The production of sustainable carbon-based materials from palm kernels through hydrothermal method, investigation of pollution removal and supercapacitor performance

The main purpose of this master's study is to prepare carbon-based materials from inert biomass, to contribute to the effect of these materials in removing pollution from water and to determine the suitability of their use as a supercapacitor. In recent years, one of the methods used to obtain hydrochar (HC) from biomass is the hydrothermal method. In this thesis, the palm kernels, of which serious waste is generated during Ramadan, were used as raw material. Optimal values and characterization, adsorption capacity and supercapacitor properties of hydrochar obtained from palm kernel were studied. In addition, optimal values and characterization studies were carried out in magnetic palm kernel hydrochar (MPKHC) obtained from hydrochar. HC obtained from the palm kernel by hydrothermal method was combined with Fe(NO3)3 and Co(NO3)2 to become a composite material. The adsorption of methyl orange (MO) and methylene blue (MB) from aqueous solution with HC and composite material was investigated. The effect of temperature and time on the hydrothermal carbonization of the palm kernel was investigated and its characterization was made. As a result of the studies carried out at 180oC, 200oC, 240oC temperatures and 6, 12 and 24 hours. The experiment showed that 200oC temperature and 6 hours were determined as optimal values. FT-IR images to determine the surface functional groups of HC and composite material, SEM analysis to determine morphological properties, XRD analysis to examine crystal properties and particle size, elemental analysis to determine the amounts of C, H, N and S were performed.9 solutions with different concentrations were prepared from the 500 mg/L stock solution of MO and MB solutions. Composite material was prepared by mixing 0.1g of HC and the composite at a shaking speed of 100 rpm with 25oC for 24 hours. An isotherm study was carried out on palm kernel hydrochar (PKHC) and MPKHC. Isotherm data were evaluated in Langmuir and Freundlich isotherm models. Using the correlation coefficient (R2) and other isotherm parameters, it was observed that the most suitable adsorption for MO and MB at 298 K fit the Langmuir isotherm model. The maximum amount of MO removed from the Langmuir isotherm model was 45.87 mg/g, and the amount of MB was determined as 20.58 mg/g. This means that the adsorption of MO is higher than that of MB. This means that PKHC adsorbs MO more than MB. In Table 4.1, KF values are 11,6267 (mg/g)(L/mg)-(1/n) for MO and 3,9785 (mg/g)(L/mg)-(1/n) for MB. Similarly, in the Freundlich isotherm model, it is seen that the MO adsorption is more. Considering the R2 and other isotherm parameters for MPKHC, it is observed that Langmuir is the most suitable adsorption model for MO and MB. According to the Langmuir isotherm model, the maximum amount of MO removed was 82.65 mg/g, and the amount of MB was determined as 60.98 mg/g. This means that MPKHC adsorbs MO more than MB. The KF values in Table 4.2 are 10,8341 (mg/g)(L/mg)-(1/n) for MO and 9,9922 (mg/g)(L/mg)-(1/n) for MB. In the Freundlich isotherm model, it is seen that MO adsorption is higher for MPKHC.As a result of the experiments, it was determined that the use of magnetic material increased the amount of adsorbed material for MO and MB.The capacitance properties of PKHC and MPKHC obtained from the palm kernel were determined and the suitability of their use as electrodes in supercapacitors was examined.In addition, the capacitance properties of PKHC and MPKHC obtained from palm kernels were determined and their suitability for use as supercapacitors was examined. The capacitive performances of the electrodes formed by preparing electrodes from PKHC and MPKHC were investigated by the cyclic voltammetry (CV) technique. The studies were carried out in 0.5 M Na2SO4 electrolyte against Ag/AgCl reference electrode at a scanning speed range of 5-100 mV/s and a potential range of -0.5-0 V. When the electrodes obtained from PKHC and MHÇHK are compared with each other; It was determined that the PKHC electrode (13.69 F/g) had a higher capacitive performance than the MPKHC (1.20) at a scanning rate of 5 mV/s