Federal government releases dilbit study

The federal government recently released a research study on the behaviour of diluted bitumen (dilbit) that demonstrates the product floats in salt water.

The study, commissioned by Environment Canada, Fisheries and Oceans Canada and Natural Resources Canada, examined the environmental risks of a dilbit spill and the clean-up options. It looked at whether dilbit will float on salt water and whether it will continue to float as it is changed by environmental exposure. It also looked at whether chemical dispersants (not permitted for use in Canada at present) are effective for dilbit spill response.

The major results of the studies were:

  • Like conventional crude oil, both diluted bitumen products floated on saltwater (free of sediment), even after evaporation and exposure to light and mixing with water.
  • Under conditions simulating breaking waves, where chemical dispersants have proven effective with conventional crude oils, a commercial chemical dispersant (Corexit 9500) had quite limited effectiveness in dispersing dilbit.
  • Application of fine sediments to floating dilbit was not effective in helping to disperse the products.
  • The two diluted bitumen products display some of the same behaviours as conventional petroleum products (i.e. fuel oils and conventional crude oils), but also significant differences, notably for the rate and extent of evaporation.
  • When fine sediment was suspended in the saltwater, with the addition of high-energy waves, this resulted in some dilbit sinking or being dispersed.

The full study is available here.

Leave a Reply