Table 9 Advantages, disadvantages, and bio-oil yield of different pyrolysis reactors; source [78]
From: Microwave pyrolysis of lignocellulosic biomass––a contribution to power Africa
Reactor type | Advantages | Disadvantages | Bio-oil yield (%) |
|---|---|---|---|
Fixed bed | Simple design Reliable Biomass size independent | High carbon conservation Long solid residence time Low ash carry over Difficult to remove char | 35–50 |
Bubbling fluidized bed | Simple design Easy operation Good temperature control Suitable for large scale | Small particle sizes are needed | 70–75 |
Circulating fluidized bed | Well-understood technology Good thermal control Large particle sizes can be used | Unlikely to be suitable for large Scale Complex hydrodynamics Char is finer | 70–75 |
Rotating cone | Centrifugal force moves heated sand and biomass No carrier gas required Less wear | Complex process Small particle sizes needed Not proven yet for large scale | 65 |
Vacuum | Produces clean oil Can process larger particles of 3–5 cm No carrier gas required Lower temperature required Easier liquid product condensation | Slow process Solid residence time is too high Require large scale equipment Poor heat and mass transfer rate Generates more water | 35–50 |
Ablative | Inert gas is not required Large particle sizes can be processed System is more intensive Moderate temperature required | Reactor is costly Low reaction rate | 70 |
Auger | Compact No carrier gas required Lower process temperature | Moving parts in hot zone Heat transfer in large scale is not suitable | 30–50 |
PyRos | Compact and low cost High heat transfer Short gas residence time | Complex design Solids in the oil Alkali dissolved in the oil High temperature required | 70–75 |
Plasma | High energy density High heat transfer High temperature Very good control | High electrical power consumption High operating costs Small particle sizes required | 30–40 |
Microwave | Efficient heat transfer Exponential control Compact High heating rate Large size biomass can be processed Uniform temperature distribution High temperature | High operating costs | 60–70 |
Solar | Use renewable energy High heating rate High temperature | High costs Weather dependant | 40–60 |