Due to the impending landfall of Hurricane Humberto in the United States, oil refineries in the affected region went off-line, sending oil prices over $80 per barrel for the first time in history. Although the price has since fallen, this and related incidents will no doubt continue to generate interest in both traditional and alternative fuels. One common laboratory method for the analysis of fuels is flash point analysis.

The flash point for a liquid substance is the minimum temperature at which vapors can be ignited near the surface of the liquid. Liquids with low flash points are consequently easier to ignite. This phenomenon has implications for the use of fuels in engines. For instance, the flash point of automotive gasoline is approximately -40°C; this is low enough that automobile engines can operate under most conditions. In contrast, mainly for reasons of safety in transporting and using it, jet fuel is required to have a much higher flash point. Jet-A, a commercial jet fuel in the United States, has a flash point of 38°C.

To determine the flash point, a sample of the liquid is heated until a nearby ignition source is able to ignite the vapors. There are two main methods of flash point analysis: open cup and closed cup. As their names indicate, the difference between the methods is whether the sample cup is open or closed. One advantage of the closed cup test is that no fumes are released into the laboratory. However, confining the vapors in the closed cup has the effect of lowering the measured flash point with respect to open cup measurements. In most circumstances, flash point testing falls under the purview of certain regulations that require a particular test method, such as Pensky Martens Closed Cup or Cleveland Open Cup tests.

Since the methods are prescribed, flash point instruments are designed expressly with a particular test in mind. In some cases, multiple test types can be performed on the same instrument. The level of automation is the feature that most distinguishes different instruments.

Applications of flash point testing understandably center on crude and refined fuels and lubrication oils. One particular application is the analysis of used lubricant; as engine oils change chemically through use, the flashpoint changes, signaling degradation. Flash point testing is also used with a variety of other flammable liquids, generally for the purposes of labeling and safety. There are also interesting applications involving fragrance oils used in commercial products such as scented candles. In addition to standard laboratory units, online flash point analyzers exist for fuel processing operations.

There are relatively few vendors of flash point instruments, with the largest being PAC (a Roper Industries company) and Koehler Instrument. Other significant participants in the market include Petrotest, Stanhope-Seta, Tanaka, and Grabner Instruments (part of AMETEK). The total laboratory market for flash point analysis was about $22 million in 2006.

Flash Point Analyzers at a glance:

Leading Flash Point Analyzer suppliers: PAC (Roper), Koehler Instrument

Largest markets: energy, petrochemicals

Flash Point Analyzer cost: $1K to $30K