Long-Term Coprocessing of Used Cooking Oils with Refinery
Petroleum Fractions: A Comprehensive Study of Catalyst Activity and
Biofuel Production Effects
posted on 2024-07-31, 04:14authored byDominik Schlehöfer, Ivana Hradecká, Aleš Vráblík, Lucie Šindelářová, Pavel Šimáček, Vladimír Hönig, Héctor de Paz Carmona
Nowadays, sustainable biofuel production
is a hot topic. However,
studying the processing of new alternative materials on an industrial
scale is very expensive. According to this fact, testing on pilot
plants is a suitable method for studying the effects of alternative
feedstocks on catalyst activity or product quality parameters. The
present work deals with the effect of coprocessing used cooking oil
(5–30 wt %) with refinery petroleum fractions on product properties
and hydrotreating catalyst activity. The experiment was performed
on a pilot unit at industrial operating conditions (5.5 MPa, WHSV
1.1 h–1, H2/feed ratio 327 Nl·l–1) using a commercial NiMo/γ-Al2O3 catalyst. Operating temperature (341–352 °C)
played the most significant role in catalyst activity to get products
with 10 mg·kg–1 sulfur content. The obtained
products were evaluated based on the standard analytical methods specified
in the EN 590 standard. Furthermore, the following advanced analytical
methods were chosen for qualitative and quantitative analyses: GCxGC-FID,
GCxGC-SCD, Fourier transform infrared spectroscopy with attenuated
total reflectance FTIR-ATR, and Raman spectroscopy. The increase of
used cooking oil (UCO) on the feed during coprocessing increased nC15–nC18 alkanes
with the consequent changes in the product properties such as density
at 15 °C and cetane index. The increase in light gases (C1–C4) and CO2 indicates the promotion
of the decarboxylation pathway during coprocessing. Overall, our results
indicate the necessary changes in the operating conditions during
coprocessing to get the EN 590 requirements with up to 30 wt % of
UCO in the feed, which is the line of future advances for biofuel
production at the industrial scale.