1、Designation: D7901 14Standard 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 in paren
2、theses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers dimethyl ether (DME) for useas a fuel in engines specifically designed or modified for DMEand for blending with liquefied pe
3、troleum gas (LPG). Thisspecification is for use by manufacturers of dimethyl ether, byengine developers of purpose-built engines, in contracts for thepurchase of DME for fuel purposes, and for the guidance ofconsumers of this type of fuel.NOTE 1The generation and dissipation of static electricity ca
4、n createproblems in the handling of DME. For more information on the subject,see Guide D4865.1.2 The values stated in SI units are to be regarded asstandard. Units in parentheses are for information only.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with
5、 its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1265 Practice for Sampling Liquefied Petroleum (LP)Gases, Manual Me
6、thodD1267 Test Method for Gage Vapor Pressure of LiquefiedPetroleum (LP) Gases (LP-Gas Method)D1838 Test Method for Copper Strip Corrosion by LiquefiedPetroleum (LP) GasesD2158 Test Method for Residues in Liquefied Petroleum(LP) GasesD2163 Test Method for Determination of Hydrocarbons inLiquefied Pe
7、troleum (LP) Gases and Propane/PropeneMixtures by Gas ChromatographyD3700 Practice for Obtaining LPG Samples Using a Float-ing Piston CylinderD4865 Guide for Generation and Dissipation of Static Elec-tricity in Petroleum Fuel SystemsD6667 Test Method for Determination of Total VolatileSulfur in Gase
8、ous Hydrocarbons and Liquefied PetroleumGases by Ultraviolet FluorescenceD6897 Test Method for Vapor Pressure of Liquefied Petro-leum Gases (LPG) (Expansion Method)D7756 Test Method for Residues in Liquefied Petroleum(LP) Gases by Gas Chromatography with Liquid, On-Column InjectionD7828 Test Method
9、for Determination of Residue Compo-sition in Liquefied Petroleum Gas (LPG) Using Auto-mated Thermal Desorption/Gas Chromatography (ATD/GC)2.2 Other Documents:NFPA 77 Recommended Practice on Static Electricity3ISO/DIS 17196 Dimethyl ether (DME) for fuelsDetermination of impuritiesGas chromatographicm
10、ethod4ISO 17197 Dimethyl ether (DME) for fuelsDeterminationof water contentKarl Fischer titration method43. Terminology3.1 Abbreviations:3.1.1 DMEdimethyl ether, the chemical compound(CH3OCH3).3.1.2 LPGliquefied petroleum gas.4. Chemical Composition and Other Requirements4.1 The DME fuel for purpose
11、-built engines and for blend-ing with liquefied petroleum gas shall conform to the require-ments prescribed in Table 1.NOTE 2Additional information on the physical and chemical proper-ties of dimethyl ether, which are not considered necessary for fuelspecification at this point, are in Appendix X1 a
12、nd are given forinformation of fuel suppliers, OEMs, and users.4.2 The properties selected for limitation are those forwhich indications exist from experience with similar tech-niques and from initial engine developmental work that theyare required for obtaining acceptable engine performance.1This s
13、pecification is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.H0 on Liquefied Petroleum Gas.Current edition approved Jan. 1, 2014. Published January 2014. DOI: 10.1520/D7901-14.2For referenced ASTM
14、standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from National Fire Protection Association (NFPA), 1 BatterymarchPark, Q
15、uincy, MA 02169-7471, http:/www.nfpa.org.4Available from International Organization for Standardization (ISO), 1, ch. dela Voie-Creuse, CP 56, CH-1211 Geneva 20, Switzerland, http:/www.iso.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United
16、States14.3 The maximum vapor pressure limit shown in Table 1 isgiven to limit any high vapor pressure components such asgases CO and CO2 and also to ensure that the same containers(tanks, tank cars, and rail cars) designed for LPG can be usedfor DME.NOTE 3It is expected that additional requirements
17、for specifyingdimethyl ether for fuel applications could be required as purpose-builtengines and other applications develop for DME and DME LPG blends,and such additional requirements would be balloted for inclusion into thisspecification, based on need and technical data.5. Workmanship, Finish, and
18、 Appearance5.1 DME for fuel use in engines designed for DME and forblending with liquefied petroleum gas shall have a colorlessappearance and not contain any components or contaminantsthat would be detrimental to the intended use of the material.6. Sampling6.1 Review all intended test methods prior
19、to sampling tounderstand the importance and effects of sampling technique,proper containers, and special handling required for each testmethod.6.2 Samples shall be representative of the batch of productand shall be collected from an appropriate storage container(typically an aboveground storage tank
20、) or pipeline by asuitable sampling procedure such as Practice D1265 or PracticeD3700.6.3 Sample SizeA minimum of 1 litre is recommended.6.3.1 Follow the same safety procedures when samplingDME as when sampling LPG, and leave an ullage space of atleast 20 % in a high pressure sampling cylinder.7. Te
21、st Methods7.1 The requirements of this specification shall be deter-mined in accordance with the methods listed below. The scopesof some of the test methods listed below do not includedimethyl ether. Refer to the listed test methods to determineapplicability or required modifications for use with di
22、methylether. The precision of these test methods can differ from thereported precisions when testing dimethyl ether.7.2 CompositionTest Method D2163.7.2.1 Laboratory experience has shown that Test MethodD2163 requires the use of a 150 metre methyl silicone columnin order to analyze samples of DME.7.
