First steps towards green asphalt production: levelized product cost of aggregates drying with a beam-down linear Fresnel solar field

• A Beam-Down Linear Fresnel Reflector (BDLFR) is coupled with a conveyor belt receiver. • A lumped drying model is proposed and validated experimentally. • The Levelized Cost of the Product compared fossil-fuel rotary kiln with BDLFR. • Future CO2 emission costs are calculated to make competitive the solar technology. The integration of solar concentrating technologies for the industrial drying and heating is a compelling approach to reduce the carbon emissions associated with low-to-mid temperature processes. This work couples the Beam-Down Linear Fresnel (BDLFR) solar technology with a conveyor belt receiver to dry and heat the virgin aggregates employed in asphalt industry. A novel lumped drying model for a fixed bed of dolomitic lime particles with low moisture content serves to explore the feasibility of the BDLFR technology for sustainable asphalt production. On-sun drying tests have been performed to validate the model for average heat fluxes of 2–5 kW/m 2 . It has been found that shallow beds operated with low heat fluxes received at the bed surface are not affected by horizontal mass transfer diffusion, and provide the maximum drying in the final products. The estimated BDLFR cost using a conveyor belt receiver is 366.2 € per m 2 of primary mirrors. The Levelized Cost of the Product calculated considers a lifetime of 20 years, an inflation rate of 3.5 % and a real discount rate of 7.6 %. The production cost of the BDLFR prototype would range between 13.6 € / t o n < L C O P < 43 € / t o n depending on the drying time, and the average solar concentration. The solar technology might be competitive when the CO 2 emission costs are C CO 2 = 35 € / t o n for fuel oil, and C CO 2 = 41 € / t o n for natural gas.