The Behavior of Methane Bubbles in a Liquid Metal Reactor for Hydrogen Production

Understanding the dynamics of a methane bubble in a liquid metal bubble column reactor is important for optimizing the reactor design and improving efficiency. To better understand methane bubble dynamics and the reaction to produce hydrogen, we employ ANSYS Fluent to investigate the gas-liquid interface, to relate the surface area where reaction occurs to bubble size, and to determine coalescing behavior as a function of dimensionless numbers. Once the simulation is verified by comparing bubble velocity [1], shape [2], and coalescing distance [3] for a water-air system, a methane bubble in liquid bismuth at 1000 k is examined [4] [5]. Experimentally obtained kinetic parameters for the reaction are used in the computations. The bubble interfacial area to volume ratio is maximized at a diameter of 4mm and does not induce breakage of the bubble. The coalescing distance for two bubbles of methane in bismuth is a third of the distance for air in water bubbles.

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