Unit 4 - Energy from Fossil Fuels Flashcards
Define the terms joule and watt. How do these measurements relate to one another?
A joule is the electrical energy needed to maintain a flow of one ampere for one second at a potential of one volt; a watt is a unit of power defined as the consumption of one joule of electrical energy per second.
Why did the British begin using coal as their main energy source soon after the onset of the Industrial Revolution?
Soon after the beginning of the Industrial Revolution, it became apparent that wood could not meet the rapidly expanding needs for energy: the demand for wood was threatening to deforest Britain.
Where, according to Craig, Vaughan, and Skinner, will the Fossil Fuel Era fit into human history?
The period from about 1880 to about 2100–2200 AD will probably be called the Fossil Fuel Era.
List, in decreasing order of importance, the energy sources used by most industrial nations today.
The energy sources used by most industrial nations (in decreasing order of importance) are natural gas, crude oil and lease condensate, coal, hydropower, nuclear power, and “other” sources.
What percentage of the organic matter produced is geologically preserved?
Only about one per cent of all organic matter is geologically preserved as hydrocarbons.
Which sediment source accounts for the largest percentage of organic carbon found within the Earth? Which accounts for the least?
The largest source of organic hydrocarbon (by far) is tied up in mudrocks and siltstones. Fossil fuels (coal, oil shales, oil, gas) and living organic matter, combined, account for the least.
What is swamp gas, and how does it form?
What is commonly called organic swamp gas is actually methane gas. It forms as the primary product of the metabolism of bacteria, fungi, and other micro-organisms as they act on organic matter buried at shallow depths.
Identify the major similarities and differences among fossil fuels.
All fossil fuels are chemically composed of hydrocarbon molecules. They differ in the arrangement and sizes of these molecules and in the differing ratios of hydrogen to carbon content.
What is the difference between humic coal and sapropelic coal?
Most coal is humic coal, composed of organic material from angiosperms that have gone through a peat stage. Humic coal contains macerals. Sapropelic coal is composed primarily of spores and fine-grained algal debris that collected in oxygen-deficient ponds, lakes, and lagoons.
What conditions are necessary for coal to accumulate and develop?
For coal to develop, organic debris must accumulate in swamp-like conditions where stagnant, oxygen-poor water inhibits the decomposition and oxidation of dead plant material. The resulting layer of peat must be buried by sediments to great depths, where pressure and heat transform the peat into coal. Coal beds are most commonly located in former low-lying, coastal swamps that were subjected to a cycle of inundation and emergence from a shallow sea over long periods of time.
Why are temperate, not tropical, climates most favourable to peat production?
In tropical climates, plant material is totally consumed by bacterial action, leaving none for peat formation. In temperate to cold climates, there is enough precipitation for abundant plant growth, but the cold temperatures inhibit bacterial growth.
In which geological periods was peat production (responsible for present-day coal deposits) most prolific?
Peat production was greatest in the Late Carboniferous (Mississippian) and Permian periods, between 310 and 232 million years ago.
Define coalification.
Coalification is the process that turns peat into coal. It basically involves the action of heat and pressure on the organic matter or peat.
List the ranks of coal in increasing order, and describe the most important chemical change that results in coal of the highest rank.
The textbook lists peat as the lowest order of coal. However, this is misleading, as peat is not a type of coal, but merely the first stage in the formation of coal. The actual order should read: lignite (or brown coal)—bituminous coal-anthracite. The most important chemical change from the lowest order to the highest order involves a progressive decrease in oxygen and hydrogen content, and a resulting increase in carbon content. As the carbon content increases, more and more recognizable plant remains change into shiny black macerals.
Which method (other than direct combustion) is being researched as a future use for peat as an energy source?
Researchers are exploring the conversion of peat into methane gas by bacterial digestion or by thermal breakdown at 400–500 °C.
Which are the major coal producing regions in Canada?
The major coal producing regions in Canada are in central and southern Alberta and southern Saskatchewan. In these areas, the coal occurs in easy-to-mine, sub-horizontal seams that lie just below the Earth’s surface. Deposits of coal that lie deeper are found in the foothills and mountains between Alberta and British Columbia. The thrusting associated with mountain-building in this area has produced coal seams with steeply dipping structures. Coal is also produced in eastern Canada at the Sydney coalfield in Nova Scotia and at the Minto coalfield in New Brunswick.
