ASTM D5797-21

Standard Specification for Methanol Fuel Blends (M51–M85) for Methanol-Capable Automotive Spark-Ignition Engines

ABSTRACT
This specification covers the methanol fuel blend, M70-M85, for use in ground vehicles that run on automotive spark-ignition engines. Fuels are grouped into three vapor pressure classes (Classes 1, 2, and 3) on the basis of seasonal and geographical volatility. The fuel blends shall undergo chemical analysis for methanol, higher alcohols, hydrocarbon/aliphatic ether, acidity as acetic acid, solvent washed and unwashed gum content, total chlorine as chloride, lead, phosphorus, water, sulfur, and inorganic chloride. The product's appearance shall be clear and bright, visibly free of suspended or precipitated contaminants.
SCOPE
1.1 This specification covers the requirements for automotive fuel blends of methanol and gasoline for use in ground vehicles equipped with methanol-capable flexible-fuel, and dedicated methanol spark-ignition engines. Fuel produced to this specification contains 51 % to 85 % by volume methanol. This fuel is sometimes referred to at retail as “M85.” Appendix X1 discusses the significance of the properties specified. Appendix X2 presents the current status in the development of a luminosity test procedure (flame visibility) for methanol fuel blends (M51–M85).  
1.2 The vapor pressure of methanol fuel blends is varied for seasonal climatic changes. Vapor pressure is increased at lower temperatures to ensure adequate vehicle operability and safety. Methanol content and selection of gasoline blendstocks are adjusted by the blender to meet these vapor pressure requirements.  
1.3 The United States government has established various programs for alternative fuels. Many of the definitions of alternative fuel used by these programs can be more or less restrictive than the requirements of this specification. See Annex A1 for additional information on alternative fuels containing methanol.  
1.4 The values stated in SI units are to be regarded as the standard.  
1.4.1 Exception—Non-SI units are provided for information only. In most cases, U.S. federal regulations specify non-SI units.  
1.5 The following precautionary caveat pertains only to the test method portions–Appendix X2 of this specification. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 30-Sep-2021
• ICS: 75.160.20 - Liquid fuels
• Technical Committee: D02 - Petroleum Products, Liquid Fuels, and Lubricants
• Drafting Committee: D02.A0.02 - Oxygenated Fuels and Components

Relations

• Refers: ASTM D3231-24 - Standard Test Method for Phosphorus in Gasoline
• Effective Date: 01-Mar-2024
• Refers: ASTM E203-24 - Standard Test Method for Water Using Volumetric Karl Fischer Titration
• Effective Date: 01-Jan-2024
• Refers: ASTM D4814-24 - Standard Specification for Automotive Spark-Ignition Engine Fuel
• Effective Date: 01-Jan-2024
• Refers: ASTM D4175-23a - Standard Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
• Effective Date: 15-Dec-2023
• Refers: ASTM D86-23ae1 - Standard Test Method for Distillation of Petroleum Products and Liquid Fuels at Atmospheric Pressure
• Effective Date: 01-Dec-2023
• Refers: ASTM D86-23a - Standard Test Method for Distillation of Petroleum Products and Liquid Fuels at Atmospheric Pressure
• Effective Date: 01-Dec-2023
• Refers: ASTM D4814-23a - Standard Specification for Automotive Spark-Ignition Engine Fuel
• Effective Date: 01-Dec-2023
• Refers: ASTM D4175-23e1 - Standard Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
• Effective Date: 01-Jul-2023
• Refers: ASTM D4953-20 - Standard Test Method for Vapor Pressure of Gasoline and Gasoline-Oxygenate Blends (Dry Method)
• Effective Date: 01-May-2020
• Refers: ASTM D4814-20 - Standard Specification for Automotive Spark-Ignition Engine Fuel
• Effective Date: 01-Feb-2020
• Refers: ASTM D4814-19a - Standard Specification for Automotive Spark-Ignition Engine Fuel
• Effective Date: 01-Dec-2019
• Refers: ASTM D4806-19a - Standard Specification for Denatured Fuel Ethanol for Blending with Gasolines for Use as Automotive Spark-Ignition Engine Fuel
• Effective Date: 15-Sep-2019
• Refers: ASTM D5453-19a - Standard Test Method for Determination of Total Sulfur in Light Hydrocarbons, Spark Ignition Engine Fuel, Diesel Engine Fuel, and Engine Oil by Ultraviolet Fluorescence
• Effective Date: 01-Jul-2019
• Refers: ASTM D5798-19b - Standard Specification for Ethanol Fuel Blends for Flexible-Fuel Automotive Spark-Ignition Engines
• Effective Date: 01-Jul-2019
• Refers: ASTM D7923-19 - Standard Test Method for Water in Ethanol and Hydrocarbon Blends by Karl Fischer Titration
• Effective Date: 01-Jun-2019

Overview

ASTM D5797-21 specifies the quality and performance requirements for methanol fuel blends containing 51% to 85% methanol by volume-commonly referred to as “M85”-for use in automotive spark-ignition engines specifically designed to operate on such fuels. These methanol-gasoline blends are critical for flexible-fuel and dedicated methanol vehicles, providing an alternative to conventional petrol fuels with potential benefits for air quality and energy diversification.

This international standard ensures methanol fuel blends are safe, reliable, and environmentally compliant, addressing seasonally and geographically variable volatility with three vapor pressure classes tailored for different temperatures. It also establishes limits on contaminants and impurities to protect vehicle engines and emission control systems.

Key Topics

• Methanol Fuel Blend Composition: Specifies blends with 51% to 85% methanol by volume, along with gasoline blendstocks. The blends must meet clarity and purity requirements, with limits on contaminants such as water, lead, sulfur, phosphorus, inorganic chloride, and sulfate.
• Vapor Pressure Classes: Methanol blends are classified into three categories-Class 1, 2, and 3-based on regional and seasonal temperature requirements. This ensures vehicle operability and safety across diverse climates.
• Quality and Purity Requirements: Properties such as acidity, gum content, hydrocarbon content, and the presence of higher alcohols are tightly controlled to maintain consistent engine performance and minimize corrosion or deposit formation.
• Sampling and Testing: The standard outlines best practices for fuel sampling, container selection, and sample handling, as well as reference methods for laboratory analysis (e.g., ASTM D7920 for methanol content, ASTM D5453 for sulfur).
• Regulatory Alignment: Complies with U.S. and international regulatory standards. Additional criteria may be required for “alternative fuels” as designated by government programs, notably for federal fleet use.

