Dual-Functionalized Palm Kernel Shell Biochar as a Heterogeneous Catalyst for Glycerol Acetylation toward Biofuel Additives

Heny Dewajani, Listiyana Candra Dewi, Asalil Mustain, Rosita Dwi Chrisnandari, Deni Fadilah Akbar

Abstract

Indonesia generates abundant palm kernel shell residues with high carbon content, offering strong potential for valorization into functional materials. In this study, palm kernel shell biochar was developed as a heterogeneous catalyst through a dual-functionalization approach involving sulfonation and nickel impregnation to enhance catalytic performance in glycerol acetylation. The sulfonation and nickel impregnation steps were designed to introduce Brønsted- and Lewis-type acidic functionalities, aiming to create synergistic effects that improve reaction efficiency. Biochar was prepared via batch carbonization at 500 °C for 3 h, followed by sulfonation using concentrated sulfuric acid and subsequent nickel impregnation (5 wt%). The catalysts were characterized using SEM–EDX, BET, FTIR, and XRD analyses, confirming successful incorporation of functional groups and metal species. The sulfonated/nickel-impregnated biochar exhibited a significantly higher specific surface area (180.015 m² g⁻¹), indicating improved pore structure and accessibility of active sites. Catalytic evaluation showed that glycerol conversion increased from 43.59% for sulfonated biochar to 50.43% after nickel impregnation, suggesting a beneficial effect of combining sulfonated and nickel-modified biochar functionalities. Product analysis indicated the formation of acetylated glycerol derivatives, tentatively identified as monoacetin, diacetin, and triacetin based on GC-MS library matching. Application testing revealed that adding 7 vol% bioadditive to commercial gasoline increased the octane number from 94 to 104, reduced CO emissions from 4.46% to 2.47%, and increased CO₂ emissions from 3.50% to 5.53%, indicating improved combustion efficiency. These results demonstrate that dual-functionalized palm kernel shell biochar is a promising catalyst for glycerol valorization and biofuel additive production, offering a sustainable approach that integrates biomass utilization with enhanced fuel performance. A limitation of this study is that catalyst acidity was not directly quantified; therefore, the proposed Brønsted-type and Lewis-type acidic behavior is inferred from indirect structural, compositional, and catalytic-performance evidence.

Keywords

References

[1] Badan Pusat Statistik, Statistik Tanaman Perkebunan Tahunan Indonesia 2024 (Kelapa Sawit, Kopi, Kakao, Karet, Teh, dan Komoditas Perkebunan Unggulan). Indonesia: Badan Pusat Statistik, 2024.

[2] T. E. Awoh, J. Kiplagat, S. Kimutai, and A. C. Mecha, “Current trends in palm oil waste management: A comparative review of Cameroon and Malaysia,” Heliyon, vol. 9, no. 11, Art. no. e21410, 2023, doi: 10.1016/j.heliyon.2023.e21410.

[3] R. K. Mishra, B. Singh, and B. Acharya, “A comprehensive review on activated carbon from pyrolysis of lignocellulosic biomass: An application for energy and the environment,” Carbon Resources Conversion, vol. 7, no. 4, Art. no. 100228, 2024, doi: 10.1016/j.crcon.2024.100228.

[4] D. Hantoko, “Biomass pyrolysis: A comprehensive review of production methods, derived products, and sustainable applications in advanced materials,” Applied Science and Engineering Progress, vol. 18, no. 2, Art. no. 7645, 2025, doi: 10.14416/j.asep.2024.11.009.

[5] Y. X. Seow, Y. H. Tan, J. Kansedo, I. S. Tan, B. L. F. Chin, N. M. Mubarak, M. N. B. Mohiddin, P. N. Y. Yek, Y. S. Chan, and M. O. Abdullah, “Pyrolysis assessment of palm kernel shell waste valorization to sulfonated magnetic biochar from techno-economic and energy perspectives,” Discover Applied Sciences, vol. 6, Art. no. 398, 2024, doi: 10.1007/s42452-024-06079-7.

[6] L. J. Konwar, P. Mäki-Arvela, and J.-P. Mikkola, “SO₃H-containing functional carbon materials: Synthesis, structure, and acid catalysis,” Chemical Reviews, vol. 119, no. 22, pp. 11576–11630, 2019, doi: 10.1021/acs.chemrev.9b00199.

