SIST EN 16723-2:2017

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Zemeljski plin in biometan za uporabo v prometu in biometan za dodajanje v omrežje zemeljskega plina - 2. del: Specifikacije goriv za motorna vozilaErdgas und Biomethan zur Verwendung im Transportwesen und Biomethan zur Einspeisung ins Erdgasnetz - Teil 2: Festlegungen für Kraftstoffe für KraftfahrzeugeGaz naturel et biométhane pour utilisation dans le transport et biométhane pour injection dans les réseaux de gaz naturel - Partie 2 : Spécifications du carburant pour véhicules automobilesNatural gas and biomethane for use in transport and biomethane for injection in the natural gas network - Part 2: Automotive fuels specification75.160.30Plinska gorivaGaseous fuels43.060.40Sistemi za gorivoFuel systemsICS:Ta slovenski standard je istoveten z:EN 16723-2:2017SIST EN 16723-2:2017en,fr,de01-september-2017SIST EN 16723-2:2017SLOVENSKI
STANDARD



SIST EN 16723-2:2017



EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 16723-2
June
t r s y ICS
t yä s { râ
y wä s x rä u r English Version
Natural gas and biomethane for use in transport and biomethane for injection in the natural gas network æ Part
tã Automotive fuels specification Gaz naturel et biométhane pour utilisation dans le transport et biométhane pour injection dans les réseaux de gaz naturel æ Partie
t ã Spécifications du carburant pour véhicules automobiles
Erdgas und Biomethan zur Verwendung im Transportwesen und Biomethan zur Einspeisung ins Erdgasnetz æ Teil
tã Festlegungen für Kraftstoffe für Kraftfahrzeuge This European Standard was approved by CEN on
s r April
t r s yä
egulations which stipulate the conditions for giving this European Standard the status of a national standard without any alterationä Upætoædate lists and bibliographical references concerning such national standards may be obtained on application to the CENæCENELEC Management Centre or to any CEN memberä
translation under the responsibility of a CEN member into its own language and notified to the CENæCENELEC Management Centre has the same status as the official versionsä
CEN members are the national standards bodies of Austriaá Belgiumá Bulgariaá Croatiaá Cyprusá Czech Republicá Denmarká Estoniaá Finlandá Former Yugoslav Republic of Macedoniaá Franceá Germanyá Greeceá Hungaryá Icelandá Irelandá Italyá Latviaá Lithuaniaá Luxembourgá Maltaá Netherlandsá Norwayá Polandá Portugalá Romaniaá Serbiaá Slovakiaá Sloveniaá Spainá Swedená Switzerlandá Turkey and United Kingdomä
EUROPEAN COMMITTEE FOR STANDARDIZATION COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre:
Avenue Marnix 17,
B-1000 Brussels
9
t r s y CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Membersä Refä Noä EN
s x y t uæ tã t r s y ESIST EN 16723-2:2017



EN 16723-2:2017 (E) 2 Contents Page European foreword . 3 Introduction . 4 1 Scope . 6 2 Normative references . 6 3 Terms and definitions . 6 4 Parameters and test methods . 8 4.1 General . 8 4.2 Standard reference conditions . 8 4.3 Requirements, limit values and related test methods for natural gas and biomethane as automotive fuels . 9 4.4 Requirement on climate-dependant characteristic and test methods for natural gas and biomethane as automotive fuels . 10 5 Sampling . 10 6 Marking, labelling and packaging . 10 Annex A (informative)
Parameters . 11 A.1 Total silicon . 11 A.2 Hydrogen . 11 A.3 Compressor oil, dust impurities and biogenic materials . 12 A.4 Water dew point . 12 A.5 Hydrocarbon dew point temperature . 13 A.6 Hydrogen sulfide plus Carbonyl sulfide . 13 Annex B (informative)
Odorization and sulfur . 14 B.1 CEN/TC 408 approach . 14 B.2 General . 14 B.3 Total sulfur from Odorants . 14 Annex C (informative)
Properties of gases at the extremities of the Wobbe index ranges of the gas groups for gases of the second family . 15 C.1 Introduction . 15 C.2 Basis of calculations of indicative ranges . 16 C.3 Calculated properties . 17 C.4 Conclusions . 17 Annex D (informative)
Voluntary dedicated grades . 20 Bibliography . 22 SIST EN 16723-2:2017



