Continuous selective deoxygenation of palm oil for renewable diesel production over Ni catalysts supported on Al2O3 and La2O3–Al2O3. Issue 15 (24th February 2021)

• Record Type: Journal Article
• Authors: Papageridis, Kyriakos N.; Charisiou, Nikolaos D.; Douvartzides, Savvas; Sebastian, Victor; Hinder, Steven J.; Baker, Mark A.; AlKhoori, Ayesha A.; AlKhoori, Sara I.; Polychronopoulou, Kyriaki; Goula, Maria A.
• Is Part Of: RSC advances. Volume 11:Issue 15(2021)
• Page Start: 8569
• Page End: 8584
• Publication Date: 2021-02-24
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/d0ra08541c
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Highly selective and stable Ni supported on La2 O3 –Al2 O3 catalyst on the deCO/deCO2 reaction paths for the production of renewable diesel. Abstract : The present study provides, for the first time in the literature, a comparative assessment of the catalytic performance of Ni catalysts supported on γ-Al2 O3 and γ-Al2 O3 modified with La2 O3, in a continuous flow trickle bed reactor, for the selective deoxygenation of palm oil. The catalysts were prepared via the wet impregnation method and were characterized, after calcination and/or reduction, by N2 adsorption/desorption, XRD, NH3 -TPD, CO2 -TPD, H2 -TPR, H2 -TPD, XPS and TEM, and after the time-on-stream tests, by TGA, TPO, Raman and TEM. Catalytic experiments were performed between 300–400 °C, at a constant pressure (30 bar) and different LHSV (1.2–3.6 h −1 ). The results show that the incorporation of La2 O3 in the Al2 O3 support increased the Ni surface atomic concentration (XPS), affected the nature and abundance of surface basicity (CO2 -TPD), and despite leading to a drop in surface acidity (NH3 -TPD), the Ni/LaAl catalyst presented a larger population of medium-strength acid sites. These characteristics helped promote the SDO process and prevented extended cracking and the formation of coke. Thus, higher triglyceride conversions and n -C15 to n -C18 hydrocarbon yields were achieved with the Ni/LaAl at lower reaction temperatures. Moreover, the Ni/LaAl catalyst was considerably more stable during 20 h of time-on-stream. Examination of the spent catalysts revealed that both carbon deposition and degree of graphitization of the surface coke, as well as, the extent of sintering were lower on the Ni/LaAl catalyst, explaining its excellent performance during time-on-stream.