We demonstrate that by a simple solvothermal treatment followed by carbonization, plastic waste can be turned into graphitic carbon nanosheets, with an excellent photothermal conversion efficiency (99%) that is capable of generating a high evaporation rate (1.50 L m⁻² h⁻¹ at 1 kW m⁻²) in a solar evaporator, and these are among the best values reported thus far.

Numerical simulations were carried out to assess the technical and economic feasibility of a solar water desalination system that has a novel hybrid Concentrating Photovoltaic Thermal (CPVT) collector coupled with a Vacuum Membrane Distillation (VMD) process. A special characteristic of this CPVT is its triangular receiver with PV cells facing the reflecting surface. This type of receiver has the advantage of generating more electricity with less PV surface area and great potential to be used to hybridize conventional parabolic thermal collectors. TRNSYS was employed to analyze the annual performance of the CPVT-VMD system evaluating parameters such as solar fraction, specific permeate production and specific energy production for different coastal cities. In the dynamic simulations, local annual weather data and specific information about the characteristics and operating conditions of a real CPVT collector and a VMD module were considered. From the parametric analysis the optimal surface area of collectors and the input temperature of the VDM module were determined. A maximum specific permeate of 218.410 m ³/m²_VMD for Acapulco, MX, and a minimum of 170.365 m ³/m²_VMD for Singapore, SG, were achieved for the proposed CPVT-VMD system of four solar collectors with an operating set temperature of 55 °C. An economic profit was found after 7 years for Acapulco city, which showed great potential to use solar energy from hybrid CPVT collectors for a VMD process to provide freshwater in coastal cities.

The pore structure and strength of carbon membrane are controlled by introducing different additives into raw materials. It is indicated that sesbania powder has an obvious effect on the pore structure of carbon membrane, and the obtained pores have the maximum diameter of 0.723 µm, average diameter of 0.319 µm and minimum diameter of 0.241 µm, respectively; whereas, medium temperature pitch has an obvious effect on the strength of carbon membrane, and increases th e linear pressure and flexural strength to 13.68 N/mm and 19.80 MPa, respectively.