Solar desalination evaporator made of black round plastic lunch box and black garbage bag

Abstract

So far, it is generally believed that black matter means that it can strongly absorb nearly 57 % of the energy in the incoming light of the sun. In the field of photothermal interface evaporation, there are many substances which surface is black but not concerned. Inspired by the above understanding, this paper selects disposable black round plastic lunch boxes and black garbage bags as solar absorption materials to make photothermal desalination evaporators for the first time, to prove that these black disposable wastes can not only be recycled, but also can be used to make interfacial evaporators. Polyester cloth is used as the water delivery channel, and the two-dimensional evaporation device made of black round plastic lunch box successfully achieves a high level of steam output. The value even exceeds 1.45 kg m-2 h-1. In addition, we also prepared a three-dimensional evaporator using a black garbage plastic bag as only solar energy absorber. The three-dimensional evaporator uses radiation cooling film as diffuse reflection substrate. The radiation cooling film and polyester cloth can multiple reflect and absorb the incident solar energy, so that the black plastic bag can multiple re-absorb the incident solar light. The solar energy absorption rate of the three-dimensional evaporator is as high as 95.14 %, and the steam output is as high as 8.91 kg m-2h-1.