Adsorption of asphaltene from crude oil using magnetic chitosan and carboxymethyl cellulose bionanocomposites: Kinetic, and thermodynamic studies

During crude oil production, asphaltene molecules can accumulate and eventually deposit on reservoir rock, pipes and surface facilities. Chitosan (CTS) and carboxymethyl cellulose (CMC) are considered as promising adsorbents for the removal of various materials results in the abundance of functional groups in their structures. In this novel study, magnetite nanoparticles (MNPs), magnetic bionanocomposites of CTS-MNPs and CMC-MNPs cross-linked by glutaraldehyde (GA) and iron chloride, respectively, were prepared, characterized, and used for asphaltene removal from crude oil under different conditions to address the knowledge gap regarding the comparative performance of CTS-MNPs and CMC-MNPs. The adsorption capacities were 242, 201, and 179 mg/g for CTS-MNPs, CMC-MNPs, and MNPs, respectively, highlighting the effectiveness of the prepared adsorbents, with corresponding asphaltene removal percentages of 30.33%, 25.20%, and 22.49%. The adsorption kinetics, isotherm, thermodynamics and the effect of different parameters on the process were investigated. The results showed that the kinetics of the process reached equilibrium in a short time of about 10 minutes and the experimental data followed the pseudo-second-order adsorption model. Also, the isotherm data showed a good fit with the Langmuir model. According to the thermodynamic data, the process was exothermic with a decrease in entropy.