Precautions for processing/blending high-sulfur, high-acid, high-chlorine crude oils, blending plans
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This post was last edited by 328104062 on 2017-1-18 at 20:44. As the title suggests, we have always processed low-sulfur paraffinic (intermediate base) crude oil, with very low values for acid number, chloride ions, metal content, and NaCl content. The materials and design of our processing facilities were chosen based on these characteristics of the crude oil. In reality, the properties of the actual crude oil are better than those assumed in the design, meaning there is a certain degree of redundancy in the design. However, this high-quality crude oil comes at a higher cost. Now, there is a type of crude oil that is high in sulfur, acid (naphthenic acid), and chloride content; it is still paraffinic in nature but costs less, around 60% of the original cost. Preliminary estimates suggest that processing one ton of this oil can save 1,000 yuan in costs, resulting in higher profits. Yet, the evaluation data for this crude oil is not satisfactory: 1. The acid number and total sulfur content of various straight-run fractions are very high, with corrosion levels reaching grade 3 for all such fractions. 2. The aromatic content in straight-run gasoline is low, less than 20%, while the arsenic content is around 150 ppm. 3. The freezing point of straight-run kerosene (jet fuel) is below -60°C, which does not meet the requirements for kerosene. 4. The naphthenic acid content (acid number) in the second and third fractions of crude oil is very high. ... I would like to ask everyone: 1. What criteria should be used to determine the plan for blending in this lower-quality oil? (It is said that some plants experience almost no corrosion in their distillation columns when processing 100% of this oil.) How should the blending ratio be determined? Do anyone have any suggestions? 2. What aspects need attention when mixing in small amounts? Let’s talk about units such as those for normal pressure operation, hydroprocessing of coal diesel, reforming, and FCC
Metals are a bit easier to work with. A high sulfur content is really a problem; it has a significant impact on the atmospheric and vacuum distillation steps in the initial processing, as well as on subsequent catalytic, hydrogenation, and reforming processes. It causes equipment corrosion and makes it difficult to control product quality. . .
It sounds like it’s the oil from Sudan’s Zone 37; the route had to be changed several times before success was achieved. With this oil, in addition to severe corrosion, another major problem is the high consumption of FCC catalysts; therefore, the blending ratio cannot be high from the start, and it must be increased gradually.
I’m in charge of catalysis. Do you have a vacuum distillation tower? Is there any residue hydrogenation? Is it such that after atmospheric pressure separation, the heavy fractions go straight into the catalytic process?