Obata, K.; Mokeddem, A.; Abdi, F.F.: Multiphase fluid dynamics simulations of product crossover in solar-driven, membrane-less water splitting. Cell Reports : Physical Science 2 (2021), p. 100358/1-19
10.1016/j.xcrp.2021.100358
Open Access Version
Abstract:
Efficient separation of product gases is essential for the safe operation of large-scale, solar-driven water-splitting devices. To date, most demonstration devices use membranes, but a membrane-less configuration that separates products via hydrodynamic control offers an attractive alternative without the complexity associated with using membranes. In the present study, multiphase fluid dynamics simulations are introduced to investigate product crossover in a membrane-less, solar-driven water-splitting device. Specific emphasis is placed on implementing a realistic tilt condition of the device and the buoyancy effects on product gas bubbles. Our simulations reveal that gas bubbles, often disregarded, can be a major source of crossover rather than dissolved gases. Controlling the bubble formation and characteristics (e.g., diameter) therefore plays an important role in achieving efficient product separation. Finally, universal design criteria to control the product crossover are further discussed based on dimensionless analysis.