Valorization of Different Fractions from Butiá Pomace by Pyrolysis: H(2) Generation and Use of the Biochars for CO(2) Capture

This work valorizes butiá pomace (Butia capitata) using pyrolysis to prepare CO(2) adsorbents. Different fractions of the pomace, like fibers, endocarps, almonds, and deoiled almonds, were characterized and later pyrolyzed at 700 °C. Gas, bio-oil, and biochar fractions were collected and characterized. The results revealed that biochar, bio-oil, and gas yields depended on the type of pomace fraction (fibers, endocarps, almonds, and deoiled almonds). The higher biochar yield was obtained by endocarps (31.9%wt.). Furthermore, the gas fraction generated at 700 °C presented an H(2) content higher than 80%vol regardless of the butiá fraction used as raw material. The biochars presented specific surface areas reaching 220.4 m(2) g(−1). Additionally, the endocarp-derived biochar presented a CO(2) adsorption capacity of 66.43 mg g(−1) at 25 °C and 1 bar, showing that this material could be an effective adsorbent to capture this greenhouse gas. Moreover, this capacity was maintained for 5 cycles. Biochars produced from butiá precursors without activation resulted in a higher surface area and better performance than some activated carbons reported in the literature. The results highlighted that pyrolysis could provide a green solution for butiá agro-industrial wastes, generating H(2) and an adsorbent for CO(2).