EN 16723-2:2017 (E) 3 European foreword This document (EN 16723-2:2017) has been prepared by Technical Committee CEN/TC 408 “Natural gas and biomethane for use in transport and biomethane for injection in the natural gas grid”, the secretariat of which is held by AFNOR. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by December 2017, and conflicting national standards shall be withdrawn at the latest by December 2017. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN shall not be held responsible for identifying any or all such patent rights. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association. EN 16723 consists of the following parts, under the general title “Natural gas and biomethane for use in transport and biomethane for injection in the natural gas network”: — Part 1: Specifications for biomethane for injection in the natural gas network — Part 2: Automotive fuel specification According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. SIST EN 16723-2:2017



EN 16723-2:2017 (E) 4 Introduction This European Standard was prepared by CEN/TC 408 in response to the European Commission standardization mandate M/475. The mandate asks for the development of a set of quality specifications for biomethane to be used as a fuel for automotive vehicle engines and to be injected in natural gas pipelines (network). However, the scope of the standard was widened according to BT decision C109/2012 that redefined the scope of CEN/TC 408: 'Standardization of specifications for natural gas and biomethane as automotive vehicle fuel and of biomethane for injection in the natural gas grid, including any necessary related methods of analysis and testing. Production process, source and the origin of the source are excluded'. NOTE The CEN Technical Board (CEN/BT) is responsible for coordinating the work between technical bodies in order to achieve a coherent set of standards and to avoid overlaps. One of the aims of European policy in the field of energy is to increase the security of energy supply in the EU, as well as to contribute to reducing the emission of greenhouse gases accepted by the EU at Kyoto. In this context, special focus is given to the development and use of energy from renewable sources of biological and non-biological origin. Figure 1 provides a visual representation of some applications of biomethane. Mandate M/475 indicates that the requirements for natural gas quality for injection in the natural gas network are developed by CEN/TC 234 in answer to Mandate M/400 on natural gas quality. CEN/TC 408 should consider the work of the pending mandate M/400 on gas quality, and should refer to the parameters as defined and specified in EN 16726. This standard should exclude the definition of any parameters or substances that are addressed in EN 16726. However, it may specify more strict limits for parameters or substances unique to biomethane if deemed technically necessary. If needed, additional parameters or substances should be defined. SIST EN 16723-2:2017



EN 16723-2:2017 (E) 5
Key 1 biogas from digestion or thermos-chemical process 7 non-grid sourced natural gas 2 upgrading 8 local dedicated infrastructure 3 injection into the gas grid 9 automotive use 4 natural gas grid 10 domestic and industrial use 5 conditioning 11 Part 1: grid specification 6 refuelling station 12 Part 2: automotive specification Figure 1 — Representation of some flows and uses of biomethane and natural gas SIST EN 16723-2:2017



EN 16723-2:2017 (E) 6 1 Scope This European Standard specifies the requirements and test methods for natural gas (group L and H, as in EN 437), biomethane and blends of both at the point of use as automotive fuels. This European Standard applies to the previously mentioned fuels irrespective of the storage state (compressed or liquefied). To check compliance with some requirements set by the standard, LNG or liquefied biomethane should be re-gasified prior to testing. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 437, Test gases - Test pressures - Appliance categories EN 16726:2015, Gas infrastructure - Quality of gas - Group H EN 16942, Fuels - Identification of vehicle compatibility - Graphical expression for consumer information EN ISO 10715, Natural gas - Sampling guidelines (ISO 10715) EN ISO 13443, Natural gas - Standard reference conditions (ISO 13443) 3 Terms and definitions For the purposes of this document, the terms and definitions given in EN 16726 as well as the following apply. 3.1 biogas gas, comprising principally methane and carbon dioxide, obtained from the anaerobic digestion of biomass 3.2 biomass biological material from living, or recently living organisms, typically this may be plants or plant-derived materials 3.3 biomethane gas comprising principally methane, obtained from either upgrading of biogas or methanation of bio-syngas 3.4 bio-syngas gas, comprising principally carbon monoxide and hydrogen, obtained from gasification of biomass 3.5 compressed natural gas CNG natural gas used as a fuel for automotive vehicles, typically compressed up to 20 000 kPa in the gaseous state SIST EN 16723-2:2017



