Hydrocracking Unit schemes

Fina developed the technology which was practiced in their own refineries before they decided to license it in cooperation with Akzo Nobel to other companies. Akzo Nobel has successfully marketed the technology with eleven licenses sold today in Europe, North America and Japan. The process scheme is identical to typical hydrotreating units. Process conditions are similar to what is practiced in LGO or VGO hydrotreating or mild hydrocracking units. Catalysts applied in the process are only available under license. 

The mild hydrocracking process uses operating conditions similar to those of a VGO desulfurizer to convert VGO to yield significant lighter products. Consequently, the flow scheme for a mild hydrocracking unit is virtually identical to that of a VGO desulfurizer. 

ARDS unit works as the springboard in the new scheme of Mina Abdulla Refinery operation Primarily a desulfurization unit, ARDS also reduces the metals, asphaltenes and nitrogen in the products, thereby, ensuring proper quality of feed for downstream conversion units. As an additional benefit, ARDS is also a mild hydrocracking process, partially upgrading high sulfur atmospheric residue to low boiling products like naphtha and distillate. 

A severe hydrotreating plant will have a flow scheme similar to the hydrofinishing unit shown in Fig. 1.11. Hydrocracking is a highly exothermic reaction, so cold hydrogen must be injected at several points in the catalyst bed to moderate the temperature rise. Operating conditions are severe, with pressures of 100-180 bar and reaction temperatures of 350 20°C. 

A modem petroleum refinery may have four or more hydrotreating units. Strictly speaking, hydrotreaters are not conversion imits because the breaking of carbon-to-carbon bonds is minimal. However, it is convenient to discuss hydrotreating together with hydrocracking and mild hydrocracking because they employ similar catalysts and process flow schemes. 

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