Platinum (Pt) loaded activated carbons (ACs) were synthesized by the thermal decomposition of platinum (II) acetylacetonate (Pt(acac)₂) over chemically activated glucose-based biochar. The effect of Pt loading on surface area, pore characteristics, surface chemistry, chemical structure, and surface morphology were determined by various techniques. XPS studies proved the presence of metallic Pt⁰ on the AC surface. The graphitization degree of Pt loaded ACs were increased with the loaded Pt⁰ amount. The electrochemical performance of the Pt-loaded ACs (Pt@AC) was determined not only by the conventional three-electrode system but also by packaged supercapacitors in CR2032 casings. The capacitive performance of Pt@AC electrodes was investigated via cyclic voltammetry (CV), galvanostatic charge-discharge curves (GCD), and impedance spectroscopy (EIS). It was found that the Pt loading increased the specific capacitance from 51 F/g to 100 F/g. The ESR drop of the packaged cell decreased with the Pt loading due to the fast flow of charge through the conductive pathways. The results showed that the surface chemistry is more dominant than the surface area for determining the capacitive performance of Pt loaded AC-based packaged supercapacitors.

This study comparatively investigates the effects of graphite and titanium electrodes on process performance, energy consumption, and product quality in the electrolysis-based production of biodiesel from waste cooking oil (WCO). To optimize the production parameters, a Taguchi L18 orthogonal array and Response Surface Methodology (RSM) were systematically employed. The results demonstrated that while graphite electrodes operate effectively at lower voltages (approximately 20 V), titanium electrodes require higher voltage levels (60 V) to achieve significant conversion. Under optimized conditions, titanium electrodes achieved a remarkably high biodiesel conversion yield of 93.00% with a specific energy consumption (SEC) of approximately 1.19 kWh/kg, whereas graphite electrodes yielded 83.45% with a significantly lower SEC of 0.25 kWh/kg. Statistical analysis (ANOVA) revealed that the KOH catalyst concentration was not a statistically significant factor within the narrow range tested (0.5-1.0 wt%), suggesting that electrolysis operates through a different catalytic mechanism involving in-situ ion generation. Fuel property characterizations, including GC-MS analysis and cold-flow properties (CFPP of -26.86 C for graphite and − 23.67 C for titanium), confirmed that biodiesels produced with both electrode types show a close alignment with EN 14,214 standards. This research highlights that electrode material selection is a decisive factor influencing not only the conversion efficiency and energy intensity but also the molecular-level characteristics of the resulting fuel.

In this work, various waste biomasses were subjected to hydrothermal carbonization under mild conditions. The effect of operating temperature, duration time, and biomass-to-water ratio on the chemical and combustion characteristics of the hydrochars were determined. The results were compared to MKP Alpagut lignite to understand the future of hydrochars as an effective and environmentally friendly solid fuel. It was found that the temperature dominantly affects the yield and the chemical characteristics of the hydrochars compared to the duration time and biomass-to-water ratio for real biomasses. Hydrochars obtained from real biomasses showed higher combustion temperatures and slightly higher ignition temperatures. Moreover, the HHV of hydrochar is significantly higher than the MKP lignite and raw biomass. Our results prove that the hydrothermal carbonization process can be assessed as one of the best techniques for the thermochemical conversion of waste biomass into high-value-added valuable solid fuels.