6.5: Fossil Fuels

Question 1

Product of fossil fuel combustion

Answer 1

Reaction between oxygen and hydrocarbons releases energy as heat and produces CO2 and water as products

Question 2

Combustion and the Carbon Cycle

Answer 2

Hydrocarbons (FFs) are burned to release energy and the carbon stored in them reacts with oxygen in the air to form carbon dioxides

Wood and biomass work the same where carbon burned reacts with oxygen

Question 3

Environmental Consequences of Coal

Answer 3

• Habitat destruction from clearing land for mining
• Releases the most Co2 out of all other fossil fuels which contributes to global warming
• Releases soot which can cause respiratory irritation and toxic ash contamined with lead, mercury, and arsenic
• Releases sulfur and nitric oxides which can cause respiratory irritation in organisms and contribute to smog and acid precipitation
• Depending on how it is stored (landfill or ash pond), it can leak into surface waters and soil

Question 4

Electricty and fossil fuel efficiency

Answer 4

Coal is 30% efficient, Nat. Gas 60%

Question 5

CHP

Answer 5

Combined heat and power systems are around 90% efficient

Question 6

Environmental Consequences of Tar Sands

Answer 6

• Habitat destruction to clear land for roads, drilling equipment and digging through the ground to reach deposits can lead to biodiversity loss
• Ground or surface water deleption from using the steam to melt the bitumen to washing impurities
• Tailing ponds (holes dug for storing wastewater) can overflow and leach into groundwater or run into nearby surface waters
• Benezene (carcinogen) salts, acids, hydrocarbons, bitumen is toxic to plants and animals
• Carbon dioxide released by machinery during extraction, transport, refinement

Question 7

Environmental Consequences of Crude Oil/Petroleum

Answer 7

• Possibility of spills
  1. Water spill of crude oil can block the sun disrupting biodiversity (alters food chain at the primary level), clog fish gills, suffocate ocean animals, stick to bird feathers
  2. On land, it is toxic to plant roots, surface or groundwater contamination can also result

Question 8

Fracking in detail

Answer 8

Vertical well is drilled down to sed, rock layer, then drill turns horizontally into the rock layer
1. The perforating gun fractures the rock layer around the well making it more permeable
2. Fracking fluid (water, salt, detergent, acids) is pumped into the well at high pressure to crack the rock even more and allow the natural gas to flow out
3. The natural gas is collected and shipped for processing/use
4. The used fracking fluid flows back out, is collected and stored in ponds nearby

Question 9

Environmental Consequences of Fracking

Answer 9

• Storage ponds can overflow or leach into the ground and contaminate soil and surface waters with fracking fluid which can be toxic to plants and animals
• Depletion of ground and surface waters for fracking fluid
• Increased seismic activity has been linked with waste waster injection wells
• Habitat loss and fragmentation from clearing land for drilling and extraction
• CH4/GHG release