Ajman University Environmental Sciences Resources PDF

Ajman University Unit of General Studies - Institute of Environment, Water and Energy Environmental Sciences Resources Resources Lecture Three Resources I. Air, Water and Soil Resources A. Air Resources B. Water Resources C. Soil...

Ajman University Unit of General Studies - Institute of Environment, Water and Energy Environmental Sciences Resources Resources Lecture Three Resources I. Air, Water and Soil Resources A. Air Resources B. Water Resources C. Soil Resources II. Living Resources A. Food Resources B. Land Resources C. Plant and Animal Resources III. Energy and Mineral Resources A. Non-Renewable Energy Resources B. Renewable Energy Resources C. Mineral Resources  Energy Resources United States  Energy Resources Nuclear power  Renewable energy 6%  Non-renewable energy Hydropower, geothermal,  Future availability Solar, wind  Net energy yield Natural 7%  Cost Gas 23%  Environmental effects Biomass 12% Coal 22% Oil Energy Resources in 30% the World Energy Resources Energy Resources Energy Resources Energy Resources Energy Resources Energy Sources. Primary sources of energy are fossil fuels such as oil, natural gas, coal, and to a lesser extent, nuclear by fission of radioactive elements (in France however, majority of electricity is produced by nuclear), solar in direct heating, in photovoltaic cells, rivers that provide hydroelectricity which in certain regions such as the United States Pacific Northwest and in Norway and Sweden is very significant (note that it is the solar energy that actually "drives" the rivers), wind for turning turbines to generate electricity, geothermal, biomass, and possibly oil shale in the future. Energy Resources Energy Resources Energy use over the next two decades is expected to increase significantly throughout the world, with highest growth rates in Asia. By the year 2015 world energy demand is projected to be around 562 quadrillion Btu or 593x109 Giga Joules. This growth represents more than a 50% increase over the consumption in 1995. Two- thirds of this increase in energy consumption is expected to be due to the developing countries concentrated mostly in Asia where energy growth is projected to be on an average of 4.2% annually, while for industrialized economies it is projected to be 1.3%. Energy Resources Other than nuclear power, all sources of energy are projected to grow: Oil use is expected to exceed 100 million barrels per day by 2015 which is a growth of 50% over 1995. Coal use is projected to be in excess of 7.3 billion ST or 6.6 billion MT or Mega Grams by 2015 on a world wide basis, compared to 5.1 billion ST or 4.6 billion MT or Mega Grams in 1995. Natural gas usage is expected to increase at 3.1% annually and by 2015 and is projected to be the principal fossil fuel for the world. Due to these tremendous increases in fossil fuel usage world wide, the carbon emissions to the atmosphere are expected to increase by about 60% by 2015 over the 1990 level. Energy Resources Fossil Fuels Oil, Natural gas, and coal are the three (fossil) fuels that are abundantly used. These fuels are remains (fossils) of life forms such as marine organisms and plant life, that flourished on our planet millions of years ago. This energy is thus a stored form of solar energy that accumulated over millions of years, and at the current and projected rates of consumption, fossil fuels will be used up in a fraction of time compared to the time it took to collect the energy from the sun.  III.A Non-Renewable Energy Resources Common oil traps Anticline, fault, salt dome, and stratigraphic traps III.A Non-Renewable Energy Resources 1. Oil Petroleum resources occur in most part of the world to some degree, however, the major commercially valuable resources occur in relatively few locations where geological conditions were appropriate for the formation and storage of these fuels underground. It is believed that petroleum was formed from deposits of plant and animal remains since petroleum deposits are found almost exclusively in sedimentary rock formations laid down millions of years ago when plant life flourished. Petroleum is a mixture of a number of hydrocarbons with some sulfur, nitrogen and organo-metallic compounds also present. A number of processing steps are involved in producing the various high value salable fuel streams such as gasoline, diesel and jet fuel from the petroleum. III.A Non-Renewable Energy Resources Petroleum resources, both liquid and gaseous, have become the major sources of energy in many countries because