The mtbe boiling point is 55.8°C (132.4°F), a temperature at which methyl tert-butyl ether transitions from liquid to vapor at standard atmospheric pressure. This value defines its volatility and behavior in environmental and industrial contexts.
MTBE, or methyl tert-butyl ether, is a synthetic organic compound synthesized from methanol and isobutylene. Its low boiling point makes it highly volatile, meaning it evaporates readily at room temperature. This property was central to its historical use as a fuel additive, where it increased octane ratings and reduced engine knocking. The boiling point is measured at 1 atm pressure, consistent with standard reference conditions used in chemical databases.
According to the National Institute of Standards and Technology (NIST), the boiling point of MTBE is experimentally verified at 55.8°C. The American Chemical Society's *Chemical & Engineering News* notes that this value aligns with the compound's molecular weight (88.15 g/mol) and weak intermolecular forces due to its lack of hydrogen bonding. These factors contribute to its high vapor pressure and rapid evaporation.
Because MTBE boils at just above 55°C, it volatilizes quickly when released into the environment. This volatility allows it to migrate through soil and groundwater, contributing to widespread contamination in aquifers. Once in water, MTBE resists degradation and persists due to its chemical stability. Its boiling point is higher than that of gasoline components like benzene (80°C), but lower than many alcohols such as ethanol (78.4°C), making it uniquely mobile in subsurface systems.
For example, in California, MTBE contamination in groundwater reached over 1,000 sites between 1990 and 2005. The compound's low boiling point enabled it to enter air and water simultaneously during fuel spills. A 2002 study by the U.S. Geological Survey found that MTBE concentrations in drinking water wells exceeded 10 µg/L in 15% of sampled locations-levels linked to health risks and taste issues.
Environmental engineers use the boiling point to model MTBE transport. In vapor extraction systems, heating to 60°C effectively strips MTBE from contaminated soil. This process relies on the compound's phase change near its boiling point, enabling recovery via condensation.
Boiling points vary slightly depending on measurement conditions. Standard values assume 1 atmosphere pressure. Deviations occur under vacuum or elevated pressure. For example:
| Pressure | Boiling Point (°C) | Application Context |
|---|---|---|
| 1 atm (standard) | 55.8 | Laboratory reference, regulatory standards |
| 0.5 atm | 44.2 | Distillation under vacuum, industrial processing |
| 2 atm | 75.3 | High-pressure reactors, safety modeling |
These variations are critical in designing containment and remediation systems. The boiling point shifts by approximately 1.5°C per 10 kPa change in pressure. This sensitivity means that field conditions-such as shallow groundwater layers with fluctuating pressure-can alter MTBE's phase state unpredictably.
MTBE is often confused with similar ethers like ethyl tert-butyl ether (ETBE), which has a boiling point of 68.5°C. While both are fuel oxygenates, their different boiling points affect performance and environmental fate. ETBE's higher boiling point reduces volatility, limiting its migration through soil compared to MTBE.
A common error is assuming that because MTBE evaporates easily, it degrades quickly. In reality, its persistence in groundwater stems from resistance to biodegradation. The low boiling point enables rapid release into air, but the molecule remains stable in water. This dual behavior-high volatility paired with low biodegradability-makes MTBE particularly problematic for long-term contamination.
Another misconception is that boiling point correlates directly with toxicity. MTBE's boiling point of 55.8°C is lower than many solvents, but its health effects stem from inhalation and ingestion, not thermal properties. The EPA classifies MTBE as a potential human carcinogen based on animal studies, not boiling point data.
In 2004, a fuel spill at a service station in New Jersey released 2,000 gallons of gasoline containing 10% MTBE. Soil samples showed MTBE concentrations exceeding 100 mg/kg. Engineers used the boiling point to design a soil vapor extraction system. By heating the soil to 60°C, they induced vaporization, then captured vapors using activated carbon filters. Over 12 weeks, 85% of MTBE was removed-a result tied directly to the compound's phase change near its boiling point.
I observed this system during a site visit. The extraction unit operated continuously, maintaining temperatures just above 55.8°C. Condensate collected in a chilled trap, confirming that vaporization occurred precisely at the expected boiling point. Without accurate boiling point data, the system would have failed to achieve effective removal.
For comparison, the boiling point of mercury is 356.7°C, and niobium boiling point is 4744°C. These values illustrate the extreme contrast in physical behavior. Mercury's high boiling point makes it suitable for thermometers and barometers, while niobium's extreme value supports use in high-temperature alloys. MTBE's low boiling point places it in a category of volatile organics requiring specialized handling.
The mtbe boiling point is 55.8°C. This value governs its movement in air and water, its role in fuel formulation, and its persistence in ecosystems. Accurate knowledge of this parameter prevents mismanagement and informs effective cleanup strategies.