Biofuels Flashcards
What are the main to types of Biofuel
Biodiesel and Bioethanol
How is biodiesel usually formed
produced from vegetable oils
How is Bioethanol usually formed
Fermentation of sugars
What are uses of biofuels
Heating, Electricity and transport
What are first generation biofuels
Biofuels that can be considered human food such as rapeseed and palm oil
What is the main disadvantage of first generation biofuels
Takes up space that could be used for food crops
What are second generation biofuels
Ones that are derived from inedible parts of plants such as husks, leaves and shoots
What are 3rd generation biofuels
Biofuels derived from microalgae
What are 4th generation biofuels
Biofuels which have been derived from genetically engineered microalgae
What is an expeller
Cheap method of oil extraction, hopper system with a rotating screw press
What is transesterification
A method to reduce the viscosity of a feedstock so it can be used as a biofuel
What is the added value of microalgae as a biofuel, ie what you will get from microalgae that you cannot achieve from any other biofuel
CO2 absorption
Water Treatment
Syn Gas
Potential for genetic engineering
What are the advantages of microalgae as a biofuel
Sustainable On/off shore Not competing for cropland use Sequester of CO2 Has Other uses Can be grown on brown sites High quality fuel
What are disadvantages of using microalgae as a biofuel
Difficult to scale up
Not competitive with fossil fuels
Complex process
Currently not commercialised
What is the range of oil yields achieved by microalgae
1200-10000 Gallons/Acre
What are the 5 processes involved in producing fuel from microalgae
Growth Solid Separation De watering Extraction Refine
What can microalgae be grown in
Photobioreactors
Raceways
Indoors/outdoors
Closed pond systems
What is the typical range of growth of microalgae
2-5g/(L-day)
What is the typical range of heating value of microalgae biomass
14-35MJ/kg
What are the costs associated with growing microalgae
Land pumping Nutrients CO2 Filtration Centrifuge Drying Chemicals
What are the revenue potentials of growing microalgae
Biofuels Chemicals Food CO2 sequestration Sewage treatment Water purification
What is an example of a refining process used in biofuels from microalgae
transesterification
What are some methods of microalgae extraction
Laser, microwave, ultrasonic, blender, waterbath,
What extraction methods have high figures of merit and what have low
High- Ultrasonic, Waterbath, Microwave
Low- Laser, blender
