The question of how to establish an effective ethanol uplift model has become common in the context of gasoline blending. With a majority of gasoline products containing 10% ethanol, accurately predicting the final fuel properties is essential to mitigate margin erosion. Drawing on years of experience in blending optimisation projects, Trindent has developed specific expertise in this area. Here are our expert insights. 

Each refinery has its unique configuration, influenced by the specific molecules it produces. Therefore, selecting the right independent variables is critical at the outset of model development. Understanding the principle behind the Octane Number (ON) and its relation to the chemical composition of gasoline is fundamental. Typically, a refinery may utilise seven to eight independent variables and go through approximately 10 to 15 iterations to identify an accurate and intuitive model. The model’s complexity must strike a balance; it should be sophisticated enough to provide the desired accuracy while remaining straightforward enough for easy integration into existing systems.

Once a model is developed, the next step is optimising it. In addition to adjusting the ON of the neat blend stock – often the primary focus for most refineries – facilities can also optimise other properties and compositional requirements to maximise the overall benefit of ON uplift.

Although much emphasis is placed on the ethanol model’s ON, it is vital to consider other properties affected by ethanol.

A robust ethanol model system should also account for key properties such as Reid Vapor Pressure (RVP), distillation, and vapor-liquid (V/L) ratio. An effective ethanol model will enable a refinery to achieve a high level of repeatability for all constrained parameters, ultimately maximising benefits related to production cost management.