Biomass Fly Ash

Ground Biomass Fly Ash

Ground Biomass Fly Ash


Problem: Large brewery wishes to recycle waste grain and malt from the brew process for the production of electric power. Handling the biomass ash cleanly and economically was required.

Solution: Macawber pneumatic conveying systems were used to convey boiler bottom ash and fly ash away to storage. The biomass is dried and transferred to a boiler where it is burned with #6 oil. The biomass fly ash is gathered from four electrostatic precipitator (ESP) hoppers and pneumatically conveyed to an ash silo. The bottom ash is crushed and transferred a short distance via customer’s mechanical conveyor to a pneumatic conveyor where it is transferred to an ash silo for truck loading.

Download Case Study: Ground Biomass Fly Ash (pdf)


  • Material: Brewer Grain Fly Ash, Brewer Grain Bottom Ash, (brewer grain fired with #6 oil)
  • Bulk Density: Aerated 570-730 kg/m3 (36-76 lb/ft3)
  • Size: Fly Ash: 100%<100mesh, Bottom Ash: 300x150x65mm (max)
  • Temperature: 161°C – 300°C
  • Moisture Content: ~0%
  • Condition: Free flowing when aerated
Ground Biomass Fly Ash


  1. Minimize wear and air usage.
  2. Reliable and consistent conveying.
  3. Operate with -15.1” wc vacuum in baghouse.
  4. Operate with elevated bottom ash temperature of 300ºC.


  • Transfer Capacity BA: 635 kg/hr (1400 lb/hr), FA: 657 kg/hr (1450 lb/hr)
  • Conveying Distance BA: 120m (394ft), FA: 56m (184ft)
  • Reception Points: One
Ground Biomass Fly Ash System


1. System operation is stable, reliable and efficient
2. System capacity exceeded specified rates
3. Air consumption was below MEI quoted average