Industrial production of activated carbon using circular bioeconomy principles: Case study from a Romanian company

This work discloses an industrial multi-ton scale methodology implemented by a Romanian company (Explocom GK) to use bio-wastes to produce biochar, demonstrating a case of bio-economy circularity associated with economic growth. The pyrolysis process was able to produce ∼20%w of high-quality biochar (550 m²/g) starting from forest-based and agricultural wastes. A fraction of ∼60%w is converted into condensates, including wood vinegar, wood tar, alcohol, etc. that can be recovered and purified because of the large scale of the process. The energy contained in the volatile syngas produced (∼20%w) is stored and used instead of fossil fuels for heating the pyrolysis reactor. Some of this syngas and wood vinegar can also be used to activate a fraction of the biochar into high-quality activated carbon (value of activated carbon/value of biochar >3, depending on the market and required properties). The transformation of a fraction of the produced biochar into activated carbon increases the overall profitability of the plant while manufacturing a product that does not use fossil fuels or chemicals for activation. This material locally produced can also reduce emissions from transport of activated carbons currently exported from other continents.