Asphaltenes Help Make Asphalt

Asphalt Chemistry:

Asphalt is a complex mixture of hydrocarbons which can be separated into two major fractions - asphaltenes and maltenes (petrolenes)

Separating of asphaltenes and maltenes fractions is done by diluting asphalt with straight chain, saturated hydrocarbons (n-alkanes) such as: Pentane (C5H12)

Normal Pentane.JPG (13799 bytes)

and Heptane (C7H16) (below)

Heptane.JPG (9764 bytes)

Asphaltenes are the portion of asphalt which precipitates out when treated as above. It is then a dark brown to black solid with a molecular weight of 1800 - 3000.  One attempt to derive its chemical formula (based on Athabasca bitumen) was C200H246N2S7O4.   The maltenes remain in solution in the n-alkane solvent.

Asphalt Products from the Lloydminster Refinery

  •     Paving Asphalts  
     
  •     Road Oils
  •     Polymer Modified Asphalts (PMA)
  •     Roofing Asphalts

Asphalt Specifications

Two principal specifications are available to the paving industry:

  1.     Canadian General Standards Board (CGSB) "Asphalt Cements for Paving   Purposes", CAN/SGSB - 16.3 - M.90
            - Penetration - Viscosity Graded Asphalts
            - Temperature Susceptibility
  2.     Strategic Highway Research Program (SHRP)
            - Performance Graded Asphalt
            - Six newly developed tests to grade asphalt by performance rather than by physical tests.