Abstract:
This study primarily focuses on the anaerobic digestion process of kitchen waste (substrate) in the presence of sewage sludge (inoculum) at mesophilic temperature (37 °C). The main objective is to investigate the effect of substrate pretreatment on the production of biogas and biomethane, using inoculum-to-substrate ratios of 1/3 and 1/2, and applying different dilution rates (no dilution, 50%, and 70%).
Two pretreatment methods were employed:
Chemical pretreatment: involving the use of sulfuric acid (H₂SO₄) at pH = 2 and a temperature of 24 °C.
Thermal pretreatment: consisting of heating the substrate to temperatures ranging from 70 °C to 200 °C under pressure for a specific period of time.
The experimental results showed that chemical pretreatment led to higher biogas and methane yields compared to thermal pretreatment and the untreated substrate.
Mathematical modeling was carried out using Origin Pro 19 software, applying two kinetic models: the Gompertz and Modified Gompertz models available in the program's database.