Biomass Energy and Biofuels L7 Flashcards
1
Q
Challenges in converting biomass to energy and fuels
A
- Reduction of production cost
- Increasing conversion efficiency
- Minimizing negative impacts on environments
- Cost of biomass transportation and handling increase with quantity needed for plant
2
Q
Costs vs Efficiency
A
Liquid and gaseous fuels from biomass are complicated due to the complicated nature of biomass
- Overall efficiency is low
- Waste liquids and gas emissions may be generated that cause negative impacts on the environment
3
Q
Current state of thermochemical conversion technologies and development
A
Combustion
- Mature and widely used in NZ
Gasification
- Demonstrative plants in USA and Europe
- Small to medium commercial plants in Europe
Pyrolysis
- Pilot plant scales for fast pyrolysis in NZ, Europe, North America
- Large commercial plants in operation in Canada and USA
4
Q
Densification of Woody Biomass
A
- Bulk woody biomass is compressed into fire logs and pellets
- Densified wood is self bonded by mechanical compression of wood particles and chemical bonding my lignin
Advantages of biomass densification
- Easier handling and feeding due
- High resistance to damage
- Low costs for transportation and storage due to higher density
- Reduction of combustion emission due to lower moisture content
5
Q
Densification of Biomass on site by pyrolysis
A
- Converting biomass to a slurry of bio-oil and char
- Energy self-sufficient using non-condensable gases
- A fluidised bed reactor with internal gas as fluidisation agent
- Self-generated bio-oil is circulated to quench and condense the pyrolysis vapour.
6
Q
Requirement of raw material for wood pellets and fire logs
A
- Particle size: average 3 mm and in a range of 0.1 - 5 mm
- MC: 10-12%
