Use of residual lignocellulosic biomass for energetic uses and environmental remediation through pyrolysis

Abstract

This study analyzes the potential of an agricultural residue, hazelnut shells, as raw material in a combined thermochemical process to obtain pyro-gas and biochar for environmental remediation. The novelty of this study relies on the definition of a pyrolytic polygeneration process to simultaneously attain an energy-type product and abiochar to maximize the versatility of the products and their usage. To this aim, the heating value of the gas and its potential to feed a micro combined heat and power (micro-CHP) system was evaluated. Additionally, the resulting biochar was chemically activated and tested as adsorbent for the removal of contaminants from an aqueous solution. Results show that the pyro-gas from the shell-type residue was suitable to be used as feed stream in a micro-CHP unit, which was able to operate near the full-load (91.9%) with electrical and thermal efficiencies of 27.6% and 57.9%, respectively. In the case of the biochar fraction, poor results were found for the char prior to activation. Instead, once it was activated with KOH, the resulting activated carbon presented high effectiveness as adsorbent and complete removal of the measured compound (methylene blue) was achieved.