A refinery has to satisfy product deliveries contracted with its customers over a given time period. Several products such as fuel or diesel can be shipped through various shipment types like trucks or pipelines. As a consequence, a set of operations is planned to meet the product delivery requirements.

The main operation type consists of hydrocarbon blends for which components are blended to generate the final product to be delivered. The calculation engine based on Artelys Knitro optimizes the blend recipes as well as the planning of these mixtures in order to minimize the costs of the operations carried out as well as the delays of the customer deliveries while meeting the product quality requirements.

The model complexity comes from the quality specification constraints of the blends and deliveries which involve complex nonlinear equations. The project leverages the advanced black box capabilities of Artelys Knitro to efficiently tackle instances with dozens of product qualities, specifications and planned operations over several weeks.