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 ($\frac{R}{P}$) → 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