1、Designation: D7901 14aD7901 14bStandard Specification forDimethyl Ether for Fuel Purposes1This standard is issued under the fixed designation D7901; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A numbe
2、r in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This specification covers dimethyl ether (DME) for use as a fuel in engines specifically designed or modified for DME andfor blending with
3、liquefied petroleum gas (LPG). This specification is for use by manufacturers of dimethyl ether, by enginedevelopers of purpose-built engines, in contracts for the purchase of DME for fuel purposes, and for the guidance of consumersof this type of fuel.NOTE 1The generation and dissipation of static
4、electricity can create problems in the handling of DME. For more information on the subject, seeGuide D4865.1.2 The values stated in SI units are to be regarded as standard. Units in parentheses are for information only.1.3 This standard does not purport to address all of the safety concerns, if any
5、, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1265 Practice for Sampling Liquefied Petroleum (LP) G
6、ases, Manual MethodD1267 Test Method for Gage Vapor Pressure of Liquefied Petroleum (LP) Gases (LP-Gas Method)D1838 Test Method for Copper Strip Corrosion by Liquefied Petroleum (LP) GasesD2158 Test Method for Residues in Liquefied Petroleum (LP) GasesD2163 Test Method for Determination of Hydrocarb
7、ons in Liquefied Petroleum (LP) Gases and Propane/Propene Mixtures byGas ChromatographyD3700 Practice for Obtaining LPG Samples Using a Floating Piston CylinderD4865 Guide for Generation and Dissipation of Static Electricity in Petroleum Fuel SystemsD6667 Test Method for Determination of Total Volat
8、ile Sulfur in Gaseous Hydrocarbons and Liquefied Petroleum Gases byUltraviolet FluorescenceD6897 Test Method for Vapor Pressure of Liquefied Petroleum Gases (LPG) (Expansion Method)D7756 Test Method for Residues in Liquefied Petroleum (LP) Gases by Gas Chromatography with Liquid, On-Column Injection
9、D7828 Test Method for Determination of Residue Composition in Liquefied Petroleum Gas (LPG) Using Automated ThermalDesorption/Gas Chromatography (ATD/GC)2.2 Other Documents:NFPA 77 Recommended Practice on Static Electricity3ISO/DIS 17196 Dimethyl ether (DME) for fuelsDetermination of impuritiesGas c
10、hromatographic method4ISO 17197 Dimethyl ether (DME) for fuelsDetermination of water contentKarl Fischer titration method43. Terminology3.1 Abbreviations:3.1.1 DMEdimethyl ether, the chemical compound (CH3OCH3).1 This specification is under the jurisdiction ofASTM Committee D02 on Petroleum Products
11、, Liquid Fuels, and Lubricants and is the direct responsibility of SubcommitteeD02.H0 on Liquefied Petroleum Gas.Current edition approved June 1, 2014Oct. 15, 2014. Published July 2014October 2014. Originally approved in 2014. Last previous edition approved in 2014 asD7901 14.D7901 14a. DOI: 10.1520
12、/D7901-14a.10.1520/D7901-14B.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 Available from National Fire P
13、rotection Association (NFPA), 1 Batterymarch Park, Quincy, MA 02169-7471, http:/www.nfpa.org.4 Available from International Organization for Standardization (ISO), 1, ch. de la Voie-Creuse, CP 56, CH-1211 Geneva 20, Switzerland, http:/www.iso.org.This document is not an ASTM standard and is intended
14、 only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current v
15、ersionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.1.2 LPGliquefied petroleum gas.4.
