env100 fossil fuels

was just refused for rop so i'm sad af

Conventional sources of energy

• non-renewable: coal, oil & natural gas, unconventional fossil fuels (oil sand, shale gas), nuclear energy

• renewable/ replenishable/ inexhaustible: hydropower, traditional biomass

emerging sources of energy

• new biomass

• solar/wind/geothermal/ocean energy

• batteries and chemical fuels

energy resources can be renewable, inexhaustible, or nonrenewable

/

renewable energy sources

those that are naturally replenished over a timescale relevant to humans

• wind/ocean energy

• hydroelectric power

• biomass

inexhaustible energy sources

may not be replenished over a timescales relevant to humans, but the energy reserve is so large that they are effectively inexhaustible on the scale of human civilization

• solar energy

• geothermal energy

nonrenewable energy sources

finite once these resources are depleted, they cannot be replenished over a timescale relevant to humans

• fossil fuels

• nuclear energy

power

the rate at which energy is transformed for human use

power vs energy

power is a rate

energy = power x time is an amount

We are not in danger of running out of energy. The question is the availability of energy that is:

• technologically recoverable

• economically extractable

• affordable

• socially acceptable

• environmentally friendly

Energy return on investment (EROI)

• ratio of energy obtained/ energy invested. Higher EROI -> more energy than invested

• Non-renewable resources: ratios decline over time when we extract the easiest deposits first and then must work harder to extract the remaining reserves

• Renewable/ inexhaustible: ratios depend on the expected lifetime of the technology (initial investment/ length of time it functions)

Reserves

the resource must have a proven, probable, or possible understanding of its existence

fossil fuel

• hydrocarbon-based energy sources that formed from the remains of plants and animal buried and subjected to high heat and pressure over 300-600 million years

• Fossil fuels are produced when organic matter decomposes in anaerobic conditions. Because of low oxygen conditions, decomposition is slow and therefore organic matter is preserved

kerogen

organic material found in sedimentary rocks

Maturation

• under further heat and pressure, kerogen can be converted into liquid or gaseous hydrocarbons through processes like thermal cracking and pyrolysis

Catagenesis

• when long-chain hydrocarbons break into shorter chains

• What are fossil fuels used for?

• energy generation (electricity, heating), transportation, industrial processes

• plastics, chemicals, manufacturing

• reduction is fossils fuels is happening in most sectors except aviation, shipping & industry

• no good alternatives to jet fuel or ship diesel

coal

• the world’s most abundant fossil fuel

• Coal is formed from plant material compressed and altered to form dense, solid hydrocarbon compounds

• Coal contains lignin, a tough constituent of plants

• Coal is formed by anaerobic decomposition in swamps

• Coal is now used primarily for generating electricity

• Coal forms from burial of woody plant matter

the most environmentally damaging fossil fuel

coal

coalification

• metamorphosis of coal

• pressure + heat over time -> increase in carbon content. decrease in moisture content and volatile matter -> results in different grades of coal

ways to mine coal

• subsurface mining

• strip mining

subsurface mining

underground deposits are reached by digging deep underground

strip mining

• heavy machinery removes overburden to expose and extract the coal

petroleum

• crude oil + its refined products

• complex mixture of liquid hydrocarbons with trace amounts of sulphur, nitrogen, oxygen

• types: heavy, light, sweet, sour (amount of sulphur)

• refined into many products

• natural gas is found in deposits alongside crude oil

• formed by heat and pressure underground

• formed in a shallow marine environment

petroleum and natural gas formation

tiny marine plants and animald died → buried under silt and sand → heat and pressure form oil & natural gas → human drill deep down

the world’s most used fuel

oil

how to extract oil

• drill

• exploratory drilling uses small, deep holes to determine whether oil is there and whether extraction is possible

primary extraction

the initial drilling and pumping of available oil (gushers)

secondary extraction

• solvents, water, or steam is used to remove remaining oil; expensive (EROI?)