Applications

ASTM D5797-21 is applicable in scenarios such as:

• Production and Distribution: Use by fuel producers, blenders, and distributors to ensure methanol fuel blends meet technical and legal requirements before delivery to retail channels.
• Quality Assurance: Fuel retailers and vehicle fleet operators use this standard to verify incoming fuel meets performance and safety benchmarks, avoiding engine damage or regulatory violations.
• Vehicle Operation: Automotive manufacturers and maintenance professionals use the specification to ensure optimal performance and durability of spark-ignition engines specifically calibrated for high-methanol fuels.
• Seasonal Adaption: Regional fuel managers leverage the designated vapor pressure classes to adapt fuel blends for winter and summer conditions, ensuring consistent vehicle starting, drivability, and emissions control in all climates.

Related Standards

For thorough compliance and best practices, ASTM D5797-21 should be used alongside several other standards:

• ASTM D4814 - Specification for Automotive Spark-Ignition Engine Fuel
• ASTM D4806 - Specification for Denatured Fuel Ethanol for Blending with Gasolines
• ASTM D5798 - Specification for Ethanol Fuel Blends for Flexible-Fuel Automotive Engines
• ASTM D4953 / D5191 - Vapor Pressure of Petroleum Products
• ASTM D7920 - Test Method for Methanol Content in Fuel Blends
• ASTM D5453 - Test Method for Total Sulfur in Fuels
• ASTM D381 - Test Method for Gum Content in Fuels
• ASTM D1613 - Test Method for Acidity
• ASTM D3231 - Test Method for Phosphorus in Gasoline
• ASTM D4057 / D4177 - Practices for Manual and Automatic Sampling

By adhering to ASTM D5797-21 and associated standards, fuel stakeholders ensure methanol-blended fuels consistently meet safety, quality, and environmental goals while supporting the broader adoption of alternative automotive fuels.

