ECOTERRA Journal of Environmental Research and Protection Implementation of the European quality standards concerning wood biomass in logistic centres 1

Corina M. Berkesy, 1Mihaela Begea, 2Laszlo E. Berkesy, 1Ioan M. Crăciun, 1 Maria Someşan 1

S.C. ICPE Bistriţa S.A., Bistrita, Romania; 2 University Babeş-Bolyai from Cluj-Napoca, Faculty of Environmental Sciences and Engineering, Cluj–Napoca, Romania. Corresponding author: C. M. Berkesy, [email protected]

Abstract. Biomass contains important quantities of stored energy used more and more for commercial purposes. Other energy sources are renewable, easy to store and their negative effects are rather small what CO2 emissions concern compared to other categories of biofuels. To check the conformity with European standards is an efficient means to differentiate on a competitive market. And what is more, to make products or services to be conform with said standards, increases their compatibility against those produced or offered by others and thus potential sales go up and also improve their acceptance on a large scale. It also contributes to the growth of confidence of the clients, the growth of the market and of the technological evolution. To implement quality standards for wooden biomass allows an efficient and profitable competition through factors like: differentiation of the product. The better consumers are informed regarding their choice, the conformity with the accepted standards it becomes more and more important to implement them. In this paper we discuss the standards that are specific for wood biomass (pellets, briquettes, wood chips), as well as the implementation of said standards for heating products in our country based on wood biomass. Key Words: wood biomass, pellets, briquettes, wood chips, logistic centre, quality parameters.

Introduction. The growth and diversification of the national as well as the European markets of energetic products based on wood biomass led also to the growth of the demand for a better and better quality. This is how the necessity appeared to have a common frame to assure its quality by creating comparable international certificates. The quality indicators such as moisture and dimensions of particles, as well as other characteristics such as the species of wood are decisive for the quality of the wood biomass that is to be used in order to produce energy by influencing its caloric power. The general use of the standards is considered to be a good measure to build up a more dynamic and stable European market for solid biofuels, as well as for the optimization of the interactions between producers of fuels, deliverers and final users (www.biomasstradecentre2.eu). The requirements concerning final users from the point of view of quality may considerably vary from one scale to another. There are two types of final users of solid biofuels: final users on a small scale, where high powered fuels are asked, with few specifications about the fuel, and large scale final users with heating installations designed adequately and flexible what the fuel is concerned, where only cheap raw materials are demanded but with detailed specifications about the fuel (Contract BiomassTradeCentre2, Manual de biomasa - Sisteme de asigurare a calităţii şi măsuri de control al calităţii, 2014). The scope of implementation of quality assuring systems. It is mainly to offer the possibility of an adequate sale of solid biofuels to an adequate price on the European market and thus the final user can rely on the quality of solid biofuels; and on the other hand the producers will be able to improve, check and make their products according to the demand on the market. ECOTERRA Journal of Environmental Research and Protection

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The conformity with the European standards, that are valid on a large scale, is an efficient means to differentiate on a competitive market. And what is more, to make products or services to be conform with said standards increases their compatibility against those produced or offered by others and thus potential sales increase and also improve their acceptance on a large scale. It also goes to inspire the confidence of the clients, the growth of the market and of the technological evolution. Standardization makes clients confident that the market will grow and that technology will develop. The better consumers are informed regarding their choice the more important it becomes to ensure the conformity with the accepted standards and to implement them. There are two examples of European standards for biomass and European standards for solid biofuels (series EN 14961). Quality requirements and reference standards. The European standard Specifications and Classes of Fuels was issued by a team for biofuels to give a correct classification for solid fuels. In the standard SR EN14961-1 the classification and origin of wood biomass are shown and are classified as follows: 1. wood biomass, 2. grass biomass, 3. fruit biomass, 4. intentioned or unintentional mixture of different sorts of biomass. As for the treatment of the biomass, the standard does not specify chemical treatments with heavy metals or halogenated compounds; the products are treated with air, water and heat (Contract BiomassTradeCentre2, Manual – Combustibili lemnosi, 2011). The most important technical specifications deal with the CEN/TS 14961 classification and specification and quality assurance of solid biofuels (CEN/TS 15234). The classification of solid biofuels is made according their origin and their source. In the following we give a list of important technical specifications issued by CEN 335: - EN 14588:2010 Solid biofuels - Terminology, definitions and descriptions; - EN 14961-1:2011 Solid biofuels - Fuel specifications and classes; - EN 15234-1:2011 Solid biofuels - Fuel quality assurance; - EN 14774-1:2011 Solid biofuels - Determination of moisture content - Oven dry method - Part 1: Total moisture - Reference method; - EN 14774-2:2009 Solid bio fuels - Determination of moisture content - Oven dry method - Part 2: Total moisture - Simplified method; - EN 14774-3:2009 Solid biofuels - Methods to determine moisture – Drying in a Dry Box - Part 3: Moisture in the analyse sample; - EN 14778 :2011- Solid biofuels - Eşantionare - Part 1: Sampling methods; - EN 14918:2000 Solid Biofuels - Determination of calorific value; - EN 15103:2009 Solid biofuels - Determination of bulk density; - EN 15296:2011 Solid biofuels - Conversion of analytical results from one basis. Qualitative classification of solid biofuels is defined at European level by Technical Specification CEN/TS 14961 (Solid biofuels, fuel specification and classes, 2010-2011). The next step is to define the kinds of wood fuels that are being traded (Table 1) and how they are commonly prepared. Table 1 Major traded forms of wood fuels (Serup & Kofman 2005) Fuel name Briquettes Pellets Fuel powder Sawdust Wood chips Hog fuel Logs Whole wood