Much of our oil and natural gas comes from

• offshore drilling

• Drilling takes place on the seafloor, mainly on continental shelves

refining

crude oil is separated into various components such as gasoline, diesel, jet fuel, heating oil, and petrochemical feedstocks

refine steps

• 1. separation or distillation – separates molecules by weight

• 2. conversion or cracking – remaining heavy/long-chain molecules are broken into lighter components

• 3. treatment – reducing or removing components that cause pollution, especially sulphur

natural gas

• natural gas consists primarily of methane (CH4) with other volatile hydrocarbons

• can be liquid at ambient temperatures and pressures in subsurface reservoirs; becomes a gas at the surface

• commonly occurs with oil

liquefied natural gas (LNG)

natural gas in liquid form, that can be shipped long distances in refrigerated tankers

natural gas is formed in 2 ways

• thermogenic gas = results from compression and heat deep underground (like oil, and often occurs with oil), formed in shallow marine environment

• biogenic gas = forms at shallow depths (fresh or marine) because of bacterial anaerobic decomposition of organic matter

natural gas extraction become more challenging with time

• the first gas fields simply required an opening and the gas moved upward on its own

• most remaining fields require pumping by horsehead pumps

• gas is now extracted using sophisticated techniques (fracking)

fracking

 is hydraulic fracturing: pumping water in to cause fissures in rocks that then release the gas that is then collected. It has many associated environmental concerns (leakage, earthquakes)

what is the dominated fuel source then and now

then: coal

now: oil

Why unconventional fossil fuels now?

• Huge demand for energy but decline in availability of conventional oil and ga resources

• Desire for energy independence (lack of reliance on foreign oil imports) also drove demand for ways to exploit unconventional reservoirs

unconventional fossil fuels are

• hydrocarbon resources that require more complex extraction and processing techniques compared to conventional fossil fuels like crude oil, natural gas, and coal

• often present technical, economic, and environmental challenges due to their geological characteristics and the extraction methods involved

• differences in the quality of the resource, and the characteristics of the reservoir

major unconventional sources

• tight oil (shale oil)

• unconventional natural gas (UG)

• oil shale

• tar sands

tight oil

• Tight oil is crude oil that is trapped within low-permeability rock formations, such as shale, limestone, or sandstone (sometimes called shale oil)

• unlike conventional oil reservoirs, where oil flows freely through interconnected pore spaces, tight oil is stored in the pores of dense and impermeable rock formations, making it more difficult to extract

• typically extracted by fracking

• often occurs with natural gas

Tight oil extraction

• fracking wells run horizontally for thousands of meters – high labour & material costs

• once the well is drilled & perforated, water, proppants (materials (e.g., sand) introduced to keep the fracture open) and chemicals are pumped down the hole to fracture the formation and allow the oil to flow back into the pipe to be pumped out

• much more expensive extraction than conventional crude oil deposits

Economic feasibility of tight oil

• fluctuates wildly with the cost of conventional oil – when the price rises, the ROI of tight oil increases

• when oil prices go down, tight oil operations start to operate at a loss

Environmental impacts of tight oil

• although natural gas is often found in the same formations as tight oil, it’s often too expensive to recover, so it is flared off, contributing to GHGs

• methane leaks

• water, air, noise pollution

• risk of spills

• induced earthquakes caused by fracking + wastewater disposal from oil production

• fracking extracts natural salts, heavy metals, and radioactive materials from the shale, posing risks to ecosystems and public health

Unconventional natural gas (UG)

• natural gas trapped in shale or sandstone formations

• coal-bed methane (CBM) in coal seams – called “sweet gas” because of its lack of sulphur

• extracted via fracking (mostly)

• account for a major portion of US natural gas production

oil shale

• organic-rich fine-grained sedimentary rock containing kerogen from which liquid hydrocarbons can be produced

• can be marine or terrestrial

• can be burned directly in furnaces as a low- grade fuel

• used as a raw material in chemical and construction-materials processing

• can be heated to release shale oil

tar sands (oil sands)

