Valorization of Chrysotile Asbestos Waste into Hierarchically Porous Adsorbents for Thermal-Contact Demetallization of Heavy Oil: Mechanistic Insights and Process Optimization

The increasing use of heavy petroleum feedstocks necessitates the efficient removal of vanadium and nickel compounds that contribute to catalyst deactivation and coke formation. This study investigates the valorization of chrysotile-asbestos waste (CAW) as a porous adsorbent for the thermal-contact demetallization of heavy petroleum feedstock. The adsorbent was prepared by sequential magnetic separation, hydrochloric acid leaching (0.45 M HCl, 75 ^oC), and thermal activation at 650 ^oC. The treatment converted the original fibrous material into a predominantly amorphous silica-based matrix containing thermally stable forsterite, while increasing the specific surface area from 27.3 to 318.4 m²/g. The FTIR and EPR analyses indicated the formation of silanol-containing surface functionalities and paramagnetic defect centers that can contribute to the interaction with metal-containing petroleum species. Under thermal contact conditions at 360 ^oC and 8–10 atm, the resulting adsorbent achieved removal of vanadium and nickel, while sulfur removal remained substantially lower. The results demonstrate that controlled chemical-thermal transformation of chrysotile-asbestos waste can simultaneously reduce the hazardous fibrous morphology and produce a functional adsorbent suitable for pretreatment of heavy petroleum feedstocks.

Chrysotile-asbestos waste; Demetallization; Guard-bed adsorbent; Heavy oil; Sustainability

Adami, L., Ardit, M., Bonadiman, C., Dondi, M., Mancinelli, M., Lepore, G. O., Spagnoli, E., Nodari, L., Tassinari, R., Zoleo, A., Montegrossi, G., & Di Benedetto, F. (2025). When colour makes minerals unique: The case of the green dolomite from malentrata (pom arance, tuscany, italy). European Journal of Mineralogy, 37 (4), 517–533. https://doi.org/10.5194/ejm-37-517-2025

Aitkaliyeva, G., Ashimova, S., Baidullayev, I., Merkibayev, Y., Yelubay, M., Toleutay, G., & Oliviero Rossi, C. (2025). Oil sludge as a rejuvenator for aged bitumen: Structural and thermal effect. Applied Sciences, 15 (12), 6757. https://doi.org/10.3390/app15126757

Ali, M. F., & Abbas, S. (2006). A review of methods for the demetallization of residual fuel oils. Fuel Processing Technology, 87 (7), 573–584. https://doi.org/10.1016/j.fuproc.2006.03.001

Alizadehhesari, K., Golding, S. D., & Bhatia, S. K. (2012). Kinetics of the dehydroxylation of serpentine. Energy & Fuels, 26 (2), 783–790. https://doi.org/10.1021/ef201360b

Amiour, I., Bouzerara, F., Sahnoune, F., & Alluqmani, S. (2025). Low-temperature synthesis of forsterite (Mg2SiO4) via solid-state reaction. Science of Sintering, (00), 23–23. https://doi.org/10.2298/SOS250314023A

Anbalagan, G., Sivakumar, G., Prabakaran, A. R., & Gunasekaran, S. (2010). Spectroscopic characterization of natural chrysotile. Vibrational Spectroscopy, 52 (2), 122–127. https://doi.org/10.1016/j.vibspec.2009.11.007

Baigenzhenov, O., Khabiyev, A., Mishra, B., Aimbetova, I., Yulusov, S., Temirgali, I., Kuldeyev, Y., & Korganbayeva, Z. (2022). Asbestos waste treatment—an effective process to selectively recover gold and other nonferrous metals. Recycling, 7 (6), 85. https://doi.org/10.3390/recycling7060085

Baigenzhenov, O. S., Kozlov, V. A., Luganov, V. A., Mishra, B., Shayahmetova, R. A., & Aimbetova, I. O. (2015). Complex processing of wastes generated in chrysotile asbestos production. Mineral Processing and Extractive Metallurgy Review, 36 (4), 242–248. https://doi.org/10.1080/08827508.2014.955610

Bloise, A., Catalano, M., Barrese, E., Gualtieri, A. F., Bursi Gandolfi, N., Capella, S., & Belluso, E. (2016). Tg/dsc study of the thermal behaviour of hazardous mineral fibres. Journal of Thermal Analysis and Calorimetry, 123 (3), 2225–2239. https://doi.org/10.1007/s10973-015-4939-8