[7] J. Keogh, P. Inrirai, N. Artioli, and H. Manyar, “Nanostructured solid/liquid acid catalysts for glycerol esterification: The key to convert liability into assets,” Nanomaterials, vol. 14, no. 7, Art. no. 615, 2024, doi: 10.3390/nano14070615.

[8] P. Ounsuk, S. Triampitak, J. Leetrakul, K. Sudsakorn, A. Seubsai, C. Prapainainar, and P. Prapainainar, “Catalyst screening and optimization condition of green solvent for BHD production using Ni-based catalysts,” Applied Science and Engineering Progress, vol. 17, no. 3, Art. no. 7352, 2024, doi: 10.14416/j.asep.2024.03.002.

[9] U. I. Nda-Umar, I. Ramli, E. N. Muhamad, N. Azri, and Y. H. Taufiq-Yap, “Optimization and characterization of mesoporous sulfonated carbon catalyst and its application in modeling and optimization of acetin production,” Molecules, vol. 25, no. 22, Art. no. 5221, 2020, doi: 10.3390/molecules25225221.

[10] M. R. Ika, N. Ravina, P. Herry, and H. Nur, “Performances of carbon-based catalysts for glycerol acetylation,” in Proc. 8th Int. Conf. Engineering, Technology, and Industrial Application, Surakarta, Indonesia, Dec. 15–16, 2021.

[11] M. Tabatabaei et al., “Environmental impact assessment of the mechanical shaft work produced in a diesel engine running on diesel/biodiesel blends containing glycerol-derived triacetin,” Journal of Cleaner Production, vol. 223, pp. 466–486, 2019, doi: 10.1016/j.jclepro.2019.03.106.

[12] T. Kalyani, L. S. V. Prasad, and A. Kolakoti, “Effect of triacetin as an oxygenated additive in algae biodiesel fuelled CI engine combustion, performance, and exhaust emission analysis,” Fuel, vol. 338, Art. no. 127366, 2023, doi: 10.1016/j.fuel.2022.127366.

[13] H. Dewajani, A. Chumaidi, A. S. Suryandari, E. N. Dewi, and M. H. Ahsan, “Characterization and preparation of Ni/γ-Al₂O₃ catalyst for acetylation of glycerol in a fixed bed reactor applied as an octane booster for commercial fuels,” Jurnal Bahan Alam Terbarukan, vol. 10, no. 2, pp. 60–68, 2021.

[14] H. Dewajani, W. Zamrudy, H. Saroso, S. Paramarta, and W. Mulya, “Conversion of crude glycerol from by-product biodiesel into bio-additive of fuel through acetylation reaction based on modified zeolite catalyst,” Alchemy: Journal of Chemistry, vol. 7, no. 2, p. 46, 2019.

[15] A. P. da Luz Corrêa, P. M. M. da Silva, M. A. Gonçalves, R. R. C. Bastos, G. N. da Rocha Filho, and L. R. V. da Conceição, “Study of the activity and stability of sulfonated carbon catalyst from agroindustrial waste in biodiesel production: Influence of pyrolysis temperature on functionalization,” Arabian Journal of Chemistry, vol. 16, no. 8, Art. no. 104964, 2023.

[16] Badan Standardisasi Nasional, Standar Nasional Indonesia Arang Aktif Teknis, SNI 06-3730-1995. Jakarta, Indonesia: Badan Standardisasi Nasional, 1995, pp. 1–21.

[17] O. M. Ikumapayi and E. T. Akinlabi, “Composition, characteristics and socio-economic benefits of palm kernel shell exploitation-An overview,” Journal of Environmental Science and Technology, vol. 11, no. 5, pp. 220–232, 2018.

[18] R. Chen, L. Li, Z. Liu, M. Lu, C. Wang, H. Li, W. Ma, and S. Wang, “Preparation and characterization of activated carbons from tobacco stem by chemical activation,” Journal of the Air and Waste Management Association, vol. 67, no. 6, pp. 713–724, 2017, doi: 10.1080/10962247.2017.1280560.

