transfer reactions (olefin consuming), is an important metric in FCC analysis. FCC2 has been designed by optimising the acid site density of the base catalyst while introducing ZSM-5 to further boost LPG olefin yields and selectivities. Given the properties of this py-oil, the coke yield is lower compared to typical gasoil feedstock, with 3.2 wt% and 1.2 wt% for FCC1 and FCC2, respectively (Table 1). Consequently, the FCC unit at a commercial scale might require the addition of fossil-based feedstocks, such as gasoil or resid, to maintain its heat balance and to overcome any shortage of alternative co-feedstocks. Conclusions Plastic recycling has gained attention in the circular economy due to its potential for making the plastic lifecycle more sustainable. Chemical recycling is a promising alternative that can overcome the challenges found with mechanical recycling of all plastic waste. Among the different methods of plastic recycling, Valmet advocates pyrolysis as a promising method of converting plastics to their monomers. In scenarios where decentralised processing is advantageous, the liquid products from pyrolysis are often more valuable than other products. Here, the utilisation of the catalyst is crucial. In the first approach, catalytic pyrolysis optimises the content of pyrolysis oil, and in the second approach, after thermal pyrolysis, the waxes are catalytically degraded to produce oil. In this work, during the catalytic fast pyrolysis of polyolefins, even though the catalyst increased the formation of non- condensable gases from 10% to roughly 20%, the gasoline-range products increased from 15% to approximately 85%. This outcome is particularly noteworthy, as it underscores the potential for generating high-value products from plastic waste. In the second approach, upgrading the waxy fraction from a thermal pyrolysis process appears to be a valuable option for a co-processing application through the FCC unit. BASF demonstrated that the catalyst can be fine-tuned to either produce more sustainable chemicals, such as LPG olefins, or more transportation fuels, such as gasoline. FCC units appear to be well suited for co-processing
ACE cracking results of waxy py-oil from LDPE with FCC1 and FCC2 catalysts at a 7.0 cat-to-oil ratio
FCC1
FCC2
Cat-to-oil ratio, wt%/wt%
7.0
7.0
Conversion, wt%
92.8
93.6
Hydrocarbon yields
H 2 , wt% CH 4 , wt% C 2 =, wt% C 3 , wt% C 3 =, wt% Ethane, wt%
0.08 1.08 0.60 1.12 1.97 11.2
0.07 0.48 0.43 6.17 3.02 24.4
n-butane, wt% i-butane, wt% n-butenes, wt% Isobutylene, wt%
1.7 6.9
1.4 3.8
10.0
12.7
4.6
8.3
Naphtha (C 5 -232°C), wt% LCO (232-360°C), wt%
50.4
31.6
4.2 2.9 3.2
3.2 3.2 1.2
HCO (360°C+), wt%
Coke, wt%
Calculated values
Naphtha + total LPG, wt%
86.77
88.42
Total dry gas, wt%
2.88
7.15
Total LPG, wt%
36.37
53.62
LPG olefinicity, wt%/wt%
0.71 14.6 0.85 0.63
0.85 21.0 0.89 0.80
Total C 4 =, wt%
C 3 olefinicity, wt%/wt% C 4 olefinicity, wt%/wt%
Table 1
alternative feedstocks, where catalysts can be fine-tuned to reach refiner objectives while reducing the carbon intensity of the finished products. In a collaborative effort, Valmet and BASF are developing technological solutions to facilitate the commercial-scale integration of circular carbon solutions.
Disclaimer: BASF’s contributions to this article were limited to catalyst development and application.
VIEW REFERENCES
Tooran Khazraie tooran.khazraie@valmet.com Guillaume Vincent guillaume.vincent@basf.com
www.decarbonisationtechnology.com
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