lec 11

Question 1

what is a fuel

Answer 1

any substance that provides heat + energy when burned

Question 2

how long ago did we start using firewood, and what was its purpose?

Answer 2

1.7 to 2 million years ago

1. warmth + lighting
2. warding off predators
3. creating more advanced tools
   4. cooking

Question 3

in developing nations, what is the primary purpose of energy consumption?

Answer 3

cooking food (~50%)

Question 4

what are wood pellets? how are they made?

Answer 4

wood pellets are small pellets made from the scraps of wood
1. moisture is removed
2. wood is ground into dust and compressed into pellets
3. heat is applied, activating lignin (natural polymer in wood that acts like a glue)

result is a super high energy yield fuel!

Question 5

what is charcoal?

Answer 5

partially burned material u can get some extra use out of (ex. wood, coconut shells, bamboo, etc)

Question 6

what are nonfood crops? what are the two categories of nonfood crop?

Answer 6

crops grown to provide biomass, typically grown on marginal (undesirable) land

categories are herbaceous and short rotation woody

Question 7

what are the traits of herbaceous nonfood crops?

Answer 7

• perennial
• grasses that take 2-3 years to mature and harvest

switchgrasses, miscanths, sweet sorghums, tall fescue, wheatgrass

Question 8

what are the traits of short rotation woody nonfood crops?

Answer 8

• fast growing hardwood trees
• harvested within 5 to 8 years of planting

Question 9

what is a biofuel? how do they compare to fossil fuels?

Answer 9

any fuel derived from a biomass

produced very quickly + renewable!

Question 10

what are the two most common types of fuel?

Answer 10

ethanol and biodiesel

Question 11

what is ethanol made of? what is it useful for?

Answer 11

ethanol is made from various plant materials (mostly starches, particularly corn starch)

u can add it to octane to incr the quality of gasoline, cutting down on CO and other smog emissions

Question 12

what is the process of making ethanol?

Answer 12

1. milling: take some corn and grind it to a meal
2. liquefaction: add water to corn meal + cook (add alpha-amylase to catalyze the reaction)
3. saccharification: break down starches into sugars (glucoamylase catalyzes)
4. fermentation: convert sugar to ethanol via yeast
5. distillation: evaporate + condense down
6. denaturation: add to gasoline!

My Love Sucks Fucks Dicks Dean [???]

Question 13

what is a biodiesel?

Answer 13

liquid fuel produced from renewable resources, such as new/used vegetable oil or animal fats

Question 14

what is the process of making biodiesl?

Answer 14

extract oil, refine it, transesterify (add alcohol) and boom u have biodiesel and also some glycerol

many plant oils can be used, incl canola, flax, palm, sunflower, etc

Question 15

jatropha is toxic… what can we use it for?

Answer 15

high in oil content! can use for biodiesel

Question 16

what are some high % oil seeds we could use for biodiesel?

Answer 16

jatropha, mahua, pongamia (Pinch My Jugs)