Microwave-assisted pyrolysis for carbon catalyst, nanomaterials and biofuel production

• Published in: Fuel (Guildford) 2022-04, Vol.313, p.123023, Article 123023
• Main Authors: Vignesh, Nagamalai Sakthi, Soosai, Michael Rahul, Chia, Wen Yi, Wahid, Safiyyah N., Varalakshmi, Perumal, Moorthy, Innasi Muthu Ganesh, Ashokkumar, Balasubramaniem, Arumugasamy, Senthil Kumar, Selvarajoo, Anurita, Chew, Kit Wayne
• Format: Article
• Language: English
• Subjects: Biodiesel fuels; Biofuels; Biomass; Carbon; Carbon fibers; Carbon nanotubes; Catalysts; Charcoal; Commercialization; Electronic waste; Energy efficiency; Life cycle analysis; Life cycle assessment; Life cycles; Lignocellulose; Lignocellulosic biomass; Microwave absorbers; Municipal solid waste; Municipal waste management; Nanofibers; Nanomaterials; Nanotechnology; Nanotubes; Pyrolysis; Solid waste management; Synthesis gas; Waste oils
• ISSN: 0016-2361; 1873-7153
• DOI: 10.1016/j.fuel.2021.123023

•Microwave heating method offers many benefits as compared to conventional heating.•Microwave-assisted pyrolysis (MAP) can be employed to turn waste into biofuels.•Carbon material like biochar can be used as both a catalyst and microwave absorber.•There is almost 91% recovery of energy from biomass in the MAP process.•Hydrocarbons present in bio-oil and syngas serve for carbon nanotube formation. The current scenario of environment urgently needs alternative biologically synthesized fuels, value-added products, and preparation of catalyst to create a pollution free environment. Usually, several methods are available for the synthesis of various commodities from many biological resources. Microwave-assisted pyrolysis (MAP) is a relatively new process and has emerged as a promising technique to transform biomass feedstock into biofuels, including bio-oil, syngas and biochar. This paper provides a state-of-art review on MAP of several wastes such as lignocellulosic biomass, waste oils, municipal solid waste and electronic waste, discussing on the biofuels produced (bio-oil, syngas and biochar) as well as the synthesis of carbon nanomaterials (carbon nanotubes and carbon nanofibers). The use of microwave adsorbent and catalyst in MAP process are reviewed, including utilization of biochar as one of the microwave absorbers. Life cycle analysis and scale-up process with the global view of MAP are presented to contribute to the further advancement and commercialization of this technology. Although there are several challenges to be resolved, MAP has a high energy efficiency and is an increasingly feasible technique to be scalable, economical and environmental friendly.