Regional political instabilities and global changes in the fuel consumption forced refineries to increase their flexibility for immediately shifting between different crude oils.
The global competition between oil refineries dictates refineries to sell their products with competitive prices, otherwise they will not withstand the challenge of survival. Today, refineries are obliged to feed their crude distillation unit with lowest cost crude oils, while maintaining highest production capacity of high valued refinery products,to increase the refining margin.
It is up to the refinery to compose the efficient crude feed by blending various types of crude oils. To optimize the crude feed price, the blend must contain highest possible quantities of low cost, heavy sour and opportunity crudes, but still bearing those physical and chemical properties, which allow efficient processing and provide maximum guard of the production units against corrosion, and minimum investment in downstream processes, such as desulphurisation processes.
Aside from importance of the crude oil and blend composition from a hydrocarbon point of view, the salt content from a hydrocarbon point of view, the water content, H2S, content, sulphur content and total acidity are critical parameters, which play and important role in the corrosion that is caused by crude oils, including plugging and fouling of pipelines. By taking appropriate preventive actions to reduce the content of corrosives substances in crude prior to feeding it into the CDU, dozens of millions of dollars are annually saved in maintenance corrosion and fouling treatment in CDU, pipelines, heat exchangers etc.
Several solutions can be employed in reducing the corrosive properties of crude oils for being distilled in the CDU:
- Dilution of low cost sour and heavy crudes with more expensive sweet crudes, by blending, chemical treatment desalting etc.
- Use of chemicals to remove acidic materials, such as TAN and H2S
- Desalting of crude oil and by reducing the formation of corrosive HCl.
The success of the above actions in preventing corrosion, can only be effective, by application of on-line process analyzers which indicate the efficiency of the treatment of the crude oil, such as salt in crude oil analyzers, TAN analyzers, H2S analyzers etc. Real time monitoring of critical crude oil parameters by on-line crude analyzers, provides an excellent tool to optimize the crude oil treatment, by changing the process parameters as such, maximum performance is achieved at minimum cost of chemicals and energy.
Without any doubt, the MOD 4100 on-line process crude analyzer plays an important role in the crude oil chain from the oil well through the terminals and blending stations until entering the CDU.