Keywords: ASTM D5797-21, methanol fuel blends, M85, automotive spark-ignition engines, vapor pressure classes, alternative fuels, methanol-gasoline blends, fuel quality, ASTM standards, flexible-fuel vehicles, fuel specifications, emissions compliance, fuel sampling, seasonal volatility.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation:D5797 −21
Standard Specification for
Methanol Fuel Blends (M51–M85) for Methanol-Capable
Automotive Spark-Ignition Engines
This standard is issued under the fixed designation D5797; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope* 1.6 This international standard was developed in accor-
dance with internationally recognized principles on standard-
1.1 This specification covers the requirements for automo-
ization established in the Decision on Principles for the
tive fuel blends of methanol and gasoline for use in ground
Development of International Standards, Guides and Recom-
vehicles equipped with methanol-capable flexible-fuel, and
mendations issued by the World Trade Organization Technical
dedicated methanol spark-ignition engines. Fuel produced to
Barriers to Trade (TBT) Committee.
this specification contains 51% to 85% by volume methanol.
Thisfuelissometimesreferredtoatretailas“M85.”Appendix
2. Referenced Documents
X1 discusses the significance of the properties specified.
2,3
2.1 ASTM Standards:
Appendix X2 presents the current status in the development of
D86Test Method for Distillation of Petroleum Products and
a luminosity test procedure (flame visibility) for methanol fuel
Liquid Fuels at Atmospheric Pressure
blends (M51–M85).
D130Test Method for Corrosiveness to Copper from Petro-
1.2 Thevaporpressureofmethanolfuelblendsisvariedfor
leum Products by Copper Strip Test
seasonalclimaticchanges.Vaporpressureisincreasedatlower
D381Test Method for Gum Content in Fuels by Jet Evapo-
temperatures to ensure adequate vehicle operability and safety.
ration
Methanol content and selection of gasoline blendstocks are
D525Test Method for Oxidation Stability of Gasoline (In-
adjusted by the blender to meet these vapor pressure require-
duction Period Method)
ments.
D1193Specification for Reagent Water
D1266TestMethodforSulfurinPetroleumProducts(Lamp
1.3 The United States government has established various
Method)
programs for alternative fuels. Many of the definitions of
D1613Test Method for Acidity in Volatile Solvents and
alternative fuel used by these programs can be more or less
Chemical Intermediates Used in Paint, Varnish, Lacquer,
restrictive than the requirements of this specification. See
and Related Products
Annex A1 for additional information on alternative fuels
D3231Test Method for Phosphorus in Gasoline
containing methanol.
D4057Practice for Manual Sampling of Petroleum and
1.4 The values stated in SI units are to be regarded as the
Petroleum Products
standard.
D4175Terminology Relating to Petroleum Products, Liquid
1.4.1 Exception—Non-SI units are provided for information
Fuels, and Lubricants
only. In most cases, U.S. federal regulations specify non-SI
D4177Practice for Automatic Sampling of Petroleum and
units.
Petroleum Products
1.5 The following precautionary caveat pertains only to the
D4306Practice for Aviation Fuel Sample Containers for
test method portions–Appendix X2 of this specification. This
Tests Affected by Trace Contamination
standard does not purport to address all of the safety concerns,
D4806Specification for Denatured Fuel Ethanol for Blend-
if any, associated with its use. It is the responsibility of the user
ing with Gasolines for Use asAutomotive Spark-Ignition
of this standard to establish appropriate safety, health, and
Engine Fuel
environmental practices and determine the applicability of
D4814Specification for Automotive Spark-Ignition Engine
regulatory limitations prior to use.
Fuel
1 2
This specification is under the jurisdiction of ASTM Committee D02 on Reference to the following documents is to be the latest issue unless otherwise
Petroleum Products, Liquid Fuels, and Lubricants and is under the direct responsi- specified.
bility of Subcommittee D02.A0.02 on Oxygenated Fuels and Components. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Oct. 1, 2021. Published October 2021. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1995. Last previous edition approved in 2018 as D5797–18. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/D5797-21. the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5797−21
D4953Test Method for Vapor Pressure of Gasoline and tional gasoline blendstock for oxygenated blending (CBOB),
Gasoline-Oxygenate Blends (Dry Method) and reformulated gasoline blendstock for oxygenate blending
D5059Test Methods for Lead and Manganese in Gasoline (RBOB).
by X-Ray Fluorescence Spectroscopy 3.2.7 hydrocarbon—acompoundcomposedsolelyofhydro-
D5191Test Method for Vapor Pressure of Petroleum Prod- gen and carbon.
ucts and Liquid Fuels (Mini Method)
3.2.8 methanol, n—methyl alcohol, the chemical compound
D5453Test Method for Determination of Total Sulfur in
CH OH.
Light Hydrocarbons, Spark Ignition Engine Fuel, Diesel
3.2.9 methanol fuel blend (M51–M85), n—ablendofmetha-
Engine Fuel, and Engine Oil by Ultraviolet Fluorescence
nol and hydrocarbons of which the methanol portion is
D5798Specification for Ethanol Fuel Blends for Flexible-
nominally 51 % to 85 % by volume.
Fuel Automotive Spark-Ignition Engines
D5854Practice for Mixing and Handling of Liquid Samples 3.2.9.1 Discussion—In the abbreviation, MXX, the XX
of Petroleum and Petroleum Products
representsthevolumepercentageofmethanolinthefuelblend.
D7328Test Method for Determination of Existent and Po-
4. Ordering Information
tential Inorganic Sulfate and Total Inorganic Chloride in
Fuel Ethanol by Ion Chromatography Using Aqueous
4.1 The purchasing agency shall:
Sample Injection 4.1.1 Indicate the season and locality in which the fuel is to
D7667Test Method for Determination of Corrosiveness to
be used,
Silver by Automotive Spark-Ignition Engine Fuel—Thin 4.1.2 If requested, ensure that the methanol concentration
Silver Strip Method
meetstherequirementsforanalternativefuelforUnitedStates
D7671Test Method for Corrosiveness to Silver byAutomo- federal fleets.
tive Spark–Ignition Engine Fuel–Silver Strip Method
4.1.3 For further information, see Annex A1 of this speci-
D7757Test Method for Silicon in Gasoline and Related fication.
Products by Monochromatic Wavelength Dispersive
5. Methanol Fuel Blends Performance Requirements
X-ray Fluorescence Spectrometry
D7920Test Method for Determination of Fuel Methanol 5.1 Methanol fuel blends shall conform to the requirements
in Table 1.
(M99) and Methanol Fuel Blends (M10 to M99) by Gas
Chromatography
NOTE1—MostoftherequirementscitedinTable1arebasedonthebest
D7923Test Method for Water in Ethanol and Hydrocarbon
technical information currently available.As greater experience is gained
Blends by Karl Fischer Titration
from field use of methanol-capable vehicles, some of these requirements
will change.
E203Test Method for Water Using Volumetric Karl Fischer
Titration
5.1.1 Thecomponentsusedtoproducemethanolfuelblends
are limited to methanol and gasoline blendstock as defined in
3. Terminology
5.2.
5.1.2 The intentional addition of lead or phosphorus com-
