Question

Can you tell me why in some experiments (such as biodiesel production) do we need to test the cloud point and pour point? What is the purpose?

Answer 1

One of the major concerns regarding the use of biodiesel is its unfavorable cold flow properties. In cold climates , it can be a challenge to fuel vehicles with high blends of biodiesel becuase biodiesel tends to gel/ freeze at high temperature than does conventional diesel. A diesel fuels cold weather characteristics are measured by cloud point, pour point, etc.

The cloud point (CP) is the temperature of the fuel at which small, solid crystals ca be observed as the fuel cools.It is the temperature at which the crystals of solid biodiesel first become visible. The pour point (PP) is the lowest temperature at which there is movement of the fuel when the container is tipped. Biodiesel tends to have a much narrower range of temperatures between the cloud point and the pour point.

The tests for cloud point and pour point are relatively quick easy. Cloud point is the temperature at which wax (paraffin) begins to separate when oil chilled to a low temperature, and it serves as an important indicator of practical performance in automotive applications in low temperatures.