1. world energy
DESCRIPTION
World EnergyTRANSCRIPT
§1. WORLD ENERGY
JAMES A. CRAIG OMEGA 2011
World Energy Production
World Energy Consumption
Types of EnergyBiomass HydropowerNuclearRenewable (Geothermal, Wind, Solar)Fossil
Future Energy Use
Energy production has steadily increased.According to US DOE
215.4 quadrillion BTU in 1970.417.1 quadrillion BTU in 2003.Primary energy has increased by 94% from
1970 to 2003.
WORLD ENERGY PRODUCTION
World primary energy production by source (1970 – 2003)
Source: US DOE (Annual Energy Review, 2004)
Top energy producing countries (2003)
Source: US DOE (Annual Energy Review, 2004)
Energy consumption is directly related to quality of life.
Quality of life is quantified (by UN) using HDI (Human Development Index).
Factors considered in HDI include:Life expectancyEducationGDP – output of goods & services (economic
growth).
WORLD ENERGY CONSUMPTION
UN HDI versus annual energy consumed per capita (1999)
Sources: UN Human Development Report (2001) & US DOE (2002)
World primary energy consumption by region (1980 – 2003)
Source: US DOE (International Energy Annual, 2003)
Types to consider:Biomass HydropowerNuclearRenewable (Geothermal, Wind, Solar)Fossil
TYPES OF ENERGY
Biomass (biological mass) refers to organic material (e.g. plant, animal waste, wood, algae & seaweed, and garbage).
They are basically used for lighting, cooking, heating, & making simple artefacts.
Biomass can be converted to biofuel by thermochemical conversion and biochemical conversion.
Biomass
Thermochemical Conversion
Heating biomass in an oxygen-free or low-oxygen atmosphere.
Materials are transformed into simpler substances that can be used as fuels.
Examples include charcoal and methanol.Anaerobic digestion (in sewage treatment
plants) is used to generate methane gas.
Biochemical Conversion
Uses enzymes, fungi, or other microorganisms.High-moisture biomass is converted into liquid
or gaseous fuels.Example includes using bacteria to convert
manure, agricultural wastes, paper, and algae into methane.
Using yeast to decompose carbohydrates (e.g. corn and sugar), yielding ethyl alcohol (ethanol). Ethanol can be mixed with gasoline to create gasohol.
Disadvantages of BiomassDeforestation from cutting down trees, which
can in turn leads to soil erosion and mudslides.Pollution of environment from burning of wood.
Hydropower was originally used to turn waterwheels of mills to grind grains.
Dams (hydropower plants) are built to convert the energy of flowing water into mechanical energy (turning turbines) to create electricity.
In 2006, the world’s largest dam (3 Gorges Dam) was completed on the Yangtze River, China. Capacity is 84.7 billion kWh/year of electricity.
Hydropower
Size Electricity Generating Capacity (MW)
Micro < 0.1
Small 0.1 – 30
Large > 30
AdvantageLow operating costs.
DisadvantagesExpensive to buildDrought conditions can affect water supplyReliance on rain and melting snowEnvironmental concerns (ruined streams, dried
up waterfalls, and altered aquatic habitats).
Nuclear energy can be obtained from 2 principal types of reactions:Fission – splitting of 1 large nucleus into 2
smaller nuclei.Fusion – joining of 2 small nuclei into 1 large
nucleus.Nuclear reactors are designed primarily for
electricity generation.They also provide power for ships
(submarines & aircraft carriers) and serve as training & research facilities .
Nuclear
Pressurized water reactor
Source: US DOE (DOE/EP0026, 1981)
The Palo Verde Nuclear Power Facility in Arizona, USA.
Core of the reactor
Top 10 producers of electrical energy from nuclear energy (2000)
Source: US DOE (EIA website, 2002)
Dependence of nations on nuclear energy (2000)
Source: US DOE (EIA website, 2002)
AdvantagesA long-term source of abundant energyPower plants do not produce greenhouse gases
(CO2 and methane).
DisadvantagesWaste disposal: end products of nuclear fission
are highly radioactive and have half-life in thousands of years.
Nuclear plants can contaminate air, water, the ground, and the biosphere.
Renewable energy is naturally regenerated.Sources include:
Geothermal – heat of the earth.WindSolar – the sun
Sometimes, hydropower and biomass are included in this category.
Renewable
Geothermal energy is the natural, internal heat of Earth trapped in rock formations deep underground.
Only a fraction of it can be extracted.Examples are hot springs, geysers, and
fumaroles.Hot water or steam from these sources are
used for heating buildings and processing food.
Geothermal
Pressurized hot water or steam can be directed toward turbines for electricity generation.
Geothermal energy is usable only when it is concentrated in one spot (thermal reservoir).
There are 4 types of reservoirs:Hydrothermal reservoirsDry rock reservoirsGeopressurized reservoirsMagma
Hydrothermal ReservoirsUnderground pools of hot water covered by a
permeable formation through which steam escapes.
