1、PUBLISHED DOCUMENT PD CEN/TR 15591:2007 Solid recovered fuels Determination of the biomass content based on the 14 C method ICS 75.160.10 PD CEN/TR 15591:2007 This Published Document was published under the authority of the Standards Policy and Strategy Committee on 30 April 2007 BSI 2007 ISBN 978 0
2、 580 50522 5 National foreword This Published Document was published by BSI. It is the UK implementation of CEN/TR 15591:2007. The UK participation in its preparation was entrusted to Technical Committee PTI/17, Solid biofuels. A list of organizations represented on PTI/17 can be obtained on request
3、 to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Amendments issued since publication Amd. No. Date Comments TECHNICAL REPORT RAPPORT TECHNIQUE TECHNISCHER BERICHT CEN/TR 15591 February 2007
4、ICS 75.160.10 English Version Solid recovered fuels - Determination of the biomass content based on the 14 C method Combustibles solides de rcupration - Dtermination de la teneur en biomasse, base sur la mthode du C 14Feste Sekundrbrennstoffe - Bestimmung des Gehaltes an Biomasse nach de 14 C-Method
5、e This Technical Report was approved by CEN on 1 January 2007. It has been drawn up by the Technical Committee CEN/TC 343. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Irelan
6、d, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart,
7、36 B-1050 Brussels 2007 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. CEN/TR 15591:2007: E2 Contents Page Foreword3 0 Introduction4 1 Scope 7 2 Terms and definitions .7 3 Symbols and abbreviations 7 4 Methods of measurement .8 4.1 P
8、rinciple8 4.2 Sampling.8 4.3 Transport and storage.8 4.4 Preparation of the test portion from the laboratory sample .9 4.5 Analysis by Proportional Scintillation-counter Method (PSM) .9 4.6 Analysis by -ionisation (proportional gas counting) (BI)10 4.7 Analysis by Accelerator Mass Spectrometry (AMS)
9、 10 5 Equipment and reagents.10 5.1 For the preparation of the test portion 10 5.2 For the analysis by PSM .11 5.3 For the analysis by -ionisation (BI) .11 5.4 For analysis by AMS (example from Utrecht University).11 6 Procedure .11 6.1 For sampling 11 6.2 For the preparation of the test portion 12
10、6.3 Procedure for analysis 13 7 Calculations13 7.1 General13 7.2 Calibration 14 7.3 Example for the calculation of a RDF sample analysed with PSM .15 8 Uncertainty of measurement (PMS and BI measurements) based in Poisson statistics.15 9 Strengths and weaknesses.16 9.1 Comparison of 14 C based metho
11、ds with SDM 16 9.2 Comparison of PSM, Gas Counting (BI) and AMS .17 10 Legislative aspects17 10.1 General17 10.2 Austria.17 10.3 The Netherlands.17 10.4 Finland 18 11 Conclusions .18 Annex A (informative) Origin of expertise present in the technical report19 Annex B (informative) List of European la
12、bs with radio carbon expertise.22 Bibliography 33 CEN/TR 15591:2007 3 Foreword This document (CEN/TR 15591:2007) has been prepared by Technical Committee CEN/TC 343 “Solid recovered fuels”, the secretariat of which is held by SFS. Attention is drawn to the possibility that some of the elements of th
13、is document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. CEN/TR 15591:20074 0 Introduction 0.1 General This document has been prepared as a result of the CEN/TC 343/WG 3 meeting in Amsterdam in April 2005. It sum
14、marizes the state of the art in 14 C-based methods applied to determining the biomass content of SRF; as of yet no technical CEN standards for the application of 14 C-based methods to determine biomass content are available. The purpose of this Technical Report is to present the information availabl
15、e on this subject at this moment to assess if an extension of the available methods for determining the biomass content of SRF is required, wanted and technically possible. Analytically proven standards exist for determining the biomass content of SRF by manual sorting and by selective dissolution (
16、CEN/TS 15440 1). In the Netherlands these methods are available as NTA (National Technical Agreement) and have been in use for some years. Important advantages of these standards are their applicability using basic laboratory equipment and available personnel. However, they are not applicable to all
17、 kinds of solid recovered fuels. The manual sorting method fails if the constituents of the sample are shredded too finely, if they are strongly intertwined or compressed or if they cannot be recognized visually. The selective dissolution method fails if biomass constituents are present that do not
18、dissolve, or fossil components that do. Both methods fall short if fossil and biomass carbon are mixed at the molecular level. 14 C based methods do not use chemical or morphological properties of the sample but physical properties of the carbon atoms themselves. Because 14 C based methods are based
