The first step to treating and refining crude oil is crude desalting. Inorganic chlorides, suspended solids, and trace metals found in untreated crude must be removed by chemical or electrostatic desalting. This reduces the risk of acid corrosion, plugging, fouling and catalyst poisoning in downstream units. The salts most frequently found in crude oil are calcium, sodium and magnesium chlorides.
Desalting units typically remove unwanted compounds either through a chemical additive that aids in the separation of the compounds from the oil, or through the use of an electrostatic field that creates force to separates the compounds. One-stage units or two-stage units can be utilised for crude desalting.
Magnetrol® has produced an applications brochure for the petroleum refining industry detailing measurement challenges and solutions for each step of the refining process. This blog post is part of an occasional series exploring each application in detail.
Level Measurement Challenges and Considerations
Measurement of the oil/water interface in the desalter is crucial in separating the cleansed crude from contaminants. But coating and build-up on probes may create interface measurement errors. In addition, instruments susceptible to electrostatic grid interference may require special filters in order to render accurate measurements. Interface-dedicated level transmitters fitted with quick-disconnect probes provide optimum performance while reducing cleaning and maintenance time.
Level Measurement Solutions
MAGNETROL has produced level measurement solutions for crude desalting that are equipped to deal with the challenges of interface:
- Model A15 displacer-actuated level switch
- Eclipse® Model 706 guided wave radar transmitter
- E3 Modulevel® displacer-actuated transmitter
For more information on level solutions for crude desalting and other petroleum refining applications, download the petroleum refining brochure. And to learn more about interface level measurement, download the interface brochure.