ASTM D7794 Standard Practice for Blending Mid-Level Ethanol Fuel Blends for Flexible-Fuel Vehicles with Automotive Spark-Ignition Engines
4. Summary of Practice
4.1 This practice provides procedures for blending automotive spark-ignition engine fuels with ethanol concentrations greater than those suitable for conventional-fuel vehicles and less than the minimum ethanol content limit of Specification D5798. It addresses in detail the various factors which need to be considered when blending. These considerations include selection of fuel components for blending and general handling information.
5. General Requirements
5.1 The fuel blending components specified in this practice shall meet the performance requirements of Specifications D4814, and either D5798 or D4806 and all applicable regulatory fuel requirements.
5.2 The blending party, being responsible for the finished product, shall be provided, at the time of delivery of the fuel, on product transfer documents, an invoice, bill of lading, shipping paper, or other documentation, a declaration of the product type and grade of the fuels that are the intended fuel blending components. It is recommended that the blending party conduct testing and inspections to determine applicable properties that are necessary to ensure the blending of compliant mid-level ethanol fuel blends.
5.3 Product transfer documents alone may not be sufficient to demonstrate conformance. A Certificate of Analysis representative of the fuel being delivered is recommended to ensure compliance.
5.4 The fuel blender or testing analyst, or both, is warned that some requirements and test methods applicable to automotive spark-ignition engine fuels depend on whether the fuel is a gasoline, a gasoline-ethanol blend, or ethanol fuel blend. Once the amount of ethanol is known for the gasoline or gasoline-ethanol blend component and for the Specification D5798 ethanol fuel blend or Specification D4806 fuel ethanol component, the appropriate blending ratios can be determined for the blending of the two components.
5.4.1 Test Method D5501 shall be used for determination of the volume percent ethanol for the fuel ethanol component (that is, high concentration ethanol) and to verify the mid-level blend fuel, and Test Methods D4815 or D5599 shall be used for the gasoline or gasoline-ethanol blend component (that is, low concentration ethanol).
5.5 In order to ensure the presence of no more than 1 mg/kg inorganic chloride in the finished fuel or in Specification D5798, the ethanol component specified herein shall meet all the requirements of Specification D4806 with a more restrictive inorganic chloride limit as determined in Test Methods D7319 and D7328. The hydrocarbon blending component specified herein shall meet all the requirements of Specification D4814.
5.6 Mid-level ethanol fuel blends shall be visually free of water, sediment, and suspended matter. It shall be clear and bright at the point and condition of custody transfer and display no indication of phase separation.
5.7 The finished fuel shall also be free of any adulterant or contaminant that could render the fuel unacceptable for its commonly used applications.
