ASTM D7794-12

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D7794 − 12
StandardPractice for
Blending Mid-Level Ethanol Fuel Blends for Flexible-Fuel
Vehicles with Automotive Spark-Ignition Engines
This standard is issued under the fixed designation D7794; 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 1.6 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
1.1 This practice applies to the blending of automotive
responsibility of the user of this standard to establish appro-
spark-ignition engine fuels with ethanol concentrations greater
priate safety and health practices and determine the applica-
than those suitable for conventional-fuel vehicles and less than
bility of regulatory limitations prior to use.
the minimum ethanol content specification limits of Specifica-
tion D5798.
2. Referenced Documents
1.2 Thesemid-levelethanolfuelblendsareonlysuitablefor
2.1 ASTM Standards:
use in ground flexible-fuel vehicles equipped with spark-
D4057 Practice for Manual Sampling of Petroleum and
ignition engines. Flexible-fuel vehicles are designed to operate
Petroleum Products
on gasoline or gasoline-ethanol blends that meet the require-
D4175 Terminology Relating to Petroleum, Petroleum
mentsofSpecificationD4814,ethanolfuelblendsthatmeetthe
Products, and Lubricants
requirements of Specification D5798, or any combination of
D4177 Practice for Automatic Sampling of Petroleum and
these. In the United States, these vehicles are certified by the
Petroleum Products
U.S. EPA as emissions compliant with these types of fuels.
D4806 Specification for Denatured Fuel Ethanol for Blend-
ing with Gasolines for Use as Automotive Spark-Ignition
1.3 The mid-level ethanol fuel blend shall be blended from
Engine Fuel
either:
D4814 Specification for Automotive Spark-Ignition Engine
1.3.1 Denatured fuel ethanol conforming to the require-
Fuel
mentsofSpecificationD4806withareducedlimitoninorganic
D4815 Test Method for Determination of MTBE, ETBE,
chloride content that will ensure no more than 1 mg/kg
TAME, DIPE, tertiary-Amyl Alcohol and C to C Alco-
1 4
inorganic chloride in the finished fuel and from spark-ignition
hols in Gasoline by Gas Chromatography
engine fuel conforming to Specification D4814 (often at a
D5191 Test Method for Vapor Pressure of Petroleum Prod-
distribution terminal or bulk plant), or
ucts (Mini Method)
1.3.2 Ethanol fuel blends conforming to Specification
D5501 Test Method for Determination of Ethanol and
D5798 and from spark-ignition engine fuel conforming to
Methanol Content in Fuels Containing Greater than 20%
Specification D4814 (often at a retail site).
Ethanol by Gas Chromatography
1.4 This practice describes the required procedures for
D5599 Test Method for Determination of Oxygenates in
blending various mid-level ethanol fuel blends for flexible-fuel
Gasoline by Gas Chromatography and Oxygen Selective
vehicles at the bulk distribution point or retail/commercial
Flame Ionization Detection
delivery site. These requirements may be applied at other
D5798 Specification for Ethanol Fuel Blends for Flexible-
pointsintheproductionanddistributionsystemwhenprovided
Fuel Automotive Spark-Ignition Engines
by agreement between the purchaser and the supplier.
D5842 Practice for Sampling and Handling of Fuels for
Volatility Measurement
1.5 The values stated in SI units are to be regarded as
D5854 Practice for Mixing and Handling of Liquid Samples
standard. No other units of measurement are included in this
of Petroleum and Petroleum Products
standard.
D6469 GuideforMicrobialContaminationinFuelsandFuel
Systems
This practice is under the jurisdiction of ASTM Committee D02 on Petroleum
Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcom- For referenced ASTM standards, visit the ASTM website, www.astm.org, or
mittee D02.A0.02 on Oxygenated Fuels and Components. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Current edition approved April 15, 2012. Published May 2012. DOI: 10.1520/ Standards volumeinformation,refertothestandard’sDocumentSummarypageon
D7794–12. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7794 − 12
D7319 Test Method for Determination of Existent and Po- applicable regulatory jurisdictions, that can volumetrically
tential Sulfate and Inorganic Chloride in Fuel Ethanol and combine two different base products into newly formed
Butanol by Direct Injection Suppressed Ion Chromatog- blended products that may be dispensed through a single hose
raphy or multiple hose dispenser configuration.
