Ch9 Energy From Biomass Flashcards
Define the term Biomass
A general term of material derived from plants or animal manure
State the categories of biomass
- Organic materials
- Wood
- Agricultural Crops
- Agricultural and municipal wastes
Identify 3 crops grown to provide biomass
- Willow
- Poplar
- Elephant grass
- Maize
- Sugar Cane
What are the advantages of using biomass instead of fossil fuels
- Renewable
- Can be replaced in a human lifetime - Carbon Emissions
- Crops will take carbon from the air during their growing phase that they may produce when burnt
What are the disadvantages of using biomass
- Land Use
- Farmers transitioning from growing food crops to energy crops lowers food supplies and raises the prices of food - Lower Efficiency
- Biomass is less efficient than fossil fuels - Cost
- Biomass is more expensive to grow and use than other fuels
State the typical (%) of energy from combustion that is
obtained from biomass
90%
Explain the term moisture content
The amount of water that is present in the biomass, usually expressed as a percentage.
Explain the term energy density
Energy density is the amount of energy stored in a given material per unit volume or mass
Explain the term porosity
Porosity is a measure of the quantity of voids existing in the wood compared to its overall volume.
What are the advantages of converting wood into woodchips
- Transport
- Accelerated drying
- Automatic feeding boilers
What properties are a requirement of determining its effectiveness as a fuel
- Moisture content
- Energy density
- Particle size
Explain the process of gasification with biomass
- Gasification is a process that converts organic of fossil based carbonaceous materials into carbon monoxide, dioxide and hydrogen
- This is acheived by reacting the materials at a high temperature with oxygen or steam without combustion to produce syngas
Describe the process of gasification with biomass
- Biomass is converted into a mixture of carbon monoxide and hydrogen commonly known as syngas
List 3 of the applications in which the main product of the
gasification of biomass can be used
- Production of ammonia
- Production of methanol
- An intermediate in prodcing synthetic petroleum
- Lubricant in chemical processes
- As a fuel in internal comubstion engines
Describe the process of anaerobic digestion
- Biological process that results in the breakdown of organic matter
- by naturally occuring bacteria that occurs in an environmetn that lacks oxygen
What is produced by the anaerobic digestion of biomass
- Biogas
- Methane and Carbon Dioxide
What is the dangers associated with methane
- Highly flammable
- Dangerous if inhaled
- 25X more potent GHG than carbon dioxide
