Alkylate (Refinery Gasoline Blendstock) Storage & Tank Compatibility
Storing Alkylate (Refinery Gasoline Blendstock)? Start Here
Alkylate is a high-octane, low-volatility gasoline blendstock produced in the refinery alkylation unit by reacting isobutane with light olefins (propylene and butylenes). The result is a clean-burning mixture of branched C5–C12 isoparaffins — rich in trimethylpentanes such as isooctane — with very low sulfur, aromatics, and olefin content. Refiners prize it for boosting octane while improving combustion quality, making it a premium component in both motor and aviation gasoline.
Because it is a saturated aliphatic hydrocarbon fuel, alkylate is extremely flammable (flash point well below -40 °F) and is handled like gasoline. Materials of construction (MOC) matter because hydrocarbons permeate and swell polyethylene and because vapor-air mixtures ignite readily. Proper storage demands grounded, bonded metal tanks engineered for flammable-liquid fuel service, with fuel-compatible seals and full vapor and static-discharge controls.
Is Polyethylene (HDPE / XLPE) Suitable for Alkylate?
No. Alkylate is an aliphatic-hydrocarbon gasoline blendstock, and polyethylene is not recommended for fuel or hydrocarbon storage. Gasoline-range hydrocarbons permeate the HDPE/XLPE wall, causing swelling, softening, stress, and loss of mechanical integrity over time; HDPE chemical-resistance charts rate gasoline and aliphatic fuels as conditional-to-not-recommended, degrading further with temperature. Equally important, alkylate's extremely low flash point makes it a flammable-liquid hazard that requires grounded, bonded, vapor-controlled metal storage. Specify carbon steel (UL-142 / API), stainless steel, or fuel-rated FRP with FKM (Viton) or PTFE seals. Do not store alkylate in polyethylene tanks.
Material compatibility at a glance
Alkylate is a flammable, aliphatic-hydrocarbon gasoline blendstock. The dominant material-compatibility driver is hydrocarbon permeation plus extreme flammability, so storage belongs in grounded, bonded steel (UL-142 / API) or stainless tanks with fuel-rated seals (FKM/PTFE). Polyethylene is not suitable.
| Material | Rating | Note |
|---|---|---|
| HDPE / XLPE | U | Aliphatic hydrocarbon fuel permeates, swells, and softens polyethylene; not recommended for fuel storage. |
| Carbon steel (UL-142 / API) | S | Industry standard for gasoline and blendstocks; bond and ground; manage static and vapor. |
| Stainless steel (304/316) | S | Excellent for fuel and refinery streams; common in process equipment. |
| FRP (fuel-grade vinyl ester) | C | Use only resins specifically rated for gasoline/fuel service; verify liner. |
| Fluoropolymer (PTFE/PVDF) | S | Excellent for seals, gaskets, and lined components in hydrocarbon service. |
| Viton (FKM) | S | Preferred elastomer for fuel-wetted seals and hoses. |
| Nitrile (NBR) | C | Common low-cost fuel seal; verify grade and monitor for swell over time. |
Ratings: S suitable · C conditional / limited · U unsuitable. Verify against the cited resistance charts and your concentration/temperature before specifying.
The safety that actually matters
- Extremely flammable (H225): Flash point below -40 °F; vapor forms ignitable air mixtures — eliminate all ignition sources, no smoking, no sparks.
- Static and vapor control: Ground and bond all containers and transfer equipment; use explosion-proof, non-sparking equipment; store in a cool, well-ventilated, locked area.
- Aspiration hazard (H304): May be fatal if swallowed and enters airways — do NOT induce vomiting; seek immediate medical care.
- Chronic health hazards (H340 / H350 / H361): Classified as a germ-cell mutagen and carcinogen and suspected reproductive toxicant — minimize exposure; obtain special instructions before use.
- CNS effects and irritation (H336 / H315): Vapors may cause drowsiness or dizziness; liquid causes skin irritation — use ventilation, gloves, and respiratory protection.
- Environmental (H411): Toxic to aquatic life with long-lasting effects — prevent release; collect spillage; provide secondary containment.
Common questions
- Can I store alkylate in a poly (HDPE/XLPE) tank?
- No. Alkylate is an aliphatic-hydrocarbon gasoline blendstock that permeates and swells polyethylene, and its extremely low flash point makes it a flammable-liquid hazard. Use grounded, bonded carbon steel (UL-142/API), stainless steel, or fuel-rated FRP instead.
- What is alkylate made of?
- It is a refinery-produced mixture of branched C5–C12 isoparaffins (predominantly trimethylpentanes such as isooctane) with very low sulfur, aromatics, and olefins, produced by reacting isobutane with light olefins in the alkylation unit.
- Why is alkylate so flammable?
- It is a saturated gasoline-range hydrocarbon with a flash point well below -40 °F and high vapor pressure, so it readily forms ignitable vapor-air mixtures. Handle it like gasoline: control ignition sources, static, and vapors.
- What tank material is best for alkylate?
- Grounded, bonded carbon steel built to UL-142 or API standards is the industry norm; stainless steel and properly fuel-rated FRP are also used. Pair with FKM (Viton) or PTFE seals and full vapor/static controls.
How we build Alkylate (Refinery Gasoline Blendstock) storage
Alkylate (Refinery Gasoline Blendstock) is a flammable solvent that permeates polyethylene. It is built in listed steel or stainless, bonded and grounded.
Sources & References
All compatibility ratings, hazard classifications, and chemical identifiers on this page are sourced from authoritative third-party publications. Verify against the original references before final specification.
- Alkylate Safety Data Sheet (Delek US, Rev. 09/16/2025) — Formulation-specific source: GHS Danger; H225/H304/H315/H336/H340/H350/H361/H411; pictograms GHS02/07/08/09; flash point < -40 °C; boiling 37.8–204.4 °C; specific gravity 0.68–0.69; CAS 64741-64-6. s204.q4cdn.com
- Naphtha (petroleum), full-range alkylate, butane-containing SDS (Mercuria) — Confirms alkylate naphtha hazard profile (extremely flammable, aspiration, mutagen/carcinogen, aquatic toxicity); SDS-dependent ratings. mercuria.com
- Integrated alkylation process to make blended alkylate gasoline (US Patent 8,987,159) — Composition basis: alkylate is predominantly C5–C10 branched isoparaffins (>65% C8 trimethylpentanes), >98% saturated, very low aromatics/olefins, high octane. image-ppubs.uspto.gov
- HDPE Chemical Resistance Chart (King Plastic Corp.) — Polyethylene resistance source: gasoline and aliphatic hydrocarbon fuels rated conditional-to-not-recommended for HDPE, degrading with temperature. www.kingplastic.com
- INEOS HDPE Chemical Resistance Guide — Secondary polyethylene reference: hydrocarbon fuels/naphtha cause swelling and are not recommended for long-term HDPE storage. www.ineos.com
- NFPA 704: Standard System for the Identification of the Hazards of Materials for Emergency Response — NFPA 704 source for the representative Health/Flammability/Reactivity diamond used for gasoline-class hydrocarbons. www.nfpa.org
- UN Globally Harmonized System of Classification and Labelling of Chemicals (GHS), Rev. 10 — Authoritative source for GHS hazard (H) statement codes, signal words, and pictogram definitions cited above. unece.org