Dr. Rudolf Diesel is well-known as the inventor of the diesel engine in the late 1800s. Diesel's idea was revolutionary because his engine design didn't require a spark for combustion. Instead, it relied on frictional heat generated by high pressure in the cylinder to ignite the fuel-air mix for power.
While the basic architecture of the diesel engine hasn't changed in more than 100 years, today, another Rudolf is pushing the boundaries of diesel fuel.
Dr. Rudolf Gunnerman has created GDiesel, a new fuel for diesel engines that combines conventional ultralow sulfur diesel with natural gas, which is mostly methane. The result is a fuel blend that has cleaner emissions but costs less to produce than today's No. 2 diesel that's sold for use in cars and trucks. That's because natural gas helps GDiesel burn more completely than standard diesel during combustion, and it currently costs less than the equivalent amount of diesel fuel.
Gunnerman's company, Advanced Refining Concepts, blends ultralow sulfur diesel and natural gas at a 2-1 ratio — a gallon of diesel and a half-gallon of natural gas — using a proprietary set of four metallic catalysts that facilitate process. The methane and diesel fuel react chemically, with the diesel absorbing methane's component atoms, hydrogen and carbon.
In some cases, GDiesel is also said to yield up to a 30 percent improvement in fuel economy. It's also compatible with existing fuel storage and dispensing equipment and requires no modifications to vehicles or power-generating equipment.
ARC is in the final stages building a refining facility in Nevada that will be able to produce up to 100,000 gallons of GDiesel a day. In the future, smaller GDiesel refineries may be built near ready supplies of natural gas and methane, such as by a garbage dump or large farm, where methane can be harvested as a waste product.
Rudolf Diesel originally envisioned his engines would run on vegetable oil, but modern feedstock fuels have been unpopular because they use valuable cropland or aren't available in large enough quantities to drive down fuel prices. Rudolf Gunnerman's solution doesn't impact food supplies, and the U.S. has abundant supplies of natural gas. Perhaps the two Rudolfs a century apart point the way to diesel's future.