Catalysis 2024 Issue

Simulated distillation



PE/PS m ix

WEEE Rubber shred

90 80 100





100 130 tr 0 40 0 190 10 230 0

110 120 70 0 40 0 220 30 680 0


110 140 110 100 20 0 380 0 150 0

120 2 , 640 6 , 870

FeO ppm MgO ppm NiO ppm CaO ppm Cl ppm Br ppm

Methyl-styrene (166˚C)

0 30 20 10 40 50 60 70

Styrene (145˚C)

10 200 10


PP PE/PS blend WEEE Rubber PS

Phenol (181˚C)


ppm ppm ppm ppm

190 240 7 , 320



20 , 660 4 , 086 0.73 21

50 <1 , 500

30 <1 , 500

640 62 , 244

Xylenes (138˚C) Toluene (110.6˚C)

Oxygen ConCarbon, wt% API ppm

1.77 13.7

0.06 49.5

0.02 32.4







Temperature (˚F)

Figure 3 An example of the diversity in the properties and composition of WPOs and their dependency on the source WP

have flame retardant and other atypical metals. Due to these elevated metals (see Figure 3 ), WEEE will need addi - tional processing before sending to refining units like the FCC. There are more than one billion cars on the road glob - ally. These vehicles need to replace tyres regularly. Isolating contaminants (WPO) There is an increasing focus on mechanically and chemically (pyrolysis/liquefaction) recycling these tyres.1 Tyres contain plastics that are high in nitrogen (polyurethane, nylon 6), sulphur (vulcanised rubber), and oxygen (polyurethane, polymethyl methacrylate, nylon 6). The FCC will require hydroprocessing or other types of contaminate removal before co-processing at high levels. Ketjen has received a wide range of WPOs produced from various feedstocks and liquefaction/pyrolysis pro - cesses. In one such collaboration, neat WPOs from vari - ous liquefaction/pyrolysis processes were received from a company producing WPO. By isolating PP, PE, PS, WEEE, and tyres, the hydrocarbon types, metal levels, and other properties can be identified (see Figure 3 ). Assays of the received WPO samples were completed while also suc - cessfully evaluating FCC cracking performance, product yields, and properties to provide FCC unit yield projections and models for refiners. Biogenic feed options Over the last two decades, Ketjen has evaluated various biogenic feed options for both hydroprocessing and FCC The use of crude FOGs that have not undergone pretreatment processes can help reduce feedstock costs to the refiner, but it will create additional FCC operational and catalytic issues

applications. Like WPO, biogenic feed options can be diverse in composition, properties, and challenges for FCC co-processing. The biogenic sourced feedstock options include FOG and bio-oils (Figure 1). FOGs are mainly tri - glycerides from edible and non-edible plant-derived oils (palm oil, soybean oil, rapeseed/canola oil, distillers’ corn oil, jatropha oil, and pongamia oil), tallow, extracted lipids from algae, and UCO. The paraffinic nature of triglycerides in FOG makes the co-feed highly crackable in the FCC unit. FOGs are solu - ble in conventional fossil feeds, do not contain free water, and have relatively low oxygen content (~11 wt%) that can be readily removed through hydroprocessing or catalytic cracking. They are produced at an industrial scale, exceed - ing 1 Mb/d in 2023. Regional availability and direct com - petition for use can lead to high pricing and greater price fluctuation. Competing conversion pathways for this feed - stock include bio-/renewable diesel, SAF-HEFA, and food products.2 In the US, increased biodiesel, renewable diesel pro - duction, and sustainable aviation fuel (SAF) have inflated the price of soybean oil (SBO), as reflected by SBO price increases of more than 100% over the last few years. The use of crude FOGs that have not undergone pretreatment processes can help reduce feedstock costs to the refiner, but it will create additional FCC operational and catalytic issues. While UCO and inedible animal fats/greases do not directly compete for food use and are generally lower cost, they contain higher levels of metal contaminates and free fatty acids. Although there is considerable fluidity in regulatory policies, financial incentives, and economics surrounding UCO and tallow, the increased incentives and mandates for use of waste oils have created strong competition for UCO supply, resulting in spot pricing comparable to virgin SBO. Evolving regulations and incentives, particularly in the EU and US, will place a higher value on renewable die - sel and SAF derived from UCO (as a waste feedstock that does not compete with food or land usage). As a result, it is forecasted that demand for UCO could exceed the supply, further driving pricing for UCO over the price of SBO and canola oil in the next several years.


Catalysis 2024

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