Maximization of the refining margin forms the platform of today’s refinery economics. It dictates refineries to maximize the production capacity of highly demanded refinery products, while reducing the cost of their crude oil feed. Furthermore, refineries must be flexible to cope with unexpected geopolitical changes in oil producing countries, shifting toward an increased demand of middle distillation and extreme fluctuations in crude oil prices force refineries be competitive.
On-line characterization of crude oil qualities provides an effective tool to utilize crude oils to receive the highest refining margin at lowest cost. This obliges refineries and blending stations frequently to change the crude oil quality, according to the refinery equipment and the global market prices of different crude oils.
Aside from distillation of expensive conventional crude oils, the strategy of modern refineries and blending stations is to produce low cost crude blend compositions to which the existing refinery equipment can easily process. Optimized crude oil blends a in general a compromise between the cost of the final blend and its quality, where variety of different quality parameters which have an impact on the crude quality must be taken into consideration, such as:
- API gravity/Density
- Sulphur content
- Tan Content
- Pour point
- Heavy Metal Content
Linear Programming is a common tool that is used by refineries and blenders calculate a blend composition with predicted the physical properties. However, optimized production of such a blend can only be achieved by ongoing fine-tuning of the ratio between the blend components, and required real time analytical data of different components entering the blending head and the final blend alike.
Crude oil blending is not the only process that will have commercial benefits from on-line process analysers. Application of on-line process analysers is not only essential in crude blending but also to guard the Crude Distillation unit from corrosion, and fouling of pipes mi controlling properties like salt content and TAN content of the crude oil entering the CDU, which of course in creases the cost of maintenance.
A variety of different process analytical solutions and process analyzers exist, that form an efficient tools to control critical quality parameters while minimizing the cost of the CDU feed-stock, and by that increasing the refining margin, with a minimum damage to the refinery equipment resulting from corrosion etc.
The utilization of on-line process analyzers from upstream to downstream to improve refinery economics has widely been described in the following article published in Hydrocarbon Engineering 02-17>>