Pour point

determine the pour point is one of important properties of lube oil properties

1. Duhok Polytechnic University
Zakho Technical Institute
Petroleum Department



Scientific Report


Name: Taha Samir Ali

Stage: 2
nd
Stage

Subject: Petroleum and Gas Technology
2
LAB

Experiment: Standard Test Method for
Pour Point of Petroleum Products D 97 , IP 15

Experiment No. : 4

2. Objective:

Determination of the pour point of a sample of lubricating oil.

Introduction:
The pour point of a petroleum fraction is the lowest temperature at
which the oil will pour or flow when it is cooled without stirring under
standard conditions Pour point represents the lowest temperature at
which oil can be stored and still capable of flowing under gravity. When
temperature is less than pour point of a petroleum product it cannot be
stored or transferred through pipelines. In crude a high pour point is
generally associated with high paraffin content. It is related to the
amount of wax content present indicate preferred, The cloud point is
the lowest temperature at which wax crystals begin to form by a
gradual cooling under standard conditions At this temperature the oil
becomes cloudy and the first particles of wax particles are observed.
Cloud points usually occur at 4- 5 °C above the pour point. It is one of
the important characteristics crude oils under low temperature
conditions, as temperature decreases below the cloud point formation
of wax crystals is accelerated. Wax crystals can plug the filters which
could lead to stalling aircraft and diesel engines fuel system lines and
under cold conditions Freezing point pure there are freezing point of
the heaviest compound in the mixture t is the temperature at which a
liquid solidifies at 1 atm pressure.
Procedure:
1. The specimen is poured to the level mark into a test jar having a cork
2. The specimen is heated without stirring to 98 C above the expected

3. 3. The test jar is transferred to a water bath maintained at a lower
4. Care is taken as not to disturb the specimen as paraffin wax crystals
holding a thermometer pour point in a bath maintained at 12 °C above
the expected pour temperature to cool the sample and is observed for
pour point. are formed after cooling the specimen.
5. The jar is then tilted to check for movement of the specimen.
6. If the specimen still flows the jar is returned to the bath until the
specimen in the test jar does not flow when tilted.
7. The jar is then held in a horizontal position for 5 seconds. If the
specimen shows any movement, the test jar is replaced in the jacket
and the test is repeated for flow at the next temperature-3°C lower.
8. This is continued until the specimen in the jar does not move and
temperature is reported as the pour point.
Results: Report the observed thermometer reading as the pour point of
the lube oil under test.
Discussion:
1. How is pour point related to paraffinicity or aromaticity of the
lube oil?
-The paraffin is rich with wax which is increase pour point and the
aromatic is decrease the pour point which is good, the bottom line is
the lower the pour point, the lower the paraffin content and the
greater the content of aromatics.

2. How can low pour point be achieved for lube oil in industry?
- It can be achieved by removing the wax, although a lowering of the pour
point about (-6.67Cº to -1.1Cº) is more common.

4. 3. What is cloud point? If the pour point of a given product is – 20
°C, what would be its cloud point?
-It’s a lowest temperature at which wax crystals begin to form by
gradual cooling under standard conditions, cloud points usually
occur at 4 – 5 above the pour point so it’s going to 25°C.



4. What would happen if the temperature decreases below the
cloud point of the fuel in a diesel engine?
- Diesel fuel composition plays an extremely important role in low
temperature operability the blending of waxy streams or biodiesel
on their own may result in low temperature issues or may cause
additives not to work as designed.



5. What is the freezing range of petroleum fractions?
- As a petroleum product, all types of non-synthetic motor oil will not
freeze solid, though they will lose their liquid qualities at low
temperatures, this change is the result of the precipitation of
dissolved waxes contained in the oil. Gasoline does not contain these
waxes, which is why it is not as sensitive to cool temperatures as
petroleum-based motor oils.