What ores are considered to be non-renewable resources? ChosenEvery ore deposit is a non-renewable resource. Having said that it is the job of technology to make the price of a metal competitive, affordable. Initially when not much in demand the technology of mining it, extraction needs to pick up bringing its price down. Later demand may push up its price and the extra expenditure for adding to its supply may become unaffordable, making it appear non-renewable. A stage will come when a particular metal or more metals may have to be recycled as the quantum of it is fixed in nature.
Water as consumable is no exception. So far as Sun is renewing it by sucking it from oceans, forming clouds and precipitating it in the form of rains, man need not pay his attention there. He has immense quantity of unusable water of seas (“Water, water everywhere | not a drop to drink”) as an alternative!. in particular Aluminum recycling is picking up as the Electric power input, the most essential raw ingredient in its production is becoming scarce faster. Copper ore is becoming scarcer partly for same reason, against rising demand.
Metals like Silicon and Calcium (even Iron) is widespread on Earth but are very difficult to extract, hence can be termed non-renewable. There are other metals not much in demand but might move in importance as alternatives to the ones that are getting priced out. Only technology separating it from reaching the market. Thorium as an alternative to Uranium is one such. However, if we go by the definition of non-renewable resources to mean Coal and Oil which are consumed without trace and cannot be replaced, none of the metals are so in that narrow sense.
Economics has a habit of bending ‘semantics’ to suit its purpose. Is coal a non-renewable or renewable resource? Coal is a non-renewable resource… … because when you use it all, it’s gone, and there’s no more. It takes extreme pressure and millions of years for decomposing organic matter to turn into coal. And we haven’t got that long to wait for new supplies to form. So when it’s burnt, it’s gone for ever. No, it takes coal thousands (if not millions) of years to form from fossils of dead plant/animal material. Coal Coal Basics Coal Takes Millions of Years To Create
Coal is a combustible black or brownish-black sedimentary rock composed mostly of carbon and hydrocarbons. It is the most abundant fossil fuel produced in the United States. Coal is a nonrenewable energy source because it takes millions of years to create. The energy in coal comes from the energy stored by plants that lived hundreds of millions of years ago, when the Earth was partly covered with swampy forests. For millions of years, a layer of dead plants at the bottom of the swamps was covered by layers of water and dirt, trapping the energy of the dead plants.
The heat and pressure from the top layers helped the plant remains turn into what we today call coal. Source: National Energy Education Development Project (Public Domain) Types of Coal Coal is classified into four main types, or ranks (anthracite, bituminous, subbituminous, and lignite), depending on the amounts and types of carbon it contains and on the amount of heat energy it can produce. The rank of a deposit of coal depends on the pressure and heat acting on the plant debris as it sank deeper and deeper over millions of years. For the most part, the higher ranks of coal contain more heat-producing energy.
Anthracite contains 86-97% carbon, and generally has a heating value slightly higher than bituminous coal. It accounts for less than 0. 5% of the coal mined in the United States. All of the anthracite mines in the United States are located in northeastern Pennsylvania. Bituminous coal contains 45-86% carbon. Bituminous coal was formed under high heat and pressure. Bituminous coal in the United States is between 100 to 300 million years old. It is the most abundant rank of coal found in the United States, accounting for about half of U. S. coal production.
Bituminous coal is used to generate electricity and is an important fuel and raw material for the steel and iron industries. West Virginia, Kentucky, and Pennsylvania are the largest producers of bituminous coal. Subbituminous coal has a lower heating value than bituminous coal. Subbituminous coal typically contains 35-45% carbon. Most subbituminous coal in the United States is at least 100 million years old. About 46% of the coal produced in the United States is subbituminous. Wyoming is the leading source of subbituminous coal. Lignite is the lowest rank of coal with the lowest energy content.