23、3 WaterISO 17197.7.4 SulfurTest Method D6667 should be used for sulfurdetermination.7.5 Vapor PressureTest Methods D1267 and D6897 maybe used for vapor pressure determination. In case of dispute,Test Method D1267 shall be the referee test method.7.6 CorrosionTest Method D1838.7.7 ResidueTest Method
24、D2158.8. Keywords8.1 dimethyl ether; DMEAPPENDIXES(Nonmandatory Information)X1. PHYSICAL AND CHEMICAL PROPERTIES OF DIMETHYL ETHERX1.1 A selection of physical and chemical properties ofdimethyl ether, as outlined in Table X1.1, has been assembledfrom a variety of sources. These are believed to be th
25、e bestavailable data. The table will be updated as new or morereliable data is developed.X1.2 Additional information on the properties of dimethylether can be found in the “DME Handbook Supplement”English Edition ISBN 978-4-9903839-1-6, publishedOctober, 2011.55Available from Japan DME Forum (JDF),
26、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 1 Detailed Requirements for Dimethyl Ether for FuelPurposesProperty Test Method RequirementDimethyl Ether, mass %, min.AD2163 98.5Methanol, m
27、ass %, max. D2163 0.05Water, mass %, max. ISO 17197 0.03Methyl Formate, mass % D2163 reportSulfur, mg / kg, max.BD6667 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 evaporation of 100 mL, mL, max,O
28、il stain observationD21580.05passAThe required minimum ensures that DME for fuel purposes will have a minimumestimated cetane number of 55.BThe sulfur limit does not include the sulfur from an odorant such as ethylmercaptan that might be required by some regulatory agencies in some fuelapplications.
29、 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.D7901 142X2. SIGNIFICANCE OF ASTM SPECIFICATIONS FOR DIMETHYL ETHER FOR FUEL APPLICATIONSX2.1 DME is a ne
30、w fuel that could address environmentaland fuel security issues. A fuel specification for DME isnecessary for several reasons:(1) To give manufacturers of DME, intended to be used asa fuel, a specification to meet;(2) To give OEMs a standard specification they can use todesign new, purpose-built eng
31、ines and applications. Someheavy-duty vehicle manufacturers are actively developingengines specifically for DME and have announced their sup-port for the development of a standard fuel specification.(3) Since DME can be produced from biomethane, aspecification encourages development of this as an in
32、itialbiofuel for commercial and consumer uses in purpose-builtengines.(4) To establish a product specification for DME for use ina 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 Agricul
33、ture,Division of Measurement Standards (CDFA) is a strong pro-ponent of the development of a DME fuel standard. CDFA hasjurisdiction within the State over fuel quality standards as theyrelate to vehicle performance and driveability. California lawrequires that all fuel sold or distributed within the
34、 State have afuel specification established by a consensus organization, suchas ASTM or SAE. This definition does not preclude the use ofan ISO standard or ISO test methods.X2.1.1 This initial specification is based on the best, butlimited, available information about DME in fuel applications.This s
35、pecification will allow development of purpose-builtapplications (such as diesel engines) using a consistent fuel,and it is expected that modifications could be proposed to thisspecification as new applications and equipment are developed.X2.2 CompositionX2.2.1 Dimethyl EtherCommercial production pr
36、ocessesfor converting natural gas or biomethane into dimethyl etherproduce a high purity product. Therefore, setting the minimumcomposition of DME at 98.5 % by mass is a reasonablecompromise between the higher cost of very high purity DMEused for specialty chemical applications, such as aerosolprope