[19] A. S. Suryandari, T. Nurtono, W. Widiyastuti, and H. Setyawan, “Hydrophobic modification of sulfonated carbon aerogels from coir fibers to enhance their catalytic performance for esterification,” ACS Omega, vol. 8, no. 30, pp. 27139–27145, 2023.

[20] M. M. Marcelino, G. A. Leeke, G. Jiang, J. A. Onwudili, C. T. Alves, A. L. F. de Sousa, D. M. de Santana, F. A. Torres, S. A. B. Vieira de Melo, and E. A. Torres, “Effect of nickel nanocatalyst loading on supercritical water gasification of coconut shell,” Energies, vol. 17, no. 4, Art. no. 872, 2024, doi: 10.3390/en17040872.

[21] M. Dizbay-Onat, “Evaluation of physical adsorption properties of the activated carbon layers used in commercial face-mask inserts,” Engineering, vol. 4, no. 1, pp. 434–443, 2023, doi: 10.3390/eng4010026.

[22] H.-S. Jeong and B.-J. Kim, “Effects of nickel impregnation on the catalytic removal of nitric oxide by polyimide-based activated carbon fibers,” Nanomaterials, vol. 13, no. 16, Art. no. 2297, 2023, doi: 10.3390/nano13162297.

[23] M. Thommes, K. Kaneko, A. V. Neimark, J. P. Olivier, F. Rodriguez-Reinoso, J. Rouquerol, and K. S. W. Sing, “Physisorption of gases, with special reference to the evaluation of surface area and pore size distribution (IUPAC Technical Report),” Pure and Applied Chemistry, vol. 87, no. 9–10, pp. 1051–1069, 2015.

[24] G. Fu, Z. Wang, Y. Zhang, Z. Huang, J. Liu, J. Zhou, and K. Cen, “Effect of raw material sources on activated carbon catalytic activity for HI decomposition in the sulfur-iodine thermochemical cycle for hydrogen production,” International Journal of Hydrogen Energy, vol. 41, no. 19, pp. 7854–7860, 2016, doi: 10.1016/j.ijhydene.2015.12.212.

[25] A. Allwar, N. Indriyani, R. Maulina, and F. Rahmawati, “Hydrocracking optimization of palm oil over NiMoO4/activated carbon catalyst to produce biogasoline and kerosine,” Open Chemistry, vol. 20, no. 1, pp. 1643–1652, 2022, doi: 10.1515/chem-2022-0270.

[26] P. Maneechakr and S. Karnjanakom, “Improving the bio-oil quality via effective pyrolysis/deoxygenation of palm kernel cake over a metal (Cu, Ni, or Fe)-doped carbon catalyst,” ACS Omega, vol. 6, no. 30, pp. 20006–20014, 2021 , doi: 10.1021/acsomega.1c02999.

[27] S. Ammaji, G. S. Rao, and K. V. R. Chary, “Acetalization of glycerol with acetone over various metal-modified SBA-15 catalysts,” Applied Petrochemical Research, vol. 8, no. 2, pp. 107–118, 2018, doi: 10.1007/s13203-018-0197-6.

[28] K. Jagadeeswaraiah, M. Malyaadri, and K. D. Reddy, “Synthesis of glycerol acetins as fuel additives: Acetylation of glycerol with SnTPA catalyst,” Journal of Chemical Sciences, vol. 137, Art. no. 20, 2025, doi: 10.1007/s12039-025-02359-w.

[29] G. D. Yadav and S. O. Katole, “Synthesis of green bioadditives via esterification of glycerol with acetic acid catalysed by modified heteropolyacid on clay support,” Journal of the Indian Chemical Society, vol. 102, Art. no. 101623, 2025 , doi: 10.1016/j.jics.2025.101623.

[30] M. Elkelawy, M. M. Sayed, and A. A. Mohamed, “Sustainable combustion enhancement in CI engines using advanced fuel additives,” Pharos Engineering Science Journal, vol. 2, no. 2, pp. 309–318, 2025, doi: 10.21608/pesj.2025.389975.1033.

Full Text: PDF

DOI: 10.14416/j.asep.2026.08.013

Refbacks

There are currently no refbacks.

Username
Password
Remember me