1、Designation: D7901 14D7901 14aStandard 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 number
2、 in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope Scope*1.1 This specification covers dimethyl ether (DME) for use as a fuel in engines specifically designed or modified for DME andfor blending
3、with 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 st
4、atic 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, i
5、f any, 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 (
6、LP) Gases, 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 Hydr
7、ocarbons 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
8、Volatile 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 Inje
9、ctionD7828 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 impurities
10、Gas chromatographic 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 Pro
11、ducts, Liquid Fuels, and Lubricants and is the direct responsibility of SubcommitteeD02.H0 on Liquefied Petroleum Gas.Current edition approved Jan. 1, 2014June 1, 2014. Published January 2014July 2014. Originally approved in 2014. Last previous edition approved in 2014 as D7901 14.DOI: 10.1520/D7901
12、-14.10.1520/D7901-14a.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 Protecti
13、on 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 only t
14、o 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 versiono
15、f 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. Chemica
16、l Composition and Other Requirements4.1 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 properties of dimethyl ether, which are not considered necessa
17、ry for fuel specificationat this point, are in Appendix X1 and are given for information of fuel suppliers, OEMs, and users.4.2 The properties selected for limitation are those for which indications exist from experience with similar techniques and frominitial engine developmental work that they are
18、 required for obtaining acceptable engine performance.4.3 The maximum vapor pressure limit shown in Table 1 is given 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.
19、NOTE 3It is expected that additional requirements for specifying dimethyl ether for fuel applications could be required 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
20、 need and technical data.5. Workmanship, Finish, and Appearance5.1 DME for fuel use in engines designed for DME 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.
21、6. Sampling6.1 Review all intended test methods prior to sampling to understand the importance and effects of sampling technique, propercontainers, and special handling required for each test method.6.2 Samples shall be representative of the batch of product and shall be collected from an appropriat
22、e storage container(typically an aboveground storage tank) or pipeline by a suitable sampling procedure such as Practice D1265 or Practice D3700.6.3 Sample SizeA minimum of 1 litre is recommended.6.3.1 Follow the same safety procedures when sampling DME as when sampling LPG, and leave an ullage spac
23、e of at least20 % in a high pressure sampling cylinder.7. Test Methods7.1 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 dete
24、rmine applicability or requiredmodifications for use with dimethyl ether. The precision of these test methods can differ from the reported precisions when testingdimethyl ether.TABLE 1 Detailed Requirements for Dimethyl Ether for FuelPurposesProperty Test Method RequirementDimethyl Ether, mass %, mi
25、n.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. 1ResidueResidue on evapor
26、ation of 100 mL, mL, max,Oil stain observationD21580.05passLubricity CAThe The required minimum ensures that DME for fuel purposes will have aminimum estimated cetane number of 55.BThe The sulfur limit does not include the sulfur from an odorant such as ethylmercaptan that might be required by some
27、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 testi
28、ng 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 such
29、as DME. Until such a test is available, suppliers ofDME intended for use as a fuel in compression ignition engines shall consult theengine or vehicle manufacturer for guidance on appropriate lubricity requirements.D7901 14a27.2 CompositionTest Method D2163.7.2.1 Laboratory experience has shown that
30、Test Method D2163 requires the use of a 150 metre methyl silicone column in orderto analyze samples of DME.7.3 WaterISO 17197.7.4 SulfurTest Method D6667 should be used for sulfur determination.7.5 Vapor PressureTest Methods D1267 and D6897 may be used for vapor pressure determination. In case of di
31、spute, TestMethod D1267 shall be the referee test method.7.6 CorrosionTest Method D1838.7.7 ResidueTest Method D2158.8. Keywords8.1 dimethyl ether; DMEAPPENDIXES(Nonmandatory Information)X1. PHYSICALAND CHEMICAL PROPERTIES OF DIMETHYL ETHERX1.1 A selection of physical and chemical properties of dime
32、thyl ether, as outlined in Table X1.1, has been assembled from avariety 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 S
33、upplement” 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)
34、 To give manufacturers of DME, intended to be used as a fuel, a specification to meet;5 Available from Japan DME Forum (JDF), 3F Shinsei Bldg. 6-5-5, Shinbashi, Minato-ku, Tokyo 105-0004. Tel: +81-3-5403-0035, Fax: +81-3-5403-0038, Email:infodmeforum.jp, Website: www.dmeforum.jp/TABLE X1.1 Physical
35、and Chemical 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
36、at 20 C, g/cm3 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,
37、 (cal/cm3)0.5 7.3Wobbe Index, kJ/m3 46198Acentric factor 0.204D7901 14a3(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 their sup
38、port 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 a blend wi
39、th 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 jurisdiction within
40、 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 the use of
41、 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 isexpected th
42、at 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 minimum comp
43、osition 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 for fuel a
44、pplications.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 limited d
45、ue 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 based on its
46、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
47、 is set very low to recognize the negligible sulfur in DME as produced, which is much lower than the sulfur limit in LPG.X2.3.1 The sulfur limit does not include the sulfur from an odorant, such as ethyl mercaptan, that might be required by someregulatory agencies in some fuel applications. Note tha
48、t addition of 1 pound of ethyl mercaptan per 10 000 US gallons will increasethe sulfur content of DME by 14 milligrams sulfur per litre of DME or 21 milligrams sulfur per kilogram of DME.X2.4 Vapor PressureThe vapor pressure limit is set at the sum of the vapor pressures of DME and contaminants such
49、 asmethanol, CO, CO2, and 1 % propane (consistent with the draft ISO DME fuel specification) to limit gases and volatilecontaminants. Since this pressure is much lower than the vapor pressure of propane, the same storage and transportation tanks andcontainers used for LPG can be used for DME.X2.5 Copper CorrosionWhile aggressive sulfur species are unlikely to be present in DME as produced, there is a risk of pick-upof sulfur species during distribution in LPG facilities, so this requirement, set at the same limit as for Special Du
