Lecture 17: Biofuel Flashcards
What are biofuels?
- energy derived from biomass (in the form of gas, liquid, solid fuel)
what is biomass?
- material from living or recently living organisms or their products (eg; waste oil, ethanol)
what are the four uses of solid biomass fuels?
- direct burning = cooking / heating, electricity
- conversion to gas/liquid biofuels - biodiesel/ethanol and biogas
why is biomass the most commonly used form of renewable energy?
- traditional/most common use: burning wood for heat/cooking
What are some biomass energy innovations?
- burning biomass waste = biopower
- converting biomass to fuel = biofuel
- capturing methane gas
Describe the amount of biomass sources used in the developing world
- firewood, charcoal, manure account for 35% use in developing countries
what is indirect biomass energy?
- biomass may first be converted to another form and THEN burned
- more energy rich and less bulky: burns cleaner (less pm) and can fuel engines
What factors impact the carbon footprint of biofuels?
- the rate at which plants will absorb carbon released by burning biofuels impact short term carbon footprint
- fast growing plants are a better biofuel option since fast growth will take up carbon released
what are some environmental and economic benefits of biomass energy
- carbon neural, releasing no net carbon into atmosphere if plants are replanted
- renewable and sustainable; if plants are grown responsibly/sustainably with limited inputs of inorganic fertilizer/pesticides
- economic: supports rural economies reducing dependancy on imported fossil fuel, reduces air pollutant (PM is still release tho)
what is flex fuel?
- a type of fuel that can use multiple forms of fuel E85 means 85% is ethanol
How much energy demand comes from transportation in Canada?
- 30% of energy demand comes from transportation in Canada
What are some sources of biodiesel?
- vegetable oil (canola, palm, soybean), soybeans, algae, waste oil
- biodiesel can be used directly in a diesel engine
what are the 2 products of biodiesel? Does it have the same energy?
- glycerine: used in moisturizers and soaps
- remaining biodiesel purified and use for engines
- has less power and less fuel economy than normal diesel
Describe ethanol as a biofuel. what are it’s sourced, how energetic is it, what are it’s challenges
- sourced from sugar cane and corn
(cellulosic ethanol experimental) - 2/3 the energy of regulate gasoline
- competes for space with food crops
What percentage ethanol is all fuel in Canada?
- minimum 5% ethanol, regulations will increase this
- any vehicle can run well on E5 or E10, flex vehicles can run on E85
What are some byproducts of ethanol?
- remaining grain: can be further processed for animal feed
- ethanol
describe ethanol production from corn
- grow corn, sugars in corn undergo fermentation to produce ethanol, remaining grain sold as animal feed
Describe biodiesel production from soybeans
soybeans + water + fat + base = glycerol + fatty acids
- fatty acids + methyl alcohol = biodiesel
Which is more energetic? Ethanol or biodiesel?
- biodiesel is more energetic (like double)
between ethanol and biodiesel which is the better option?
- biodiesel has better EROEI, but must consider LCA (fertilizers, pesticides, irrigation, environmental impacts)
How is cellulosic ethanol more efficient than regular ethanol?
- doesn’t require heating like grain ethanol (less energy)
Are prairie biofuels better or worse?
- better, higher EROEI than corn or soy
