High-Performance Solar Steam Generator Using Low-Cost Biomass Waste Photothermal Material and Engineering of the Structure.

Abstract

In this work, high-performance, low-cost, environmentally friendly multilayered solar steam generation systems are fabricated by engineering the structure and using a biomass photothermal material. Remarkably, the biomass photothermal material is extracted from the pyrolysis waste of linseed (flax) grains. The introduced system desalinates water using solar energy as the renewable source of energy, and its light absorber is from the waste of a renewable source. The biomass waste powder possesses a mesoporous structure, providing high light absorption through photon scattering and its high surface area. Moreover, to harvest the incident light efficiently and manage the thermal energy generated, devices including light absorbers with cone and cubic configurations and different water manager layers are fabricated and compared to each other. To confirm the high performance of the introduced photothermal material, different systems comprising graphite, graphene oxide, and carbon nanotube light absorbers are also fabricated. Using a biomass light absorber combined with harvesting of the light in different directions (cone configuration), the system with a water evaporation rate of 1.59 kg/m2h corresponding to an efficiency of 92.9% is achieved. Furthermore, by depositing a thin layer of the transparent thermal superinsulator silica aerogel on the light absorber layer, the generated heat is localized and the heat losses are prevented, leading to a 7.5% enhancement of the water evaporation rate of the biomass system. The eco-friendly biomass-based system shows no significant change in its performance through operation for 40 desalination cycles of Persian Gulf water.