The influences of aliphatic alcohols (CnH2n+1OH, n=1-4) and their concentrations (0-1 vol.-%) on gas holdup, liquid circulation velocity, mixing time, and overall volumetric gas-liquid oxygen mass transfer coefficient were considered in a split-cylinder airlift reactor sparged with air. The carbon chain length of the alcohols and their concentration affect the airlift reactor performance. Alcohols reduced the average bubble sizes and increased the gas holdup, the interfacial area for mass transfer, and the gas-liquid mass transfer coefficient. Since butanol has the most carbon atoms in its chain, it had the most significant effect on gas holdup and mass transfer enhancement. It also decreased the liquid circulation velocity by surface tension reduction. Two correlations based on dimensionless groups were applied to investigate the effect of hydrodynamics and molecules on gas holdup and mass transfer. A satisfactory agreement between correlation and experimental results was observed.