Biofuels

Question 1

What are the 3 most commonly used fossil fuels in Australia right now?

Answer 1

1. Coal - electricity
2. Crude oil - transport
3. Natural gas - transport, heating ,electricity

Question 2

Are biochemical fuels renewable?

Answer 2

Yes - they can be replaced in a short period of time, faster than rate of consumption

Question 3

Biofuels are derived from what?

Answer 3

Plant materials

Question 4

What are some sources of biofeuls?

Answer 4

• Grains: Maize, wheat, barley, sorghum
• Sugarcane
• Vegetable oils
• Vegetable waste

Question 5

How can biofuels be used in everyday life?

Answer 5

• Burn wood for heating
• Burn ethanol from sugarcane for transport
• Burd biodiesel for transport
• Biogas from waste organic matter for heating or electricity

Question 6

Define sustainability

Answer 6

Meeting the needs of the present without compromising the ability of future generations to meet their own needs

Question 7

What are the 3 main biofuels?

Answer 7

1. Bioethanol
2. Biodiesel
3. Biogas

Question 8

Describe process of making Bioethanol

Answer 8

1. Enzymes break down starch in grain, grapes or sugarcane to form glucose
2. Yeast converts Glucose to ethanol and CO2 through enzymes

Question 9

What is the process of creating Bioethanol called?

Answer 9

Fermentation - It is anaerobic (absence of oxygen)

Question 10

Give VCAA Equation for fermentation

Answer 10

C6H12O6(aq) -> 2C2H5OH(l) + 2CO2(g)

Question 11

What are some green chemistry considerations for process of fermentation?

Answer 11

• CO2 produced is greenhouse gas- by-product is collected and sold (for dry-ice)
• Waste water and cooling water from heat exchange- recycled for crop irrigation
• Waste yeast - used as animal food

Question 12

What is Distillation for fermentation products?

Answer 12

Produces a more sustainable transport fuel. Distillation produces 95%v/v ethanol.

Question 13

What is Dehydration for fermentation products.

Answer 13

Happens after distillation. Increases ethanol concentration to 99.5% v/v.

Question 14

What is Petrodiesel?

What molecules?

Answer 14

C14 - C25 alkanes from crude oil

Question 15

What is Biodiesel made of?

Answer 15

Around 17 carbons esters

Can be saturated or unsaturated - used mainly for transport

Question 16

What is the process of making biodiesel called?

Answer 16

Transesterfication

It changes one ester into another

Question 17

What are teh sources of triglycerides for transesterfication?

Answer 17

• Pal oil
• Canola oil
• Animal fat
• Vegetable oil

Question 18

What does Hygroscopic mean?

Answer 18

Water absorbing - forms a gel like substance.

Question 19

Why is Biodiesel being hygroscopic bad?

Answer 19

It increases viscosity (resistance to flow) and thus flow along fuel lines in engines is hampered/halted

Question 20

What is Biogas comprised off?

Answer 20

Methane

Question 21

What is Biogas used for?

Answer 21

Cooking, heating and burnt for electricity

Question 22

How is Methane for Biogas produced?

Answer 22

Through anaerobic decomposition of organic waste. Anaerobic bacteria act on organic matter in digester and produce CH4 and CO2.

Question 23

Describe origions of organic waste for biogas production

Answer 23

• Farms - manure and crop waste
• Sewage plants - human faeces
• Rubbish tips - food waste
• Homes - Food, gardeb waste and human faeces
• Food processing plants - food waste

Question 24

Approximately how much of Biogas is comprised of Methane?

Answer 24

Around 65%