A winged solar biomass reactor for producing 5-hydroxymethylfurfural

Biomass-derived alcohols such as 5-Hydroxymethylfurfural represent a promising intermediary energy and species carriers for hydrogen and value-added chemical production. Solar-driven reforming of biomass to 5-HMF at the desired reaction condition (e.g., at -150 ?C and -5 bars) offers a sustainable route, but the lack of a rooftop-based solar biomass reactor represents a substantial impediment. In this work, a unique, low-profile ?winged? solar concentrator with an evacuated tube reactor was designed for the renewable production of 5HMF. The viability of this design was examined in detail, using sucrose as the feedstock for 5-HMF production in the presence of sulfuric acid. The optical study indicated that the winged structure significantly increased the effective concentration ratio (by -42%) and that the design has a broader acceptance angle (from 60? to 90?) compared to CPC alone. During outdoor experiments, the wings boosted the thermal efficiency from 18% to -25% when operating at 150 ?C, and achieved a maximum 5-HMF yield of -21 mol % (under a solar irradiance of -800 W/m2). In parallel, a transient computational fluid dynamics model was developed to further elucidate the heat and mass transfer phenomena inside the reactor and to investigate a broader range of operating conditions and reactor design parameters. The numerical and experimental results were in agreement that a specific energy consumption for 5-HMF production of -23 kWh/kg was achievable and that a full-scale system (-3 L reactor volume, 2.1 m2 gross area) can produce -0.45 kg of 5-HMF per day, with an average daily solar input of 5 kWh/m2.

Automated summary

A unique solar concentrator design was developed for renewable production of 5HMF, showing increased efficiency and high yield in experiments. A computational model was also developed to explore a wider range of operating conditions and reactor design parameters.