Sustainable biofuel production from non-edible oils utilizing modified montmorillonite based porous clay heterostructures

ABSTRACT

Surface modification was performed for montmorillonite clay by grafting phenyl triethoxy silane moiety followed by sulfonation to obtain the heterogeneous acidic catalyst. The prepared catalyst was recognized using numerous analytical procedures. FTIR spectra inspected the functional groups of the original clay and gave an insight view on the sulfonated clay. XRD provided information on sulfonation of original clay by the shifting of signals at 2θ at 18.5°, 26.55°, and 61.89° peaks to 17.8° (003), 25.5° (003). TPD profile showed the presence of different acidic sites on the surfaces of the studied compounds identified as weak, moderate, and strong types; further, the sulfonation step generated high intensity of the strong acidic sites on the clay surface. Surface area analysis showed that the introduction of sulfonate moieties within the clay framework crowded the pores and decreased their effective area and volume to 66.31 m²/g and 0.11 cm³/g. TGA identification indicated that the introduction of sulfonate groups within the clay framework increased its thermal stability by up to 600°C, due to the hydrogen bonding between the hydroxyl groups of clay and sulfonate groups. The analyses pointed out the successful grafting and sulfonation on the clay. The prepared catalyst was employed during catalytic conversion of used cooking oil and Jatropha oil into their corresponding biofuels. B10 blends of Jatropha oil and used cooking oil by petroleum Jet A-1 have exhibited densities at 0.8037 and 0.8040 g/cm³, while flashpoints were 46°C and 46°C, also the freeze points were also identical at −54 ^oC. The yield % of Jatropha oil and used cook oil biofuels using the optimum catalyst ratio (0.8% by weight) were 95% and 86%. The biofuels and their blend specifications were measured and compared using the fossil diesel Jet A-1.

KEYWORDS:

• Clay
• sulfonation
• phenyl triethoxy silane
• heterogeneous catalyst
• catalytic conversion

Abbreviations

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Acknowledgments

I would like to thank Taif University Researcher supporting project number (TURP-2020/243), Taif University, Taif, Saudi Arabia. I would also like to thank Prof. Dr. Nabel A. Negm, Prof. Dr. Salwa M. Morsy, thanks to the Egyptian Petroleum Research Institute (EPRI).

Disclosure statement

No potential conflict of interest was reported by the author(s).