PTQ Q4 2022 Issue

The catalyst testing database gives refiners access to many more catalysts than they would consider on their own. Combined with a dual-sourcing strategy, it yields benefits in:  Margin improvement  Fast replication of success  Catalyst cost savings  Supply flexibility. These four factors should be compared to a passive, stick-with-the incumbent strategy or a strategy that relies on internal knowledge and paper studies based on vendor estimates, which are generally unreliable.5 Catalyst suppliers offer over 200 options for hydropro- cessing catalysts involving many different ‘flavours’ of prod- ucts, including, for example, nickel-molybdenum (NiMo), cobalt molybdenum (CoMo), tri-metallics, high density, low density, trilobe, quadrilobed, base metal, regenerated, reju- venated, and stacked beds in various configurations. For each flavour, there are special catalysts for diesel, FCC pretreat, and hydrocracking pretreat applications. With such a wide range of offerings and conflicting claims, refinery engineers must simplify catalyst selection and need a way to verify and calibrate suppliers’ performance claims against each other. We use a standardised 15-day pilot plant test to rank diesel hydrotreating catalysts on desulphurisation activity. The ‘scoreboard chart’ in Figure 1 allows refiners to directly compare raw pilot plant data for any catalyst combination among 44 samples tested in a five-year period. Each column in the table at the top of Figure 1 is for one pilot plant run. For example, the highlighted second column labelled 2010-2 is for the second pilot plant run of the year

2010. The spreadsheet user has checked the four check- boxes in that column to display the product sulphur results for each of the catalysts tested in that pilot plant run. Referring to the gold data points for the gold catalyst, there are five gold line segments with three data points, each showing the daily product sulphur results for the gold catalyst during the 15-day test. Within each three-day segment, the reactor conditions are fixed, and we are see- ing the transient line-out of product sulphur during that three-day test period. The test begins on straight-run light diesel, an easy feed, at the ‘cold’ test temperature. On day 4, the more difficult 20% light cycle oil (LCO) feed is introduced for days 4-6 and the product sulphur increases in response to the harder feed. Then, the temperature is raised to ‘warm’ for days 7-9, and ‘hot’ for days 10-12, and returned to warm for days 13-15. To expect a real impact on commercial margin improve- ment, the pilot plant test must show a clear, strong separa- tion from the previous tier. Figure 1 shows the grey catalyst gives high product sulphur and is unstable. It was rejected from consideration. Any of the other three competitive cata- lysts would be an excellent choice for a ULSD hydrotreater. With this spreadsheet, a user can easily compare the raw data for any catalyst we have tested with others and make their own informed judgements, incorporating their knowl- edge from experience with different catalysts. This standard pilot plant test also gives an industry-best measurement of denitrogenation, hydrogen consumption, and the reaction of individual sulphur species for every test condition on every catalyst. FCC pretreat catalyst testing has not yet been carried

2010-1 red 1 green 1 EOC 1 orange 1

2010-2

2011-1

2011-2

2012-1

2012-2

2013-1

2013-2

2014-1

2014-2

red 3 gold 3 black 3 gray 3

red 4 purple 4 tan 4 blue 4

red 5LP pink 5LP tan 5LP purple 5LP

purple 6LP drk blu 6LP maroon 6LP gold 6LP

purple 8 drk blu 8 carribean 8 mango 8

maroon 9LP brown 9LP scarlet 9LP goldrod 9LP

Axens scrt Albem scrt red 7LP bluviolet 7LP

purple 10 KSU prp 10 olive 10 burgundy 10

red 11 gold 11 black 11 gray 11

Increase temperature

Decrease temperature

Add 20% LCO

Straight run feed

Increase temperature

50

0

0

3

6

9

12

15

18

Days

Figure 1 The catalyst test ‘scoreboard’ chart has checkboxes facilitating comparison of raw pilot plant test data for any combination of catalysts among 44 samples tested in the standardised ‘Hoekstra 10-20 catalyst test’

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PTQ Q4 2022

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