16、Hazards4.1 WarningDimethyl ether is a highly flammable, colorless gas with a faint ether-like odor. It is shipped and stored in apressurized, liquefied state, much like LPG. Unlike LPG, dimethyl ether has a wide flammability range and a low autoignitiontemperature. Further, dimethyl ether in this sp
17、ecification is intended for use in a diesel (compression-ignition) engine. Many usersof diesel engines are familiar with the relative safety of storing and handling diesel fuel. However, dimethyl ether has significantlyhigher flammability hazards than diesel fuel. A leak of dimethyl ether could resu
18、lt in a dangerous fire or explosive situation, butthe intrinsic ether-like odor is mild and not alarming, as is the case with odorized natural gas or LP gases. Users of dimethyl etherare advised to determine proper odorization or alternative leak detection precautions.4.2 Consult a Material Safety D
19、ata Sheet for dimethyl ether for additional hazards.5. Chemical Composition and Other Requirements5.1 The DME fuel for purpose-built engines and for blending with liquefied petroleum gas shall conform to the requirementsprescribed in Table 1.NOTE 2Additional information on the physical and chemical
20、properties of dimethyl ether, which are not considered necessary for fuel specificationat this point, are in Appendix X1 and are given for information of fuel suppliers, OEMs, and users.5.2 The properties selected for limitation are those for which indications exist from experience with similar tech
21、niques and frominitial engine developmental work that they are required for obtaining acceptable engine performance.chosen from otherspecifications for DME which have relevance to engine operation and to related experience (for example, LPG).5.3 The maximum vapor pressure limit shown in Table 1 is g
22、iven to limit any high vapor pressure components such as gasesCO and CO2 and also to ensure that the same containers (tanks, tank cars, and rail cars) designed for LPG can be used for DME.NOTE 3It is expected that additional requirements for specifying dimethyl ether for fuel applications could be r
23、equired as purpose-built engines andother applications develop for DME and DME LPG blends, and such additional requirements would be balloted for inclusion into this specification,based on need and technical data.6. Workmanship, Finish, and Appearance6.1 DME for fuel use in engines designed for DME
24、and for blending with liquefied petroleum gas shall have a colorlessappearance and not contain any components or contaminants that would be detrimental to the intended use of the material.TABLE 1 Detailed Requirements for Dimethyl Ether for FuelPurposesProperty Test Method RequirementDimethyl Ether,
25、 mass %, min.A D2163 98.5Methanol, mass %, max. D2163 0.05Water, mass %, max. ISO 17197 0.03Methyl Formate, mass % D2163 reportSulfur, mg / kg, max.B D6667 3Vapor Pressure, kPa (psig),at 37.8 C (100 F), max.D1267, D6897 758 (110)Corrosion, Copper Strip,at 37.8 C (100 F), max.D1838 No. 1ResidueResidu
26、e on evaporation of 100 mL, mL, max,Oil stain observationD21580.05passLubricity CA The required minimum ensures that DME for fuel purposes will have a minimumestimated cetane number of 55.B The sulfur limit does not include the sulfur from an odorant such as ethylmercaptan that might be required by
27、some regulatory agencies in some fuelapplications. Note that addition of 1 pound of ethyl mercaptan per 10 000 USgallons will increase the sulfur content of DME by 14 milligrams sulfur per litre ofDME or 21 milligrams sulfur per kilogram of DME.C Experience in both laboratory and full scale vehicle
28、testing indicates pure DMEhas poor natural lubricity. Adequate precautions shall be taken to ensure thelubricity is sufficient to meet the needs of the end use application. At present, noindustry accepted test method or limit value is available to define the lubricity ofhighly volatile liquid fuels
29、such as DME. Until such a test is available, suppliers ofDME intended for use as a fuel in compression ignition compression-ignitionengines shall consult the engine or vehicle manufacturer for guidance on appro-priate lubricity requirements.D7901 14b27. Sampling7.1 Review all intended test methods p
30、rior to sampling to understand the importance and effects of sampling technique, propercontainers, and special handling required for each test method.7.2 Samples shall be representative of the batch of product and shall be collected from an appropriate storage container(typically an aboveground stor
31、age tank) or pipeline by a suitable sampling procedure such as Practice D1265 or Practice D3700.7.3 Sample SizeA minimum of 1 litre is recommended.7.3.1 Follow the same safety procedures when sampling DME as when sampling LPG, and leave an ullage space of at least20 % in a high pressure sampling cyl
32、inder.8. Test Methods8.1 The requirements of this specification shall be determined in accordance with the methods listed below. The scopes of someof the test methods listed below do not include dimethyl ether. Refer to the listed test methods to determine applicability or requiredmodifications for
33、use with dimethyl ether. The precision of these test methods can differ from the reported precisions when testingdimethyl ether.8.2 CompositionTest Method D2163.8.2.1 Laboratory experience has shown that Test Method D2163 requires the use of a 150 metre methyl silicone column in orderto analyze samp
34、les of DME.8.3 WaterISO 17197.8.4 SulfurTest Method D6667 should be used for sulfur determination.8.5 Vapor PressureTest Methods D1267 and D6897 may be used for vapor pressure determination. In case of dispute, TestMethod D1267 shall be the referee test method.8.6 CorrosionTest Method D1838.8.7 Resi
35、dueTest Method D2158.9. Keywords9.1 dimethyl ether; DMEAPPENDIXES(Nonmandatory Information)X1. PHYSICALAND CHEMICAL PROPERTIES OF DIMETHYL ETHERX1.1 A selection of physical and chemical properties of dimethyl ether, as outlined in Table X1.1, has been assembled from aTABLE X1.1 Physical and Chemical
36、 Properties of Dimethyl EtherProperty ValueChemical Formula CH3OCH3CAS No. 115-10-6Molecular weight, g/mol 46.07Melting point, C -141.5Boiling point, C -25.1Vapor pressure at 20 C, kPa 510Critical temperature, C 126.85Critical pressure, MPa 5.37Critical volume, cm3/mol 178Liquid density at 20 C, g/c
37、m3 0.67Specific Gravity of DME Vapor (versus Air) 1.59Color ColorlessOdor Faint “ether” smellFlammability Limits in Air, vol % 3.4 to 17Estimated Cetane Number 55Calorific Value, LHV, kcal/L, 20 C(net heat of combustion)4600DME solubility in water, g/100 mL at 18 C 7Solubility parameter, (cal/cm3)0.