of the availability and convenience of these fuels for both transportation engines and Oil which contains more than 300 molecular species needs to be atomized (less than 10 microns to provide large surface area), and within the combustor it has to vaporize and mix before combustion can occur. Non-Renewable Energy Resources Oil transportation is not a very safe process. III.A Non-Renewable Energy Resources 2. Natural Gas Natural gas like petroleum is generally believed to be derived from deposits of plant and animal remains from millions of years ago. Natural gas may be found along with oil or by itself as in many gas fields where little or no oil is found. Natural gas as supplied is the cleanest fuel with sulfur removed (except for small amounts of odorants added), no ash and only molecular nitrogen, and a high hydrogen to carbon (H/C) ratio which minimizes the greenhouse gas CO2 emission. Along with methane which is by far the major combustible constituent of natural gas, other light hydrocarbons, namely ethane, propane, and butane are present in the natural gas. Raw natural gas may contain CO2 and sometimes N2 which have no heating value. III.A Non-Renewable Energy Resources CO2 is typically removed from the natural gas while ethane, propane, and butane are usually removed and marketed separately as special fuels. A number of other elements and compounds are also found in natural gas such as, H2, H2S and He. H2S is also removed from the natural gas before it is pipelined for sale. About 900 of the next 1000 US power plants will use natural gas? Domestically produced and readily available to end-users through the existing utility infrastructure, natural gas has also become increasingly popular as an alternative transportation fuel. Natural gas is clean burning and produces significantly fewer harmful emissions than reformulated gasoline. Natural gas can either be stored on board a vehicle in tanks as compressed natural gas (CNG) or cryogenically cooled to a liquid state, liquefied natural gas (LNG). III.A Non-Renewable Energy Resources 3. Coal Coal was formed from plant life under the action of immense pressures and temperatures prevailing within the earth's crust over a period encompassing millions of years. The major elements present in the "organic portion" of coal are carbon, hydrogen, oxygen, nitrogen and sulfur. Sulfur (mostly as iron pyrite) is also present as part of the "inorganic portion" or ash in the coal along with oxides of alumina, silica, iron, alkaline earths and alkalis. Coal also contains some chlorine. Coal is classified into the following four types according to the degree of metamorphism:  anthracite which is low in volatile matter (which forms tars, oils and gasses when coal is heated) and consists of mostly carbon (fixed carbon)  bituminous which contains significant amounts of the volatile matter and typically exhibit swelling or caking properties when heated III.A Non-Renewable Energy Resources  sub-bituminous is a younger coal and contains in addition to the volatile matter, significant amounts of moisture  lignite is the youngest form of coal (when peat is not included in the broader definition of coal types) and is very high in moisture content resulting in a much lower heating value than the other types of coal. Coal has a very complex structure and being a solid is more difficult to burn. Coal combustion undergoes de-volatilization and combustion of the released gases, char combustion and fly ash formation which are particles 10 microns in size (the low visibility around certain coal fired power plants is due to the fly ash). One quarter of the world’s coal reserves are found within the United States, and the energy content of the US coal resources exceeds that of all the world’s known recoverable oil. III.A Non-Renewable Energy Resources Locations of coal ore in the United States III.A Non-Renewable Energy Resources Coal is also the workhorse of the nation’s electric power industry, supplying more than half the electricity consumed by Americans. III.A Non-Renewable Energy Resources Coal Formation III.A Non-Renewable Energy Resources 4. Oil Shale The most extensive deposits of oil shale are found in what use to be large shallow lakes and seas millions of years ago, where subtropical, stagnant conditions were favorable for the growth and accumulation of algae, spores and pollen. The organic solids in oil shale rock are a wax like material called kerogen. The kerogen is extracted by heating in retorts in the absence of air where the kerogen decomposes forming oil, gas, water and some carbon residue. Production of gasoline or jet fuel from the oil produced from the oil shale, however requires more extensive processing than most petroleum. The shale oil also contains more nitrogen than petroleum does which if left in the fuels produced from the shale oil would result in significant NOx emissions. The U.S. has significant deposits of oil shale concentrated in Colorado and Utah.  