Insights into biochar and hydrochar production and applications: A review

• Published in: Energy (Oxford) Vol. 171; pp. 581 - 598
• Main Authors: Zhang, Zhikun, Zhu, Zongyuan, Shen, Boxiong, Liu, Lina
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 15-03-2019; Elsevier BV
• Subjects: Air pollution; Anaerobic digestion; Biochar; Biochar characteristics; Biomass; Carbon dioxide; Carbon dioxide emissions; Catalysts; Charcoal; Composting; Economic analysis; Electrochemistry; Energy balance; Energy storage; Environmental impact; Formation mechanism; Production technique; R&D; Reaction mechanisms; Research & development; Soil amendment; Technology assessment; Utilization; Biochar characteristics; Utilization; Biomass; Production technique; Biochar; Formation mechanism
• ISSN: 0360-5442; 1873-6785
• DOI: 10.1016/j.energy.2019.01.035

Recently, there is an upsurge interest of using biomass derived char products in various fields, in order to address some of the most urgent energy and environmental problems we are facing today, such as CO2 emission, energy crisis and environmental pollution. In this review paper, most recent studies on biochar/hydrochar production, characterization and prospective utilizations are summarized. Fundamentals and reaction mechanisms of biochar/hydrochar formations are discussed in detail. The energy balance and economic flexibility of biochar production technology is also analysed. The effects of reaction temperature, feedstock types, and thermochemical conversion modes on biochar are compared. In addition, we highlighted benefits and potential challenges in promoting biochar application in energy and environmental fields, including the applications in adsorbents, precursor of catalysts, soil amendment, anaerobic digestion and composting, and electrochemical energy storage materials. This paper not only summarises recent advances in engineered biochar technology but also demonstrates insights on new directions for biochar research and development in the future.
•Biochar has enormous potential for ever-increasing energy and environmental demands.•Formation, properties and applications of biochar/hydrochar are summarized.•Biochar properties are influenced by temperature, feedstock and conversion modes.•The mechanisms of biochar/hydrochar generation are comprehensively summarized.•Biochar applications in energy, waste management and agriculture are reviewed.