APES Unit 6: Fossil Fuels

Synthetic fuels

liquid fuels that have same properties as fossil fuels but are produced artificially

Synthetic crude

created by upgrading bitumen or synthesizing liquid hydrocarbons from oil shale

Bitumen

tar like substance found in oil sands

Oil sand

mixture of clay, sand, bitumen, and water; ¾ Supply in Canada

how are oil sands created

when conventional oil escapes from porous rock and is degraded into tar by bacteria and groundwater

how does bitumen form

forms when bacteria degrades crude oil over time

what is bitumen used for

binding agent in road asphalt

oil sand extraction near surface

dug up by electric shovel, brought to processing plant, mixed with hot water to extract bitumen, which is cooked until it can be refined

oil sand extraction deep underground

inject stream into one well, suck bitumen out with another

Oil shale

fine grained sedimentary rocks containing kerogen (large supplies but low quality)

kerogen

solid, insoluble matter in sedimentary rocks

consists if a variety of organic materials, including dead plants, algae, and other microorganisms

what does kerogen consist of?

organic materials such as dead plants, algae, and other microorganisms that have been compressed and heated by geological processes

oil shale extraction

distilled from crushed rock by heating, shale oil then heated to remove impurities, and increase flow rate so that it can be sent through pipeline

oil sand and shale benefits

• large potential supply

• easily transported once heated

oil sand and shale tradeoffs

• low net energy yield

• large amounts of water needed

• land disruption

• air & water pollution

• keystone pipeline

oil

ancient planktonic remains settled to sea or lake bottoms, mixing with sediments and buried

keratogenic formation

as many layers of ancient planktonic remains settled, intense pressure builds in lower regions creating a waxy material

catagenesis

cracking process which results in conversion of organic kerogens into hydrocarbons

hydrocarbons

organic compound consisting of hydrogen and carbon found in crude oil, natural gas, and coal

hydrocarbon pyrolysis

the process to turn crude oil into usable petroleum

difference between petroleum and oil

petroleum includes crude oil and products, crude oil is JUST unprocessed oil

environmental impact of oil extraction

causes moderate damage to earth’s land, but transporting it results in spills

refining crude oil

• components are removed at various levels in a giant distillation column

• most volatile components with lowest boiling points are removed at the top

oil benefits

• high net energy

• well developed tech

• high net energy

oil disadvantages

• running out

• low prices encourages waste

• air pollution, greenhouse gases

• 50-60 yr supply

ANWR in news positives

bring jobs and money to Alaska, increase US oil supply, reduce oil imports

ANWR in news negatives

only a small amount of oil present for degradation of protected habitats

ANWR

• found on Alaska’s north slope and contains more than 1/5 of all land in the US Wildlife Refugee System

• Harsh, extreme fragile ecosystem

how big is a barrel of oil

43 gallons

78% of the world’s oil reserves comes from

Algeria, Indonesia, Iran, Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi Arabia, United Arab Emirates, Venezuela

why is the US dependent on foreign supplies?

declining domestic oil reserves, high production cost for domestic reserves, increased oil use

Natural gas

50-90% methane, burned for electricity and heat

types of natural gas

conventional and unconventional

how is natural gas produces

fossil deposits on seafloor

conventional natural gas

• lies above reservoirs of crude oil

• requires natural gas pipelines to be built over oil deposit

• unwanted byproduct

unconventional natural gas (Barnett Shale)

• largest onshore producible reserves of natural gas in US

• collected via fracking

Largest oil reserve

Canada; 40% tar sands

methane hydrates (unconventional NG)

• small bubbles of BG trapped in ice crystals under permafrost and deep ocean sediments

• 2x much energy in hydrates than oil, NG, and coal resources combines

• too costly

natural gas benefits

• ample supply

• high net energy

• cleanest burning fossil fuel

natural gas disadvantages

• releases CO2

• requires pipelines

• water contamination

• air pollution

• land subsidence

• earthquakes

nonrenewable energy

• not replenished within a useful time scale

• depleted faster than can be replenished

• exhaustable

Renewable energy resource

normally replenished by natural processes

not depleted by moderate use

inexhaustible on human time scale

direct solar capital

99% of all energy we use comes from the sun

indirect solar capital

wind, water, biomass (sun makes everything work)

coal benefits

• ample supply (200 years +)

• high net energy

• tech well developed

coal disadvantages

• high env. impact

• land disturbance

• air pollution

• toxic mercury and radioactive materials released

peat

(first stage of coal production) partially decayed plant water in swamps and bogs, low heat content

lignite coal

(second stage) low heat content, low sulfur, limited supplies

bituminous coal

(third stage) extensively used as a fuel because high heat content and large supplies, high sulfur content

anthracite

(fourth stage) highly desirable fuel bc of high heat content and low sulfur content, supplies are limited in most areas

how is coal formed

remains of plants undergo extreme heat and pressure

mostly carbon

what is coal used for

electricity (strip mined)

geological