Sodium bicarbonate is produced by the Solvay process from salt (NaCl), ammonia gas (NH 3 ), and CO 2 . Here, the Solvay process was modified by using ammonium hydroxide (NH 4 OH) liquid to replace NH 3 . To increase the yield of sodium bicarbonate, a froth flotation column was used. This column can generate microbubbles of CO 2 , which increases the CO 2 conversion. The parameters were studied using response surface methodology (RSM) with a central composite design of experiments. Based on the RSM analysis, the optimum conditions were identified. Analysis of variance shows that the reaction time is the most significant parameter affecting the production of sodium bicarbonate. Empirical quadratic multivariable equation models were obtained with R 2 = 0.94. The heavy metal-free product can be used as a food additive.