Standards of the Biodiesel
The American Society for Testing and Materials (ASTM) has specified to assure the correct functioning of the fuels, different tests as those that are detailed next:
Flash Point
It is important for the legal requirements in what concerns to the security in the handling and storaging of it.
Cloud Point
This way is defiened the behavior of the fuel under low temperature climatic conditions being recognized the grades starting from which begin to get formed inside the fuel, small glasses.
Viscosity
For some motors the specification of a minimum of viscosity that can be generated due to the loss of power on the part of the fuel pump and losses of fuel in the injector, can end up being a great benefit.
For design matters and motor sizes, and the characteristics of the injection system it is necessary an acceptable maximum limit that of the gas oil, for that the mixtures of this last one with Biodiesel, reduce the viscosity of it.
Sulphides
They mainly affect the performance of the emissions control systems. The efects of the sulphides presence can vary in great measure depending considerably of the operating conditions.
Sulphide Ashes
The formation of ashes can be presented in three different types::
» Abrasive solids
» Metallic soluble soaps
» Catalytic surplus
It is important to remind that the abrasive solids and the catalytic surplus can cause a premature waste of the injector, the fuel pump, pistons and hoops and the formation of deposits in the motor.
Corrosion to the Copper
It is important since it indicates the presence of acids or sulphides content that can cause corrosion in the motor.
Carbonaceous Residual
It is an indicator of the tendency of the fuel to form deposits of carbon.
Acid number
It determines the level of free fatty acids that are in the fuel. The deposits and the corrosion are avoidable with the elimination these.
Number of Cetanes
To evaluate the quality of ignition of the fuel and the presence of black smoke and starting rudeness, it is indispensable to observe the cetanes number.
That a bigger or smaller cetanes number is required depends on one hand of the design, size, load variation and speed and on the other hand of the atmospheric conditions..
Free glycerine
A high content of it inside the fuel blocks the injectors and it obstructs the fuel conducts.
Total glycerine
It is a sign of the total of glycerine in the fuel, free or not free.
If its level is low, it assures that there has been a high conversion of oils or fatty in monoalkyl esters.
If their mono level (VWER) -, bi – and triglycerides is high, it can block the injectors and affect the performance in cold climates.
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