III.A Non-Renewable Energy Resources Oil Shale and Tar Sands Mined oil shale Retort Conveyor Spent shale Above Ground Conveyor Pipeline Shale oil Impurities Hydrogen Crude oil Refinery storage removed added Air compressors Sulfur and nitrogen compounds Air Shale layer injection Shale oil pumped to surface Underground Shale heated to vaporized kerogen, which is condensed to provide shale oil III.A Non-Renewable Energy Resources 5. Nuclear The production of nuclear energy by fission involves the conversion of matter to energy in which an exceedingly large amount of energy is released. The nuclear reactions generate an excess of neutrons which permits a chain reaction to proceed making it possible to design nuclear reactors in which self-sustaining reactions occur with the continuous release of energy. Fusion of light nuclei, like those of hydrogen, into heavier elements is also an energy producing process. However, nuclear fusion is still in the research phase and only nuclear fission has been commercially practiced. The heat generated in nuclear fission reactors is transferred to a working fluid, typically water and the steam thus produced powers a steam turbine. III.A Non-Renewable Energy Resources Two principal reactor types are the pressurized water reactors (PWR) and the boiling water reactors (BWR). In a PWR, heat generated in the nuclear core is removed heavy water circulating at high pressure through the primary circuit and performs both cooling and moderation of the reactor. Heat is transferred from the primary to the secondary system in a boiler to generate steam. In the BWR the boiling takes place in the reactor itself. Safety of the reactors in terms of release of radioactive materials to the environment has been a major issue. On the other hand, nuclear energy does not generate any greenhouse gasses like the fossil fuel fired plants do. Disposal and management of the radioactive spent fuel from nuclear reactors is a major challenge and has been an impediment to its wide spread use in many countries. Some countries such as France, however, have a majority of their electricity generated by nuclear fission. III.A Non-Renewable Energy Resources Nuclear Energy III.A Non-Renewable Energy Resources Nuclear Energy Non-Renewable Energy Resources Nuclear Explosion Nuclear Power Plant Non-Renewable Energy Resources Nuclear Power Plants Non-Renewable Energy Resources Pressurized Water Reactor (PWR) Schematic Boiling Water Reactor (BWR) Schematic Non-Renewable Energy Resources Chernobyl Disaster III. A Non-Renewable Energy Resources Thanks III.B Renewable Energy Resources III.B Renewable Energy Resources III.B Renewable Energy Resources 1. Biomass Energy The term biomass means any plant derived organic matter available on a renewable basis, including dedicated energy crops and trees, agricultural food and feed crops, agricultural crop wastes and residues, wood wastes and residues, aquatic plants, animal wastes, municipal wastes, and other waste materials. Bioenergy technologies use renewable biomass resources to produce an array of energy related products including electricity, liquid, solid, and gaseous fuels, heat, chemicals, and other materials. Bioenergy ranks second (to hydropower) in renewable US primary energy production and accounts for 3% of the primary energy production in the United States. III.A Non-Renewable Energy Resources III.A Non-Renewable Energy Resources One of the energy resources available to us is the organic waste material generated by humans and animals and includes paper, plastics, wood, animal dung, plant stalks and fibers, and food residues. These residues in many instances pose a disposal problem and also have a significant heating value. Biomass may be combusted in specially designed boilers, or gasified to generate a gas that could be utilized to generate power in internal combustion engines or fuel cells. Combustion or gasification of waste streams that contain chlorine compounds could, however, produce highly toxic pollutants such as dioxins and furans and proper design measures should be taken to limit these emissions. Biomass derived energy accounted for 3.02 quadrillion