Lignite coal deposits tend to be relatively young coal deposits that were not subjected to extreme heat or pressure, containing 25%-35% carbon. Lignite is crumbly and has high moisture content. There are 19 lignite mines in the United States, producing about 7% of U. S. coal. Most lignite is mined in Texas and North Dakota. Lignite is mainly burned at power plants to generate electricity. back to top Mining and Transporting Coal Mining the Coal Diagram of Surface Mining Source: National Energy Education Development Project (Public Domain) A Typical Deep Mine
Source: Adapted from National Energy Education Development Project (Public Domain) Coal Being Transported by Rail Source: Stock photography (copyrighted) Coal miners use giant machines to remove coal from the ground. They use two methods: surface or underground mining. Many U. S. coal beds are very near the ground’s surface, and about two-thirds of coal production comes from surface mines. Modern mining methods allow us to easily reach most of our coal reserves. Due to growth in surface mining and improved mining technology, the amount of coal produced by one miner in one hour has more than tripled since 1978.
Surface mining is used to produce most of the coal in the United States because it is less expensive than underground mining. Surface mining can be used when the coal is buried less than 200 feet underground. In surface mining, giant machines remove the top soil and layers of rock known as “overburden” to expose the coal seam. Once the mining is finished, the dirt and rock are returned to the pit, the topsoil is replaced, and the area is replanted. Underground mining, sometimes called deep mining, is used when the coal is buried several hundred feet below the surface. Some underground mines are 1,000 feet deep.
To remove coal in these underground mines, miners ride elevators down deep mine shafts where they run machines that dig out the coal. Processing the Coal After coal comes out of the ground, it typically goes on a conveyor belt to a preparation plant that is located at the mining site. The plant cleans and processes coal to remove other rocks and dirt, ash, sulfur, and unwanted materials, increasing the heating value of the coal. Transporting the Coal After coal is mined and processed, it is ready to be shipped to market. The cost of shipping coal can cost more than the cost of mining it.
About 71% of coal in the United States is transported, for at least part of its trip to market, by train. Coal can also be transported by barge, ship, truck, and even pipeline. It is often cheaper to transport coal on river barges, but barges cannot take coal everywhere that it needs to go. If the coal will be used near the coal mine, it can be moved by trucks and conveyors. Coal can also be crushed, mixed with water, and sent through a “slurry” pipeline. Sometimes, coal-fired electric power plants are built near coal mines to lower transportation costs. back to top Getting (Producing) Coal Where We Get Coal
Coal production is the amount of coal that is mined and sent to market. In 2008, the amount of coal produced at U. S. coal mines was 1,171. 8 million short tons. Coal is mined in 26 States. Wyoming mines the most coal, followed by West Virginia, Kentucky, Pennsylvania, and Texas. Coal is mainly found in three large regions, the Appalachian Coal Region, the Interior Coal Region, and Western Coal Region (includes the Powder River Basin). Appalachian Coal Region: •More than one-third of the coal produced in the United States comes from the Appalachian Coal Region. •West Virginia is the largest coal-producing
State in the region, and the second largest coal-producing State in the United States. •This region has large underground mines and small surface mines. •Coal mined in the Appalachian coal region is primarily used for steam generation for electricity, metal production, and for export. Interior Coal Region: •Texas is the largest coal producer in the Interior Coal Region, accounting for almost one-third of the region’s coal production. •This region has mid-sized surface mines. Western Coal Region: •Over half of the coal produced in the United States is produced in the Western Coal Region. Wyoming is the largest regional coal producer, as well as the largest coal-producing State in the Nation. •This region has many large surface mines. •Some of the largest coal mines in the world are in the Western Coal Region. back to top Uses of Coal Blast Furnace in a Modern Steel Works Source: BBC Almost 93% of the coal used in the United States is used for generating electricity. Except for a small amount of exports, the rest of the coal is used as a basic energy source in many industries including steel, cement, and paper. The major uses of coal are: For Electric Power
Coal is used to create almost half of all electricity generated in the United States. Power plants burn coal to make steam. The steam turns turbines (machines for generating rotary mechanical power) that generate electricity. In addition to companies in the electric power sector, industries and businesses with their own power plants use coal to generate electricity. For Industry A variety of industries use coal’s heat and by-products. Separated ingredients of coal (such as methanol and ethylene) are used in making plastics, tar, synthetic fibers, fertilizers, and medicines.
Coal is also used to make steel. Coal is baked in hot furnaces to make coke, which is used to smelt iron ore into iron needed for making steel. It is the very high temperatures created from the use of coke that gives steel the strength and flexibility for things like bridges, buildings, and automobiles. The concrete and paper industries also use large amounts of coal. back to top Coal & the Environment Environmental laws and modern technologies have greatly reduced the impact on the environment from the production and consumption of coal. What Are Some Environmental Concerns In Coal Mining?
