Separation and Recovery of Tetramethyl Ammonium Hydroxide with Zeolitic Adsorbents

Separation and recovery of tetramethyl ammonium hydroxide (TMAH) has been investigated, employing several zeolites as adsorbents. Zeolite X, prepared by using TMAH as a structure directing agent, possesses highest adsorption ability among the adsorbents investigated in the present work, which corresponds to the specific surface area and pore volume of the zeolite. The adsorption amount of TMAH with the zeolitic adsorbents increases with increase in pH value in the aqueous solution, indicating the adsorption progresses via cation exchange mechanism. The chromatographic operation is finally conducted, using granulated zeolitic adsorbents to prevent from the pressure-drop, and the quantitative adsorption-elution processing of TMAH can be achieved.