Btu (or 3.19x109 Giga Joules) or 3.2% of the total energy consumption in the U.S. in 19961. III.B Renewable Energy Resources Geothermal Reservoirs III.B Renewable Energy Resources 2. Geothermal Energy Geothermal energy is the heat from the Earth. It is clean and sustainable. Resources of geothermal energy range from the shallow ground to hot water and hot rock found a few miles beneath the Earth's surface, and down even deeper to the extremely high temperatures of molten rock called magma. Geothermal energy is the heat energy stored within the earth's crust, hot springs and geysers providing evidence of this stored energy. Until the beginning of this century, the utilization of geothermal heat has been limited to the use of warm water as in several Roman baths in England and geothermal hot springs began to enjoy wide use through out the world as therapeutic treatment. More extensive use has been made of geothermal energy for both power and non- power applications in more recent times. III.B Renewable Energy Resources Typically, the useful geothermal heat for electric power generation is available in the form of a hot brine with temperatures ranging from 300 to 400 deg F or 150 to 200 deg C. The principle characteristics of geothermal electric generating plants as compared to a fossil plant are that (1) significantly larger flow of steam is required by a geothermal plant to produce a KW of electrical power because of the significantly lower steam pressure, (2) the small output of an individual geothermal plant which is limited by the availability of the , and (3) the number of different systems may be employed for the extraction of steam from geothermal sources. For example, the heat contained in the hot geothermal brine may be recovered as steam by flashing the brine to a lower pressure and either utilizing the steam directly in a steam turbine or by transferring the heat to a second working fluid to produce power by expansion in a turbine. III.B Renewable Energy Resources Geothermal energy accounted for 0.34 quadrillion Btu (or 0.36x109 Giga Joules) or 0.36% of the total energy consumption in the U.S. in 19961. III.B Renewable Energy Resources How Geothermal Energy Works? III.B Renewable Energy Resources Geothermal Energy in the United States III.B Renewable Energy Resources 3. Hydrogen Cells If a hydrogen economy is to develop within the next 25 to 50 years, lower cost options for producing hydrogen from a wide variety of sources must be aggressively pursued. Today, most hydrogen in the United States, and about half of the world's hydrogen supply, is produced from natural gas. III.B Renewable Energy Resources  Extracting hydrogen efficiently  Storing hydrogen  Fuel cells Usable Waste high-quality heat energy Electricity, Storage The Coal, heat, and environment nuclear, or light Decomposition transport solar, wind, or Combustion Water of water H2 geothermal 2H2O 2H2 + O2 2H2 + O2 2H2O vapor Power plants III.B Renewable Energy Resources Although natural gas will likely provide the earliest affordable feedstock for hydrogen, today's costs are prohibitively expensive. To bring down costs, current research effort focuses on extracting fuel-grade hydrogen from natural gas and coal, as well as producing hydrogen through the use of nuclear energy technology. Hydrogen fuel is produced by heating or passing electricity through water in the presence of a catalyst. Water breaks down into hydrogen and oxygen. Hydrogen is a clean- burning fuel that could replace gaseous and liquid fuels. It is easy to transport but is explosive. Electricity needed to make hydrogen could be generated from solar energy, wind energy, or hydroelectric facilities. The prospects for hydrogen are questionable today because of its negative energy yield. III.B Renewable Energy Resources Hydropower III.B Renewable Energy Resources 4. Hydropower Hydroelectric power is renewable, creates no air pollution, and is relatively inexpensive. Sediment fills in reservoirs, however, giving them an average lifespan of 50 to 100 years. The potential for hydroelectric power is limited in the developed countries, because the best sites have already been developed or are located far from population centers where the energy is needed. In the developing nations sites capable of producing large amounts of energy are available, but high construction costs may impair their development. Hydroelectric power facilities in the United States can generate enough power to supply 28 million households with electricity, the equivalent of nearly 500 million barrels of oil. The