EN 16723-2:2017 (E) 7 3.6 compressed biomethane biomethane used as a fuel for automotive vehicles, typically compressed up to 20 000 kPa in the gaseous state 3.7 gas infrastructure pipeline systems including pipework, underground gas storages and their associated stations or plants for the transmission and distribution of gas 3.8 hydrocarbon dew point temperature temperature above which no condensation of hydrocarbons occurs at a specified pressure 3.9 liquefied natural gas LNG natural gas which has been liquefied, after processing, for storage or transportation purposes 3.10 liquefied biomethane biomethane which has been liquefied, after processing, for storage or transportation purposes 3.11 methane number MN rating indicating the knocking characteristics of a gaseous fuel Note 1 to entry: MN has a similar use as the octane number for petrol. Note 2 to entry: MN expresses the volume percentage of methane in a methane/hydrogen mixture which, in a test engine under standard conditions, has the same tendency to knock as the gaseous fuel to be examined. 3.12 natural gas complex gaseous mixture of hydrocarbons, primarily methane, but generally includes ethane, propane and higher hydrocarbons, and some non-combustible gases such as nitrogen and carbon dioxide Note 1 to entry: Natural gas can also contain components or contaminants such as sulfur compounds and/or other chemical species. 3.13 natural gas network either transmission network or local distribution system 3.14 net calorific value amount of heat that would be released by the complete combustion with oxygen of a specified quantity of gas, in such a way that the pressure at which the reaction takes place remains constant, and all the products of combustion are returned to the same specified temperature as that of the reactants, all of these products being in the gaseous states Note 1 to entry: Equivalent terms used are inferior calorific value and lower heating value. SIST EN 16723-2:2017



EN 16723-2:2017 (E) 8 3.15 odorization addition of odorants to gas (normally odourless) to allow gas leaks to be recognized by smell at trace levels (before accumulating to dangerous concentrations in air) 3.16 relative density quotient of the mass of a gas, contained within an arbitrary volume, and the mass of dry air of standard composition (defined in EN ISO 6976:2016) which would be contained in the same volume at the same reference conditions 3.17 syngas gas, comprising principally of carbon monoxide and hydrogen, obtained from gasification of fossil fuel 3.18 upgrading of biogas removal of carbon dioxide and contaminants from biogas 3.19 water dew point temperature temperature above which no condensation of water occurs at a specified pressure 3.20 Wobbe index volumetric-basis heating value, at specified reference conditions, divided by the square root of the relative density at the same specified metering reference conditions 4 Parameters and test methods 4.1 General This section deals with the various parameters for which requirements are given. Natural gas, biomethane, and blends of those shall be free from any other constituents and/or impurities than the ones described in this standard that renders the fuel unacceptable for use as an automotive fuel. NOTE In the case of such other constituents and/or impurities are present, it may be necessary to obtain an approval from the competent and legitimate authority to define the acceptable risk. 4.2 Standard reference conditions Unless stated otherwise all volumes are for the real dry gas at ISO Standard Reference conditions of 15 °C and 101,325 kPa. Unless stated otherwise all calorific values and Wobbe indices are for the real dry gas at ISO Standard Reference conditions of:
15 °C (combustion);
and 15 °C and 101,325 kPa (metering). In assessing compliance with this European Standard, parameters should be determined directly at ISO Standard Reference conditions. If the properties are only available at other reference conditions and the actual gas composition is not known, then conversion to ISO Standard Reference conditions shall be carried out using the procedure described in EN ISO 13443. SIST EN 16723-2:2017



