fossil fuels and energy usage

crustal abundance

average concentration of an element in the earth’s crust, which can vary from one location to another

ores

concentrated accumulation of minerals which economically valuable materials can be extracted

metals

conduct electricity and heat energy, found in rock with sulfur, oxygen, and silicon

how do ores form?

1. when magma touches water

2. deposition of igneous rock

vein

small areas with a HIGH concentration

disseminated deposits

large areas with LOW concentration

nonmetallic minerals

clay, sand, salt, limestone, phosphate; typically occur in higher concentrations

bauxite

ore that aluminum is typically found in, formed by intense chemical weathering in tropical regions

lower concentration and accessibility leads to?

greater energy expended and greater disturbance

reserve

known quantity of how much a resource can be economically recovered

economically recoverable

extractable concentration is high enough to be profitably mined

mining technique for minerals

mining the ore and separating other materials

surface mining techniques

strip mining, open pit mining, mountain top removal, placer mining

strip mining

removes overlying vegetation (‘overburden’) to expose the ore, but disturbs the soil and causes erosion

mine tailings

unwanted waste product

open pit mining

leaves visible hole or pit, used when the ore is close to the surface but extends horizontally and vertically

mountain top removal

uses explosives to remove the entire mountain, but can deposit tailings in rivers/streams

placer mining

looking for minerals, metals, etc in river sediments

sub surface mining techniques

more expensive, usually requires a horizontal tunnel with vertical shafts

mountain top removal IMPACTS

tailings can be deposited in nearby valleys and obstruct/change river flow

placer mining IMPACTS

contaminates water

sub surface mining IMPACTS

acid mine drainage, methane is released in process

acid mine drainage

highly acidic, metal rich water is exposed to air and water which creates sulfuric acid and dissolves heavy metals

when does extraction become more expensive and destructive?

when the resource has been exhausted

coal formation

organic matter buried without air exposure, usually in tropical locations

oil formation

remains of ocean dwelling phytoplankton inside of porous sedimentary rock, which produces natural gas as well (rises above the oil)

petroleum (also oil)

aside from transportation uses, petroleum is the raw material for plastics, lubricants, pharmaceuticals, and cleaning solvents

advantages of coal

energy dense and plentiful, provides heat energy for steel production and electricity generation

disadvantages of coal

many impurities (SULFUR), trace metals, air pollution

advantages of oil

easy transport, energy dense and cleaning burning than coal

disadvantages of oil

contains sulfur and trace metals, OIL FLARING

oil flaring

burning off excess natural gas, taking place nearby homes and causing air pollution

advantages of natural gas

fewer impurities, cleanest burning out of fossil fuels

disadvantages of natural gas

release of methane

fracking (hydraulic fracturing)

method of oil/coal extraction by high pressure fluids to open existing cracks in rocks

fracking disadvantages

uses a lot water and contaminates it, releases VOCs

VOC (volatile organic compounds)

organic compound air pollutants

energy quality

ease that source can be used

escaped natural gas

“fugitive gas”

electricity generation process

1. fuel is burned in boiler

2. steam is produced by the burning

3. the steam spins a turbine

4. turbine spins a generator