DEVELOPMENT OF DEEP EUTECTIC SOLVENTS FOR AROMATIC SEPARATION FROM ALIPHATIC HYDROCARBONS
| dc.contributor.author | Aminu Abdullahi MUHAMMAD, B.Eng. (ABU, 2000) MSc. (ABU, 2011) | en |
| dc.creator | Aminu Abdullahi MUHAMMAD, B.Eng. (ABU, 2000) MSc. (ABU, 2011) | en |
| dc.date.accessioned | 2023-09-22T17:27:49Z | |
| dc.date.available | 2023-09-22T17:27:49Z | |
| dc.date.issued | 2021-04-01 | en |
| dc.description.abstract | The separation of aromatic from the aliphatic hydrocarbons poses a challenge to the petrochemical industry due to the formation of azeotropes and close boiling point components. The potential application of deep eutectic solvents (DESs) as a low cost and environmentally friendly alternative to the conventional organic solvent in the separation of aromatic/aliphatic hydrocarbon mixtures has been investigated in this thesis. Deep Eutectic Solvents (DESs) synthesis were carried out with eight 14 ammonium and phosphonium salts and 13 hydrogen bond donors (HBDs) at varied combinations of molar ratios (1- 2 ratio for salts and 1-6 ratios for HBDs). A total of two hundred and twenty-eight different types of salt: HBD combinations were tested as DESs Ten DESs were selected and re- synthesised in large quantities for the experiments on this thesis at a salt: HBD molar ratio of 1:2. The DESs were formed from tetrabutyl ammonium bromide (TBAB), tetrabutyl phosphonium bromide (TBPB) and Tetrabutyl phosphonium methane sulphonate (TBPMS) as salts, with Polyethylene Glycol 200 (PEG200), Polyethylene Glycol 600 (PEG600), Dimethyl Sulphuroxide (DMSO); and Dimethyl formamide (DMF) as HBDs. Physical properties of the selected DESs which includes density, viscosity, conductivity and refractive index were measured as function of temperature ranging from 303 K to 363 K with the exception of viscosity which was measured between 303K and 353 K at atmospheric pressure. The dependency of density and refractive index with temperature was found to be linear and the correlation coefficient for density and refractive index giving a satisfactory fitting with R2 ranging between 0.99 and 1.00 for all the studied DESs. Viscosity and conductivity were modeled using the Arrhenius-like and the Vogel-Fucher Tamman (VFT) equations for all the DESs. Model parameter fittings were done for viscosity and conductivity. The percent average absolute deviation (%AAD) VFT equation range for viscosity and conductivity are between 0.17 – 1.00 and 0.76 – 2.12 respectively. The percent average absolute deviation (%AAD) Arrhenius-like equations range for viscosity and conductivity are between 2.62 – 15.22 and 1.36 – 7.58 respectively. vii The potential applications of the synthesised DESs for the separation of aromatic from aliphatic hydrocarbons were carried out. Ternary diagrams for the DESs systems and the solute distribution coefficients and selectivity for the studied DESs were determined. The TBAB: PEG600 based DESs showed higher distribution coefficients and selectivity values ranging between 1.23 – 1.40 and 5.0 – 10.0 respectively, at low toluene composition, which indicates the extraction potentials of the DESs. Thermodynamic modelling using Non-Random Two Liquid (NRTL) model and Universal Quasi Chemical (UNIQUAC) model were carried out from the experimental liquid-liquid equilibrium compositions. The NRTL model gave a better fit when compared to UNIQUAC model with Root Mean Square Deviation (RMSD) ranging between 0.0064 – 0.0008 and 0.2472 – 0.2250 respectively. Multistage extraction processes were also carried out from model fuel of toluene and octane mixture. The toluene removal efficiency for all the DESs is greater than 90% at the eight equilibrium extraction stage. This shows the ability of the DESs to separate toluene from octane to a lower concentration. Also the removal efficiency of benzene and toluene is greater than 90% and less than 80% for xylene at the 10th equilibrium extraction stage for the three DESs (TBAB: PEG600; TBPB: PEG600 and TBPMS: PEG600) during multistage extraction with synthetic naphtha feed. DESs regeneration were also carried out. The regenerated DESs shows a performance similar to the original DESs. After the three regeneration cycles the toluene removal efficiency of the studied DESs ranged between 20 – 30 percent. | en |
| dc.identifier.uri | https://teras.ng/api/asset/document/2089d484-9262-4e28-bfc6-93e04b3e44b8 | en |
| dc.identifier.uri | https://teras.ng/catalog-item/dd4724bf-a43f-4f76-a582-c9a2eb156244 | en |
| dc.identifier.uri | http://dspace.teras-network.net:4000/handle/123456789/40080 | |
| dc.publisher | Ahmadu Bello University Zaria | en |
| dc.title | DEVELOPMENT OF DEEP EUTECTIC SOLVENTS FOR AROMATIC SEPARATION FROM ALIPHATIC HYDROCARBONS | en |
| dc.type | Post Graduate Theses | en |
| thesis.degree.level | Phd | en |
| thesis.matric.number | (P14EGCE9003) | en |