At the surface, the steam is purified and piped directly to electrical generating station.
Cheapest and simplest form of geothermal energy.
Dry RockMost common geothermal sources.Typical more than 6,000 ft below the surface.Water is injected into hot rock formations and
the resulting steam or water is collected.
Geopressurized ReservoirsThey contain hot water & methane gas.Supplies of geopressurized energy remain
uncertain.Drilling is expensive.
MagmaMolten or partially liquefied rock.Found from 10,000 ft – 30,000 ft below the
surface.Temperature ranges from 900 oC – 1,205 oC.Extraction is still in the experimental
stages.
DisadvantagesGeothermal plants are not efficient.They must be built near a geothermal source,
so accessibility to consumers is a challenge.Noise pollution.Harmful pollutants may be released: NH3, H2S,
arsenic, boron, & radon.Collapse of the land & water shortages due to
massive water withdrawal.
Historical applications include sailing and driving windmills.
Early windmills were used to pump water and grind grain in mills.
When “harvested” by turbines, wind can be used to generate electricity.
A wind farm (or park) is a collection of wind turbines. The areal extent of the farm depends on the radius of the rotor blades.
Wind
AdvantagesClean energy. No emission of greenhouse
gases.
DisadvantagesRotating blades can kill birds, interfering with
migration patterns of birds.Noise pollution.
A wind farm in Albany
The luminosity of sun ≈ 3.8 x 1026 W.Radiation from sun is comparable to the
radiation emitted by a black body at 6,000 oK.Solar constant (≈ 1,370 W/m2) is the amount
of radiation from the sun that reaches the earth’s atmosphere.
In the atmosphere, solar radiation can be absorbed or scattered away from the earth’s surface by atmospheric particles (air, water vapour, dust particles, and aerosols).
Solar
Passive solarBuilding design with environmental factors
that enable the capture or exclusion of solar energy.
Mechanical devices are not used in applications.
Examples are roof overhang & thermal insulation.
Roof overhang Thermal insulation
tan tanS W
S WL
high lowwall
wall wall wallwall wall
T TTH k A k A
h h
Active solarBuilding design & construction of systems that
collect and convert solar energy into other forms of energy (heat & electrical energy).
Mechanical devices are used in applications.Examples are solar heat collector & solar
power plant.
Solar heat collector
Solar power plant
Fossils are dead, decayed, & transformed organisms (plants & animals).
Fossil energy comes from the combustion of fossil fuels.
Fossil fuels include:CoalHydrocarbon (crude oil & natural gas)
Fuel fuels are still the primary fuels for generating power.
Fossil
Fossils
Coal is a black, combustible, mineral solid.Coal is formed from organic debris by
coalification process.It developed over millions of years in an
airless space under increased temperature & pressure.
Organisms that form coal include: algae, zooplankton, phytoplankton, bacteria decay of plants, & animals.
Coal is used as a fuel and in the production of coal gas, water gas, coal-tar compounds, & coke.
There are 4 types of coal: anthracite, bituminous, sub-bituminous, & lignite.
Coal
AnthraciteHard coal & jet-black. Highest ranked.Moisture content < 15%Heating value ≈ 22 million – 28 million BTU/ton.Used for electricity generation & space heating.
BituminousSoft coal, dense & black.Moisture content < 20%Heating value ≈ 19 million – 30 million BTU/ton.Used for electricity generation, space heating, &
coke production.
Sub-bituminousDull black. Also known as black lignite.Moisture content = 20% – 30%Heating value ≈ 16 million – 24 million
BTU/ton.Used for electricity generation & space heating.
LigniteBrownish-black. Lowest ranked.Moisture content highHeating value ≈ 9 million – 17 million BTU/ton.Used for electricity generation.
Coal MiningThe method used depends on the terrain & the
depth of the coal. There are 2 methods:
Underground Mining – coal depth > 200 ft below surface. Some coal must be left untouched to form pillars that prevent the mines from caving in. Popular till early 1970s.
Surface Mining – coal depth < 200 ft. There 2 types: area surface mining & contour surface mining.
Coal is transported to consumers by ground transportation, especially by trains.
Shaft mine (underground)
Slope mine (underground)
Drift mine (underground)
Area surface mine (surface)
Contour mine (surface)
Top coal producing countries (2003)
Top coal consuming countries (2003)
Hydrocarbons are organic compounds, composed entirely of carbon and hydrogen.
They may also contain impurities like sulphur, nitrogen, oxygen, & metals.
Another name for hydrocarbon is petroleum.
