Commercial or Pilot-Scale Pyrolysis Units for Conversion of Biomass to Bio-Oils: State of the Art

Abstract

AbstractEnergy is vital for human growth. The exponential rise in the energy demand is fulfilled from fossil fuels which disturbs the ecological imbalance and threatens climate changes, human health, and greenhouse gas emissions. The search for renewable energy sources can overcome these issues. Biomass includes grass, agricultural waste, domestic waste, wood can be converted into biofuels and Bioenergy. Physical or Mechanical, Biological, and Thermochemical routes are used to convert the biomass into value-added products. Thermochemical conversion processes gained more attention as compared to biological conversion processes due to their advantages. In the Thermochemical process, the reaction time is less, i.e., few seconds and minutes, while the biological process is slow and reaction is carried out in hours, days and weeks, or years. The product obtained from the thermochemical conversion is a multiple and complex product mixture (bio-oil), while ethanol or biogas is the final product of the biological process. The various thermochemical techniques are Combustion, Gasification, and Pyrolysis. Combustion is biomass burning in air/oxygen to get heat for steam production and generation of electricity. The burning of biomass in partial oxidation is known as gasification. Fuel gas consists of Carbon dioxide, Carbon monoxide, Hydrogen, and Methane, obtained as gasification product and used to generate heat and electricity. Pyrolysis is biomass thermal disintegration process done in the absence of oxygen. Gas, Liquid (bio-oil) and Solid (biochar) are the products of the pyrolysis process and have various industrial applications. There are different pyrolysis processes and can be categorized based on the requirement and utilization of the products. This chapter includes the various pyrolysis technologies reported earlier along with the recent advancement in this process. This chapter emphasizes the emerging pyrolysis technology and commercial plants available worldwide used to produce liquid fuels.KeywordsBiomassConversion routesPyrolysisFast pyrolysisBiofuels