Chen, F., Liu, Q., Xu, Z., Sun, X., Shi, Q., & Zhao, S. (2013). Adsorption kinetics and thermodynamics of vanadyl etioporphyrin on asphaltene in pentane. Energy & Fuels, 27 (11), 6408–6418. https://doi.org/10.1021/ef400533t

Djekoune, L., Maaliou, A., Salem, Z., Ziani, D., Kamel, R., Ouakouak, A., Baigenzhenov, O., Bokov, D. O., Ivanets, A., & Hosseini-Bandegharaei, A. (2024). Phosphate adsorption on dried alum sludge: Modeling and application to treatment of dairy effluents. Environmental Research, 252, 118976. https://doi.org/10.1016/j.envres.2024.118976

Fritsch, E., Balan, E., Petit, S., & Juillot, F. (2021). Structural, textural, and chemical controls on the oh stretching vibrations in serpentine-group minerals. European Journal of Mineralogy, 33 (4), 447–462. https://doi.org/10.5194/ejm-33-447-2021

Hashizume, H. (2022). Natural mineral materials. Springer Japan. https://doi.org/10.1007/978-4-431-56924-4

Iarlori, S., Ceresoli, D., Bernasconi, M., Donadio, D., & Parrinello, M. (2001). Dehydroxylation and silanization of the surfaces of ?-cristobalite silica: An ab initio simulation. The Journal of Physical Chemistry B, 105 (33), 8007–8013. https://doi.org/10.1021/jp010800b

Karolczak, J., Kowalska, D., Lukaszewicz, A., Maciejewski, A., & Steer, R. P. (2004). Photophysical studies of porphyrins and metalloporphyrins: Accurate measurements of fluorescence spectra and fluorescence quantum yields for soret band excitation of zinc tetraphenylporphyrin. The Journal of Physical Chemistry A, 108 (21), 4570–4575. https://doi.org/10.1021/jp049898v

Kirgizov, A. Y., Ding, B., Spiridonov, A. A., Liu, L., Laskin, A. I., Cao, C., Il’yasov, I. R., Al-Muntaser, A. A., Zhou, X., Zinnatov, R. A., Lamberov, A. A., Yuan, C., & Varfolomeev, M. A. (2022). Ex situ upgrading of extra heavy oil: The effect of pore shape of co-mo/?-al2o3 catalysts. Catalysts, 12 (10), 1271. https://doi.org/10.3390/catal12101271

Kusiorowski, R., Zaremba, T., Piotrowski, J., & Adamek, J. (2012). Thermal decomposition of different types of asbestos. Journal of Thermal Analysis and Calorimetry, 109 (2), 693–704. https://doi.org/10.1007/s10973-012-2222-9

Laziri, K., Djemli, A., Redaoui, D., Sahnoune, F., Dhahri, E., Hassan, S. F., & Saheb, N. (2024). Kinetics of formation, microstructure, and properties of monolithic forsterite (mg2sio4) produced through solid-state reaction of nano-powders of mgo and sio2. Ceramics International, 50 (22), 45179–45188. https://doi.org/10.1016/j.ceramint.2024.08.357

Li, W., Bao, J., Zeng, S., Zheng, J., Fang, W., Yi, X., Yang, Q., & Lai, W. (2025). Al2o3@sio2 supported nimo catalyst with hierarchical meso-macroporous structure for hydrodemetallization. Catalysts, 15 (7), 646. https://doi.org/10.3390/catal15070646

Maldybaev, G. K., Sharipov, R. K., Nurzhanova, S. B., Baigenzhenov, O. S., Alimzhanova, A. M., & Khambarkyzy, A. (2026). Method for producing an adsorbent for demetallization of oil residues [Kazakhstan Patent No. 38105, published 26 June 2026].