19、 on these physical properties they avoid the problems of manual sorting and selective dissolution methods. On the other hand they need more instrumentation and skilled personnel. They are proposed here as an addition to the manual sorting and selective dissolution methods because they resolve analyt
20、ical problems that are otherwise irresolvable. The application of 14 C based methods for similar purposes are not new 2 3. In this document the information available in Europe and the USA concerning biomass carbon content determination in solid recovered fuels with 14 C based methods is presented to
21、 give the reader background information about possibilities and drawbacks of these methods. 0.2 Basis of the 14 C method The 14 C method is a well-known method in global use, for determining the age of carbon containing matter. 14 C is a radioactive isotope; its presence in the air is a result of th
22、e interaction of cosmic radiation and the nitrogen in the atmosphere (see Figure 1). Fossil carbon contains no 14 C, however a trace amount of 14 C is present in living matter. The 14 C isotope is quickly converted to 14 CO 2after formation and enters living matter when atmospheric 14 CO 2is convert
23、ed in the biosphere by photosynthesis to sugars and further converted to e.g. cellulose. The concentration of 14 C in air is considered constant all over the world. In living material the concentration of 14 C is stable and in equilibrium with the air concentration. In dead material the concentratio
24、n of 14 C slowly diminishes to zero as the radioactive 14 C isotope decays. Measuring the amount of 14 C in solid recovered fuels is the basis for determining biomass content based on the 14 C method. CEN/TR 15591:2007 5 Figure 1 Illustration of the basis of the 14 C method Organic material is used
25、for many purposes. One of the objectives is direct use as a fuel which is outside the scope of this report. However, after completing their primary use, many of these organic materials may ultimately be used in the form of solid recovered fuels. Examples of organic materials in solid recovered fuels
26、 are: Packaging materials; Paper; Wood used in buildings; Kitchen waste; Waste (dung and offal) from the bio industry; Plastics; Car tires. Carbon present in material produced by living organisms, immobilized as fuel in present times is called biomass. Carbon present in material produced by living o
27、rganisms immobilized as fuel in a past geological era is called fossil fuel. The difference between the two is that CO 2from biomass or biomass origin does not CEN/TR 15591:20076 contribute to a higher concentration of CO 2in the atmosphere as its carbon has been recently extracted from the atmosphe
28、re. In solid recovered fuels, the combustible carbon originates from fossil (mainly in the form of plastics), mixed sources like rubber tyres and packaging materials, and from biomass origin (e.g. wood, paper). Authorities require that emissions of CO 2from fossil origin by companies is made known,
29、thus, in order to determine these companies, knowledge about the biomass content by total carbon content of mixed fuels should be acquired. For this reason, methods such as the solid dissolution method and 14 C method were developed. International acceptance of a 14 C based method can be expected, a
30、s can be illustrated by the recent publication of ASTM, ASTM D 6866-05, Standard Test Method for determining the Bio based Content of Natural Range Materials Using Radiocarbon and Isotope Ratio Mass Spectrometry Analysis2. CEN/TR 15591:2007 7 1 Scope This Technical Report gives an overview of the su
31、itability of 14 C-based methods for the determination of the fraction of biomass carbon in solid recovered fuels, using detection by scintillation, gas ionization and mass spectrometry. 2 Terms and definitions For the purposes of this document, the following terms and definitions apply. 2.1 biodegra
32、dable carbon mass fraction of the total carbon that is capable of undergoing biological anaerobic or aerobic decomposition under conditions naturally occurring in the biosphere 2.2 biogenic carbon mass fraction of total carbon that was produced in natural processes by living organisms but not fossil
33、ized or derived from fossil resources 2.3 biomass carbon equivalent to biogenic carbon 2.4 isotope abundance fraction of atoms of a particular isotope of an element 2.5 repeatability extent of the agreement between the results of subsequent measurements of the same quantity, performed under the same
34、 measuring conditions 2.6 reproducibility extent of the agreement between the results of measurements of the same quantity, performed under variable measuring conditions. 3 Symbols and abbreviations This Technical Report uses the following symbols and abbreviations: 14 C Carbon isotope with an atomi