Typical particle size Ø > 25 mm Ø < 25 mm < 1 mm 1-5 mm 5-100 mm Varying 100-1000 mm > 500 mm

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Common preparation method Mechanical compression Mechanical compression Milling Cutting with sharp tools Cutting with sharp tools Cutting with blunt tools Cutting with sharp tools Cutting with sharp tools

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Technical specifications for logs and wood chips. The European Standard EN 149611 offers information that is to be taken into account when they issue contracts for biofuel delivery and quality statements (Tables 2 and 3). Table 2 Log wood with technical specification EN 14961-1 (Contract BiomassTradeCentre2, Manual – Wood Fuels, 2011) Traded form Dimensions: Length (L) Thickness (D) (maximum diameter of a single chop) P200– P200 P250 P330 P500 P1000 P1000+ M20 M30 M40 M65

≤ ≤ ≤ ≤

Log woods

L < 200 and D < 20 (ignition wood) L = 200 Ø 20 and 40 ≤ D ≤ 150 mm L = 250 Ø 20 and 40 ≤ D ≤ 150 mm L = 330 Ø 20 and 40 ≤ D ≤ 160 mm L = 500 Ø 40 and 60 ≤ D ≤ 250 mm L = 1000 50 and 60 ≤ D ≤ 350 mm L > 1000 (actual value has to be stated ) Moisture (M) Oven-ready log Seasoned in the storage Seasoned in the forest Fresh, after cut in the forest

20% 30% 40% 65%

Table 3 Wood chips dimension classes compliance with technical specification EN 14961-1 (Contract BiomassTradeCentre2, Manual – Wood Fuels, 2011) Dimension classes

(mm) P16 P45 P63 P100 U20 U30 U40 U55 U65 C0.7 C1.5 C3.0 C6.0 C1.5

Composition of particle size % Main amount > 80% of wt.

3.15 3.15 3.15 3.15

< < <
100 mm > 200 mm

 20% dried fit for storage  30% limited for storage  40%  55%  65% Ashes (% compared to its weight in dry condition)  0.7%  1.5%  3.0%  6.0%  10.0%

The production chain for solid biofuels. The purchase chains of solid biofuels consist of one or more processes, each of them running through a single or more operations. Operations may be carried out by different companies or within the same company. The purchase chain of each of these is divided into three different processes: the process concerning the raw material, production and sales. In order to define the indicated quality it is important to understand the relation between the three phases, as within the ECOTERRA Journal of Environmental Research and Protection

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chain of purchase there may be involved any other phase (Contract BiomassTradeCentre2, Manual – Wood Fuels, 2011). The QA/QC system was designed for small producers and sellers of biomass in compliance with the corresponding CEN (EN) standards and the regarding technical reports (CEN/RT). To implement the QA/QC system on a large scale is not possible for small producers because of the high costs of laboratory tests and audit. This system may be implemented with producers of more than 1000 tons/year and thus they can check the basic quality parameters, the goods are tested and declared to be conform from the point of view of quality. Biomass Centre. The wood mass is stored in a biomass in centre where it is conditioned, sorted and processed (Figures 1 and 2). Biomass storage centres are infrastructures that are fundamental for the production and professional marketing of wood fuels as such, and which make it possible to make products available on the market if they meet technical specifications.

Figure 1. Biomass Centre – Storage of the wood material for heating purposes and raw materials to produce pellets and briquettes.

