Module 11.3 Homework

What are some of the disadvantages of using algae for biodiesel production?

Algae require expensive nutrient supplements. Algae are susceptible to contamination by microorganisms. Algae need ideal conditions to maximize oil production.

Which statements describe why high‑demand engines such as those in airplanes and large trucks use biodiesel instead of ethanol?

Biodiesel contains more energy per volume than ethanol. Biodiesel can be used directly in most newer diesel engines.

Which fuel would be the most environmentally friendly choice based on total environmental impact and greenhouse emissions?

Brazilian sugarcane ethonal

Any kind of organic matter has the potential to be converted to biogas or liquid biofuel. However, some materials are more suitable or convenient sources of direct biomass energy, and some are more suitable as indirect biomass energy sources. Some materials are suitable as both direct and indirect sources of biomass energy. Classify the sources of direct.

Manure, peat

What are the advantages of using cellulosic, polyculture plots over monoculture plots for ethanol production?

Polyculture crops have a higher energy returned on energy invested. Polycultures can be grown on agricultural lands with marginal soil. Polyculture plots capture and sequester more carbon dioxide.

Classify some of the advantages of biofuel use.

Potential to be carbon-neutral, versatility as a fuel, marginal land use, renewability.

Why are fast‑growing plants a better option for biofuels?

Replacement growth will quickly remove the CO2 released from the biofuels.

Any kind of organic matter has the potential to be converted to biogas or liquid biofuel. However, some materials are more suitable or convenient sources of direct biomass energy, and some are more suitable as indirect biomass energy sources. Some materials are suitable as both direct and indirect sources of biomass energy. Classify the sources both direct and indirect.

Wood and forest products. Cornstalks. Sunflower stalks and hulls.

What are some strategies that can maximize fuel efficiency while driving?

avoiding idling, avoiding aggressive driving, driving a fuel‑efficient car

When comparing the net energy balance of biofuels, which one provides the highest energy return on energy investment?

biomass ethanol

When producing cellulosic ethanol, which step is slow, expensive, and energy‑intensive?

getting the yeast to digest the cellulose

What are the advantages of biofuels derived from current biomass?

low carbon footprint. locally produced. considered renewable

Classify some of disadvantages of biofuel use.

lower EROEI, redesign of equipment, water consumption, increases in food prices, particulate matter pollution.

Any kind of organic matter has the potential to be converted to biogas or liquid biofuel. However, some materials are more suitable or convenient sources of direct biomass energy, and some are more suitable as indirect biomass energy sources. Some materials are suitable as both direct and indirect sources of biomass energy. Classify the sources of indirect.

sunflower seeds, corn kernels, sugar cane, grasses, restaurant fry grease