Maldybayev, G., et al. (2024). Synthesis of chemical adsorbent for purification of heavy oil residue. International Journal of Technology, 15 (3). https://doi.org/10.14716/ijtech.v15i3.6507

Maletaški?, J., Stankovi?, N., Daneu, N., Babi?, B., Stoiljkovi?, M., Yoshida, K., & Matovi?, B. (2018). Acid leaching of natural chrysotile asbestos to mesoporous silica fibers. Physics and Chemistry of Minerals, 45 (4), 343–351. https://doi.org/10.1007/s00269-017-0924-z

Marafi, A., Albazzaz, H., & Rana, M. S. (2019). Hydroprocessing of heavy residual oil: Opportunities and challenges. Catalysis Today, 329, 125–134. https://doi.org/10.1016/j.cattod.2018.10.067

Marhoon, A. A., Hasbullah, S. A., Asikin-Mijan, N., & Mokhtar, W. N. A. W. (2024). Adsorption of metal porphyrins using chitosan/zeolite-x composite as an efficient demetallization agent for crude oil: Isotherm, kinetic, and thermodynamic studies. International Journal of Biological Macromolecules, 274, 133358. https://doi.org/10.1016/j.ijbiomac.2024.133358

Marian, N. M., Giorgetti, G., Magrini, C., Capitani, G. C., Galimberti, L., Cavallo, A., Salvini, R., Vanneschi, C., & Viti, C. (2021). From hazardous asbestos-containing wastes (ACW) to new secondary raw material through a new sustainable inertization process: A multi-methodological mineralogical study. Journal of Hazardous Materials, 413, 125419. https://doi.org/10.1016/j.jhazmat.2021.125419

Mironov, N., Tazeeva, E., Milordov, D., Yakubova, S., & Yakubov, M. (2024). Use of near-to-microporous silica gel for selective separation of petroleum vanadyl porphyrins from asphaltene clusters. Energy & Fuels, 38 (18), 17412–17424. https://doi.org/10.1021/acs.energyfuels.4c03180

Mohammed, M. Y., Ali, A. M., & Albayati, T. M. (2023). Segregation of metal complexes from real heavy crude oil in the existence of prepared deep eutectic solvents. Chemistry Africa, 6 (3), 1595–1603. https://doi.org/10.1007/s42250-022-00568-1

Nguyen, T.-H., Nguyen, Q.-A., Cao, A. N. T., Ernest, T., Nguyen, T. B., Pham, P. T. H., & Nguyen, T. M. (2022). Hydrodemetallization of heavy oil: Recent progress, challenge, and future prospects. Journal of Petroleum Science and Engineering, 216, 110762. https://doi.org/10.1016/j.petrol.2022.110762

Okunev, A. G., Parkhomchuk, E. V., Lysikov, A. I., Parunin, P. D., Semeikina, V. S., & Parmon, V. N. (2015). Catalytic hydroprocessing of heavy oil feedstocks. Russian Chemical Reviews, 84 (9), 981–999. https://doi.org/10.1070/RCR4486

Rana, M. S., Sámano, V., Ancheyta, J., & Diaz, J. A. I. (2007). A review of recent advances on process technologies for upgrading of heavy oils and residua. Fuel, 86 (9), 1216–1231. https://doi.org/10.1016/j.fuel.2006.08.004

Santos Silva, H., Sodero, A. C. R., Korb, J.-P., Alfarra, A., Giusti, P., Vallverdu, G., Bégué, D. D., Baraille, I., & Bouyssiere, B. (2017). The role of metalloporphyrins on the physical-chemical properties of petroleum fluids. Fuel, 188, 374–381. https://doi.org/10.1016/j.fuel.2016.10.065

Schroeder, C., Siozios, V., Hunger, M., Hansen, M. R., & Koller, H. (2020). Disentangling brønsted acid sites and hydrogen-bonded silanol groups in high-silica zeolite h-zsm-5. The Journal of Physical Chemistry C, 124 (42), 23380–23386. https://doi.org/10.1021/acs.jpcc.0c06113

Vishnyakov, A. (2023). Vanadium and nickel recovery from the products of heavy petroleum feedstock processing: A review. Metals, 13 (6), 1031. https://doi.org/10.3390/met13061031

Xie, D., Yu, M., Kadakia, R. T., & Que, E. L. (2020). 19f magnetic resonance activity-based sensing using paramagnetic metals. Accounts of Chemical Research, 53 (1), 2–10. https://doi.org/10.1021/acs.accounts.9b00352

Yusubov, F. V. (2021). Optimal conditions of delayed coking. Coke and Chemistry, 64 (10), 460–464. https://doi.org/10.3103/S1068364X21100070

Zhao, X., Xu, C., & Shi, Q. (2015). Porphyrins in heavy petroleums: A review. In C. Xu & Q. Shi (Eds.), Structure and modeling of complex petroleum mixtures (pp. 39–70, Vol. 168). Springer International Publishing. https://doi.org/10.1007/430_2015_189