Comparative Study of Thermal, Catalyst-Mediated, Biomass-Assisted, and Combined Upgrading Routes for Nigerian Bitumen over a Hierarchical CoMo/ZSM-5 Zeolite Catalyst

• Fadimatu N. DABAI

  Author

• Abdulkadir M. SANI

  Author

• Abdulwasiu ABDURRAHMAN

  Author

Heavy oil and bitumen tend to be thick, dense, and low in API gravity, and those properties make them more expensive to extract, transport, and refine than conventional crude. This study looked at upgrading Nigerian bitumen using four different approaches: thermal cracking on its own, a hierarchical CoMo/ZSM-5 zeolite catalyst, rice husk biomass acting as a hydrogen donor, and a combined catalyst and biomass system. Each run took place in a batch reactor, with temperature raised from 25 to 350°C under an inert nitrogen atmosphere and then held for 3 hours. The upgraded products were checked for viscosity, density, and API gravity, and both the evolved gas stream and the liquid products were analyzed using Gas chromatography mass spectrometry (GCMS) and Fourier transform infrared (FTIR) spectroscopy. Viscosity dropped sharply, from 28,700 mPa s in the raw feed, down to 285.0, 91.0, 84.6, and 38.2 mPa s for the thermal, catalyst, biomass, and combined runs. API gravity rose from 7.0° to 43.2°, 40.2°, 48.5° and 12.9° across those same runs. Methane showed up as the dominant gas in every case, peaking at 57.1% around the 17 min mark in the catalyst only run. GCMS analysis showed that oxygenated alcohols dominated the thermal and catalyst runs, while carboxylic acids and alkanoate esters dominated the biomass runs; FTIR confirmed oxygenated and aliphatic groups throughout all the products. Taken together, the results show rice husk biomass and the CoMo/ZSM-5 catalyst each improve bitumen's flow properties on their own, but combining them led to an unexpected drop in API gravity, a result that calls for closer mechanistic study.

• 78_Dabai et al. (2026)

Copyright (c) 2026 Fadimatu N. DABAI, Abdulkadir M. SANI, Abdulwasiu ABDURRAHMAN (Author)

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