Rates of heat and liquid‐solid mass transfer in a square bubble column with semicylindrical turbulence promoters at its wall were measured using the electrochemical technique in the bubbly flow regime. Turbulence promoters enhanced the wall liquid‐solid mass or analogous heat transfer coefficients and the corresponding volumetric mass transfer coefficients by factors up to 2.36 and 3.76, respectively, depending on the working conditions. The rate of liquid‐solid mass transfer was improved with increasing superficial gas velocity and decreasing turbulence promoter diameter. The importance of the turbulence promoters as a catalyst support and a built‐in cooler was highlighted. Power consumption measurements revealed that the gas‐sparged reactor outperforms the mechanically stirred reactor.