Читать книгу Handbook of Biomass Valorization for Industrial Applications - Группа авторов - Страница 71

The initial step for the refining of crude glycerol is pre-treatment using strong acid which removes the catalyst and soaps. The acids commonly used for the acidification process include phosphoric acid, sulfuric acid, and hydrochloric acid. The reaction of base catalyst and acid will generate salt and water, and its reaction with soap gives free fatty acids. The pre-treatment of crude glycerol will form three separate layers. The bottom layer is made up of inorganic salts. The glycerol is present in the middle layer with free-floating fatty acids at the top. The glycerol with 93.3% purity was obtained on chemical and physical treatment at pH 1 which is followed by neutralization using 12.5 M NaOH [15].