Biomass fast pyrolysis: A thermochemical process to convert raw biomass into pyrolysis oil ("bio-oil"), biochar and a mixture of non-condensable gases.
Fast pyrolysis is the rapid thermal decomposition of carbonaceous organic matter in the absence of oxygen. This process occurs at low pressure, moderate temperatures and in a very short amount of time. Fast pyrolysis produces three products: biochar, pyrolysis oil and non-condensable gases. Yields are dependent on many factors including process conditions (reactor temperature, pressure, residence time) and feedstock composition. Optimal biomass processing conditions include: reaction temperatures near 500°C, high heating rates, and rapid cooling of the pyrolysis vapors after biochar has been sufficiently removed.
Biomass fast pyrolysis systems include feedstock preparation and handling, a reactor, solid particulate removal, a pyrolysis oil collection system, and product storage. Main reactor types include bubbling and circulating fluidized bed reactors, rotating cone reactors, auger reactors, ablative reactors, vacuum reactors, and free fall reactors.