Techno-Economic Analysis of Biodiesel Production from Dairy Waste Scum Oil (DWSO) via Microwave Heating Transesterification
摘要
Fossil fuel dependency in the transport sector presents urgent sustainability and climate concerns. Biodiesel offers a renewable alternative, especially when derived from waste-based feedstocks. This study evaluates the techno-economic feasibility of producing biodiesel from dairy waste scum oil (DWSO) via microwave-assisted transesterification, using experimentally optimized lab-scale conditions (65℃, 15 min, 3 wt. % Li-ECaO catalyst, 16:1 methanol-to-oil ratio). The process achieved a biodiesel yield of 75.4 wt. %, with 77% methanol and 95% catalyst recovery. These values were scaled to an annual production of 1.20 million kg of biodiesel and 126,540 kg of crude glycerol. Capital expenditure (CAPEX) was estimated at $3.69 million (RM 17.35 million), and annual operating expenditure (OPEX) at $0.36 million (RM 1.70 million). At a biodiesel price of $0.43/kg (RM 2.04/kg), the model yielded $0.52 million (RM 2.45 million) in annual revenue, with a net present value (NPV) of $3.58 million (RM 16.84 million), a payback period of 7.65 years, and a return on investment (ROI) of 6.47%. Sensitivity analysis was performed on five critical parameters: biodiesel price ($0.38–0.53/kg; RM 1.80–2.50/kg), methanol recovery (60–90%), catalyst reuse cycles (5–20), feedstock cost ($0.00–0.064/kg; RM 0.00–0.30/kg), and operating time (6000–8400 h/year). Variations in these inputs shifted NPV from $0.49 to $6.74 million (RM 2.30–RM 31.70 million), and the payback period (PBP) from 4.5 to 12.6 years. Enhancing methanol recovery and extending catalyst reuse increased NPV to $4.02 million (RM 18.90 million), demonstrating the system’s economic resilience and scalability for decentralized waste-to-energy applications.
Graphical Abstract