Catalytic cracking evaluation of plastic pyoil and VGO at 550°C with catalyst FCC(a) and FCC(b) at iso-conversion (72 wt%)
FCC(a)
FCC(b)
100% VGO
10% Pyoil
100% VGO
10% Pyoil
Cat-to-oil, wt/wt Hydrocarbon yields H₂, wt%
4.0
3.5
4.9
4.4
0.06 0.98 0.62 0.84 1.11 5.40 0.88 3.59 4.95 2.20
0.05 0.79 0.53 0.73 0.99 5.52 0.83 3.50 5.26 2.35
0.13 0.86 0.71 4.19 2.62
0.11 0.67 0.58 5.01 2.95
Methane, wt% Ethane, wt% Ethylene, wt% Propane, wt% Propylene, wt% n-Butane, wt% i-Butane, wt% n-Butenes, wt% i-Butylene, wt% Naphtha, wt%
14.28
15.70
1.08 2.97 6.75 4.40
1.22 2.93 7.35 4.84
49.15 16.32 11.68
49.70 16.22 11.78
31.99 16.67 11.33
29.03 15.95 12.05
LCO, wt%
Bottoms, wt%
Coke, wt%
2.21
1.75
2.03
1.63
Calculated values Total valuable liquids * , wt%
83.60
84.36
80.75
79.95
Total dry gas, wt%
2.51
2.10
5.89
6.37
Total LPG, wt%
18.13
18.45
32.10
34.97
LPG olefinicity, wt/wt
0.69 7.14 0.83 0.62
0.71 7.61 0.85 0.64
0.79
0.80
Total C₄=, wt%
11.15
12.18
C₃ olefinicity, wt/wt C₄ olefinicity, wt/wt
0.84 0.73
0.84 0.75
* Total valuable liquids defined as LPG + naphtha + LCO
Table 2
FCC(b) with 10% pyoil produced fewer valuable liquids (LPG + naphtha + LCO) compared to 100% VGO. In fact, the olefin-inducing characteristics of FCC(b) con- verted some naphtha-range olefins, already present or formed after cracking reactions, to ethylene. For FCC(a), the difference in terms of LCO and bottoms yields is rather marginal between both feeds, while the difference is more
noticeable for FCC(b). In fact, this might be explained by the presence of bottom precursors in this pyoil that cannot be easily cracked in the range of 72 wt% conversion, but it can be improved at higher conversion levels with FCC(b). More valuable products, including naphtha and LPG, can be further produced as the ratio of pyoil increases because of a higher H/C ratio and better crackability.
20 24 22 26 28 30 32 34 36 38 40 42 46 48 50 44 52
12
11
10
9
8
7
6
5
4
3
2
3
4
5
6
7
3
4
5
6
7
C/O
C/O
FCC (a)
FCC (c)
FCC (d)
Figure 2 Impact of catalysts on light olefins and BTX yields by upgrading 100% of plastic pyoil at 550°C
25
PTQ Q3 2025
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