total US hydropower capacity is about 95,000 megawatts. III.A Non-Renewable Energy Resources The harnessing of energy of flowing water by turning water wheels for grinding of grain was practiced as early as Roman times. This resource became important in more modern times with the development of efficient electric generators and transmission technology which allowed the location of hydroelectric plants several hundred miles from the energy users. The energy that may be recovered from flowing water depends on the quantity of flow of water and the height through which the water can be made to fall from the reservoir to a hydraulic turbine. The construction of diversion and storage dams for hydroelectric power plants requires suitable topography and other site conditions, and a steep drop in the elevation of the river. Construction of hydroelectric plant is capital intensive but the operating costs are low since there are no fuel costs associated with a hydroelectric plant. III.B Renewable Energy Resources Hydropower III.A Non-Renewable Energy Resources Hydroelectric Dam III.B Renewable Energy Resources Researchers are working on advanced turbine technologies that will not only help maximize the use of hydropower, but also minimize adverse environmental effects. III.B Renewable Energy Resources Solar Energy III.B Renewable Energy Resources 5. Solar Energy Approximately 1.55 x 10l8 KW hours of solar energy reach the earth's outer atmosphere annually. Approximately a third of this energy is reflected back into space and some absorbed by the atmosphere while approximately half reaches the earth's surface. Actually, wind, waves, rivers and ocean thermal gradients are all the various forms of solar energy, as they exist in nature. The form that is being harnessed more and more in recent times is the photosynthetic radiation for direct use for heating or conversion into electricity using solar cells. Solar energy accounted for 0.07 quadrillion Btu (or 0.074 x109 Giga Joules) or.075% of the total energy consumption in the U.S. in 1996. III.B Renewable Energy Resources 5. Solar Energy III.B Renewable Energy Resources Developing technologies that take advantage of the clean abundant energy of the sun is important to reducing greenhouse gasses. Examples of solar technologies being developed by the US Department of Energy and Industry are:  Photovoltaic cells  Concentration solar power  Low-temperature solar collectors Photovoltaic cells convert sunlight directly into electricity and are made of semiconductors such as crystalline silicon or various thin-film materials. Photovoltaic cells can provide tiny amounts of power for watches, large amounts for the electric grid, and everything in between.  III.B Renewable Energy Resources Using Solar Energy to Provide Heat and Electricity  Passive solar heating  Active solar heating Summer Heat to house sun (radiators or forced air duct) Heavy Heavy insulation Pump Superwindow insulation Hot Winter Superwindow Water Super- sun tank Heat window Stone floor and wall for heat storage exchanger PASSIVE ACTIVE III.B Renewable Energy Resources 5. Solar Energy III.B Renewable Energy Resources 5. Solar Energy III.B Renewable Energy Resources 5. Solar Energy  Renewable Energy Cost Trends 40 100 Wind PV 30 80 COE cents/kWh 60 20 40 10 20 0 0 1980 1990 2000 2010 2020 1980 1990 2000 2010 2020 10 70 15 Geothermal 60 Solar thermal Biomass 8 12 COE cents/kWh 50 6 40 9 30 6 4 20 2 10 3 0 0 0 1980 1990 2000 2010 2020 1980 1990 2000 2010 2020 1980 1990 2000 2010 2020 Levelized cents/kWh in constant $20001 III.B Renewable Energy Resources Concentrating solar power technologies use reflective materials to concentrate the sun's heat energy, which ultimately drives a generator to produce electricity. These technologies include dish/engine systems, parabolic troughs, and central power towers. Low-temperature solar collectors also absorb the sun's heat energy, but the heat is used directly for hot water or space heating for residential, commercial, and industrial facilities. III.A Non-Renewable Energy Resources Wind Energy  III.A Non-Renewable Energy Resources Producing Electricity from Wind Gearbox Electrical generator Power cable III.B Renewable Energy Resources 5. Wind Wind energy uses the energy in the wind for generating electricity, charging batteries, pumping water, or grinding grain. Wind turbines convert the kinetic energy of the wind into other forms of energy. Large, modern wind turbines operate together in wind farms to produce electricity for utilities. Small turbines are used by homeowners