Hydrocarbon
Element Composition (% by mass)
Carbon 84 – 87%
Hydrogen 11 – 14%
Sulphur 0.6 – 8%
Nitrogen 0.02 – 1.7%
Oxygen 0.08 – 1.8%
Metals 0 – 0.14%
Phases of HydrocarbonGas – natural gas (free or associated)Liquid – crude oilSolid – tar sand, asphalt, pitch blend, waxy
crude
PhaseComponents (%)
Carbon Hydrogen Sulphur Nitrogen Oxygen
Gas 65 – 80 1 – 25 Traces 1 – 15 --
Liquid 82 – 87 11 – 15 0.1 – 6 0.1 – 1.5 0.1 – 4.5
Solid 80 – 85 8 – 11 2 – 8 0 – 2 --
Constituents Content (% in
Volume)
Wet Dry
Hydrocarbons
Methane 84.6 96
Ethane 6.4 2
Propane 5.3 0.6
i-Butane 1.2 0.18
n-Butane 1.4 0.12
i-Pentane 0.4 0.14
n-Pentane 0.2 0.06
Hexanes 0.4 0.01
Heptanes 0.1 0.08
Non-Hydrocarbons
Carbon Dioxide 0.5
Helium 0.05
Hydrogen Sulphide 0.5
Nitrogen 0.1
Argon 0.005
Radon, Krypton, Xenon
Traces
Composition of typical natural
gas
Classes of HydrocarbonParaffins
Saturated hydrocarbonsCnH2n+2
Examples are methane (CH4) & ethane (C2H6).
NaphthenesSaturated hydrocarbons with a ring structure.CnH2n
Example is cyclopentane (C5H10).
AromaticUnsaturated hydrocarbons with one or more
carbon rings.Example is benzene (C6H6).
Major Impurities & Their SourcesH2 – volcanic activity releases & radioactivity.
N2 – atmospheric; carried by run of water.
CO2 – since hydrocarbon is a covalent bond, ions released can combine to form CO2.
H2S – free sulphur plus hydrogen.He – radioactivity from volcanic activity.S – free sulphur.
Effects of Major ImpuritiesH2 – reduces gas combustibility. Forms water.
N2 – affects Energy output per unit volume.
CO2 – negligible effect.
H2S – causes bronchi constriction.He – negligible effect.S – causes coking & plugging, increases
power consumption in refinery cost, reduces crude oil value.
Fluid Classifications
Also, natural gas can be classified by quality:Sweet gas – little or no H2S present in the gas.Sour gas – appreciable amount of H2S present
in the gas.
Phase Fluid Type Separator GOR (SCF/STB)
Gas
Dry gas No surface liquids
Wet gas > 100,000
Condensate 3,000 – 100,000
Liquid
Volatile oil 1,500 – 3,000
Black oil 100 – 1,500
Heavy oil 0
Density of Crude Oil
Degree API is widely used.
10 – 20 oAPI ► Heavy crude.20 – 30 oAPI ► Medium crude.30 – 40 oAPI ► Light crude.> 40 oAPI ► Very light crude and condensate
@60
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Density of Gas (Gas Specific Gravity)
Ma = apparent molecular weight.
Nc = number of components
yi = mole fraction of component i
Mi = molecular weight of component i
gas gas
air 29a a
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M M
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Uses of Hydrocarbons
Energy – to run internal combustion (IC) engines.
IC engines are found in automobiles, ships, tractors, generators, & armoured tanks.
Raw materials – used as raw materials in manufacturing of many products.
Crude oil
RefineryCooking gas
GasolineJet fuel
KeroseneDieselOthers
Petrochemical plant
Solvent for paintsInsecticides
Enamel, MedicinesSynthetic fibers
Detergents Weed killers & fertilizers
Cosmetics, PlasticsSynthetic rubberPolish, Roofing
Protective paintsPhotographic films
World crude oil production, OPEC, MMBbl/day (1960 – 2004)
World crude oil production, non-OPEC, MMBbl/day (1960 – 2004)
Top crude oil-producing countries (2004)
World petroleum consumption, OECD (2003)
World oil reserves. Source: Oil & Gas Journal
Middle East – 57% of World oil reserves
North America – 18% of World oil reserves
Central & South America – 8% of World oil reserves
Eastern Europe & Former USSR – 7% of World oil reserves
Africa – 6% of World oil reserves
Asia & Oceania – 3% of World oil reserves
Western Europe – 1% of World oil reserves
Disadvantages of fossil energyNon-renewable – limited.Pollution – emission (carbon based) from
burning fossil fuel reacts with oxygen & nitrogen in the atmosphere to form Greenhouse gases (CO2, CO, NOx), leading to Global warming.
These gases trap the solar energy reflected by the earth’s surface and reradiate the energy in the form of infrared radiation.
Carbon sequestration is a means of capturing & storing greenhouse gases in geologic formations.
The carbon cycle
Today’s Energy85.5 percent → fossil fuels (oil, gas, coal)14.5 percent → nuclear and all other sources
By 202587 percent → fossil fuels (oil, gas, coal)13 percent → nuclear and all other sources
FUTURE ENERGY USE