Life cycle and techno-economic assessment of a solar-biogas hybrid dryer for banana drying.

This study evaluates the environmental impact and economic viability of a solar-biogas hybrid dryer using life cycle assessment (LCA) and techno-economic analysis. The LCA, in accordance with ISO 14040/14044, employs a cradle-to-grave approach using the ReCiPe 2016 Midpoint method. Results indicate a global warming potential of 1,100 kg CO₂-eq per functional unit, primarily from mild steel (69.4%) and aluminium (18.8%), representing 40-50% lower emissions than solar-electric and solar-diesel hybrid systems. Total energy consumption is 9,110 MJ per functional unit, with fossil fuels dominating (82.4%), while renewable energy use remains minimal. Human toxicity is significant, with mild steel and aluminium contributing 71.6% and 13.2% to carcinogenic toxicity, respectively. Integrating biogas reduces dependence on grid electricity and lowers operational emissions by 85%. Techno-economic analysis shows capital expenditure (CapEx) of USD 3,618.20 and operational expenditure (OpEx) of USD 9,458, with a payback period of 1.3 years and return on investment of 76.39%, indicating strong economic viability. Sensitivity analysis reveals that reductions in banana prices decrease operating expenses and the payback period, while reductions in biogas costs increase net cash flow and return on investment. The dryer demonstrates lower global warming potential and energy use compared with conventional dryers, supporting its adoption for sustainable agricultural processing in sub-Saharan Africa.