MTBE (Methyl Tertiary Butyl Ether)
Description
Methyl Tertiary Butyl Ether (MTBE) is a colorless liquid with a characteristic mild odor. Its principal characteristics are miscibility with gasoline, low blending vapor pressure and distillation properties. MTBE is slightly soluble in water without phase separation problems. Compared to other oxygenated fuels, it has lower blending density, lower blending vapor pressure and no corrosion problems.
Properties
| Unit | Quantity |
|---|
| Specific gravity at 20°C/20°C | °C | 0.74 |
| IBP at 1.0 atm | °C | 50.5 min |
| FBP at 1.0 atm | °C | 74.5 max |
Specifications
| Unit | Quantity | Test Method ASTM |
|---|
| MTBE | wt % | 98 min | D-5441 |
| C4-hydrocarbons | wt % | 0.5 max | D-5441 |
| C5-hydrocarbons | wt % | 1 max | D-5441 |
| Methanol | wt % | 0.7 max | D-5441 |
| Ter-butyl alcohol | wt % | 0.6 max | D-5441 |
| Di-isobutene | wt % | 0.6 max | D-5441 |
| Water | ppm | 500 max | D-1364 |
Hazards and safety
MTBE’s toxicological effect is largely similar to that of lead-free gasoline. It has no special toxic effects, symptoms or hygienic requirements.
| Unit | Quantity |
|---|
| Flash point | °C | -26 |
| Flammable limits | vol % in air | 1.6-84 |
| Ignition temperature | °C | 430 |
Applications
MTBE is used mainly as a high octane gasoline blending component. It replaces lead compounds and provides good anti-knock characteristics.
Storage and handling
MTBE can be shipped or stored in conventional fuel tanks. Nitrogen purging is strongly recommended in case of loading vessels in hot weather. Acid or iron rust contamination should be avoided. MTBE does not form peroxide compounds on long period storage.
Packaging
MTBE is shipped in fuel tanks (similar to those used for gasoline). Each shipping tank or container must bear the label “Flammable Liquid”. UN or ID No. 2398.
Operating companies
Saudi European Petrochemical Company (IBN ZAHR).
National Methanol Company (IBN SINA).
Saudi Petrochemical Company (SADAF).
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