Biofuels

Question 1

what does electricity split water into

Answer 1

oxygen and hydrogen

Question 2

what do the bacterium use as an energy source, and for what

Answer 2

hydrogen, to take in Co2 and convert it to a biofuel

Question 3

what are the 4 types of fuels

Answer 3

alcohols - bioethanol and biobutanol
vegetable oils and biodiesel
biogas
biohydrogen

Question 4

what are the two main production strategies

Answer 4

grow crops high in starch

grow crops high in oils

Question 5

an example of crops high in starch and how they are used

Answer 5

corn, maize - high in sugar - yeast fermentation - ethanol

Question 6

examples of crops with high amounts of oil and how it is used

Answer 6

soybean, algae - chemically processed into biodiesel - can be burned directly in diesel engine

Question 7

what are the problems with using corn/sugar cane

Answer 7

more energy in than out, low yield, competes for crop land

Question 8

what are the problems with rapeseed oil/ biodiesel

Answer 8

compete for crop land, low yield, reduces diversity in cleared areas

Question 9

problems with biogas

Answer 9

not concentrated enough, not enough demand

Question 10

what are second generation biofuels made from

Answer 10

biomass - living and dead biological material

Question 11

what are cellulosic biofuels and what is cellulose

Answer 11

wood/grasses - the non edible parts of plants

complex carb, supports most plant structures, most abundant naturally occurring molecule

Question 12

How are cellulosic biofuels made

Answer 12

enzymes used to break down cellulose - sugar - microbes ferment sugars to ethanol, then purified

Question 13

what are 3rd generation biofuels

Answer 13

biofuel carbon derived from light and Co2

Co2 produced from powerstations and industrial plants used to feed the process - biofixation of Co2

Question 14

3 benefits of bioethanol

Answer 14

high oxygen content
less toxic
uses renewable energy

Question 15

3 disadvantages of bioethanol

Answer 15

highly corrosive
food vs fuel debate
higher production costs

Question 16

what is biobutanol

Answer 16

4 carbon alcohol produced by the fermentation of biomass

Question 17

3 benefits of biobutanol

Answer 17

higher energy content, less corrosive, can be blended with petrol at higher concentration

Question 18

2 disadvantages of biobutanol

Answer 18

higher production costs

low yield

Question 19

what bacterium produces a high ethanol yield, has a higher rate of sugar uptake, and a higher ethanol tolerance

Answer 19

Zymomonas mobilis - causes cider sickness and the spoiling of beer

Question 20

describe this bacterium

Answer 20

rodshaped, gram -ive non-sporulating, facultative anaerobic

Question 21

what is clostridia

Answer 21

a bacteria, oxygen is toxic to them - they lack aerobic respiration, gram +ive, wide spread in soil

Question 22

what is ABE fermentation

Answer 22

Acetone Butanol Ethanol fermentation

most common way to produce biobutanol

Question 23

what differs about the sugars bacteria use vs yeast

Answer 23

bacteria use pentose sugars, yeast don’t

Question 24

if you ferment a bushel of corn, which method of fermentation would produce the highest concentration of ethanol

Answer 24

yeast fermentation, not ABE

Question 25

why is butanol superior to ethanol

Answer 25

low product yield vs solvent toxicity - waste - acetone
substrate costs - sugar and starch competition with food
costs of downstream processing - distillation expensive

Question 26

what is CBP

Answer 26

consolidated bioprocess

organism degrades lignocellulose and ferments the sugar released into fuel

Question 27

what is the name of gas eating/carbon fixing bacteria

Answer 27

clostridium

Question 28

what is the pathway called that the carbon fixing bacteria use and what do they produce from it

Answer 28

wood-ljungdahl pathway

acetyl-CoA

Question 29

what are homoacetogenic bacteria and what do they do

Answer 29

acetogens - anaerobic microos that make Acetate from carbon units in their energy metabolism - they can have Co2 as their sole energy source

Question 30

what did lanzatech do

Answer 30

made a fermentation process that used industrial waste gas as sole energy and carbon source - completely outside of the food chain

Question 31

what is in synthetic gas

Answer 31

hydrogen, carbon monoxide, carbon dioxide

Question 32

2 problems with acetate production

Answer 32

toxic at low concentrations

takes away from ethanol production

Question 33

what is the future for biofuels

Answer 33

using cellulosic biomass

Question 34

what are the challenges in cellulosic biofuel production

Answer 34

sustainable feedstock availability
the cost of biomass deconstruction
construction of better more efficient biofuel pathways