What is the ASTM Distillation Test?
We know that gasoline is a mixture of various hydrocarbons. At boiling temperature, the volatility of gasoline starts to fluctuate and it directly affects the performance of your engine. So we should know the volatility of the fuel that we are using. There are two methods for determining the volatility of fuels:
Apparatus for ASTM distillation test:
- 100cc Graduated Cylinder
- 100cc Flask
- A Condenser
- Flask Stand
- Take fuel in the 100cc flask and put it on the flask stand as shown in fig.
- Start the burner and apply proper heat to the fuel in the flask. The vapor will form in the flask and it will get condensed in a condenser.
- Record the temperature of the first drop of condensate in the graduated cylinder and label it as the Initial Boiling Point.
- As we know that the gasoline is a mixture of different hydrocarbons of various boiling temperatures. Due to heating the temperature of fuel continuously rise and evaporation and condensation of the fuel take place.
- Record vapor temperature every time, when there is 10 cc of condensate, adds in the graduated cylinder.
- In the end, when the last drop is condensed of the vapor, record this temperature as the End Point Temperature.
- Also, record the mass of remaining residue in the flask
Now we need to draw the ASTM distillation curve using the above readings.
This curve is plotted between the percentage of the volume of fuel evaporated from the flask and the recorded temperature after every 10cc of condensate is called the ASTM distillation curve.
ASTM Distillation Curve:
|Diagram of ASTM Distillation Curve|
The above graph shows the sample of the ASTM distillation curve. The blue line indicates that oil is heavy whereas the green line indicates that oil is less volatile hence can be used as aviation fuel.
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