and remote villages to help meet energy needs. A portion (approximately 25,800 KW hours annually) of the total solar energy falling on the earth, is converted into motion of air. A small fraction of this energy resource is currently being harnessed. Winds only in certain speed ranges, however, may be harnessed at the current time. The distribution of wind is not uniform over the earth, wind resources are higher in polar and temperate zones than in tropical zones and also higher in coastal areas than inland. III.B Renewable Energy Resources The wind energy is harnessed by installing rotating machines (typically propellers) that are connected to electric generators. Because of friction losses, wind power machines usually do not operate at wind velocities much lower than 10 miles/hour, while with winds of gale force the rotors of wind machines are usually feathered to prevent damage. Wind derived energy accounted for 0.04 quadrillion Btu (or 0.042x109 Giga Joules) or.043% of the total energy consumption in the U.S. in 19961. III.B Renewable Energy Resources Tidal Energy Mineral Resources C. Mineral Resources Key Concepts  Types of mineral resources  Formation and location of mineral resources  Extraction and processing of mineral resources  Increasing supplies of mineral resources  Major types, acquisition, advantages, and disadvantages of fuel resources  C. Mineral Resources Nature and Formation of Mineral Resources Undiscovered Identified Mineral resources Economical  Metallic Reserves Non-metallic Decreasing cost of extraction   Energy resources Other resources  Magma Hydrothermal Not economical   Weathering  Reserve  Ore Decreasing certainty Known Existence  C. Mineral Resources Mineral resources Ore refers to useful metallic minerals that can be mined at a profit and in common usage to some nonmetallic minerals such as fluorite and sulfur To be considered of value, an element must be concentrated above the level of its average crustal abundance C. Mineral Resources Finding Nonrenewable Mineral Resources  Satellite imagery  Aerial sensors (magnetometers)  Gravity differences  Core sampling  Seismic surveys  Chemical analysis of water and plants C. Mineral Resources Removing Nonrenewable Mineral Resources 1. Surface mining  Overburden  Spoil  Open-pit  Dredging  Strip mining 2. Subsurface mining  Room and Pillar  Longwall C. Mineral Resources C. Mineral Resources Mineral resources and igneous processes Some of the most important accumulations of metals are produced by igneous processes that concentrate the desirable materials Examples of igneous mineral resources Magmatic segregation Separation of heavy minerals that crystallize early or enrichment of rare elements in the residual melt Diamonds Originate at great depths Crystals are disseminated in ultramafic rock called kimberlite  C. Mineral Resources Mineral resources and igneous processes Hydrothermal solutions Among the best known and important ore deposits Majority originate from hot, metal rich fluids that are remnants of late-stage magmatic processes Move along fractures, cools, and precipitates the metallic ions to produce vein deposits C. Mineral Resources Hydrothermal solutions C. Mineral Resources Mineral resources and metamorphic rocks Many of the most important metamorphic ore deposits are produced by contact metamorphism Sphalerite (zinc) (Zn, Fe)S Galena (lead) Chalcopyrite (copper) CuFeS2  C. Mineral Resources Mineral resources and metamorphic rocks Regional metamorphism can also generate useful deposits Talc Mg3Si4O10(OH)2 Graphite (C ) C. Mineral Resources Weathering and ore deposits Secondary enrichment – concentrating metals into economically valuable concentrations Bauxite Principal ore of aluminum Forms in rainy tropical climates from chemical weathering and the removal of undesirable elements by leaching C. Mineral Resources Weathering and ore deposits Other deposits, such as many copper and silver deposits, result when weathering concentrates metals that are deposited through a low-grade primary ore Placer deposits Placers – deposits formed when heavy metals are mechanically concentrated by currents Involve heavy and durable minerals Examples include Gold Platinum Diamonds C. Mineral Resources Nonmetallic mineral resources Use of the word “mineral” is very broad Two common groups Building materials Natural aggregate (crushed stone, sand, and gravel) Gypsum (plaster and wallboard) Clay (tile, bricks, and cement) Nonmetallic mineral resources Two common groups Industrial minerals Fertilizers Sulfur Salt C. Mineral Resources Thanks