Publication: Catalytic cracking of waste cooking oil using sulfonated activated carbon supported la/ce bimetallic catalysts for biofuel production
| datacite.subject.fos | oecd::Engineering and technology::Chemical engineering | |
| dc.contributor.author | Samah Zaki Naji | |
| dc.date.accessioned | 2025-05-13T05:11:38Z | |
| dc.date.available | 2025-05-13T05:11:38Z | |
| dc.date.issued | 2023-08-01 | |
| dc.description.abstract | The biofuel industry is poised for exponential growth due to increasing global fuel demand, environmental regulations, and energy security concerns. The aim of this study was to assess the performance of different catalysts based on modified activated carbon in the catalytic cracking of waste cooking oil (WCO) into alkane-based hydrocarbons. The catalysts were prepared by subjecting the coconut-shell activated carbon (AC) to acidification using varying concentrations of sulfuric acid to increase surface acidity and subsequent incorporation with lanthanum (La) and cerium (Ce) metals enhancing both physical and chemical properties. The objective was to determine the most effective catalyst formulation that would yield the highest amount of alkane-based hydrocarbons. The catalytic cracking activity was evaluated in a fixed bed reactor under N2 flow at 450 °C and a weight hourly space velocity (WHSV) of 8 hr-1 with 60 min collection time. The physical and chemical properties of the prepared catalysts were characterized using a range of techniques, including BET, SEM-EDX, XRD, TPD-NH3/CO2, FTIR, and TGA. The synthesized catalysts were tested in terms of organic liquid yield (OLP), coke, gas, hydrocarbon yields, and n(C15+C17) selectivity along with alkane yield. Response surface methodology (RSM) was applied to determine the optimal La and Ce loading concentrations for maximizing OLP and hydrocarbon yields. La and Ce metal loading were tested in the range of 0 to 5 wt.% and 0 to 10 wt.%, respectively, on sulfonated activated carbon using central composite design (CCD). The results showed that the optimum metal loading concentrations were 5 wt.% of La and 5 wt.% of Ce over sulfonated AC. Overall, the optimum catalyst (5La-5Ce/SAC) achieved an OLP yield of 83.91% comprising 97.77% hydrocarbons that were mostly alkane (82.04%) and n-(C15+C17) selectivity (57%). the effect of operating conditions was examined in terms of catalyst performance. These include reaction temperature (390 ̊C to 510 ̊C), WHSV (4 hr-1 to 12 hr-1), and reaction time (60 min to 240 min). The optimum operating conditions were identified as 450 ̊C reaction temperature, 8 hr-1 WHSV, and 60 min reaction time. The recyclability of 5La-5Ce/SAC was then being carried out at optimum operating conditions. 5La-5Ce/SAC showed significant catalytic cracking with high activity for the first recycled run but decrease after the second recycled run due to coke formation that deposits on the catalyst's surface. Besides, the mechanism of palmitic and oleic acids during catalytic cracking over 5La-5Ce/SAC was also studied using model systems. The major reaction pathway of both acids over 5La-5Ce/SAC catalyst was found to be decarbonylation reaction. The kinetics of catalytic cracking of palmitic and oleic acids have been studied over a temperature range of 350°C to 450 °C using 5La-5Ce/SAC catalyst and WHSV of 6hr-1 to 10hr-1. The reaction activation energies of palmitic and oleic acid were found to be 45.47 kJ/mole and 19.50 kJ/mole respectively. | |
| dc.identifier.uri | https://erepo.usm.my/handle/123456789/21607 | |
| dc.language.iso | en | |
| dc.title | Catalytic cracking of waste cooking oil using sulfonated activated carbon supported la/ce bimetallic catalysts for biofuel production | |
| dc.type | Resource Types::text::thesis::doctoral thesis | |
| dspace.entity.type | Publication | |
| oairecerif.author.affiliation | Universiti Sains Malaysia |