Valorisation of lignocellulosic wastes from the candied chestnut industry. Sustainable activated carbons for environmental applications

Abstract High surface area activated carbons were obtained from chestnut shells, a lignocellulosic waste of the food industry generated by the peeling process in the preparation of candied products. KOH activation, preceded by a pyrolysis step, was performed in different conditions of activation temperature and inert flow gas. At 750 °C were prepared activated carbons at different KOH/precursor weight ratio. The adsorbent materials obtained were mainly microporous. The best results ( S BET 1792 m 2  g −1 and V TOT 0.729 cm 3  g −1 ) were obtained in the activated carbon obtained at 750 °C with the largest KOH/precursor weight ratio (2:1). The adsorbents were tested in a CO 2 , CH 4 and H 2 adsorption process at high pressure. The activated carbons appear to be excellent candidates in terms of adsorption capacity, selectivity towards CO 2 and for natural gas storage. The highest CO 2 adsorption capacity achieved was equal to 587.86 mg g −1 at 3 MPa and 25 °C.