The invention of Diesel was financed by M. A. N. of Augsburg (Mathur and Sharma 2000).
Diesel has a boiling range of about 180°C to 300°C. It is widely used because it is cheap and has better thermal efficiency. Today Diesel is produced in three ways: Petroleum Diesel, Synthetic Diesel and BioDiesel.
1. Petroleum Diesel: Petroleum diesel is also called as Fossil Diesel. This diesel is produced from fractional distillation of crude oil. The supply of petroleum diesel is fast depleting and hence the search for other types is becoming all the more important.
2. Synthetic Diesel: Synthetic diesel is made by processing natural gas through a technology which converts the natural gas into Synthetic Diesel. Synthetic diesel is free from sulphur and provides numerous other environmental benefits over petroleum diesel. Synthetic diesel is cleaner, cleaner-burning and can be formulated for superior cold weather performance. The following diagram shows the emission reductions compared to typical California diesel:
3. Biodiesel: Biodiesel is a renewable diesel fuel substitute. It can be made from a variety of natural oils and fats. Biodiesel is made by chemically combining any natural oil or fat with an alcohol such as methanol or ethanol. Methanol has been the most commonly used alcohol in the commercial production of biodiesel (National Renewable Energy Laboratory, May 1998).
The diesel cycle is the theoretical cycle for slow speed compression-ignition or diesel engines. In a diesel cycle the heat is added at constant pressure. The pressure drop at the end of expansion is still at constant volume. This cycle is shown in the following T-s diagram.
The process 1-2 is reversible adiabatic (isentropic) compression of air. Heat is then added at constant pressure, represented by 2-3. In actual engine heat addition takes place in the form of injection of fuel which self-ignites due to high temperature caused by high compression