GPA STD 2108
GPA Midstream Fractionation Grade Product Specifications
|Publication Date:||1 January 2020|
These specifications generally define physical properties and characteristics of NGLs as a feedstock to and products from fractionation facilities which make them suitable for private, commercial, and industrial applications. These specifications do not purport to specifically define all possible requirements to meet all possible applications. Therefore, the user is cautioned to exercise judgment in formulating final specifications for specific applications.
The GPA Midstream Association, its management, and supporting companies claim no specific knowledge of how manufacturers and users will produce, handle, store, transfer, or consume the products defined herein and therefore, are not responsible for any claims, causes of action, liabilities, losses, or expenses resulting from injury or death of persons and/or damage to property arising directly or indirectly from the use of NGLs or these specifications relating to NGLs.
There are many uses for NGLs including refining, petrochemical, and heating. The seven NGL specifications represented by this standard include a demethanized mix specification, and fractionation grade specifications, which include ethane, ethane-propane mix, propane, isobutane, normal butane, and natural gasoline. All represented GPA Midstream member-company specifications were surveyed to find the common characteristics in establishing these specifications. The demethanized mix specification has limits linked with the fractionation specifications regarding contamination issues, which many facilities do not have processing equipment to mitigate. Examples include methane limits, corrosive materials (copper strip), and color contaminants (Saybolt) which have demethanized mix limits provided. Other contaminant examples which do not have demethanized mix limits include olefins, halides, oxygenates, ammonia, caustics, acids, oils, anti-foulants, and amines which, if present have regional, contractual, or other limitations due to their negative impacts on downstream processes. The demethanized mix specification also provides a section of typical compositions based on member-company survey results which are provided for educational purposes only. Examples include typical concentration ranges for components such as ethane and propane.
Typical uses for fractionation grade NGLs include, but are not limited to:
Ethane: Petrochemical, fuel.
Propane: Petrochemical, refining, fuel.
Butane: Petrochemical, refining.
Isobutane: Petrochemical, refining.
Natural Gasoline: Petrochemical, refining.
The GPA Midstream Association has another published specification for natural gas liquid products, GPA 2140. The fractionation grade propane specification is a very slight modification of the GPA 2140 Propane HD-5 specification in that it eliminates the dryness test. The fractionation grade n-butane is a variation from the commercial butane specification in that it sets minimum n-butane limits and has lower vapor pressure limits.
GPA Midstream specifications can be used throughout the industry to quickly identify a product to be "on" specification or "off" specification. Consistent specifications can be referenced in contractual agreements, environmental, safety, and engineering publications. These specifications can be used as the foundation or starting point for participants needing more stringent or less stringent specifications.