EN 16723-2:2017 (E) 9 4.3
Requirements, limit values and related test methods for natural gas and biomethane as automotive fuels Information on Wobbe index and calorific value can be found in Annex C. Table 1 — Requirements, limit values and related test methods for natural gas and biomethane as automotive fuels Parameter Unit Limit valuesa Test method (informative) Min Max Total volatile silicon (as Si) mgSi/m3
0,3b EN ISO 16017-1:2000 TDS-GC-MS Hydrogen % mol/mol _ 2 EN ISO 6974-3 EN ISO 6974-6 EN ISO 6975 Hydrocarbon dew point temperature (from 0,1 to 7 MPa absolute pressure) °C _
«2 (as in EN 16726) ISO 23874 ISO/TR 11150 ISO/TR 12148 Oxygen % mol/mol _ 1 EN ISO 6974- series EN ISO 6975 Hydrogen sulfide + Carbonyl sulfide (as sulfur) mg/m3 _ 5 (as in EN 16726) EN ISO 6326-1 EN ISO 6326-3 EN ISO 19739 S total (including odorization) mgS/m3
30c EN ISO 6326-5 EN ISO 19739 Methane Number Index 65d
(as in EN 16726)
Annex A of EN 16726:2015 Compressor oil
e ISO 8573-2 Dust impurities
e, f ISO 8573-4 Amine mg/m3
10 VDI 2467 Blatt 2:1991–08 Water dew point See 4.4 a Limit values are absolute, the number of the decimal places shall not imply the accuracy of the test methods. b Levels above 0,1 mgSi/m3 can severely harm switching type oxygen sensors of some automotive vehicles (see DNV GL report). However, a limit set at this level would present difficulty in terms of analytical measurement (current quantification limits are at best 0,10 mg Si/m3, which would imply setting a limit of 0,30 mg Si/m3). And currently biomethane production processes cannot guarantee a level of siloxanes below 0,5 mgSi/m3. c Currently, there is a difference between the automotive industry needs for sulfur content (10 mgS/m3 including odorization) and the values the gas industry can provide (30 mg/m3 including odorization). See Annex B. It is possible to cover this parameter in a national foreword. d The methane number depends on the composition of the distributed natural gas. It should be noted that only a small fraction of the distributed natural gas has a methane number below (MWM) of 70. e The fuel shall be free from impurities other than “de minimis” levels of compressor oil and dust impurities. In the context of this European Standard, “de minimis” means an amount that does not render the fuel unacceptable for use in end user applications. f Fuelling stations providing LNG should ensure a maximum particle contamination of 10 mg/l of LNG to protect the automotive vehicle system from debris, providing performance equivalent to a filter with maximum pore size of 5 and 10
% efficiency. SIST EN 16723-2:2017



EN 16723-2:2017 (E) 10 Test methods other than those listed in the relevant standards column in Table 1 may be applied, provided their fitness for purpose can be demonstrated and validated. Some test methods have not been validated for biomethane or mixtures with natural gas, however further work is undertaken towards validation. Additional information on the components listed in Table 1 can be found in Annex A. Several values in this table are based on values in EN 16726. They shall be reviewed if values in EN 16726 are changed. Table 1 does not preclude the use of a dedicated grade. An example is given in Table D.1. 4.4 Requirement on climate-dependant characteristic and test methods for natural gas and biomethane as automotive fuels Three classes, A, B and C are given to allow for climate dependent limits to be adopted nationally. In a national annex to this European Standard, each country shall indicate which grade(s) it adopts. Table 2 — Climate dependant requirements and test methods Parameter Limit values Test method See normative references Water dew point Class A
«10 °C at 20 000 kPa ISO 6327 (applicability at 20 000 kPa) Class B
«20 °C at 20 000 kPa
Class C
«30 °C at 20 000 kPa
5 Sampling Components shall be sampled according to EN ISO 10715 as those of EN 16726. This sampling method has not been validated for biomethane or mixtures with natural gas, however further work is undertaken towards validation. Other components as siloxanes need special attention/validation in sampling. Measures shall be taken to avoid any contamination of the sample from the moment of sampling until the analysis can be performed. 6 Marking, labelling and packaging Information to be marked on dispensing pumps and nozzles used for delivering automotive NG/biomethane fuel and the dimensions of the label shall be in accordance with EN 16942. SIST EN 16723-2:2017



EN 16723-2:2017 (E) 11 Annex A (informative)
Parameters A.1 Total silicon Some raw biogas, in particular from landfill, sewage or municipal biowaste contains significant amounts of siloxanes volatilized during anaerobic digestion. Siloxanes are components in various household products and construction materials and can be used as de-foamers during biomass fermentation. Silicon impurities need to be removed during upgrading of biogas to biomethane. During combustion of biomethane, siloxanes and other organo silicon compounds form silica which generates deposits, e.g. on valves, lambda oxygen sensors and cylinder walls, causing abrasion, malfunction of exhaust emission control or blockage of pistons and cylinder heads, respectively. In particular, automotive vehicle engines are affected by residual silicon contamination in biomethane. Automotive vehicles with spark ignition engines are developed for fuels, e.g. gasoline, gasoline ethanol blends and natural gas which all are literally free of silicon. The absence of silicon impurities enabled the use of lambda oxygen sensors upstream of the catalyst for exhaust gas control. Deposition of silica on sensor elements impedes oxygen diffusion. Higher silicon contents misalign oxygen sensors and reduce their durability. The analysis method for silicon in natural gas has not yet been fully validated and the limit value for silicon defined in the table of parameters is preliminary. Although preliminary, the definition of a low maximum silicon limit has been considered as an important step to protect automotive vehicles from silicon contaminated gas as far as possible. Besides siloxanes, biogases may also contain organic silicon compounds other than siloxanes which are also converted to silica upon combustion. A.2 Hydrogen There are proposals to inject hydrogen (H2) from renewable sources in the natural gas network. This measure would allow the very large transport and storage capacities of the existing infrastructure, particularly underground storage facilities and high-pressure pipelines, to be used for indirect electricity transport and storage. The results of the GERG study “Admissible Hydrogen Concentrations in Natural Gas Systems” (see Bibliography [24]) show that an admixture of up to 10 % by volume of hydrogen to natural gas is possible in some parts of the natural gas system. However there are still some important areas where issues remain (GERG is the European Gas Research Group, Brussels): — underground porous rock storage: hydrogen is a good substrate for sulphate-reducing and sulfur-reducing bacteria. As a result, there are risks associated with: bacterial growth in underground gas storage facilities leading to the formation of H2S; the consumption of H2, and the plugging of reservoir rock. A limit value for the maximum acceptable hydrogen concentration in natural gas cannot be defined at the moment. (H2-related aspects concerning wells have not been part of this project); — steel tanks in natural gas automotive vehicles: specification UN ECE R 110 stipulates a limit value for hydrogen of 2 vol%; SIST EN 16723-2:2017