D7328 Test Method for Determination of Existent and Po-
3.2.8 fuel ethanol, n—a grade of undenatured ethanol with
tential Inorganic Sulfate and Total Inorganic Chloride in
other components common to its production (including water)
Fuel Ethanol by Ion Chromatography Using Aqueous
that do not affect the use of the product as a component for
Sample Injection
automotive spark-ignition engine fuels. D4806
2.2 Other Standards:
3.2.9 gasoline, n—a volatile mixture of liquid
16 CFR United States Code of Federal Regulations,Title 16,
hydrocarbons, generally containing small amounts of
Part 306
additives, suitable for use as a fuel in spark-ignition, internal
40 CFR United States Code of Federal Regulations,Title 40,
combustion engines. D4814
Part 86
3.2.10 gasoline-ethanol blend, n—a fuel consisting primar-
ily of gasoline along with a substantial amount (more than 0.35
3. Terminology
mass % oxygen) of ethanol. D4806
3.1 For general terminology, refer to Terminology D4175.
3.2.11 mid-level ethanol fuel blend, n—an automotive
3.2 Definitions:
spark-ignition engine fuel with an ethanol concentration
3.2.1 automotive fuel rating, n—the automotive fuel rating
greater than those suitable for conventional-fuel vehicles and
required under the amended Octane Certification and Posting
less than the minimum ethanol content limit of Specification
Rule (or as amended, the Fuel Rating Rule), 16 CFR, Part 306.
D5798.
3.2.1.1 Discussion—Under this Rule, sellers of liquid auto-
3.2.11.1 Discussion—Mid-level ethanol fuel blends are of-
motive fuels, including alternative fuels, must determine,
ten referred to as EXX, where XX represents the nominal
certify, and post an appropriate automotive fuel rating. The
percentage of denatured fuel ethanol.
automotive fuel rating for gasoline is the antiknock index
(octane rating). The automotive fuel rating for alternative
4. Summary of Practice
liquidfuelsconsistsofthecommonnameofthefuelalongwith
4.1 This practice provides procedures for blending automo-
a disclosure of the amount, expressed as a minimum percent-
tive spark-ignition engine fuels with ethanol concentrations
age by volume, of the principal component of the fuel. For
greater than those suitable for conventional-fuel vehicles and
alternative liquid automotive fuels, a disclosure of other
less than the minimum ethanol content limit of Specification
components, expressed as a minimum percentage by volume,
D5798. It addresses in detail the various factors which need to
may be included, if desired. This is applicable in the United
be considered when blending. These considerations include
States.
selectionoffuelcomponentsforblendingandgeneralhandling
3.2.2 conventional-fuel vehicle, n—a vehicle designed to
information.
operate on spark-ignition engine fuel that complies with
Specification D4814.
5. General Requirements
3.2.3 denatured fuel ethanol, n—fuel ethanol made unfit for
5.1 The fuel blending components specified in this practice
beverage use by the addition of denaturants under formula(s)
shall meet the performance requirements of Specifications
approved by the applicable regulatory agency to prevent the
D4814, and either D5798 or D4806 and all applicable regula-
imposition of beverage alcohol tax. D4806
tory fuel requirements.
3.2.4 ethanol, n—ethyl alcohol, the chemical compound
5.2 The blending party, being responsible for the finished
C H OH. D4806
2 5
product, shall be provided, at the time of delivery of the fuel,
3.2.5 ethanol fuel blend, n—a high concentration ethanol-
on product transfer documents, an invoice, bill of lading,
based fuel for flexible-fuel spark-ignition engines and vehicles.
shipping paper, or other documentation, a declaration of the
3.2.6 flexible-fuel vehicle, n—a vehicle designed to operate product type and grade of the fuels that are the intended fuel
on either unleaded gasoline or ethanol fuel blends or mixtures
blending components. It is recommended that the blending
of both. D5798 party conduct testing and inspections to determine applicable
3.2.6.1 Discussion—In the United States, these vehicles
properties that are necessary to ensure the blending of compli-
have U.S. EPAemissions certifications using gasoline comply-
ant mid-level ethanol fuel blends.
ing with U.S. EPA requirements and ethanol fuel blends that
5.3 Product transfer documents alone may not be sufficient
meet the requirements of Specification D5798.
to demonstrate conformance. A Certificate of Analysis repre-
3.2.7 fuel blendingdispenser,n—adeviceformeasuringand
sentative of the fuel being delivered is recommended to ensure
dispensing fuel, conforming to the standards established by the
compliance.