• oil sands, tar sands, crude bitumen, or bituminous sands

• naturally-occurring mixture of sand, clay, and water, soaked with 1-20% bitumen

• proven global reserves are massive – about 70% in Alberta

• a source of “synthetic oil” (needs to be chemically modified to substitute for natural crude oil)

• Canada has massive amount of tar sands resources/ reserves

Bitumen

• extremely sticky, viscous – asphalt

• has been used by humans for millennia (Stone Age tools have been found with traces of bitumen)

• needs to be diluted to pass through a pipeline: dilbit (diluted bitumen)

Dilbit

• dilbit is abrasive – very hard on pipelines

• if it spills, it is extremely hard to clean up (sinks in water bodies and adheres to the sediment)

Environmental impacts of oil sands

• production releases 3X more GHG emissions than conventional crude oil does

• must be extracted by energy intensive steam injection or destructive strip mining

• mines use 2.4 barrels of freshwater for every barrel of product – destroying the Athabasca River

• produces huge amounts of toxic wastewater

• produces petcoke – a highly toxic byproduct that gets into the air

• burning tar sands oil produces more air pollution than conventional crude oil

• exporting tar sands puts rivers & coastlines at risk of spills

• rail cars carrying tar sands crude pass through densely populated areas

Implication of continued fossil fuel dependency

• environmental concerns

• supply concerns

• strategic concerns

Coal mining is environmentally damaging

• strip mining causes severe soil erosion and chemical runoff

• acid mine drainage

• mountaintop removal; -enormous damage

• companies are required to restore landscapes, but the impacts are still severe and sometimes permanent

• Contaminates ground water

• Creates air pollution - releases dust laden with heavy metals

• methane leaks/ seeps

• Coal-seam fires: can burn for centuries, smoke is highly toxic

Coal mining is hazardous

• subsurface mining is especially hazardous

• coal dust explosions and mine collapse - coal mining is the most dangerous type of mining

• coal dust inhalation can cause black lung disease

• Cardiopulmonary disease, hypertension, COPD, and kidney disease are found in higher than normal rates in people who live near coal mines

Coal burning releases impurities

• coal is the most abundant but least environmentally friendly fossil fuel

• releases sulphur, mercury, arsenic, other trace metals

• high-sulphur coal burning releases sulphates; contributes to smog and acidic deposition

• negative impacts

Oil and gas extraction also have negative impacts

• infrastructure (housing for workers, transport pipelines, waste piles for removed soil)

• road networks in pristine wild areas and permafrost

• ponds for tailings that remains after oil removed

• oil drilling contamination and intensive water use

• spills and pipeline ruptures

fossil fuels contribute to atmospheric change

• alters flux rates in earth’s carbon cycle

• change greenhouse gas concentrations in the atmosphere

Unconventional fuels also have impacts

• combustion pollutes the atmosphere just as much as oil, coal, and gas

• EROI for unconventional hydrocarbons is low compared to other sources

• Environmental impacts of extraction:

• devastates landscapes

• pollutes waterways, tailings ponds

• extremely water-intensive

• negatively affects wildlife

• fracking may contribute to earthquakes

carbon offset

a reduction in CO2 or other GHGs made to compensate for emissions elsewhere

Compliance market

corporations trade or purchase carbon offsets to reduce their own emissions to comply with regulations

Voluntary market

 Individuals, companies, or municipalities purchase carbon offsets to reduce their carbon footprint and compensate for their own GHG emissions

will we run out of fossil fuels?

global reserves are finite, but the limiting factor is whether it economically feasible to extract

• We will face a crisis not when we run out of oil, but when the rate of production declines

Reserves-to-production ratio (R/P)

reserves/ annual rate of production

peak oil

refers to a hypothetical point in time when global oil production reaches its maximum rate and begins to decline

Hubbert’s curve

predict that oil production in the contiguous United States would peak around the early 1970 (it didn’t:<)

On global level, there are two significant energy problems

• energy poverty

• most of our energy still products GHG emissions

• we need safe, low carbon, cheap large scale alternatives to fossil fuels