EN 16723-2:2017 (E) 12 — gas turbines: most of the currently installed gas turbines were specified for a H2 fraction in natural gas of 1 vol% or even lower. 5 % may be attainable with minor modification or tuning measures. Some new or upgraded types will be able to cope with concentrations up to 15 vol%; — gas engines: it is recommended to restrict the hydrogen concentration to 2 vol%. Higher concentrations up to 10 vol% may be possible for dedicated gas engines with sophisticated control systems if the methane number of the natural gas/hydrogen mixture is well above the specified minimum value; — many process gas chromatographs will not be capable of analysing hydrogen. Investigations have been conducted to evaluate the impact of hydrogen as related to the above topics. At present it is not possible to specify a limiting hydrogen value which would generally be valid for all parts of the European gas infrastructure and, as a consequence, we strongly recommend a case by case analysis. A.3 Compressor oil, dust impurities and biogenic materials To avoid problems with lubricating oil carryover from refuelling station compressors, dust and/or solid particulates that can cause deposits or blockage of the automotive vehicle fuel system, oil removal filters and solid particulate filters should be installed downstream of equipment that may leak oil and emit solid particulates. It should be noted that the removal of oil and solid particulates are interdependent operations. The upstream filter will have to remove both oil and solid particulates, irrespective of filter design. It is a recommended practice for compressed gas refuelling stations to install two coalescing type filters for oil removal, one just after the oil using equipment, and another one just before the high pressure gas storage. When using mineral oil as lubricant, installation of a final adsorption filter (e.g. molecular sieve) should be considered. Presently, there is no standardized test method available for measuring compressor oil. Monitoring oil consumption and recovery within coalescing filters will enable an estimate of the oil content of the gas after compression and filtering. Most of the solid particulates will be trapped together with the oil. Additional removal of solid particulates can be secured by using a dedicated particulate filter with a nominal mesh size of less than 5 micron, placed as close as possible to the filling nozzle. Such a filter also greatly reduces the content of biogenic material such as microorganisms. The main function of the filter is to retain solid particulates. The operation of the filter should not be impaired by water, oil or hydrocarbon droplets. The filter should be of the cartridge type. The cartridge should retain 99 % of the solid particulates
· 5 99 % of liquid particulates
· 10
A.4 Water dew point Technically, the water dew point can be measured by using cooled surface condensation hygrometers. For details about the measurement method, see EN ISO 6327. The water content is the mass concentration of the total amount of water contained in a gas. The water content is expressed in grams per cubic metre. Technically, the water content can be measured by using Karl Fischer method, see EN ISO 10101-3. The correlation between water content and water dew point is given in EN ISO 18453. There are several industrial metering instruments available on the market measuring the water content of the gas and calculating the water dew point at defined pressure. SIST EN 16723-2:2017



EN 16723-2:2017 (E) 13 The working principle of these instruments is different from Karl Fisher method (optical, electrolytic, capacitance, piezoelectric, etc.) and the calculation of the water dew point from the water content might be different from the EN ISO 18453 method. To achieve unified measurement results from the different measurement methods, it is recommended to calibrate the metering instruments traceable to national/international standards. A.5 Hydrocarbon dew point temperature Hydrocarbon dew point should be measured directly (e.g. using instruments according to ISO/TR 12148) or calculate
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