Mass and heat transfer behavior of a bubble column fitted with horizontal spiral tubes in bubbly-flow regime

Slurry bubble columns are commonly used for gas-liquid-solid diffusion -controlled reactions. However, they have some shortcomings, such as the high cost of separating the final product from the catalyst particles. This study proposes the use of spiral tubes as catalyst support to address these shortcomings. The liquid-solid mass transfer behavior of spiral tubes under different conditions of gas superficial velocity, spiral tube diameter, and pitch was studied using the electrochemical technique. The mass transfer coefficient was found to increase with increasing superficial gas velocity but decrease with increasing tube diameter and pitch. The data were correlated by a dimensionless equation suitable for the design and scale-up of the reactor. In addition to serving as catalyst support, the internal surface of the spiral tube can be used as a supplementary built -in cooler in conjunction with a cooling jacket for exothermic reactions. This is beneficial for catalytic reactions and biochemical reactions, which are prone to catalyst deactivation and thermal degradation, respectively. A study of the mass transfer behavior of a bubble column fitted with multi -spiral tubes revealed a deviation from the single spiral tube behavior by an amount ranging from 10% to 20%, depending on the operating conditions. Calculation of the ratio between the volumetric mass transfer coefficient and the specific energy consumption (performance indicator for the reactor under different conditions) revealed that the reactor has a high energy utilization efficiency.