Lecture 56: Fossil Fuels II

Natural Gas

Natural Gas Use is Increasing

  • Consists primarily of methane with other volatile hydrocarbons
  • Liquid at ambient pressure and temp underground but above ground its gas
  • Provides 25% global commercial NRG consumption

Natural Gas Has Only Been Recently Widely Used

  • 1st commercial extraction in 1821
  • Local because it cannot be transported safely
  • First used to light street lamps, then for heating
  • After thousands of km of pipes were laid, natural gas transport became safer and more economical
  • Liquified Natural Gas (LNG) → Liquid gas that can be shipped through tankers and pipes

Natural Gas Forming

  • Biogenic Gas → Created at shallow depths by bacterial anaerobic decomposition of organic matter
  • Swamp Gas
  • Thermogenic Gas → Results from compression and heat deep underground
  • Source material for natural gas and oil is kerogen
  • Organic matter that results when carbon bonds begin to break

Natural Gas Extraction

  • More challenging with time
  • The first gas fields simply required an opening and the gas moved upward
  • Most remaining fields require pumping by horsehead pumps
  • Gas is now accessed by sophisticated techniques such as fracking, which pumps high-pressure salt water into rocks to crack them
  • Shale gas is likely the "next big thing" in fossil fuel resource

Some Alternates May Extend Fossil Fuel Reserves

  • "Clean" coal tech
  • Extends coal resources → Gasification, liquification
  • Clean the coal → pre-, syn-, and post-combustion clean-up
  • "Unconventional" hydrocarbon resources
  • Tar sands (oil sands)
  • Shale gas
  • Others
  • New extraction techniques

Canada Owns Massive Deposits of Oil Sands

  • Tar Sands → Sand deposits with 1-20% bitumen, a thick form of petroleum rich in carbon, poor in hydrogen
  • Degraded and chemically altered or immature oil deposits
  • Removed by strip mining
  • Requires special extraction and refining to be usable

Fossil Fuel Use has Environmental Supply, and Strategic Implications

Implications of continued fossil fuel dependency

  • Environmental and health concerns
  • Supply concerns
  • Strategic concerns

Environmental and Health Concerns

  • Strip mining causes severe soil erosion and chem runoff
  • Acid mine drainage
  • Mountaintop removal
  • Enormous damage
  • Mining companies restore landscapes, but the impacts are still severe
  • Subsurface mining is especially hazardous
  • Inhalation of coal dust can lead to black lung
  • Coal dust is extremely explosive, and mines collapse
  • Coal mining is the most dangerous type of mining
  • Coal burning releases impurities
  • Coal is the most abundant but least env friendly fuel
  • Sulphur, mercury, arsenic, other trace metals
  • High sulphur coal burning releases sulphates
  • Coal in the eastern Canada is high in sulphur
  • Contributes to acidic deposition

What is the Main NRG Source in Ontario?

  • This is a trick Q
  • It is not fair
  • Type of NRG not specified
  • NRG production does not mean consumption
  • Electricity is not the only NRG

Electricity Generation in Ontario

  • Mainly nuclear
  • Then hydro
  • Then gas
  • Then other
  • Coal was 16%, but was then abolished

Environmental Concerns with Oil and Gas Spills

  • Infrastructure
  • Housing for workers
  • Transport pipelines
  • Waste piles for removed soil
  • Road networks in pristine wild areas and permafrost
  • Ponds for the toxic sludge (tailings) that remains after oil removed
  • Spills and pipeline ruptures
  • Hydraulic fracturing - "fracking"

Pipelines

  • The trouble with "dillbit"
  • Keystone XL
  • When transporting oil from tar sands, it is too thick to transport, so they dilute it, turning it to dillbit.
  • This is very corrosive and bad. This causes major leaks

Some Fossil Fuel Burning can be Captured

  • Carbon cap and storage
  • Technology for large scale, meaningful CSS is not there yet
  • Diverts attention from development of alt NRG

Alternatives Also Have Downsides

  • EROIs for unconventional hydrocarbons is low compared to other sources
  • Combustion pollutes the atmosphere just as much as crude oil, coal, and gas
  • Severe environmental impacts of extraction
  • Devastates landscapes
  • etc


Fracking

  • Drill hole, put explosives in it to fracture rock
  • Pump mix (proponent) into the cracks so that it doesn't collapse
  • Pump solvent in to dissolve and extract the stuff (usually hot salt water)
  • The stuff is then pumped away as dillbits
  • Rest goes into tailings
  • Earthquakes and sinkholes can be triggered


Supply Concerns

Will we run out?

  • We have not run out yet
  • People keep finding more, new tech is developed to extract these lesser quantities
  • Reserves to production ratio (RP\frac{R}{P}) → The amount of total remaining reserves divided by annual rate of production
  • At current levels of production (30 billion barrels/yr) at least 50 yrs of oil left
  • We will face a crisis when the rate of production begins to decline


Supply concerns → Hubbort's peak

  • Prediction of falloff point of oil production


Strategic concerns

Reserves are Unevenly Distributed

  • Some regions have substantial reserves, whereas others have very few (Japan)
  • How long a nation's reserves will last depends on?
  • How much the nation extracts, consumes?
  • How much it imports from and exports to other nations?
  • Nearly 67% of the world's proven reserves of crude oil are in the middle east


Many Nations Depend on Foreign NRG

  • Vulnerable to supplies becoming unavail or expensive
  • Gives seller nations much control over crucial resource
  • In Canada, imports have been outweighed by exports


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