OIL & NATURAL GAS What are three concerns you have about
Americas energy future? 1) 2) 3) What are three things that make
you optimistic about Americas energy future? 1) 2) 3) OIL &
NATURAL GAS Energy Sources >85 % of energy sources are Fossil
Fuels >90 % of energy sources are Non- Renewable Petroleum:
1.What is it? 2.How does it form? 3.Where does it form? 4.How do we
find it? 5.How do we remove it? 6.How do we process it? 7.What do
we use it for? 8.How much is left? Petroleum: Petroleum or crude
oil is a naturally occurring, flammable liquid consisting of a
complex mixture of hydrocarbons of various molecular weights and
other liquid organic compounds, that are found in geologic
formations beneath the Earth's surface. What pattern do you
observe? A hydrocarbon is an organic compound consisting entirely
of hydrogen and carbon. Different types of hydrocarbons are
1.Alkanes 2.Cycloalkanes 3.Aromatic hydrocarbons (Arenes) 4.Alkenes
5.Alkynes Alkanes:(parafi ns, saturated hydrocarbons) Saturated in
hydrogen, all C-H bonds are single bonds (share two electrons) What
pattern do you observe about boiling and melting points? Which is
most similar to water? Example of Alkanes: Octane: Pentane:
Cycloalkanes: How is this different? Cycloalkane: (naphthenes) are
types of alkanes which have one or more rings of carbon atoms in
the chemical structure of their molecules. Ex: cyclobutane Aromatic
hydrocarbons (Arenes) Have alternating single and double bonds
between carbons Ex: Benzene Alkenes (olefin, or olefine) is an
unsaturated (fewer hydrogen atoms) chemical compound containing at
least one carbon-to-carbon double bond Ex: Ethylene - (C 2 H 4 )
[Compare to Ethane - (C 2 H 6 )] Alkynes (acetylenes) are
hydrocarbons that have a triple bond between two carbon atoms, with
the formula C n H 2n-2 Ex: ethyne - C 2 H 2 Petroleum:..but varies!
Petroleum: But I thought hydrocarbons were just carbon and
hydrogen? Where did the other stuff come from? Petroleum: but
varies! Natural gas - primarily methane, with 0-20% higher
hydrocarbons (primarily ethane) Gasoline (petrol) - refined alkanes
from pentane (C 5 H 12 ) to octane (C 8 H 18 ) are refined into
petrol Diesel Fuel and Kerosene (used for jet fuel) - alkanes from
nonane (C 9 H 20 ) to hexadecane (C 16 H 34 ) Fuel oil and
lubricating oil - alkanes from hexadecane upwards Paraffin wax - an
alkane with approximately 25 carbon atoms Asphalt - made from
alkanes with 35 carbon atoms and up Hydrocarbons may be mixed with
other non- hydrocarbons, to create other end products: Alkenes can
be manufactured into plastics Lubricants (light machine oils, motor
oils, and greases) Wax Bulk tar Asphalt Paraffin wax Aromatic
petrochemicals to be used as precursors in other chemical
production (such as almost all of our pharmaceuticals and
fertilizers) Fig. 7-8, p. 213 Combustion: All alkanes react with
oxygen in an exothermic combustion reaction, although they become
increasingly difficult to ignite as the number of carbon atoms
increases. The general equation for complete combustion is: C n H
2n+2 + (1.5n+0.5)O 2 (n+1)H 2 O + nCO 2 + energy (What are the end
products?) Combustion: Normally, for methane: CH 4 + 2O 2 CO 2 + 2H
2 O (the end products are water and carbon dioxide) Combustion:
However, without sufficient oxygen, carbon monoxide or even soot
can be formed: C n H (2n+2) + nO 2 (n+1)H 2 O + nCO For example,
for methane: 2CH 4 + 3O 2 2CO + 4H 2 O (note: the end products are
water and carbon monoxide) What are the steps that are needed to go
from this to this? Formation of Petroleum: 1.Ocean organisms
(algae, zooplankton) die and sink to the ocean floor million years
ago. 2.Burial is rapid (geologically!) and anoxic. 3.Deep burial
results in high temperatures that result in the cracking of complex
organic molecules (like kerogen) into lighter hydrocarbons. 4.Most
liquid and gas hydrocarbons rise up to the surface and reenter the
carbon cycle. 5.If an appropriate cap rock exists (usually shale),
then the hydrocarbons stay underground. 6.Certain geologic events
(faults, folds, salt domes) can concentrate the hydrocarbons,
making them economically viable to remove. Formation of Petroleum:
Cracking is an endothermic reaction (you need to give it energy),
but the Earth provides the energy over long periods of time! Ex:
Natural gas can be formed from glucose in the following reaction: C
6 H 12 O 6 + Energy 3CH 4 + 3CO 2 (glucose) Gas/Ice Giants Cassinis
voyage to Saturns moon Titan. Titan: only moon with a substantial
atmosphere (nitrogen) Liquid methane on a water-ice surface? Lakes
(liquid methane/ethane) at Titans north pole (Cassini) New
research: Titan could (theoretically) support microbial life that
breathes hydrogen (missing from surface) and ingests acetylene
(missing from atmosphere). Petroleum that reaches the surface is
eaten by certain types of bacteria (La Brea tar pits) Certain types
of archaea will produce methane (methanogens) The energy is
released by the oxidation of hydrogen: CO 2 + 4H 2 CH 4 + 2H 2 O
Methanogens cause marsh gas in wetlands (two billion tonnes of
methane per year), and gas from animals (cattle, termites,
etc.)
