Rudolf Diesel developed the idea for the diesel engine and obtained the German patent for it in 1892. His goal was to create an engine with high efficiency. Gasoline engines had been invented in 1876 and, at that time, not very efficient.
Diesel hoped that his engine would provide a way for the smaller industries, farmers, and "commonfolk" a means of competing with the monopolizing industries, which controlled all energy production at that time, as well as serve as an alternative for the inefficient fuel consumption of the steam engine.
Rudolf Diesel demonstrated it in the 1900 Exposition Universelle (World's Fair) using peanut oil (see biodiesel).As a result of Diesel's vision, compression ignited engines were powered by a biomass fuel, vegetable oil, until the 1920's and are being powered again, today, by biodiesel.
The main differences between the gasoline engine and the diesel engine are:
+ A gasoline engine intakes a mixture of gas and air, compresses it and ignites the mixture with a spark.
+ A diesel engine takes in just air, compresses it and then injects fuel into the compressed air. The heat of the compressed air (at a substantially higher compression ratio than a gasoline engine) lights the fuel spontaneously once it is injected into the super-heated compressed air.
+ A gasoline engine compresses at a ratio of 8:1 to 12:1, while a diesel engine compresses at a ratio of 14:1 to as high as 25:1. The higher compression ratio of the diesel engine leads to better efficiency.
+ Gasoline engines generally use either carburetion, in which the air and fuel is mixed long before the air enters the cylinder, or port fuel injection, in which the fuel is injected just prior to the intake stroke (outside the cylinder). Diesel engines use direct fuel injection -- the diesel fuel is injected directly into the cylinder.
Today there are even companies that will convert your diesel powered vehicle to run on 100% vegetable oil (new or waste), Biodiesel, and/or regular diesel, in any combination....see Lovecraft Biofuels
See also DHlovelife's biodiesel Vlog.