PTQ Q2 2024 Issue

ketones, and acrylates. These light oxygenates can undergo oligomerisation reactions, leading to gum and coke. In addi - tion, these compounds will concentrate in the WGC section of the unit if not converted in the riser. Decarbonylation rejects biogenic carbon as CO and can increase bottoms or coke yields from both biogenic and conventional oil. While hydrodeoxygenation is dominant in hydroprocess - ing units, it also occurs in FCC operations due to hydro - gen donation from the conventional feed to the biogenic oil. Removal of oxygen as water from the system results in a net decrease in the hydrogen-to-carbon (H/C) ratio of the final hydrocarbon products. Not removing the oxygen as CO or CO₂ provides the advantage of higher biogenic carbon retention in the final products (though CO and CO₂ are preferable to oxygen in the products). In terms of FCC product slate, the net result from hydro - deoxygenation can be a reduction in overall product value as the reduction in the H/C ratio leads to an increase in slurry and coke make from both biogenic and mineral feed - stocks. From the perspective of FCC unit operations, deox - ygenation of the biogenic oils through decarboxylation will maximise the H/C ratio of the final products for an improved FCC unit product slate with some loss of biogenic carbon as CO₂. Modification of deoxygenation pathways Catalytically influencing the various deoxygenation path - ways can have a significant impact on FCC product valori - sation when processing unconventional FCC feedstocks by optimising catalytic properties. Throughout the open literature, there have been mixed reports regarding the net impact of adding FOG to VGO feed under cracking test conditions. Mixed results ranging from increased coke and light cycle oil (LCO) make to reduced coke make during testing are largely due to differences in catalyst technology and balancing the catalytically active sites. Baseline performance evaluation of Ketjen’s standard FCC catalyst technology for maximising gasoline demonstrates that when 20 wt% soybean oil is added to VGO, there is a net positive feed impact of the soybean oil (see Figure 1 ). The main feed effect is an increase in gasoline yields with a reduction in coke, liquefied petroleum gas (LPG), and dry

& !"#$%#&%'()*+$,-,./'012'!34'56'!"#$%#&%'()*+$,-,./'784 9):);<=='012'!34'56'!"#$%#&%'()*+$,-,./'784

ReNewFCC - 20% SBO vs Standard Technology-VGO Standard Technology 20% SBO vs Standard Technology-VGO

% 3

" 2

# 1

-./$ 01234 Coke 650F+

5;7 <=>'789 LPG Dry gas

$ 0

5-6 789.%#:$ LCO Gasoline

!# -1

!" -1.5

and the product slate. Successfully processing higher con- centrations of FOGs requires maximising oxygen removal. The deoxygenation efficiency of oxygenated molecules in FOG is influenced by the surface chemistry of the catalyst components, porosity, fatty acid composition, and synergy between vacuum gas oil (VGO) and FOG. The ReNewFCC technologies for FOG co-processing in FCC are designed to maximise deoxygenation and drive it to increase the quality of the hydrocarbon product slate. To understand this, one must first consider the reaction pathways for deoxygenation. The four main deoxygenation pathways are dehydration, decarbonylation, hydrodeoxy - genation, and decarboxylation. The net effect of dehydra - tion results in the formation of biogenic coke, resulting in higher losses of bio-carbon from useful products. In the case of FOGs, the thermal decomposition of the triglyceride followed by dehydration can result in the for - mation of light unsaturated oxygenates such as aldehydes, Figure 1 Delta yields during co-processing of 20 wt% soybean oil in VGO over Ketjen’s standard catalyst technology and ReNewFCC formulated for maximum gasoline at an iso-conversion of 72 wt%

70%

Dehydration Water + coke (biogenic)

Inuencing deoxygenation during co-processing 20% canola oil over various grades of ReNewFCC

Biogenic coke and gum formation

60%

50%

Rejects biogenic carbon Higher slurry and coke make

Decarbonylation Water + CO (biogenic)

40%

30%

Highest biogenic-carbon retention Higher coke and reduced product H/C

Hydrodeoxygenation Water + coke (oil)

20%

Decarbonylation

10%

Maximisation of product value Biogenic carbon rejection as CO

Decarboxylation CO (biogenic)

Figure 2 Oxygen balances during co-processing 20 wt% canola oil over various grades of ReNewFCC formulated for maximum gasoline, illustrating the role of altering the catalytically active sites to influence deoxygenation pathways and the generalised impact on the FCC

PTQ Q2 2024