5.4 The fuel blender or testing analyst, or both, is warned
that some requirements and test methods applicable to auto-
Available from Standardization Documents Order Desk, DODSSP, Bldg. 4,
motive spark-ignition engine fuels depend on whether the fuel
Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http://
dodssp.daps.dla.mil. is a gasoline, a gasoline-ethanol blend, or ethanol fuel blend.
D7794 − 12
Once the amount of ethanol is known for the gasoline or 6.2.7 This review should apply to the initial handling point
gasoline-ethanol blend component and for the Specification at the terminal, through the distribution and transport system,
D5798 ethanol fuel blend or Specification D4806 fuel ethanol and ultimately to the end point—the retail point of sale.
component, the appropriate blending ratios can be determined
6.3 Determination of Blending Component Properties:
for the blending of the two components.
6.3.1 Itistheresponsibilityofthesuppliersoffuelsthatwill
5.4.1 Test Method D5501 shall be used for determination of
be used for blending mid-level ethanol fuel blends to provide
the volume percent ethanol for the fuel ethanol component
the blending parties with product transfer documents that
(that is, high concentration ethanol) and to verify the mid-level
contain, at a minimum, the information required by all appli-
blendfuel,andTestMethodsD4815orD5599shallbeusedfor
cable regulatory agencies. In the United States, this includes,
the gasoline or gasoline-ethanol blend component (that is, low
among other items, a product description and the applicable
concentration ethanol).
Automotive Fuel Rating. The fuel supplier is responsible for
5.5 In order to ensure the presence of no more than 1 mg/kg
ensuring that the product transfer documents are a true and
inorganic chloride in the finished fuel or in Specification
accurate representation of the materials being supplied. Be-
D5798, the ethanol component specified herein shall meet all
cause product transfer documents are not always required to
the requirements of Specification D4806 with a more restric-
contain all information necessary for the blending party to
tive inorganic chloride limit as determined in Test Methods
accurately determine compliance with the final blend, the
D7319 and D7328. The hydrocarbon blending component
blendingpartymustbepreparedtoeitherobtainaCertificateof
specifiedhereinshallmeetalltherequirementsofSpecification
Analysis from the fuel supplier(s), arrange for specific pur-
D4814.
chase specifications with their supplier(s), or have a sample of
each component tested periodically to determine the ethanol
5.6 Mid-level ethanol fuel blends shall be visually free of
content using Test Methods D4815 or D5599 for gasoline or
water, sediment, and suspended matter. It shall be clear and
gasoline-ethanol blends, and Test Method D5501 for Specifi-
brightatthepointandconditionofcustodytransferanddisplay
cation D5798 ethanol fuel blend, the resulting mid-level
no indication of phase separation.
ethanol fuel blend, or for Specification D4806 denatured fuel
5.7 The finished fuel shall also be free of any adulterant or
ethanol. For Specification D4806 denatured fuel ethanol, the
contaminant that could render the fuel unacceptable for its
blending party shall also determine that the inorganic chloride
commonly used applications.
content does not exceed a level that would result in finished
mid-level ethanol fuel blend that would have more that the
6. Blending Procedures
specified 1 mg⁄kg maximum of Specification D5798.
6.1 Thispracticeincludesproceduresforblendingmid-level
6.3.2 The blending party should be aware that the spark-
ethanolfuelblendsatthebulkdistributionterminalandatretail
ignition engine fuel (Specification D4814) used may contain
using a fuel blending dispenser.
ethanol up to the maximum concentrations permitted by fuel
specifications and regulations, and that this content may
6.2 A fuel blending plan shall be developed describing the
change over time. Likewise, ethanol fuel blends (Specification
necessary actions needed to achieve the targeted mid-level
D5798) may change in ethanol content depending upon the
ethanol fuel blends and performance expectations of flexible-
month and location of the intended sale of the ethanol fuel.
fuel vehicles.
These changes must be taken into account when preparing
6.2.1 Blending plans utilizing new equipment installation or
blending formulas for mid-level ethanol fuel blends.
conversion of existing equipment depend on thorough prepa-
ration and planning for the entire fuel system. 6.3.3 The blending party shall also be aware that denatured
6.2.2 The investigation and design of the wetted fuel system fuel ethanol for fuel blending (Specification D4806) contains
from 1.96 to 5.0 volume % hydrocarbons as denaturant (most
starts with a review of the flow of the fuel from receipt through
retail delivery ensuring materials compatibility with the blend- often 2.0 to 2.5 volume % denaturant). This hydrocarbon
content must also be taken into account when preparing
ing components and the blended mid-level ethanol fuel blends.
6.2.3 Fuel storage and blending systems shall be approved blending formulas f
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