Why is it easier to mine coal in the Rocky Mountains by open-pit methods rather than underground techniques?
The coal deposits in the Rocky Mountains between Alberta and British Columbia are difficult to mine by underground methods because the thrusting associated with the orogenic activity resulted in displacement and breaks in the coal seams. The coal seams are also often inclined because of the thrusting, so it is easier to extract the coal by open-pit methods than by underground techniques.
What are the six main stages that the Canadian coal mining industry goes through in exploiting coal resources?
The six main stages that the Canadian mining industry goes through in exploiting coal resources are
- exploration: deposits are identified and assessed;
- the development stage: an inclusive consultation process that receives input from economic, environmental, government, and local communities;
- the mining stage: entails the extraction of the coal and reclamation of affected land;
- the coal processing stage: a continuation of the mining stage;
- the transportation stage: the shipment and distribution of coal to the market; and
- coal use: coal is used by power plant operators, industry, (e.g., cement makers), pulp and paper manufacturers, and steel plants (to name a few).
What caused a drop in demand for Canadian coal between 1950 and 1960, and what developments ended this downturn?
Between 1950 and 1960, the discovery of crude oil in Alberta led to a downturn in the demand for Canadian coal. Railways, which had been the largest consumer of coal, suddenly switched to diesel-powered locomotives; by 1960, coal only contributed about twenty per cent of Canada’s energy supply.
After 1960, Japan began importing increasing quantities of Canadian coal. Power supply companies also commissioned new plants that used coal as an energy source. These developments caused a steady rise in the demand for coal. By 2001, the coal industry had grown by over 500 per cent.
Describe the various by-products of the coking process. How is coke used in a blast furnace?
To make coke from coal, coal is pulverized and then heated to temperatures of up to 700 °C. This process expels moisture, gases, oils, and coal tar. About 70 per cent of the original coal remains, constituting a porous material called coke. Ammonia, light oils, and coal tar are separated from the hot gases emitted by the coking process. The ammonia is used to manufacture fertilizers while the oils and tars are used in producing a range of organic solvents and fertilizers. The remains of the hot gases are used as fuel in blast furnaces.
Coke used in a blast furnace has three main functions. First, in burning, it provides the high temperatures needed to melt iron ore. Second, it provides the carbon monoxide necessary to reduce iron ore to metallic iron. Finally, it provides a strong physical structure through which the air blast and reducing gases can move evenly up through the iron ore, allowing molten iron ore to drain to the bottom of the furnace.
What oil discovery is generally recognized as the beginning of the modern oil industry?
The first American oil well is generally recognized as the beginning of the modern oil industry. It was drilled at Titusville, Pennsylvania in 1859, by Edwin Drake.
How do petroleum and natural gas differ in origin and composition?
Petroleum forms almost exclusively from the organic matter in marine sediments, while natural gas can form in both marine and terrestrial rock. Petroleum consists of many different hydrocarbon compounds, whereas natural gas is mainly (often ninety-nine per cent) composed of methane.
What is the principal difference between the organic material that forms oil and that which produces coal?
Petroleum and natural gas form from the remains of floating planktonic organisms (phytoplankton and zooplankton) that are constantly deposited on the ocean floor. This organic material is rich in lipids (fats), proteins, and carbohydrates. Coal forms from terrestrial plant remains that contain a large percentage of cellulose and lignin (woody tissue).
Outline the stages of oil and gas formation in marine sediments.
Diagenesis occurs from the surface of the ocean floor to depths of several hundred metres, where temperatures rarely exceed 50 °C. Much of the organic matter is oxidized or consumed by burrowing organisms or bacteria; these processes release considerable amounts of biogenic gas. Below this region, catagenesis takes place to depths of three and one-half to five kilometres, where pressures can reach 1500 bars (1 bar = 100 000 Newtons per square metre = approximately 1 atmosphere) and temperatures range from 50–150 °C. Here, sediments are compacted into rock, and most of the water is squeezed out. The organic matter is converted to kerogen, and produces liquid petroleum. While biogenic gas-producing processes increase, gas forms by thermal cracking of some of the kerogen. As depth, pressure, and temperature continue to increase, petroleum production ceases and gas production dominates. At temperatures higher than 150 °C and pressures greater than 1500 bars, metagenesis occurs, producing nearly pure methane and a carbon-rich residue. Below these depths carbon metamorphosizes into graphite.
