Gossypol Removal by Adsorption from Cottonseed Miscella

A variety of aluminas (acidic, basic, and neutral), silica, and synthetic magnesium silicates were screened to evaluate their potential use as adsorbents,for reducing the content of gossypol and related compounds from hexane-based cotton-seed miscella. Among the tested adsorbents, one type of silica and two types of magnesium silicate with a relatively high Brunauer-Emmet-Teller (BET) surface area (>=240 m2/g) showed a superior adsorption capacity in reducing gossypol from hexane miscella. As a possible regenerating method for the spent adsorbents, washing with acetone was tested. The effect of pH in the washing solvent was also evaluated. Adsorbents that were regenerated by washing with acetone at pH values between 7 and 7.5 performed better than those at pH values between 6.5 and 7. The pH values of washing solvent were adjusted by using a small amount of caustic and 1 M HCl.