PTQ Q2 2024 Issue

Eligible feedstocks for SAF production as per jurisdiction

EU-27

USA (RFS)

CORSIA

Feedstocks

RED II Annex IX part B

Vegetable oil (no palm oil), waste oils and fats, some rotational crops, solid waste

Vegetable oils, waste oils and fats, solid waste, rotational crops

(UCO, animal fat); Annex IX part A

(POME, CTO, MSW, etc.);

Other biogenic (not food and feed etc.)

Sustainability

No food and feed crop No high ILUC feedstocks Min. 65% GHG saving

Indirect ILUC criteria via the minimum GHG savings Min. 50% for D4/D5 RIN;

14 sustainability criteria

criteria

(including ILUC)

Minimum GHG savings

Min 10% GHG saving

Min. 60% for D3 RIN

Fossil comparator

94 gCO 2 eq/MJ RED II, Annex V

89 gCO 2 eq/MJ CORSIA model

LCA GHG calculation model

GREET model

Table 1

reduction in GHG emissions by 2026, potentially rising to 10% by 2037, and Singapore announced that it is aiming for a 1% SAF target from 2026 with plans to raise it to 3-5% by 2030. Furthermore, discussions on mandates and incentives are underway in numerous countries, including the United Arab Emirates (UAE), Turkey, New Zealand, South Korea, Australia, China, Chile, Colombia, Thailand, Malaysia, Indonesia, and more. From a fuel compliance perspective, the production of SAF is guided by two key ASTM standards: ASTM D7566, which currently outlines eight SAF pathways for standalone plants, and ASTM D1655, which details the three current co-processing pathways. The co-processing pathway dis- cussed in this article involves the co-processing of mono-, di-, and triglycerides, free fatty acids (FFAs), and fatty acid esters (FAEs), allowing co-processing up to 5 vol% with fossil feedstocks (further details can be found in Annex A1.2.2.1 of ASTM D1655). Regulatory considerations extend beyond fuel compli- ance to also include questions about permissible feedstocks, minimum greenhouse gas (GHG) savings, and GHG calcu- lation methodologies. These complex issues are addressed in various forums, but in this article, we will focus on regula- tions related to co-processing. In the EU-27, the Delegated Act on co-processing, issued on June 5, 2023, clarified the methodologies for calculating the share of renewable fuels via co-processing. 3 This regulation supersedes the methodologies previously established by specific member states like Spain and the Netherlands, which were developed in the absence of a com- mon EU approach. The Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) scheme devel- oped by the International Civil Aviation Organization (ICAO) also covers SAF by co-processing, with the co-processing methodology described in the methodology of a life-cycle assessment (LCA) and default LCA values. 4 What types of feedstocks? The feedstocks eligible for SAF production via co-process- ing vary by jurisdiction. In the EU, three types of biogenic feedstocks are permitted (according to ReFuelEU Aviation): • Waste listed in Annex IX part A

• Waste listed in Annex IX part B • Other biogenic feedstocks not listed in Annex IX, pro- vided they are not food and feed crops, intermediate crops, palm fatty acid distillate, palm and soy-derived materials, or soap stock and its derivatives. To comply, these feedstocks must achieve a minimum of 65% GHG emission savings. In the US, the choice of feedstocks depends on the type of credits sought, such as RIN in the RFS scheme, LCFS in California, or Clean Fuel Production Tax Credit (PTC) cred- its. Each scheme has specific requirements and should be examined individually. Both the RFS and IRA schemes also require GHG savings, albeit with different methodologies. Under the CORSIA, waste feedstocks are listed, and default GHG values are provided for selected feedstocks. The ICAO has also developed guidance to include addi- tional materials in the positive list. Kerosene hydrotreater: Preferred choice for SAF production Co-processing can be carried out in various refinery units, including fluid catalytic cracking (FCC), diesel hydrotreat - ers, hydrocrackers, and kerosene hydrotreaters. However, the optimal choice often hinges on the principle of selectiv- ity and optimal cost of production: Which unit will yield the highest SAF output from the renewable feedstock at the most optimal cost of production? In this context, a kerosene hydrotreater emerges as the most preferred choice. With the right catalysts, this unit can maximise the conversion of biogenic carbon into the jet fuel fraction, thereby optimising SAF production. Low-pressure reactor operation (~25-30 bar g) makes co-processing in the kerosene hydrotreater option unique with respect to the high recovery of biogenic carbon. Co-processing challenges and their solutions While co-processing in general comes up with some challenges, the limited catalyst volume, lower hydrogen partial pressure, and use of relatively simple metallurgy in a kerosene hydrotreater make this challenge even more interesting. If the end product is to obtain SAF certification, there are three main challenges to be aware of when producing SAF by means of co-processing in your kerosene unit. In

PTQ Q2 2024