3.1 For general terminology, refer to Terminology D4175.
pounds to methanol fuel blends is not permitted.
3.2 Definitions:
5.2 Gasoline blendstocks used shall meet the requirements
3.2.1 denatured fuel ethanol, n—fuel ethanol made unfit for
of Table 2. The gasoline blendstock may contain ethers as
beverage use by the addition of denaturants under formula(s)
blendingcomponentsthatareusedinautomotivefuelsinsome
approved by the applicable regulatory agency to prevent the
countries outside of North America.
imposition of beverage alcohol tax. D4806
5.3 Vapor pressure is varied for seasonal and climatic
3.2.2 ethanol, n—ethyl alcohol, the chemical compound
changesbyprovidingthreevaporpressureclassesformethanol
CH CH OH. D4806
3 2
fuel blends as follows:
3.2.3 finished fuel, n—a homogeneous mixture of blend-
(1)Class 1 encompasses geographical areas with 6 h
stocks and fuel additives meeting all specification and regula-
tenth-percentile minimum ambient temperature of greater than
tory requirements for its intended use at the location where
5 °C (41 °F).
sold.
(2)Class 2 encompasses geographical areas with 6 h
3.2.4 fuel methanol (M99), n—methanol with small/trace
tenth-percentile minimum temperatures of greater than –5 °C
alcohol and hydrocarbon impurities.
(23°F) but less than or equal to 5 °C (41°F).
(3)Class 3 encompasses geographical areas with 6 h
3.2.5 gasoline, n—volatile mixture of liquid hydrocarbons,
tenth-percentile minimum ambient temperature less than or
generally containing small amounts of additives, suitable for
equal to –5 °C (23°F).
use as a fuel in spark-ignition, internal combustion engines.
5.3.1 There is a 10 % probability that the highest tempera-
D4814
ture of the six coldest consecutive hourly temperature readings
3.2.6 gasoline blendstock, n—a liquid hydrocarbon compo-
of a 24h day will be colder than the 6h tenth percentile
nent suitable for use in spark-ignition engine fuels.
minimum ambient temperature.
3.2.6.1 Discussion—Examples of gasoline blendstock in- 5.3.2 See 5.4.2 for seasonal and geographical distributions
clude natural gasoline, raffinate, reformate, naphtha, conven- in the United States.
D5797−21
TABLE 1 Requirements for Methanol Fuel Blends (M51–M85)
A
Properties Class 1 Class 2 Class 3 Test Methods
Annex A1
D4953 or D5191
B
Vapor pressure, kPa (psi) 48–62 62–83 83–103
(7.0–9.0) (9.0–12.0) (12.0–15.0)
C
All Classes
Methanol Content, % by volume, min 51–85 D7920
D
Lead, mg/L, max 2.6 D5059
Phosphorus, mg/L, max 0.2 D3231
Sulfur, mg/kg, max 80 D5453
Acidity, as acetic acid, mg/kg, max 50 D1613
Unwashed gum content, mg/100 mL, max 20 D381
Solvent washed gum content, mg/100 mL, max 5 D381
Total Inorganic Sulfate, mg/kg, max 4 D7328
Water, % by mass, max 0.5 D7923 or E203
Total Inorganic Chloride, mg/kg, max 1 D7328
A
See 5.3 for volatility class criteria.
B
The vapor pressure overlap is intentional to cover changes associated with seasonal changes.
C
Methanol content and selection of gasoline blendstock are adjusted by the blender to meet vapor pressure requirements. See X1.3.3 for additional information and
guidance for blending.
D
With Test Methods D5059, prepare the calibration standards using methanol (reagent grade) as the solvent to prevent errors caused by large differences in
carbon-hydrogen ratios.
TABLE 2 Requirements for Gasoline Blendstock
hoseshouldbeavoidedinmethanolfuelblenddistributionand
4,5
Properties Test Methods dispensing systems.
Distillation, end point, °C (°F), max 225 (437) D86
Oxidation stability, minutes, min 240 D525 6. Workmanship
Copper strip corrosion, max No. 1 D130
6.1 The finished fuel blend shall be visually free of
Silver strip corrosion, max No. 1 D7667, D7671
A
Vapor pressure, kPa Report D4953, D5191
sediment, suspended, or undissolved matter. It shall be clear
A
While not a requirement of this specification, the blender will need to know the
and bright at the fuel temperature at the point of custody
vapor pressure of the gasoline blendstock in order to choose a suitable blend ratio
transferoratalowertemperatureagreeduponbythepurchaser
for the components to meet the vapor pressure requirement of a particular volatility
and seller.
class.
NOTE 2—Finished fuel should be resistant to phase separation or
undissolved matter at the lowest temperatures to which it is likely to be
subjected, dependent on the time and place of its intended use. See
Specification D4814, TableX7.1 for guidance.
NOTE 3—Solubility is temperature dependent.As this fuel cools, some
5.4 Regulatory and Other Requirements in the United
high molecular weight additives can become insoluble.
States:
6.2 The specification defines only a basic purity for metha-
5.4.1 Methanolcontentandotherrequirementsformethanol
nol fuel blend (M51–M85). The product shall be free of any
alternative fuel blends in the United States can be found in
adulterant or contaminant that can render the material unac-
Annex A1 of this standard.
ceptable for its commonly used applications.
5.4.2 The United States seasonal and geographical distribu-
6.2.1 Manufacturers and blenders of methanol fuel blend
tionforthethreevaporpressureclassesisshowninAnnexA1,
(M51–M85) shall avoid methanol (for example, improperly
Table A1.1.
recycled methanol), or hydrocarbon blend components con-
taminated by silicon-containing materials, or both. Silicon
5.5 Regulatory and Other Requirements Outside the United
contamination of gasoline, denatured ethanol, and their blends
States:
has led to fouled vehicle components (for example, spark
5.5.1 Users of this specification are advised to consult with
plugs, exhaust oxygen sensors, catalytic converters) requiring
the applicable regulatory agency for specific requirements for
parts replacement and repairs. Test Method D7757 is a proce-
their jurisdictions.
dure for determining silicon that might be applicable to
5.5.2 Users of the specification in geographical areas out-
methanol fuel blend (M51–M85). No specification limits have
sidetheUnitedStatesneedtodeterminethe6htenthpercentile
been established for silicon.
minimum ambient temperatures for their geographic areas and
times of year in order to select the appropriate classes of fuel. 7. Sampling, Containers, and Sample Handling
7.1 Thereaderisstronglyadvisedtoreviewallintendedtest
5.6 Use of unprotected aluminum in methanol fuel blend
methods prior to sampling to better understand the importance
distribution and dispensing equipment will introduce insoluble
aluminum compounds into the fuel causing plugged vehicle
CaliforniaEnergyCommission,“FifteenYearsofFuelMethanolDistribution,”
fuel filters. Furthermore, this effect can be exaggerated even
http://www.methanol.org/Energy/Resources/Alternative-Fuel/CEC- 1996-ISAF-
with protected aluminum by elevated fuel conductivity caused
Fuel-Meoh-Paper.aspx
by contact with a nitrile rubber dispensing hose. Therefore,
California Air Resources Board, Methanol Fuel Additive Demonstration,
unprotectedaluminumandanunlinednitrilerubberdispensing http://arb.ca.gov/research/apr/past/a832-123a
D5797−21
and effects of sampling technique, proper containers, and that determination is addressed separately in Specification
special handling required for each test method. D5797, the standard specification for methanol fuel blends.
