PERC / Battelle — Recommended Proper Use of Methanol in Controlling Water Freezing in LP Gas
Using Methanol in Propane: Choosing the right amount under the right conditions maximizes antifreeze benefits
Background
The presence of water in propane can interfere with usage, particularly when ambient temperatures fall below 40 degrees. As the temperature of the fuel approached freezing temperatures, water can come out of the solution, forming a separate layer in the tank that can freeze. This can also lead to potential ice formation in valves and regulators.
The addition of methanol to propane can reduce and even eliminate freezing problems. Methanol, a simple alcohol, prevents whatever water may be present from freezing. While the use of methanol may not affect the burners used by most residential, commercial, industrial, or agricultural customers, excessive amounts have the potential to cause operational problems with some newer applications that are more sensitive to fuel composition.
Excessive methanol use has the potential to cause problems with engine collaboration when propane is used as a fuel for internal combustion engines, resulting in increased emissions. Moreover, if there is enough water and methanol in the propane, a separate and often corrosive water-methanol layer may form at the bottom of fuel storage tanks.
Although the practice of adding methanol as an antifreeze has been in place for a long time, there is no guidance on exactly how much to add, largely because no reliable methods currently exist for measuring how much water or methanol is present in propane. Guidelines are needed to allow propane producers, distributors, and users to ascertain the amount of methanol that is actually needed. Attention to this issue can prevent operational problems and improve customer satisfaction.
For a condensed look at the report’s findings, simply download the fact sheet here.
You can also download the guide for treating propane with methanol to prevent freezing of valves and regulators.