Figure 2. Solid biofuels: a - fire wood logs; b - hog fuel; c - wood chips; d - pellets. Management of the wooden material from the logistic point of view. The wood material is stored in 3 different ways: log packages of 1 meter length or in box pallets of one cubic meter, logs of 33 cm (technical specification – Table 2) or in bulk under the roof of the shed. In the open shed the wood is conditioned until it reaches a moisture of less than 30%; after that it is chopped under a roof or sold as it is. Wood chips are a product of the raw material hewn after the wood had been stored for at least 6 months (spring, summer); wood chips are also stored in the roofed storage place. Each wood product is sold to a specific price that differs according to its moisture that is measured with a special device when the product is sold. The storage area is organized as an open place with raw materials, followed by logs of 33 cm length stored in cylindrical boxes and covered by tarpaulins that ensure that the materials beneath can breathe. If the boxes are placed on asphalt in a sunny place, the logs dry much faster. Pellets and briquettes are stored in closed places from the day they are brought until the day they are delivered.

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Evaluation from the quality point of view of biomass of the wood existing in the biomass centre where we carried out this study. Samples were taken in July 2013 according to the standard Solid biofuels – Sampling CEN/TS 15150:2005. The wood that was harvested in the forest is cleared of branches and then it is chopped to 15-35 cm. The moisture of the green wood is about 55-65% of its total weight (with beech). If the wood is stored such that it can be naturally aired, moisture will reduce after summer to about 15% of its total weight. Such decrease depends also on weather conditions and whether it was stored under a roof. The wood is most efficient when its moisture is 15% (Serup & Kofman 2005). In the storage area there are two batches of fire wood. The moisture of the batch we noted with 1 was of 15-16% and was ready for delivery (Table 4). Batch no. 2 consists of beech fire wood and had the humidity of 25%; is to be delivered in the next months. Table 4 The moisture of the batch ready for delivery Product Raw beech Dried beech

Caloric power MJ/kg 10.467 14.65

Humidity % 35 15

To determine the dimensions of hog fuel we built a system of vibrating sieves (rotating sieve) according to the requirements of the Standard CEN TR 15149-3 (SR EN149611:2010). Following the measurements made in the laboratory we determined the dimension class for batches 1 and 2 of hog fuel. The method used – the rotating sieve – is applied for lose biofuels such as hog fuel and wood chips. After the analyses, and the separation of the particles according their dimensions, we determined their dimension classes (Table 5). Table 5 Quality parameters of the hog fuel stored in the biomass centre Characteristics Raw material Dimensions mm Moisture % Caloric power MJ/kg

Batch 1 spruce P100 30 13.5

Batch 2 spruce P63 20 14.0

Notes Batch 1 –fit for storage Batch 2 - dried

The samples of spruce hog fuel in table 5 for the main fraction represent 78% compared to 75% required by the standard and batch 1 was classified in the category P100 according to the standard EN 14961-1:2010. The sample of hog fuel (fir-spruce) of batch 2 represent a main fraction of 80% compared to 75% and taking into account the other fractions, too, we can classify it as P63 9 (Table 5). As for the humidity of the two analysed batches: batch 1moisture 30% (see table 5) i.e. the product is classified in the category M30% of the standard and batch 2 (table 5) 20% i.e. category M20% of the standard. The caloric power correlates with batch 1 of the table 5 and has a caloric power of 13.5 MJ/kg and with batch 2 of table 5 with 14.0 MJ/kg. The caloric power differs from one species to another and is higher with species having a high content of lignin, i.e. with fir wood (The book of the forester 2006). We did not analyse the wood chips in our study. The dimensions of the pellets varied according to the species we analysed: with batch 1 (pellets of beech and with batch 2 pellets of fir-trees the diameter was different from the standard and was de 8.5 mm (D08) and 6 mm (D06) respectively, according to the provisions of EN 14961-1 and with batch 3 the diameter was of 8 mm, the pellets were of the D08 category. The length of batch 1 was of 15.8 mm, that of batch 2.15 mm

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and with batch 3 between 10.6 mm and was thus in compliance with the standard SR EN 14961-1 of this parameters (Table 6). Table 6 Quality parameters of pellets stored in the biomass centre Characteristics

Batch 1

Batch 2

Batch 3

Obs.

Raw material Dimensions mm Moisture % Ashes % Density kg/mc Caloric power MJ/kg

Beech sawdust L=15.8; Ø=6

Fir sawdust L=15; Ø=6

Sawdust beech + fir L=10.6; Ø=6

8.36 0.8 696.3 17.9

8