Techno-economic assessment of vegetable oils as heat transfer fluids for industrial solar thermal systems applications
Year: 2025
Type: article
Abstract: This study evaluates sunflower, safflower, and rapeseed oils as alternative heat transfer fluids (HTFs) for medium-temperature parabolic trough collector (PTC) applications and compares their performance with Therminol VP-1 and Delcoterm E15. A validated thermal–hydraulic model (R² = 98.5 %), supported by experimental measurements on a 1.5 kWth PTC system in Morocco, was used to assess HTF behavior under three operational methodologies: fixed thermal power, fixed Reynolds number, and fixed mass flow rate. Results show that vegetable oils achieve slightly higher thermal efficiency (64–65 %) than synthetic fluids (62–63.5 %), attributed to their superior thermal conductivity and specific heat. Although their higher viscosity increases pumping demand, the associated penalty (12–15 W per 1.3 kWth) represents only 0.9–1.2 % of the useful thermal output, indicating minimal impact on overall system performance. At larger scales, vegetable oils offer substantial economic advantages: a 10 MWth solar field requires 400–450 k€ less initial HTF investment than synthetic oils. Application mapping shows that vegetable oils are best suited for industrial processes below 200 °C—common in food processing, textiles, and pharmaceuticals—while Delcoterm E15 remains optimal for 150–250 °C and Therminol VP-1 for >300 °C applications. These results demonstrate that vegetable oils provide a cost-effective, environmentally benign pathway for expanding solar industrial heat deployment, particularly in developing economies and small-to-medium enterprises.
Source: Results in Engineering
Language: English
Field: Energy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,940
OpenAlex ID: W4416812408