Without proper care, mining can have a negative impact on ecosystems and water quality and alter landscapes and scenic views. Debris that chokes mountain streams can result from surface mining like mountaintop removal, and acidic water can drain from abandoned underground mines. Today restoring the land damaged by surface mining is an important part of the mining process. Because mining activities often come into contact with water resources, coal producers must also go to great efforts to prevent damage to ground and surface waters. What Emissions and Byproducts Are Produced from Burning Coal?
The combustion of coal produces several types of emissions that adversely affect the environment. The five principal emissions associated with coal consumption in the energy sector are: •Sulfur dioxide (SO2), which has been linked to acid rain and increased incidence of respiratory illnesses •Nitrogen oxides (NOx), which have been linked to the formation of acid rain and photochemical smog •Particulates, which have been linked to the formation of acid rain and increased incidence of respiratory illnesses •Carbon dioxide (CO2), which is the primary greenhouse gas emission from energy use. Mercury, which has been linked with both neurological and developmental damage in humans and other animals. Mercury concentrations in the air usually are low and of little direct concern. However, when mercury enters water — either directly or through deposition from the air — biological processes transform it into methylmercury, a highly toxic chemical that accumulates in fish and the animals (including humans) that eat fish. Reducing the Impacts of Coal Use The Clean Air Act and the Clean Water Act require industries to reduce pollutants released into the air and the water.
Industry has found several ways to reduce sulfur, nitrogen oxides (NOx), and other impurities from coal. They have found more effective ways of cleaning coal after it is mined, and coal consumers have shifted towards greater use of low sulfur coal. Power plants use flue gas desulfurization equipment, also known as “scrubbers,” to clean sulfur from the smoke before it leaves their smokestacks. In addition, industry and government have cooperated to develop technologies that can remove impurities from coal or that make coal more energy-efficient so less needs to be burned.
Equipment intended mainly to reduce SO2 (such as scrubbers), NOx (such as catalytic converters), and particulate matter (such as electrostatic precipitators and baghouses) is also able to reduce mercury emissions from some types of coal. Scientists are also working on new ways to reduce mercury emissions from coal-burning power plants. Research is underway to address emissions of carbon dioxide from coal combustion. Carbon capture separates CO2 from emissions sources and recovers it in a concentrated stream.
The CO2 can then be sequestered, which puts CO2 into storage, possibly underground, in such a way that it will remain there permanently. Reuse and recycling can also diminish coal’s environmental impact. Land that was previously used for coal mining can be reclaimed for uses like airports, landfills, and golf courses. Waste products can also be captured by scrubbers to produce synthetic gypsum for wallboard. Major Components of a Coal-fired Power Plant with Carbon Capture Source: National Mining Association Oil (petroleum) Oil (petroleum) Basics How Was Oil Formed?
Oil was formed from the remains of animals and plants (diatoms) that lived millions of years ago in a marine (water) environment before the dinosaurs. Over millions of years, the remains of these animals and plants were covered by layers of sand and silt. Heat and pressure from these layers helped the remains turn into what we today call crude oil. The word “petroleum” means “rock oil” or “oil from the earth. ” Source: U. S. Energy Information Administration (Public Domain) Crude oil is a smelly, yellow-to-black liquid and is usually found in underground areas called reservoirs.
Scientists and engineers explore a chosen area by studying rock samples from the earth. Measurements are taken, and, if the site seems promising, drilling begins. Above the hole, a structure called a ‘derrick’ is built to house the tools and pipes going into the well. When finished, the drilled well will bring a steady flow of oil to the surface. back to top Getting (Producing) Oil Where Is Oil Produced? The world’s top five crude oil-producing countries are: •Russia •Saudi Arabia •United States •Iran •China Over one-fourth of the crude oil produced in the United States is produced offshore in the Gulf of Mexico.
