilian orange juice industry is amongst the largest in the world and a large production is located in Sao Paulo, near the sugarcane production area. Unfortunately, the consumption of bagasse in the orange juice production does not create sufficient demand so as to provide a real incentive to the supply side. In fact, the demand for bagasse in the orange juice industry is presently threatened due to the availability of the Bolivian natural gas, which is leading to a review of bagasse contracts.

The market price for bagasse varies depending on the local availability and dis­tance. Usually, bagasse is sold at prices ranging from US$ 5 to 12 per ton of bagasse (representing a range of US$0.60 to 1.35/MMBTU) in the core sugarcane regions in Sao Paulo. Small enterprises are producing equipment for direct combustion of vege­table residues, including cane bagasse. Such equipment is simple in conception and is being sold at prices around US$ 1600 for a feeding capacity of 500 kg of biomass/h.

National standards, best practice lists or quality assurance manuals in the field of solid biofuels have already been developed and implemented in different countries within the European Union (e. g. Austria, Finland, Germany, the Netherlands, Sweden). This has contributed to improve the matching of fuel quality and fuel provision with conversion equipment and systems, facilitate the comparison of the quality and value of different solid biofuels, and determine and assure fuel quality.

A review of the existing national standards, best practice lists or quality assurance manuals allows for some observations regarding the harmonization of standards on terminology and classification that is needed at the European level. Table 11.2 gives an overview of the various biofuel properties which are relevant for assessing biofuel quality, and which are considered within the different EU countries. First, there are fuel properties focusing on the physical and mechanical condition of the fuel and its behavior during biofuel handling (loading, transportation, storage, feeding). Second, there are fuel properties influencing the process of energy conversion (e. g. com­bustion or gasification). And last but not least, there are chemical properties needed to calculate the flow of molecules and to assess the emissions.

With regard to the intended effects of standardization procedures at the European level, there are two main relevant fields to be considered. [12]

The terminology, definitions and descriptions as well as the fuel specifications and classes which are applied in different EU countries today are the product of the traditions and characteristics, specific to the national fuel market and their information requirements. Problems of comparability of national terms and definitions can arise due to differences in the national systems of nomenclature. These nomenclature differences make fuel comparison across EU countries difficult and serve as obstacles for trade. Standards of terminology and defini­tions as well as fuel specifications and classes can make a valuable contribution towards allowing a more direct assessment of the quality and value of solid biofuels, thus fostering trade and a broader use of biofuels as an energy source throughout Europe. Standards can also provide a vital input to facilitate broad resource and market assessments (e. g. internationally comparable results and statistics for solid biofuels) which can help shape public and industrial policy.

2. Identification and classification of the most relevant biofuel properties to ensure a cheap and trouble-free conversion with low emission levels.

The number of fuel properties used in national standards, quality guidelines and assurance manuals or recommendations to classify solid biofuels varies between 3 and 90 for wood chips. The number of classes for fuel pellets and briquettes varies between 3 and 5 only because of the compression process which makes the fuel much more homogenous in size and shape, moisture content and energy density. In Germany, for example, only a wood pellet standard is available (DIN 51731, 1996).

In EU countries, only a few important fuel properties are presently used to assess fuel quality and value (among them the moisture content, the particle size and the heating value) due to practicability and costs of performing fuel property measure­ments. A review of the existing national standards and practices indicates that an intended European classification system of solid biofuels should satisfy the following criteria (Rosch et al., 2000):

• The biofuel classification system should be universal and comprehensive so that it can be used for all kinds of biomass for energy generation;

• Classification should be restricted to the biofuel properties which are most relevant in practice, being clearly defined and easy to control;

• The range and amount of classes for each of the biofuel types should take into consideration regional diversity as well as the specific demands of different provision and combustion technologies and trading practices;

• Each biofuel should be classifiable by a plain and easy code (i. e. like the classification of coal, fuel oil or steel);

• Conversion plants using solid biofuels to produce green electricity should be able to use the biofuel class code for certification of their products.