1. C.2 Fossil fuels
Fossil fuels were formed by the reduction of biochemical molecules over the course of million years.

3. Coal is fossilized plant material containing mostly carbon, but also nitrogen, sulfur and hydrogen.
Crude oil was formed from the remains of marine organisms up to 600 million years ago.

4. Natural gas was formed alongside crude oil and consists of 85-95% methane, with varying amounts of
propane
butane
other gases
(such as hydrogen sulfide)

5. Crude oil (petroleum)
The hydrocarbons are separated and converted to useful fuels in an oil refinery by fractional distillation,
cracking, and catalytic reforming.

6. Coal

7. Crude Oil (petroleum)

8. Natural Gas

9. Fractional distillation:
The physical separation of a mixture of pure substances based on the varying boiling points of the constituents.
For crude oil, the shorter the C-C chain length, the lower the boiling point.

11. *
* Naphtha: a mixture of flammable liquids

12. Cracking
Cracking is a process where larger, less valuable hydrocarbons are broken down into smaller, more valuable ones.
Example:

13. Catalytic reforming:
A process during or after cracking where straight chain alkanes are converted into branched alkanes or cycloalkanes.
Examples:

14. Fuel efficiency
Internal combustion engines experience pre-ignition or “knocking” when excess straight-chain alkanes are in the gasoline mixture, causing the engine to run inefficiently.

15. Octane number:
A scale used to rate the efficiency of fuels burned in an internal combustion engine.
Pure heptane is assigned an octane number of zero. (poor rating)
An isomer of octane, 2,2,4-trimethylpentane is assigned an octane number of 100. (high rating)

16. * aka RON: Research Octane Number
An octane rating* is based on comparing how efficient a fuel burns (i.e., amount of knocking) compared to a mixture of these two alkanes.
For example:
A fuel with an octane rating of 95 burns as efficiently as a mixture of 95% 2,2,4-trimethylpentane and 5% heptane.
* aka RON: Research Octane Number

17. RON 15 72 93 % Fuel 22 A 58 B 20 C Sample problem:
Deduce the octane rating of a fuel containing the following mixture: %
Fuel
RON 22 A 15 58 B 72 20 C 93

18. Coal gasification and liquefaction:
chemical processes that convert coal to gaseous and liquid hydrocarbons.
The primary method is to blast coal alternatively with steam and air which produces a mixture of carbon monoxide and hydrogen gas, called “syngas” (synthesis gas).

19. Syngas can then be converted to synthetic natural gas or synthetic liquids fuels:
Examples:

21. Global warming is directly linked to the increase of carbon emissions into the atmosphere, primarily CO2.
A “carbon footprint” measures how much CO2* is produced by an activity.
* or CO2 equivalent greenhouse gases, such as methane.

22. Sample problems:
1. A heater consumes 3.70 L of propane per day. If propane has the density of g/cm3, what is the heater’s carbon footprint if it runs nonstop for four weeks?

23. 2. What is the carbon footprint of ethyne in kJ/mol, given its enthalpy of combustion is -1301kJ/mol?