§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

141.5131.5

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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

ga

M M

M

1

cN

a i ii

M y M

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