The procedure for total inorganic chloride determination will
7.2 Correct sampling procedures are critical to obtain a
be summarized:
sample representative of the lot intended to be tested. Use
8.1.10.1 Obtain a well-mixed homogeneous sample of
appropriate procedures in Practice D4057 for manual method
methanol fuel blend in a glass container, equipped with
sampling and in Practice D4177 for automatic sampling as
closures that can be well-sealed, and free of any residual or
applicable.
extractablechloride.Ifcontainershavebeencleanedandrinsed
7.3 The correct sample volume and appropriate container
with water, they should be thoroughly rinsed with Type II or
selection are important decisions that can impact test results.
better reagent water according to Specification D1193 and
Refer to Practice D4306 for aviation fuel container selection
dried prior to use.
for tests sensitive to trace contamination. Refer to Practice
8.1.10.2 Thoroughly mix the sample in its container imme-
D5854 for procedures on container selection and sample
diately prior to withdrawal of the test specimen.
mixing and handling. Where practical, methanol fuel blends
8.1.10.3 Set up the ion chromatograph in accordance with
should be sampled in amber borosilicate glass containers. If
the manufacturer’s instructions.
samples must be collected in metal containers, do not use
8.1.10.4 Equilibrate the system by pumping eluent for
soldered metal containers. The soldering flux in the containers
15min to 30min, until a stable baseline is obtained.
and the lead in the solder can contaminate the sample. Plastic
8.1.10.5 Start the chromatographic run in accordance with
containers should be avoided.
manufacturer’s instructions.
8.1.10.6 Carefully add 2.00mL of the methanol fuel blend
7.4 A minimum sample size of about 1L (~1qt) is recom-
mended. test specimen into a clean, dry, tared 15mL glass vial without
its screw cap closure.
8. Test Methods
8.1.10.7 Place the vial with sample in a hot block at 65°C
8.1 Determine the requirements enumerated in this specifi- and blow a steady stream of nitrogen gas over the sample at
cation in accordance with the following test methods: 2mL⁄minto3mL⁄minflowrate.Maintaintheseconditionsfor
15min.Removethevialfromthehotblockandallowittocool
NOTE4—TheappropriatenessofASTMtestmethodscitedhasnotbeen
to room temperature 15°C to 27°C. Note that it is probable
demonstrated for use with M51–M85. In addition, test methods contained
that a small amount of liquid remains. Do not worry about this
in the annexes and appendixes are in the developmental stages or lack
precision and bias determinations.
residue since any inorganic chloride will be extracted into the
water phase.
8.1.1 Vapor Pressure—Test Methods D4953 or D5191.
8.1.10.8 Carefully add 2.00mLofType II or better water to
8.1.2 Methanol Content—Test Method D7920.
the dried sample. Seal the vial with a screw cap, and shake the
8.1.3 Lead—Test Methods D5059. With Test Methods
vial vigorously to dissolve all of the solid salts.
D5059, prepare the calibration standards using methanol (re-
8.1.10.9 If an emulsion results after these steps, pass the
agent grade) as the solvent to prevent errors caused by large
liquid through a column or cartridge designed specifically to
differences in carbon-hydrogen ratios.
removehydrocarbonsfromliquidspriortoinjectingtheminan
8.1.4 Phosphorus—Test Method D3231.
ion chromatograph.
8.1.5 Sulfur—Test Methods D1266 or D5453.
8.1.10.10 Inject 25µL of the resulting clear solution or
8.1.6 Acidity—Test Method D1613.
eluent into the ion chromatograph, and measure the area of the
8.1.7 Gum Content, Solvent Washed and Unwashed—Test
peak corresponding to chloride ion.
Method D381.
8.1.10.11 Calculate the concentration of inorganic chloride
8.1.8 Total Sulfates—Test Method D7328.
in the original sample according to the procedures shown in
8.1.9 Water—Test Method D7923 or E203.
Section 12 of Test Method D7328.
8.1.10 Total Inorganic Chloride—Total inorganic chloride
may be determined by a modification of Test Method D7328,
9. Keywords
a standard test method for determination of total inorganic
9.1 acidity; alcohol; automotive spark-ignition engine fuel;
chloride in fuel ethanol by ion chromatography using aqueous
sampleinjection.RefertoTestMethodD7328forterminology, chloride; copper corrosion; ether; fuel methanol (M99); gaso-
equipment required, reagents and solutions, calibration line blendstock; gum content; hydrocarbon; hydrocarbon
procedures, and general procedure for the determination of blendstock; inorganic chloride; lead; methanol; methanol fuel
totalinorganicchlorideinfuelethanol.NotethatalthoughTest blends (M51–M85); MTBE; oxidation stability; oxygenates;
Method D7328 is also the standard test method for determina- phosphorus; solvent washed; sulfur; vapor pressure; volatility;
tion of existent and potential inorganic sulfate in fuel ethanol, water
D5797−21
ANNEX
(Mandatory Information)
A1. INFORMATION SPECIFIC TO THE UNITED STATES
A1.1 The composition of alternative fuels in the United this specification are advised to check with the applicable
States is regulated by various government agencies and regu-
regulatory agency for specific alternative fuel requirements.
lations including the U.S. Department of Energy (DOE) and
A1.2 Methanol fuel blends of any volatility class shall meet
U.S. Environmental Protection Agency (EPA). With regard to
the same limits for lead and phosphorus as required by U.S.
fuel properties including volatility, this specification can be
Environmental Protection Agency (EPA) regulations for un-
moreorlessrestrictivethanDOEorEPArules,regulationsand
waivers.Toqualifyasanalternativefuelforfederalfleetusein leaded gasoline. EPAregulations limit “the maximum concen-
theUnitedStates,methanolfuelblendsarerequiredtomeetthe tration of lead in unleaded gasoline to 0.013 g/L(0.05 g
U.S. Department of Energy’s definition of alternative fuels,
lead/USgal)andthemaximumconcentrationofphosphorusin
enacted under the Energy Policy Act of 1992 (Title III, Sec.
unleaded gasoline to 0.0013 g/L (0.005 g/US gal), respec-
301). For methanol, the Act defines “alternative fuel” as
tively.” Details of the EPA regulations and test methods are
“mixtures containing 85% or more (or such other percentage,
available in the United States Code of Federal Regulations,
butnotlessthan70%,asdeterminedbytheSecretary,byrule,
Title 40, Part 80.
to provide for requirements to cold start, safety, or vehicle
functions) by volume of methanol.” The U.S. government has A1.3 Table A1.1 provides the United States seasonal and
other programs and definitions for alternative fuels. Users of geographical volatility specifications for methanol fuel blends.
D5797−21
TABLE A1.1 United States Seasonal and Geographical Volatility Specifications for Methanol Fuel Blends (M51-M85)
NOTE 1—This schedule is subject to agreement between the purchaser and the seller denotes the vapor pressure class of the fuel at the time and place
of bulk delivery to fuel dispensing facilities for the end user. Shipments should anticipate this schedule.
NOTE 2—Where alternative classes are listed, either
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it 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 version