35、c mass of 14 AMS Accelerator Mass Spectrometry Beta particle, electron emitted during radioactive decay BI eta Ionisation CEN/TR 15591:20078 BP Before Present (before 1950) CPM Counts per minute DPM Disintegrations per minute ETS Emissions Trading Scheme GM Geiger Mller LSC Liquid Scintillation Coun
36、ter or Liquid Scintillation Counting PSM Proportional Scintillation-counter Method PMT Photo Multiplicator Tube RSD Relative Standard Deviation SDM Selective Dissolution Method SRF Solid Recovered Fuel STP Standard Temperature and Pressure (273,15 K (or 0 C) and 101,325 Pa (or 760 mmHg) 4 Methods of
37、 measurement 4.1 Principle The principle of the 14 C method is to determine the biomass content by total carbon by measuring the amount of 14 C present in the sample. This method utilizes the isotope abundance of 14 C similar to the way the age of objects is measured for archaeological purposes. In
38、all organisms living ashore, 14 C has a known isotope abundance equal to its isotope abundance in atmospheric CO 2 . As soon as an organism dies, the isotope abundance of 14 C in its organic material starts to decrease because 14 Cis an unstable isotope with a half-life of 5 730 yr. The isotope abun
39、dance of 14 C may be considered zero after ten half lives or 60 000 yr. The biomass content by total carbon of a material is calculated as the proportion of the isotope abundance of 14 C in that material and the isotope abundance of 14 C in the atmosphere at the time when the biomass was laid down.
40、The method is especially useful for determining biomass carbon content, however, the relationship between biomass carbon content and biomass content should be determined for every type of waste; a limitation that is also valid for other existing methods. When information is available about how carbo
41、n atoms are chemically bound, the amount of bio energy can be calculated. 4.2 Sampling For the 14 C based methods sampling procedures that are similar to those for determining major elements 4 are used. As carbon is one of the major components in solid recovered fuel, problems with homogeneity are n
42、ot to be expected with laboratory samples. Typical particle size of the sample material should be 0,2 mm. 4.3 Transport and storage For transport and storage of the samples, the same requirements are fulfilled as for normal lab samples. As part of the solid recovered fuel consists of organic materia
43、l, dry and cool storage is applied to prevent conversion of the biomass part by microbiological activities. CEN/TR 15591:2007 9 4.4 Preparation of the test portion from the laboratory sample For the PSM and BI methods sample sizes of 1 g or more are used. However at the 1 g level problems still aris
44、e with homogeneity of the sample; the use of a lab scale combustion device (e.g. rotary kiln) is recommended, allowing sample amounts of 5 g to 20 g. The AMS method only needs a few milligrams of sample. In this case combustion of samples at a scale of approximately 1g is necessary. After combustion
45、 the carbon is present in a gas phase as CO 2 , and the next step is preparing a mg size sample from the gaseous combustion products. 4.5 Analysis by Proportional Scintillation-counter Method (PSM) PSM (also called Liquid Scintillation Counter method, LSC) determines the isotope abundance of 14 C in
46、directly through its emission of (beta, electron) particles. The particles are detected through interacting with a solution of a scintillation molecule. This is possible only if the carbon is homogeneously distributed in the solution, as the particles must be able to interact with the solution inste
47、ad of being quenched in the solid fuel. Homogeneous distribution may be attained by four different methods: Conversion to CO 2 , followed by absorption in an organic amine and mixing this absorbent with the scintillation fluid. The amine is produced using fossil carbon, in order not to cause a blank
48、 signal. Conversion to CO 2 , followed by absorption in a BaCl 2or CaCl 2solution, and after drying and grinding, transfer of BaCO 3or CaCO 3into the scintillation fluid forming a suspension; or regeneration of CO 2from the precipitate, which is absorbed in an organic amine, and mixing this absorben
49、t with the scintillation fluid. Conversion to CO 2 , followed by adsorption on a solid medium, regeneration of CO 2which is absorbed in an organic amine, and mixing this absorbent with the scintillation fluid. Liquid fuels may be directly mixed with the scintillation fluid. The scintillation fluid consists of a solvent and a dissolved fluorescent agent, the fluor. When a is emitted, it rapidly transfers its energy to solvent molecu
