Development of porosity in carbons from yeast grains by activation with alkali metal carbonates

Cellular structured activated carbon samples were prepared with the aid of alkali carbonates X 2CO 3 (X = Li, Na, K, Rb, or Cs) from dry bread yeast with a milling procedure. The resultant carbon possesses a very large adsorption amount even for supercritical methane. The activation with Cs 2CO 3 gave the greatest surface area of 2420 m 2 g −1 from the subtracting pore effect method. The activation efficiency of X 2CO 3 (X = Li, Na, K, Rb, and Cs) was associated with the order of Gibbs free energy of X 2O (X = Li, Na, K, Rb, and Cs) which should play an important role in the gasification. The carbon activated with Rb 2CO 3 gave the greatest adsorption amount of supercritical methane of 90 mg g −1 at 0.9 MPa at 303 K. Novel carbon of micropores and macropores was prepared from dry bread yeast of ordered cellular structures with the aid of a series of alkali carbonates. The activated carbon produced with Rb 2CO 3 gave the greatest adsorptivity for supercritical methane. Figure: Adsorption isotherms of CH 4 on activated carbon samples at 303 K (●, Li-AC; ■, Na-AC; ▴, K-AC; □, Rb-AC; ○, Cs-AC).