Predicting the spill behavior of orimulsion using design of experiment principles

Orimulsion is a Group Five fuel consisting of an emulsion of bitumen. Predicting its behaviour under spill conditions is essential to contingency planning, response and recovery, as well as spill modelling. Design of experiment (DOE), a method that incorporates statistics into the process of experimentation has been found to be useful in minimizing the number of experiments necessary to statistically evaluate and predict the effects that multiple independent variables (in this case water temperature, spill volume, spill concentration, receiving water energy, suspended mineral load and type, etc) have on a dependent variable. In the case of Orimulsion behaviour in water, design of experiment method was successfully used to design and evaluate the results of 43 controlled bench-scale spill experiments to determine the direct and interactive effects of the receiving water's salinity, temperature, energy, bitumen concentration, suspended mineral load and type on the fate of spilled Orimulsion. The design of experiment results provided valuable insights into the fundamental processes at work and the relative importance of the independent variables in predicting the conditions under which an emulsion of bitumen will be most likely to float, settle or remain suspended. Despite the evident usefulness of the method, caution was advised projecting the results of confined bench top experiments to the 'real world' in a quantitative fashion. 10 refs., 7 tabs., 6 figs