observation on exam-- approximately half of the exams were turned in after 30 minutes. Yet few people had scores that said they couldn't improve with another 15 minutes of reviewing answers. There were usually opportunities to recognize or recall, and improve the score. These questions were not simply "do you remember..." or "did you learn..."

The basic fuels

• (wood, charcoal)
• Petroleum
• Coal
• Natural Gas
  • (mostly methane CH₄, but some propane C₃H₈, and butane C₄H₁₀ from the ground)
  • but, most of the propane and butane is manufactured from petroleum
  • odorless; scent is added to help one notice dangerous leaks

Natural Gas

example: during January -March 2001

• natural gas prices soared
• during that time virtually no ammonia (fertilizer) was produced
  • you could sell natural gas for heating for more than you couldget for ammonia made from it.
• there was a shortage of fertilizer this spring

• why was there a shortage of natural gas?
  • many argue it was a manufactured economic crisis
  • natural gas is not simply taken from ground and sent to you
  • there are large storage facilities--
  • the pipe lines can't meet peak demands
    • e.g., massive underground area by Mansfield, near Malibar Farms
  • one fills the storage areas in off times,
    • tap it at peak need
  • decisions in fall 2000 kept those facilities unfilled...

• actually, another factor-- to a certain extent
  • energy sources are interchangeable

• economics determines the choice
  • some power plants can burn either
  • oil, coal or natural gas

• BGSU, for example, just shifted entire heating system from coal to natural gas in summer 2000.
  • partly for convenience (a cost factor)
  • no trucks, bulldozers, coal feeders...
  • partly to avoid coal problems
  • (sulfur emissions, fly ash, coal dust)
• Actually, many such moves put added pressure on natural gas supply during a time of low storage.

Wood and Charcoal

• Burning wood with limited air produces charcoal
  • Charcoal is nearly pure carbon
  • because of the wood cell walls it is porous, low density
  • burns as a good clean fuel (no smoke)
    • (Charcoal briquettes are almost all pressed coal)

• Charcoal was preferred fuel for Iron
  • manufacture over the years
  • England was a major iron/steel producer
    • Virtually all the British forests were cleared for charcoal
    • (much of the British presence in the Americas was for the timber, especially for masts.)

Coal

• interesting obvious fossil material,
  • can see the plant leaves and stems in the coal and in the surrounding rocks.
• Joggins, Nova Scotia (one of my favorite places)
  • near the top of the Bay of Fundy (Maine, New Brunswick, Nova Scotia)
  • tallest tides in the world...come in fast enough that you need to walk at a brisk pace
  • ...tide may go in/out several miles
  • vertical change can be 53 feet at the end of the bay (world wide tides average 3 ft)
• cliff with a great coal seam and each day's tide exposes new fossil materials
  • can easily find 2 foot fossil palm frond or 4-6" tree trunk
  • can see tree trunks sticking out of the cliffs
    • (sorry, not in US so those should be metric dimensions)

Coal looks like carbon-- that is a black solid

• actually it's more of a hydrocarbon
  • (but big molecules)
• burns to CO₂ and H₂O, trace of SO₂, some N₂ and mineral ash
  • actually fairly close to composition (% elements) of plants and animals

• Heating coal leads to a loss of small molecules
  • (liquids, solvents, aniline)
  • (not just separating, rather breaking up)
  • solid is coke (a cleaner fuel)
• the vapors condense, forming rich mixture of starting materials
  • aniline dyes--late 1860's
  • ...make dyes from coal "tars"
  • was big deal... dyes were expensive made from plant leaves, roots
    • indigo = stuff of blue jeans
  • synthetic dyes cheaper, brighter, longer lasting
    • suddenly large agricultural societies lost all income
    • India-- British set up dye plantations
    • Revolution: Ghandi was lawyer, in province with sudden 80% unemployment

can do some alternative chemistry

• C (or coal) + steam ----> CO + H₂
  • converts a solid into gases
  • manufactured gas for heating (in areas without methane, but much riskier)
• CO is a starting point for making new materials
  • methanol, formaldehyde

Petroleum --

• Generally fluid ranging from relatively thick liquid to oozing tar to heavy deposits within shale
• LaBrea Tar Pits in Los Angeles
  • some of the best preserved mammals like Saber Toothed Tigers

• Northwestern Pennsylvania-- pools near surface used by native Americans as medicine
• Col. Drake sunk a well in Titusville... first "oil well"
  • limited market-- purify and make
    • Kerosene for lanterns
    • not an engine fuel (predated serious use of gasoline engines)
    • some lubrication, replacing animal grease on wheel axles
  • soon, the automobile and other engine relied on petroleum

There's a theme developing-- materials displacing other materials

materials to meet new needs, finding new markets

• refineries, additional oil fields including NW Ohio
  • repeats earlier notes...
    • initially refineries separated petroleum
    • range of products, varying use and value
    • gasoline, kerosene, lubricating oils had good market
    • paraffin for candles (cheaper than bees wax or tallow candles)
    • the rest (tars) were of little use or value

• gradually, some materials were used
  • to make other chemicals
  • petrochemical industry
    • ability to fragment and reassemble to meet needs

References, Web Sites

The following Web sites can provide you with additional information and perspective on fossil fuels and related issues.

• fossil fuels and alternatives, a good treatment
• petroleum as a fossil fuel
• a bit less sophisticated treatment
• petroleum, an Ontario information site
• fossil fools (an argumentative piece from the Sierra Club)
• synfuels (synthetic fuels)
  • Synthetic fuels are man-made fuels, typically modifications of existing fossil fuels. The program of tax credits was created to encourage development of alternative fuels. Another goal was to find ways of making better use of low grade fuels-- for example, processing coal to remove sulfur. As the article points out, much of current tax credits goes to activity that is just barely this side of fraud. For example, spraying a layer of raw petroleum on ground coal qualifies as synfuel, even through there are no tecnical improvements as a result-- it's simply different. In many cases, the tax credits are worth more than the materials.
• natural gas price jumps last spring
• natural gas storage (US Department of Energy)
  • return to chem 100 home page