Akademik Veri Yönetim Sistemi
Journal of Environmental Chemical Engineering, cilt.14, sa.3, 2026 (SCI-Expanded, Scopus)
In this study, hydrothermal carbonization (HTC) was employed to upgrade a 1:1 (w/w) blend of dairy cattle manure (DCM) and olive residue (OR) into a high-calorific solid biofuel. The influence of process temperature (180–260 °C), residence time (30–180 min), solid-to-liquid ratio (1:5, 1:10), and initial pH (3,6) on hydrochar yield, fuel properties, combustion behavior, and ash characteristics was systematically investigated. Increasing HTC temperature promoted dehydration and decarboxylation reactions, leading to higher carbon content and reduced O/C and H/C atomic ratios, indicating an enhanced degree of coalification. The highest calorific value (29.7 MJ/kg) was obtained at 260 °C, while maximum energy efficiency was achieved at 180 °C due to superior mass retention. Thermogravimetric analysis revealed that hydrochars exhibited improved thermal stability compared to raw biomass, with reduced volatile release in the active pyrolysis region (200–400 °C). Combustion analysis demonstrated that ignition temperature (Tᵢg) and burnout temperature (Tb) decreased with increasing HTC severity, whereas the combustion index (S) declined at higher temperatures due to reduced volatile matter content and fuel reactivity. The combustion indices (S) indicate that hydrochars exhibit suitable fuel properties. XRF and SEM–EDX analyses confirmed partial removal of alkali metals (Na, K, Cl), indicating mitigation of slagging and corrosion tendencies, although heavy metals became concentrated in the solid fraction. Overall, HTC effectively enhanced fuel quality, calorific value, hydrophobicity, and ash behavior of the biomass blend, demonstrating its potential for sustainable solid biofuel production from agricultural and animal wastes.