37、llants, and the lower manufacturing cost of DME (forexample, no costly purification steps) that give a productsuitable for fuel applications. Setting a high minimum concen-tration for DME ensures that DME for fuel purposes will haveboth a minimum concentration of contaminants and a mini-mum estimate
38、d 55 cetane number without the need to specifythis requirement in Table 1.X2.2.2 MethanolThe concentration of methanol is limiteddue to concerns about potential corrosivity and materialincompatibility.X2.2.3 WaterThe concentration of water is limited tominimize potential freezing problems in DME LPG
39、 mixturesand concerns with hydrate formation.X2.2.4 Methyl FormateWhile methyl formate should notbe present in DME based on its physical properties (muchhigher boiling point than DME), concerns have been expressedabout potential corrosion and instability issues, so a reportrequirement is proposed.X2
40、.3 SulfurDME production processes require very lowsulfur content to prevent poisoning production catalysts, so thesulfur limit is set very low to recognize the negligible sulfur inDME as produced, which is much lower than the sulfur limit inLPG.X2.3.1 The sulfur limit does not include the sulfur fro
41、m anodorant, such as ethyl mercaptan, that might be required bysome regulatory agencies in some fuel applications. Note thataddition of 1 pound of ethyl mercaptan per 10 000 US gallonswill increase the sulfur content of DME by 14 milligramssulfur per litre of DME or 21 milligrams sulfur per kilogram
42、 ofDME.TABLE X1.1 Physical 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,
43、 cm3/mol 178Liquid density at 20 C, g/cm30.67Specific 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 1
44、8 C 7Solubility parameter, (cal/cm3)0.57.3Wobbe Index, kJ/m346198Acentric factor 0.204D7901 143X2.4 Vapor PressureThe vapor pressure limit is set at thesum of the vapor pressures of DME and contaminants such asmethanol, CO, CO2, and 1 % propane (consistent with the draftISO DME fuel specification) t
45、o limit gases and volatilecontaminants. Since this pressure is much lower than the vaporpressure of propane, the same storage and transportation tanksand containers used for LPG can be used for DME.X2.5 Copper CorrosionWhile aggressive sulfur speciesare unlikely to be present in DME as produced, the
46、re is a riskof pick-up of sulfur species during distribution in LPGfacilities, so this requirement, set at the same limit as forSpecial Duty Propane, is in the specification to protect custom-ers equipment against potential corrosion.X2.6 ResidueThe limit on residue is set at the same limitas requir
47、ed in Special Duty / HD-5 propane. While contami-nation of DME by residues is not anticipated in currentproduction processes, there is a risk of pick-up of heaviercontaminants during distribution in LPG facilities, so thisrequirement is in the specification to protect customers equip-ment. Test Meth
48、ods D7756 and D7828 are gas chromato-graphic procedures for measurement of heavier soluble resi-dues that could be present in LPG, and these procedures couldbe useful for evaluating residues in DME.X2.7 Table X2.1 shows limits for properties that have beensuggested by engine manufacturers as requiri
49、ng limitation;however, no technical justification has been provided forspecifying these limits. Therefore, they are not included asrequirements in the specification.TABLE X2.1 Optional Requirements for DME for Fuel PurposesProperty Test Method RequirementHydrocarbons (up to C4) ISO/DIS 17196D2163reportCarbon dioxide (CO2), mass % ISO/DIS 17196D2163reportCarbon monoxide (CO), mass % ISO/DIS 17196D2163reportEthyl methyl ether, mass % ISO/DIS 17196 reportX3. RECOMMENDED SAFETY MEASURES FOR DIMETHYL ETHER FOR FUEL APPLICATIONSX3.1 Compat
