The physical handling of biomass fuels during collection or at a processing plant can be challenging to conveying equipment designers, particularly for solid biomass. Biomass fuels tend to vary with density, moisture content and particle size (some even being stringy in nature) and can also be corrosive. Therefore biomass fuel handling equipment is often a difficult part of a plant to adequately design, maintain and operate.
The design and equipment choice for the fuel handling system, including preparation and refinement systems is carried out in accordance with the plant configuration. This is of special importance when the biomass is not homogeneous and contains impurities, typically for forest and agro residues. Some of the common problems encountered have been the unpopular design and undersized fuel handling, preparation and feeding systems.
The fuel handling core systems and equipment are dependent on both the raw fuel type and condition as well as on the conversion/combustion technology employed. The core equipment in a biomass power plant include the following:
- Fuel reception
- Fuel weighing systems
- Receiving bunkers
- Bunker discharge systems (stoker, screw, grab bucket)
- Fuel preparation
- Fuel drying systems
- Screening systems
- Shredding systems
- Grinding systems (for pulverised fuel burners)
- Safety systems (explosion relieve, emergency discharge, fire detections etc)
- Fuel transport and feeding
- Push floors
- Belt feeders
- Conveyers and Elevators
- Tube feeders
- Fuel hoppers and silos (refined fuel)
- Hopper, bunker and silo discharge
- Feeding stokers
- Feeding screws
- Rotary valves
To enable any available biomass resource to be matched with the end use energy carrier required (heat, electricity or transport fuels) the correct selection of conversion technologies is required. Since the forms in which biomass can be used for energy are diverse, optimal resources, technologies and entire systems will be shaped by local conditions, both physical and socio-economic in nature.
As the majority of people in developing countries will continue using biomass as their primary energy source well into the next century, it is of critical importance that biomass-based energy truly can be modernized to yield multiple socioeconomic and environmental benefits.