PTQ Q3 2025 Issue

in an FCCU, especially nickel reactivation, cannot be evalu- ated from this study because no metals (nickel) deactivation was applied, and lab testing does not leave enough time for chlorides to reactivate nickel even if it were present. Refining applications Two catalyst designs were tested for upgrading two differ- ent feeds: (1) 100% VGO and (2) 10% pyoil blended with 90% VGO: • FCC(a) catalyst was oriented towards transportation fuels maximisation. • FCC(b) catalyst was oriented towards LPG olefins maximisation. FCC(a) catalyst was designed with high rare earth con- tent on zeolite for maximising conversion and naphtha yield. FCC(b) catalyst was designed with low rare earth on zeolite to minimise hydrogen transfer reactions for maximising olefins and additional functionality to convert naphtha-range olefins to LPG olefins. FCC(a) and FCC(b) catalysts were steam-deactivated at 788°C for 24 hours before being tested: • Steam-deactivated FCC(a) catalyst: TSA = 224 m²/g and rare earth oxide (REO) = 5.5 wt%. • Steam-deactivated FCC(b) catalyst: TSA = 173 m²/g and REO = 0.7 wt%. To examine the impact of the feed, the cracking evalua- tions were examined at iso-conversion (72 wt% chosen to eliminate the need for extrapolation), obtained by regres- sion of raw data for both catalysts. In the refinery industry, the conversion to naphtha and lighter products is typically expressed as 100 – LCO – bottoms. Unsurprisingly, FCC(a) with higher rare earth on zeolite induced higher activity compared to FCC(b) for both feeds tested. Co-processing 10% of this pyoil helps to further increase valuable products due to already converted material (for example, naphtha range molecules) and better K-factor entering as co-feed. As a reminder, K-factor is a correlation using density and distillation to determine the paraffinicity or aromaticity character of a feed and thus, the overall crackability in the FCC. It is often stated that a feed with a K-factor of 13.0 is purely paraffinic, while a feed with a K-factor of 10.0 is purely aromatic. This pyoil, with a K-factor of 12.7, suggests paraffinic behaviour and higher crackability compared to the VGO used in this study. Hence, this pyoil can also con- tribute as a hydrogen donor to the VGO to further increase its crackability and produce more valuable products, such as naphtha and LPG. FCC(a), promoting hydrogen transfer reactions (hydrogen consuming reactions), leads to lower hydrogen selectivity compared to FCC(b). Referring to Table 2 , blending 10% pyoil helps produce lower coke selectivity for both catalysts due to a higher H/C ratio and, hence, lower coke precursors present in the blend. Unsurprisingly, FCC(b) based on low REO on zeolite with an additional olefins-generating functionality is more selective to light olefins (such as C₂=, C₃=, and C₄=) and LPG compared to FCC(a), which is more oriented towards naph- tha selectivity. Furthermore, blending 10% pyoil further improves the propylene, C₄ olefins, and LPG selectivities for both catalysts compared to 100% VGO. At iso-conversion,

Physical and chemical properties of plastic pyoil and VGO feedstocks

Plastic pyoil

VGO

Physical properties API (S.G.)

42.7 (0.812)

24.5 (0.907)

K factor

12.7

11.8

Refractive index Pour point, °C Flash point, °C

1.4527

1.5048

46 38

149 0.26 998 0.76

Conradson carbon, wt% Total nitrogen, ppmw

0.32 447

Total sulphur, wt% Elemental analyses Al, ppmw

<0.01

0.5

n.a. n.a. n.a. n.a. 0.1 4.5 n.a. n.a. 2.8 0.1 n.a. n.a. n.a. 0.3

Br, ppmw Cl, ppmw Ca, ppmw Cu, ppmw Fe, ppmw K, ppmw Mg, ppmw Na, ppmw Ni, ppmw P, ppmw Si, ppmw Ti, ppmw V, ppmw

4.79 45.2 <0.1

0.1

0.29 <0.1 <0.1 <0.1 <0.1

<0.1 <0.1

Distillation (SimDis) IBP, °C

78.3

130.6 304.4 328.9 357.2 378.9 418.9 472.2 513.9 537.8 600.0

5%, °C 10%, °C 20%, °C 30%, °C 50%, °C 75%, °C 90%, °C 95%, °C FBP, °C

120.0 147.8 199.4 240.6 333.3 444.4 526.7 566.7 648.9

Table 1

defined as C5 to 232°C, light cycle oil (LCO) as 232°C-360°C, and heavy cycle oil (HCO or bottoms) as 360°C and higher. Lumped product yields were measured using a combina- tion of gas chromatography and liquid chromatography. Additionally, the speciation of the liquid products was determined using a mixture of liquid chromatography and mass spectrometry. Pyrolysis oil made from polyolefins (~85% LDPE and ~15% PP) was obtained from the industrial plant of Quantafuel in Skive (Denmark) and used without further pre-processing. In addition to this pyrolysis oil, a standard vacuum gasoil (VGO) feed was also used in the first part of this study. The physical and chemical properties of both feeds are shown in Table 1 . Generally, plastic pyrolysis oil is lighter than VGO feed. The contaminants profile is also quite different: the pyrol- ysis oil contains noticeable amounts of halides, phospho- rous, and silica, but less iron and sodium. This pyoil appears rather clean despite a significant level of chlorides. Its effect

PTQ Q3 2025