Waste to power systems
Utilizing paper mill waste as a source of energy
Waste as a source of power
Mill and industrial wastes are costly to handle, transport, and dispose of. In a pulp or paper mill, waste is particularly prevalent in the processing of recycled fibers. Plastics, textile, wood, iron, wires, inks, and other small contaminants are a common part of the incoming raw materials (recycled papers and boards) – and these materials are separated from the recoverable fibers used in papermaking. Another waste component is the sludge (residue from deinking processes, raw water, process water and biological water treatment. In pulp and virgin fiber mills, there is relatively clean biomass available in the form of bark, pins, and wood residuals.
Converting waste into fuels in a waste to power process
Waste to power is the process of creating energy in the form of heat or electricity using a waste source as fuel. Most processes produce heat and electricity directly through combustion, or produce a gaseous fuel (methane, methanol, ethanol, or syngas) from a waste source.
First, these waste streams must be collected and concentrated. Next, in many cases they can be treated (screened, mechanically cleaned, dewatered, dried, etc.). Then, the valuable “product” can be pelletized (for transport) or burned directly in a power boiler.
Benefits of handling residuals with a waste to power system
- Reduce deposit and energy costs
- Fulfill legal requirements (EU directive 1999/31/EC)
- Close mill internal energy loop
- Generate green electricity and reduce carbon footprint
- Achieve a higher independence degree from energy suppliers
- Increased calorific value of burnable waste
ANDRITZ waste to power processes
- Recycled fiber rejects treatment
- Recycled fiber, paper mill and waste water treatment sludge dewatering
- Thermal drying process
- Pelleting process
- Combustion process with both bubbling fluidized bed boilers and circulating fluidized bed boilers