60.0
105
60
After Topsoe UCO
100
55
50.0
95 90
50
45
85
40.0
Heavy neutral product VI values Heavy ra nate yield (%)
40
80
30.0
35
75
0
50
100
150
200
250
0
5
10
15
20
25
30
35
40
Light neutral production days of stream
2 hours basis of test run
Furthermore, Figure 7 also demonstrates that the VI results of the heavy neutral base oil product are within the target limits. Potential future improvements The lube base oil could be improved even further if the UCO quantity from the hydrocracker was increased. This would require a higher capacity in the hydrocracker, potentially shortening the hydrocracker cycle length and resulting in other operational constraints. Lowering hydrocracking conversion would also provide a higher UCO yield in the hydrocracker, providing a higher UCO quantity to be used in lube production. Operating the hydrocracker at a lower conversion would, however, result in lower refinery yields of middle distillates and, therefore, potentially have a negative effect on refinery economics. A potential option to further improve the profitability of the lube base oil plant could be to improve the VI of the UCO coming from the hydrocracker at constant conversion. This could be accommodated in future catalyst loadings, such as selecting a catalyst system capable of making even higher VI of the UCO. Having a higher VI would potentially allow the processing of crudes with even lower paraffin content than enabled by the above-described solution. Conclusion Tailoring a catalyst system for the hydrocracker to provide a UCO with a higher VI has proven to have a very positive effect on the refinery production of base oils. The UCO from the hydrocracker has proven to boost the VI of the heavy neutral base oil as well as boost the yields of both heavy and light neutral base oils. Also, the addition of high VI UCO from the hydrocracker reduced the number of off-spec base oil product batches. It allowed the refinery to achieve on-spec base oil from a greater variety of crude oils, including crude oils with significantly lower paraffin content than what has historically been considered the lower threshold for crude quality to make high-quality base oils. Bilge Karahan is a Process Lead Engineer at Tupraş in Izmir with a dec - ade of experience in hydroprocessing. Karahan has been instrumental in overseeing operations and contributing to significant projects for vari - ous hydroprocessing units. She holds a bachelor’s degree in chemical engineering from Middle East Technical University. Figure 6 Light raffinate yield (%) before and after introduc - tion of UCO from hydrocracker loaded with Topsoe catalyst
Figure 7 Heavy neutral VI results and heavy raffinate yield during processing of crude with 7% lower paraffin content
Merve Çinbar is the Lube Oil Production Technical Leader at Tupraş in İzmir. specialising in process optimisation, troubleshooting, and resolv - ing bottlenecks in lube oil production units. She holds a bachelor’s degree in chemical engineering from Middle East Technical University. Nilay Aktaş is Operational Efficiency Head at Tupraş in Izmir, with expe - rience in hydroprocessing units. Aktaş has participated in shutdown, catalyst unloading and loading, start-up activities, and application of process-related projects in hydroprocessing units. She holds a bache - lor’s degree in chemical engineering from Bogaziçi University. Peter A Nymann is Senior Solution Specialist within Clean Fuels Hydrocracking with Topsoe. Nymann graduated as a Chemical Engineer from Technical University of Denmark in 1999 and has been working in Topsoe within hydroprocessing technology since then.
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PTQ Q2 2025
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