Biofuels

Question 1

What are the main to types of Biofuel

Answer 1

Biodiesel and Bioethanol

Question 2

How is biodiesel usually formed

Answer 2

produced from vegetable oils

Question 3

How is Bioethanol usually formed

Answer 3

Fermentation of sugars

Question 4

What are uses of biofuels

Answer 4

Heating, Electricity and transport

Question 5

What are first generation biofuels

Answer 5

Biofuels that can be considered human food such as rapeseed and palm oil

Question 6

What is the main disadvantage of first generation biofuels

Answer 6

Takes up space that could be used for food crops

Question 7

What are second generation biofuels

Answer 7

Ones that are derived from inedible parts of plants such as husks, leaves and shoots

Question 8

What are 3rd generation biofuels

Answer 8

Biofuels derived from microalgae

Question 9

What are 4th generation biofuels

Answer 9

Biofuels which have been derived from genetically engineered microalgae

Question 10

What is an expeller

Answer 10

Cheap method of oil extraction, hopper system with a rotating screw press

Question 11

What is transesterification

Answer 11

A method to reduce the viscosity of a feedstock so it can be used as a biofuel

Question 12

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

Answer 12

CO2 absorption
Water Treatment
Syn Gas
Potential for genetic engineering

Question 13

What are the advantages of microalgae as a biofuel

Answer 13

Sustainable 
On/off shore 
Not competing for cropland use
Sequester of CO2 
Has Other uses 
Can be grown on brown sites 
High quality fuel

Question 14

What are disadvantages of using microalgae as a biofuel

Answer 14

Difficult to scale up
Not competitive with fossil fuels
Complex process
Currently not commercialised

Question 15

What is the range of oil yields achieved by microalgae

Answer 15

1200-10000 Gallons/Acre

Question 16

What are the 5 processes involved in producing fuel from microalgae

Answer 16

Growth
Solid Separation
De watering 
Extraction 
Refine

Question 17

What can microalgae be grown in

Answer 17

Photobioreactors
Raceways
Indoors/outdoors
Closed pond systems

Question 18

What is the typical range of growth of microalgae

Answer 18

2-5g/(L-day)

Question 19

What is the typical range of heating value of microalgae biomass

Answer 19

14-35MJ/kg

Question 20

What are the costs associated with growing microalgae

Answer 20

Land
pumping
Nutrients 
CO2
Filtration
Centrifuge
Drying 
Chemicals

Question 21

What are the revenue potentials of growing microalgae

Answer 21

Biofuels 
Chemicals
Food
CO2 sequestration
Sewage treatment 
Water purification

Question 22

What is an example of a refining process used in biofuels from microalgae

Answer 22

transesterification

Question 23

What are some methods of microalgae extraction

Answer 23

Laser, microwave, ultrasonic, blender, waterbath,

Question 24

What extraction methods have high figures of merit and what have low

Answer 24

High- Ultrasonic, Waterbath, Microwave

Low- Laser, blender

Question 25

Define figure of merit

Answer 25

Disruption per applied J/1000ml per Volume fraction

Question 26

What is a raceway

Answer 26

A shallow artificial pond used to cultivate algae

Question 27

What is a paddle wheel used for in a raceway

Answer 27

To keep water flowing continuously round the circuit to maintain water quality improving the densities that the algae can be produced

Question 28

How are microalgae produced in raceways

Answer 28

Algae is started in photobioreactors and is transferred to small raceways then to large as the density increases

Question 29

How many Tons of CO2 are produced per ton of algae

Answer 29

1.8