Decarbonisation Technology May 2025 Issue

resulting in a lower degree of isomerisation and minimal yield loss due to cracking. Conversely, for the production of high-quality arctic diesel or SAF, deep isomerisation is required, and the operating temperature will be increased. Figure 5 presents the observed production of naphtha as a function of cloudpoint reduction for various commercial HI cycles where ReNewFine 5005 was applied. It can be observed that the amount of naphtha produced remains remarkably low, even when the unit is operated in arctic diesel or SAF production mode. achieved remarkable results using ReNewFine catalyst solutions in its NEXBTL units. This journey has provided invaluable experience that is now available to the industry. The results of a dedicated campaign to produce SAF, where the HI reactor loaded with ReNewFine 5005 was run under high-severity conditions, are presented in Figure 6 . A liquid product with an average cloud point of -46°C was achieved over a one-year period, demonstrating highly effective isomerisation. Throughout this year, no significant deactivation of the catalyst system Commercial SAF production Neste, a pioneer in SAF production, has was observed, as evidenced by the stable weighted average bed temperature (WABT), highlighting the remarkable stability of the ReNewFine 5005 catalyst. Typical cycle lengths

n-C BP: 317˚C ρ : 780 kg/m

i-C single-branched BP: 311˚C ρ : 775 kg/m

∆H -10 kJ/mole

isomerisation ≈

i-C double branched BP: 306˚C ρ : 770 kg/m

i-C trip l e branched BP: 298˚C

∆H -40 kJ/mole cracking ≈

When operating an HI unit, the degree of isomerisation is tuned depending on the target product. For renewable diesel production, the operating temperature (T) will be relatively low, Figure 4b A simplified reaction scheme for isomerisation of n-C 18 , illustrating the decrease in boiling point and density that can be obtained via isomerisation

10.0%

9.0%

Renewable diesel

Arctic diesel

SAF

8.0%

7.0%

6.0%

5.0%

4.0%

3.0%

Limited cracking

Degree of isomerisation

2.0%

1.0%

0.0%

Cloud point reduction (˚C)

Figure 5 Naphtha make as a function of cloud point reduction for a number of commercial HI cycles using ReNewFine 5005