of the standard as published by ASTM is to be considered the official document.
Designation: D5797 − 18 D5797 − 21
Standard Specification for
Methanol Fuel Blends (M51–M85) for Methanol-Capable
Automotive Spark-Ignition Engines
This standard is issued under the fixed designation D5797; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope*
1.1 This specification covers the requirements for automotive fuel blends of methanol and gasoline for use in ground vehicles
equipped with methanol-capable flexible-fuel, and dedicated methanol spark-ignition engines. Fuel produced to this specification
contains 51 % to 85 % by volume methanol. This fuel is sometimes referred to at retail as “M85.” Appendix X1 discusses the
significance of the properties specified. Appendix X2 presents the current status in the development of a luminosity test procedure
(flame visibility) for methanol fuel blends (M51–M85).
1.2 The vapor pressure of methanol fuel blends is varied for seasonal climatic changes. Vapor pressure is increased at lower
temperatures to ensure adequate vehicle operability and safety. Methanol content and selection of gasoline blendstocks are adjusted
by the blender to meet these vapor pressure requirements.
1.3 The United States government has established various programs for alternative fuels. Many of the definitions of alternative
fuel used by these programs can be more or less restrictive than the requirements of this specification. See Annex A1 for additional
information on alternative fuels containing methanol.
1.4 The values stated in SI units are to be regarded as the standard.
1.4.1 Exception—Non-SI units are provided for information only. In most cases, U.S. federal regulations specify non-SI units.
1.5 The following precautionary caveat pertains only to the test method portions–Appendix X2 of this specification. This
standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user
of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory
limitations prior to use.
1.6 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2,3
2.1 ASTM Standards:
This specification is under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is under the direct responsibility of
Subcommittee D02.A0.02 on Oxygenated Fuels and Components.
Current edition approved Dec. 1, 2018Oct. 1, 2021. Published December 2018October 2021. Originally approved in 1995. Last previous edition approved in 20172018
as D5797 – 17.D5797 – 18. DOI: 10.1520/D5797-18.10.1520/D5797-21.
Reference to the following documents is to be the latest issue unless otherwise specified.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5797 − 21
D86 Test Method for Distillation of Petroleum Products and Liquid Fuels at Atmospheric Pressure
D130 Test Method for Corrosiveness to Copper from Petroleum Products by Copper Strip Test
D381 Test Method for Gum Content in Fuels by Jet Evaporation
D525 Test Method for Oxidation Stability of Gasoline (Induction Period Method)
D1193 Specification for Reagent Water
D1266 Test Method for Sulfur in Petroleum Products (Lamp Method)
D1613 Test Method for Acidity in Volatile Solvents and Chemical Intermediates Used in Paint, Varnish, Lacquer, and Related
Products
D3231 Test Method for Phosphorus in Gasoline
D4057 Practice for Manual Sampling of Petroleum and Petroleum Products
D4175 Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
D4177 Practice for Automatic Sampling of Petroleum and Petroleum Products
D4306 Practice for Aviation Fuel Sample Containers for Tests Affected by Trace Contamination
D4806 Specification for Denatured Fuel Ethanol for Blending with Gasolines for Use as Automotive Spark-Ignition Engine Fuel
D4814 Specification for Automotive Spark-Ignition Engine Fuel
D4953 Test Method for Vapor Pressure of Gasoline and Gasoline-Oxygenate Blends (Dry Method)
D5059 Test Methods for Lead and Manganese in Gasoline by X-Ray Fluorescence Spectroscopy
D5191 Test Method for Vapor Pressure of Petroleum Products and Liquid Fuels (Mini Method)
D5453 Test Method for Determination of Total Sulfur in Light Hydrocarbons, Spark Ignition Engine Fuel, Diesel Engine Fuel,
and Engine Oil by Ultraviolet Fluorescence
D5798 Specification for Ethanol Fuel Blends for Flexible-Fuel Automotive Spark-Ignition Engines
D5854 Practice for Mixing and Handling of Liquid Samples of Petroleum and Petroleum Products
D7328 Test Method for Determination of Existent and Potential Inorganic Sulfate and Total Inorganic Chloride in Fuel Ethanol
by Ion Chromatography Using Aqueous Sample Injection
D7667 Test Method for Determination of Corrosiveness to Silver by Automotive Spark-Ignition Engine Fuel—Thin Silver Strip
Method
D7671 Test Method for Corrosiveness to Silver by Automotive Spark–Ignition Engine Fuel–Silver Strip Method
D7757 Test Method for Silicon in Gasoline and Related Products by Monochromatic Wavelength Dispersive X-ray Fluorescence
Spectrometry
D7920 Test Method for Determination of Fuel Methanol (M99) and Methanol Fuel Blends (M10 to M99) by Gas
Chromatography
D7923 Test Method for Water in Ethanol and Hydrocarbon Blends by Karl Fischer Titration
E203 Test Method for Water Using Volumetric Karl Fischer Titration
3. Terminology
3.1 For general terminology, refer to Terminology D4175.
3.2 Definitions:
3.2.1 aliphatic ether, n—an oxygen-containing, ashless, organic compound in which the oxygen atom is interposed between two
carbon atoms (organic groups), has the general formula C H O with n being 5 to 8, and in which the carbon atoms are connected
n 2n+2
in open chains and not closed rings.
3.2.1.1 Discussion—
Aliphatic compounds can be straight or branched chains and saturated or unsaturated. The term aliphatic ether, as used in this
specification, refers only to the saturated compounds.
3.2.1 denatured fuel ethanol, n—fuel ethanol made unfit for beverage use by the addition of denaturants under formula(s) approved
by the applicable regulatory agency to prevent the imposition of beverage alcohol tax. D4806
3.2.2 ethanol, n—ethyl alcohol, the chemical compound CH CH OH. D4806
3 2
3.2.3 finished fuel, n—a homogeneous mixture of blendstocks and fuel additives meeting all specification and regulatory
requirements for its intended use at the location where sold.
3.2.4 fuel methanol (M99), n—methanol with small/trace alcohol and hydrocarbon impurities.
D5797 − 21
3.2.5 gasoline, n—volatile mixture of liquid hydrocarbons, generally containing small amounts of additives, suitable for use as a
fuel in spark-ignition, internal combustion engines. D4814
3.2.6 gasoline blendstock, n—a liquid hydrocarbon component suitable for use in spark-ignition engine fuels.
3.2.6.1 Discussion—
Examples of gasoline blendstock include natural gasoline, raffinate, reformate, naphtha, conventional gasoline blendstock for
oxygenated blending (CBOB), and reformulated gasoline blendstock for oxygenate blending (RBOB).
3.2.8 higher alcohols—aliphatic alcohols of the general formula C H OH with n being 2 to 8.
n 2 n+1
3.2.7 hydrocarbon—a compound composed solely of hydrogen and carbon.
3.2.8 methanol, n—methyl alcohol, the chemical compound CH OH.
3.2.9 methanol fuel blend (M51–M85), n—a blend of methanol and hydrocarbons of which the methanol portion is nominally 51
% to 85 % by volume.
3.2.9.1 Discussion—
