There are two grades of diesel fuel in Chile:
- Grade A1—the only on-road diesel fuel legally available to the public in the Santiago Metropolitan Region.
- Grade B—the diesel fuel intended for the rest of the country.
Initially, Grade A1 diesel had more stringent specifications and higher quality than Grade B diesel. Over time, the two diesel grades have become similar. The following list summarizes the steps in the evolution of the A1 and B specifications:
- Starting July 2004, grade A1 diesel [D.S. No. 58/04] had a maximum sulfur limit of 50 ppm and a lubricity requirement [D.S. No. 222/04].
- Starting in 2007, Grade B diesel fuel [D.S. No. 133/04] sulfur was limited to 350 ppm. In 2008, the cetane number of Grade B increased to 50 to match Grade A1 and in 2010, a sulfur limit of 50 ppm and an HFRR lubricity requirement for Grade B took effect [D.S. No. 319/06].
- In April 2010, new fuel requirements for Grade A1 diesel were introduced to limit sulfur to 15 ppm mass by September 2011. The new requirements also lowered the polyaromatic limit and increased the density and distillation ranges .
- From March 2012, the properties of Grade B diesel became more closely aligned with those of Grade A1 . The changes included an expansion of distillation and density ranges and a narrowing of viscosity limits. The need to report nitrogen was also eliminated from Grade B diesel.
- From September 2013, Grade B essentially aligned with Grade A1 . Only minor differences remained due to procedural reasons; namely Grade A1 still required the nitrogen content to be reported while Grade B required the biodiesel content to be reported.
In 2013, a proposal was put forward to establish a Grade B2 diesel fuel with 50 ppm sulfur and a minimum 40 cetane number for stationary engines, boilers, agricultural and mining machinery and other equipment for domestic and industrial use.
Blending of biofuels with gasoline or diesel fuel is voluntary in Chile . Only 2% or 5% blends of ethanol in gasoline or biodiesel in diesel fuel are allowed. Effective March 2013, the biodiesel content of Grade B diesel fuel must be reported.
Acknowledgement: This article based in part on information submitted by Marcelo M. Guerrero of ENAP.