Natural gasoline is a form of natural gas that becomes a liquid under regular atmospheric pressure and moderate temperatures. It can form naturally from condensates or may be obtained by the fractional distillation of wet natural gas. When natural gasoline forms from condensates, it is often referred to as drip gas. Unlike the gasoline, or petrol, that is used to power modern automobiles, natural gas has a relatively low octane rating and can be substantially more volatile. It can be combined with other substances to create gasoline, though it was also used by itself in the early days of automobiles.
The chemical composition of natural gasoline is typically hydrocarbons, such as butane, pentane, and hexane. This range of hydrocarbons can be obtained via fractional distillation or can form naturally from condensates. When this particular hydrocarbon range is distilled, it is sometimes used in the denaturing of alcohol that is meant to be used as a fuel source. This is typically intended to keep people from ingesting the fuel alcohol, as the addition of certain compounds can render it unpalatable.
In the early days of internal combustion engines, natural gasoline was a commonly used fuel source. Both early automobiles and airplanes used engines that had relatively low compression ratios, which worked well with naturally occurring drip gas as well as the commercially distilled version. Drip gas was often used to power personal vehicles in the early part of the 20th century by people that had easy access to wells. Later advancements in automobile engines resulted in higher octane requirements, so drip gas was no longer suitable.
Commercially available gasoline typically has various additives included to raise its octane rating into the 80s or 90s. This is substantially higher than the 30 to 50 that can be expected of natural gas. Despite this fact, there have been problems with people stealing drip gas from refineries and natural gas pipes. The low octane rating of natural gas typically results in engine knocking. Incomplete ignition can also result in noxious tailpipe emissions, which have been used to identify vehicles powered by stolen natural gas.
In addition to uses such as denaturing alcohol and a being burned as a fuel, drip gas can also be useful as a solvent and thinner. Since it is a very volatile substance, any use as a cleaner or solvent has to be carefully kept away from ignition sources. It can also be used as a thinner, particularly for paint. Many of the hydrocarbons present in natural gasoline can also be found in commercially available solvents, cleaners, and thinners. These products are often specifically engineered to be less volatile.