In the abbreviation, MXX, the XX represents the volume percentage of methanol in the fuel blend.
4. Ordering Information
4.1 The purchasing agency shall:
4.1.1 Indicate the season and locality in which the fuel is to be used,
4.1.2 If requested, ensure that the methanol concentration meets the requirements for an alternative fuel for United States federal
fleets.
4.1.3 For further information, see Annex A1 of this specification.
5. Methanol Fuel Blends Performance Requirements
5.1 Methanol fuel blends shall conform to the requirements in Table 1.
TABLE 1 Requirements for Methanol Fuel Blends (M51–M85)
A
Properties Class 1 Class 2 Class 3 Test Methods
Annex A1
D4953 or D5191
B
Vapor pressure, kPa (psi) 48–62 62–83 83–103
(7.0–9.0) (9.0–12.0) (12.0–15.0)
C
All Classes
Methanol Content, % by volume, min 51–85 D7920
D
Lead, mg/L, max 2.6 D5059
Phosphorus, mg/L, max 0.2 D3231
Sulfur, mg/kg, max 80 D5453
Acidity, as acetic acid, mg/kg, max 50 D1613
Unwashed gum content, mg/100 mL, max 20 D381
Solvent washed gum content, mg/100 mL, max 5 D381
Total Inorganic Sulfate, mg/kg, max 4 D7328
Water, % by mass, max 0.5 D7923 or E203
Total Inorganic Chloride, mg/kg, max 1 D7328
A
See 5.3 for volatility class criteria.
B
The vapor pressure overlap is intentional to cover changes associated with seasonal changes.
C
Methanol content and selection of gasoline blendstock are adjusted by the blender to meet vapor pressure requirements. See X1.3.3 for additional information and
guidance for blending.
D
With Test Methods D5059, prepare the calibration standards using methanol (reagent grade) as the solvent to prevent errors caused by large differences in
carbon-hydrogen ratios.
D5797 − 21
NOTE 1—Most of the requirements cited in Table 1 are based on the best technical information currently available. As greater experience is gained from
field use of methanol-capable vehicles, some of these requirements will change.
5.1.1 The components used to produce methanol fuel blends are limited to methanol and gasoline blendstock as defined in 5.2.
5.1.2 The intentional addition of lead or phosphorus compounds to methanol fuel blends is not permitted.
5.2 Gasoline blendstocks used shall meet the requirements of Table 2. The gasoline blendstock may contain aliphatic ethers as
blending components that are used in automotive fuels in some countries outside of North America.
5.3 Vapor pressure is varied for seasonal and climatic changes by providing three vapor pressure classes for methanol fuel blends
as follows:
(1) Class 1 encompasses geographical areas with 6 h tenth-percentile minimum ambient temperature of greater than 5 °C (41
°F).
(2) Class 2 encompasses geographical areas with 6 h tenth-percentile minimum temperatures of greater than –5 °C (23 °F) but
less than or equal to 5 °C (41 °F).
(3) Class 3 encompasses geographical areas with 6 h tenth-percentile minimum ambient temperature less than or equal to –5
°C (23 °F).
5.3.1 There is a 10 % probability that the highest temperature of the six coldest consecutive hourly temperature readings of a 24 h
day will be colder than the 6 h tenth percentile minimum ambient temperature.
5.3.2 See 5.4.2 for seasonal and geographical distributions in the United States.
5.4 Regulatory and Other Requirements in the United States:
5.4.1 Methanol content and other requirements for methanol alternative fuel blends in the United States can be found in Annex
A1 of this standard.
5.4.2 The United States seasonal and geographical distribution for the three vapor pressure classes is shown in Annex A1, Table
A1.1.
5.5 Regulatory and Other Requirements Outside the United States:
5.5.1 Users of this specification are advised to consult with the applicable regulatory agency for specific requirements for their
jurisdictions.
5.5.2 Users of the specification in geographical areas outside the United States need to determine the 6 h tenth percentile minimum
ambient temperatures for their geographic areas and times of year in order to select the appropriate classes of fuel.
5.6 Use of unprotected aluminum in methanol fuel blend distribution and dispensing equipment will introduce insoluble aluminum
compounds into the fuel causing plugged vehicle fuel filters. Furthermore, this effect can be exaggerated even with protected
TABLE 2 Requirements for Gasoline Blendstock
Properties Test Methods
Distillation, end point, °C(°F), max 225 (437) D86
Distillation, end point, °C (°F), max 225 (437) D86
Oxidation stability, minutes, min 240 D525
Copper strip corrosion, max No. 1 D130
Silver strip corrosion, max No. 1 D7667, D7671
A
Vapor pressure, kPa Report D4953, D5191
A
While not a requirement of this specification, the blender will need to know the
vapor pressure of the gasoline blendstock in order to choose a suitable blend ratio
for the components to meet the vapor pressure requirement of a particular volatility
class.
D5797 − 21
aluminum by elevated fuel conductivity caused by contact with a nitrile rubber dispensing hose. Therefore, unprotected aluminum
4,5
and an unlined nitrile rubber dispensing hose should be avoided in methanol fuel blend distribution and dispensing systems.
6. Workmanship
6.1 The finished fuel blend shall be visually free of sediment, suspended, or undissolved matter. It shall be clear and bright at the
fuel temperature at the point of custody transfer or at a lower temperature agreed upon by the purchaser and seller.
NOTE 2—Finished fuel should be resistant to phase separation or undissolved matter at the lowest temperatures to which it is likely to be subjected,
dependent on the time and place of its intended use. See Specification D4814, Table X7.1 for guidance.
NOTE 3—Solubility is temperature dependent. As this fuel cools, some high molecular weight additives can become insoluble.
6.2 The specification defines only a basic purity for methanol fuel blend (M51–M85). The product shall be free of any adulterant
or contaminant that can render the material unacceptable for its commonly used applications.
6.2.1 Manufacturers and blenders of methanol fuel blend (M51–M85) shall avoid methanol (for example, improperly recycled
methanol), or hydrocarbon blend components contaminated by silicon-containing materials, or both. Silicon contamination of
gasoline, denatured ethanol, and their blends has led to fouled vehicle components (for example, spark plugs, exhaust oxygen
sensors, catalytic converters) requiring parts replacement and repairs. Test Method D7757 is a procedure for determining silicon
that might be applicable to methanol fuel blend (M51–M85). No specification limits have been established for silicon.
7. Sampling, Containers, and Sample Handling
7.1 The reader is strongly advised to review all intended test methods prior to sampling to better understand the importance and
effects of sampling technique, proper containers, and special handling required for each test method.
7.2 Correct sampling procedures are critical to obtain a sample representative of the lot intended to be tested. Use appropriate
procedures in Practice D4057 for manual method sampling and in Practice D4177 for automatic sampling as applicable.
7.3 The correct sample volume and appropriate container selection are important decisions that can impact test results. Refer to