38、5 7.3Wobbe Index, kJ/m3 46198Acentric factor 0.204D7901 14b3variety of sources. These are believed to be the best available data. The table will be updated as new or more reliable data isdeveloped.X1.2 Additional information on the properties of dimethyl ether can be found in the “DME Handbook Suppl
39、ement” EnglishEdition ISBN 978-4-9903839-1-6, published October, 2011.5X2. SIGNIFICANCE OF ASTM SPECIFICATIONS FOR DIMETHYL ETHER FOR FUELAPPLICATIONSX2.1 DME is a new fuel that could address environmental and fuel security issues. A fuel specification for DME is necessary forseveral reasons:(1) To
40、give manufacturers of DME, intended to be used as a fuel, a specification to meet;(2) To give OEMs a standard specification they can use to design new, purpose-built engines and applications. Someheavy-duty vehicle manufacturers are actively developing engines specifically for DME and have announced
41、 their support for thedevelopment of a standard fuel specification.(3) Since DME can be produced from biomethane, a specification encourages development of this as an initial biofuel forcommercial and consumer uses in purpose-built engines.(4) To establish a product specification for DME for use in
42、a blend with LPG. DME is already being used in countries suchas China in a blend with LPG, and this practice could expand.(5) The California Department of Food and Agriculture, Division of Measurement Standards (CDFA) is a strong proponent ofthe development of a DME fuel standard. CDFA has jurisdict
43、ion within the State over fuel quality standards as they relate tovehicle performance and driveability. California law requires that all fuel sold or distributed within the State have a fuelspecification established by a consensus organization, such as ASTM or SAE. This definition does not preclude
44、the use of an ISOstandard or ISO test methods.X2.1.1 This initial specification is based on the best, but limited, available information about DME in fuel applications. Thisspecification will allow development of purpose-built applications (such as diesel engines) using a consistent fuel, and it ise
45、xpected that modifications could be proposed to this specification as new applications and equipment are developed.X2.2 CompositionX2.2.1 Dimethyl EtherCommercial production processes for converting natural gas or biomethane into dimethyl ether producea high purity product. Therefore, setting the mi
46、nimum composition of DME at 98.5 % by mass is a reasonable compromisebetween the higher cost of very high purity DME used for specialty chemical applications, such as aerosol propellants, and thelower manufacturing cost of DME (for example, no costly purification steps) that give a product suitable
47、for fuel applications.Setting a high minimum concentration for DME ensures that DME for fuel purposes will have both a minimum concentration ofcontaminants and a minimum estimated 55 cetane number without the need to specify this requirement in Table 1.X2.2.2 MethanolThe concentration of methanol is
48、 limited due to concerns about potential corrosivity and materialincompatibility.X2.2.3 WaterThe concentration of water is limited to minimize potential freezing problems in DME LPG mixtures andconcerns with hydrate formation.X2.2.4 Methyl FormateWhile methyl formate should not be present in DME bas
49、ed on its physical properties (much higherboiling point than DME), concerns have been expressed about potential corrosion and instability issues, so a report requirementis proposed.X2.3 SulfurDME production processes require very low sulfur content to prevent poisoning production catalysts, so the sulfurlimit is set very low to recognize the negligible sulfur in DME as produced, which is much lower than the sulfur limit in LPG.5 Available from Japan DME Forum (JDF), 3F Shinsei Bldg. 6-5-5, Shinbashi, Minato-ku, Tokyo 105-0004. Tel