Practice D4306 for aviation fuel container selection for tests sensitive to trace contamination. Refer to Practice D5854 for
procedures on container selection and sample mixing and handling. Where practical, methanol fuel blends should be sampled in
amber borosilicate glass containers. If samples must be collected in metal containers, do not use soldered metal containers. The
soldering flux in the containers and the lead in the solder can contaminate the sample. Plastic containers should be avoided.
7.4 A minimum sample size of about 1 L (~1 qt) is recommended.
8. Test Methods
8.1 Determine the requirements enumerated in this specification in accordance with the following test methods:
NOTE 4—The appropriateness of ASTM test methods cited has not been demonstrated for use with M51–M85. In addition, test methods contained in the
annexes and appendixes are in the developmental stages or lack precision and bias determinations.
8.1.1 Vapor Pressure—Test Methods D4953 or D5191.
8.1.2 Methanol Content—Test Method D7920.
8.1.3 Lead—Test Methods D5059. With Test Methods D5059, prepare the calibration standards using methanol (reagent grade)
as the solvent to prevent errors caused by large differences in carbon-hydrogen ratios.
8.1.4 Phosphorus—Test Method D3231.
California Energy Commission, “Fifteen Years of Fuel Methanol Distribution,” http://www.methanol.org/Energy/Resources/Alternative-Fuel/CEC- 1996-ISAF-Fuel-
Meoh-Paper.aspx
California Air Resources Board, Methanol Fuel Additive Demonstration, http://arb.ca.gov/research/apr/past/a832-123a
D5797 − 21
8.1.5 Sulfur—Test Methods D1266 or D5453.
8.1.6 Acidity—Test Method D1613.
8.1.7 Gum Content, Solvent Washed and Unwashed—Test Method D381.
8.1.8 Total Sulfates—Test Method D7328.
8.1.9 Water—Test Method D7923 or E203.
8.1.10 Total Inorganic Chloride—Total inorganic chloride may be determined by a modification of Test Method D7328, a standard
test method for determination of total inorganic chloride in fuel ethanol by ion chromatography using aqueous sample injection.
Refer to Test Method D7328 for terminology, equipment required, reagents and solutions, calibration procedures, and general
procedure for the determination of total inorganic chloride in fuel ethanol. Note that although Test Method D7328 is also the
standard test method for determination of existent and potential inorganic sulfate in fuel ethanol, that determination is addressed
separately in Specification D5797, the standard specification for methanol fuel blends. The procedure for total inorganic chloride
determination will be summarized:
8.1.10.1 Obtain a well-mixed homogeneous sample of methanol fuel blend in a glass container, equipped with closures that can
be well-sealed, and free of any residual or extractable chloride. If containers have been cleaned and rinsed with water, they should
be thoroughly rinsed with Type II or better reagent water according to Specification D1193 and dried prior to use.
8.1.10.2 Thoroughly mix the sample in its container immediately prior to withdrawal of the test specimen.
8.1.10.3 Set up the ion chromatograph in accordance with the manufacturer’s instructions.
8.1.10.4 Equilibrate the system by pumping eluent for 15 min to 30 min, until a stable baseline is obtained.
8.1.10.5 Start the chromatographic run in accordance with manufacturer’s instructions.
8.1.10.6 Carefully add 2.00 mL of the methanol fuel blend test specimen into a clean, dry, tared 15 mL glass vial without its screw
cap closure.
8.1.10.7 Place the vial with sample in a hot block at 65 °C and blow a steady stream of nitrogen gas over the sample at 2 mL ⁄min
to 3 mL ⁄min flowrate. Maintain these conditions for 15 min. Remove the vial from the hot block and allow it to cool to room
temperature 15 °C to 27 °C. Note that it is probable that a small amount of liquid remains. Do not worry about this residue since
any inorganic chloride will be extracted into the water phase.
8.1.10.8 Carefully add 2.00 mL of Type II or better water to the dried sample. Seal the vial with a screw cap, and shake the vial
vigorously to dissolve all of the solid salts.
8.1.10.9 If an emulsion results after these steps, pass the liquid through a column or cartridge designed specifically to remove
hydrocarbons from liquids prior to injecting them in an ion chromatograph.
8.1.10.10 Inject 25 μL of the resulting clear solution or eluent into the ion chromatograph, and measure the area of the peak
corresponding to chloride ion.
8.1.10.11 Calculate the concentration of inorganic chloride in the original sample according to the procedures shown in Section
12 of Test Method D7328.
9. Keywords
9.1 acidity; alcohol; automotive spark-ignition engine fuel; chloride; copper corrosion; ether; fuel methanol (M99); gasoline
blendstock; gum content; hydrocarbon; hydrocarbon blendstock; inorganic chloride; lead; methanol; methanol fuel blends
(M51–M85); MTBE; oxidation stability; oxygenates; phosphorus; solvent washed; sulfur; vapor pressure; volatility; water
D5797 − 21
ANNEX
(Mandatory Information)
A1. INFORMATION SPECIFIC TO THE UNITED STATES
A1.1 The composition of alternative fuels in the United States is regulated by various government agencies and regulations
including the U.S. Department of Energy (DOE) and U.SU.S. Environmental Protection Agency (EPA). With regard to fuel
properties including volatility, this specification can be more or less restrictive than DOE or EPA rules, regulations and waivers.
To qualify as an alternative fuel for federal fleet use in the United States, methanol fuel blends are required to meet the U.S.
Department of Energy’s definition of alternative fuels, enacted under the Energy Policy Act of 1992 (Title III, Sec. 301). For
methanol, the Act defines “alternative fuel” as “mixtures containing 85 % or more (or such other percentage, but not less than 70 %,
as determined by the Secretary, by rule, to provide for requirements to cold start, safety, or vehicle functions) by volume of
methanol.” The U.S. government has other programs and definitions for alternative fuels. Users of this specification are advised
to check with the applicable regulatory agency for specific alternative fuel requirements.
A1.2 Methanol fuel blends of any volatility class shall meet the same limits for lead and phosphorus as required by U.S.
Environmental Protection Agency (EPA) regulations for unleaded gasoline. EPA regulations limit “the maximum concentration of
lead in unleaded gasoline to 0.013 g/L(0.05 g lead/US gal) and the maximum concentration of phosphorus in unleaded gasoline
to 0.0013 g/L (0.005 g/US gal), respectively.” Details of the EPA regulations and test methods are available in the United States
Code of Federal Regulations, Title 40, Part 80.
A1.3 Table A1.1 provides the United States seasonal and geographical volatility specifications for methanol fuel blends.
D5797 − 21
TABLE A1.1 United States Seasonal and Geographical Volatility Specifications for Methanol Fuel Blends (M51-M85)
NOTE 1—This schedule is subject to agreement between the purchaser and the seller denotes the vapor pressure class of the fuel at the time and place
of bulk delivery to fuel dispensing facilities for the end user. Shipments should anticipate this schedule.
NOTE 2—Where alter
...