The top crude oil-producing States are: •Texas •Alaska •California •Louisiana •North Dakota About 53% of the crude oil and petroleum products used in the United States in 2009 came from other countries. back to top Offshore Drilling What Is Offshore? Image of a Coastline Source: Stock photography (copyrighted) Map Showing Exclusive Economic Zone Around the United States and Territories Source: National Energy Education Development Project (Public Domain) Diagram of Shore and Ocean Overlayed With Territorial Sea, Exclusive Economic Zone, the Continental Shelf, and Continental Slope
Source: National Energy Education Development Project (Public Domain) When you are at your favorite beach in Florida or California, you are not at the very edge of the country. Although it might seem like the ocean is the border of the United States, the border is actually 200 miles out from the land. This 200-mile-wide band around the country is called the Exclusive Economic Zone (EEZ). In 1983, President Reagan claimed the area of the EEZ in the name of the United States. In 1994, all countries were granted an EEZ of 200 miles from their coastline according to the International Law of the Sea.
There is a lot of activity just beyond the beach. The beach extends from the shore into the ocean on a continental shelf that gradually descends to a sharp drop, called the continental slope. This continental shelf can be as narrow as 20 kilometers or as wide as 400 kilometers. The water on the continental shelf is shallow, rarely more than 150 to 200 meters deep. The EEZ is part of the United States. The Federal government manages the land under the sea on behalf of the American people. The United States Minerals Management Service (MMS) leases the land under the ocean to producers.
These companies pay MMS rental fees and royalties on all the minerals they extract from the ocean floor. Individual states control the waters off their coasts out to 3 miles for most states and between 9 and 12 for Florida, Texas, and some other States. The continental shelf drops off at the continental slope, ending in abyssal plains that are three to five kilometers below sea level. Many of the plains are flat, while others have jagged mountain ridge, deep canyons, and valleys. The tops of some of these mountain ridges form islands where they extend above the water.
Most of the energy we get from the ocean is extracted from the ground. Oil, natural gas, and minerals all come from the ocean floor. People are working on other new ways to use the ocean. Solar and wind energy have been used on land, and now they are also being used at sea. Other energy sources that are being explored in the ocean are wave energy, tidal energy, methane hydrates, and ocean thermal energy conversion. Read about Energy Ant’s visit to an offshore rig or learn about jobs in the offshore. back to top What Fuels Are Made From Crude Oil?
What Fuels Are Made from Crude Oil? After crude oil is removed from the ground, it is sent to a refinery by pipeline, ship, or barge. At a refinery, different parts of the crude oil are separated into useable petroleum products. Crude oil is measured in barrels (abbreviated “bbls”). A 42-U. S. gallon barrel of crude oil provides slightly more than 44 gallons of petroleum products. This gain from processing the crude oil is similar to what happens to popcorn, which gets bigger after it’s popped. The gain from processing is more than 6%.
One barrel of crude oil, when refined, produces about 19 gallons of finished motor gasoline, and 10 gallons of diesel, as well as other petroleum products. Most petroleum products are used to produce energy. For instance, many people across the United States use propane to heat their homes. Other products made from petroleum include: •Ink •Crayons •Bubble gum •Dishwashing liquids •Deodorant •Eyeglasses •CDs and DVDs •Tires •Ammonia •Heart valves What Is a Refinery? A refinery is a factory. Just as a paper mill turns lumber into paper, a efinery takes crude oil and turns it into gasoline and many other useful petroleum products. A Night Photo of the Pascagoula Refinery in Mississippi Source: Stock photography (copyrighted) Refineries Operate 24/7 A typical refinery costs billions of dollars to build and millions more to maintain. A refinery runs 24 hours a day, 365 days a year and requires a large number of employees to run it. A refinery can occupy as much land as several hundred football fields. Workers often ride bicycles to move from place to place inside the complex. back to top Refining Process
How Crude Oil Is Refined into Petroleum Products The world uses gasoline and petroleum products to move merchandise and people, help make plastics, and do many other things. At a refinery, different parts of the crude oil are separated into useable petroleum products. Today, some refineries turn more than half of every 42-gallon barrel of crude oil into gasoline. How does this transformation take place? Essentially, refining breaks crude oil down into its various components, which then are selectively reconfigured into new products. All refineries perform three basic steps: 1. Separation 2. Conversion 3.
Treatment Source: Adapted from Chevron Separation Heavy petroleum components or “fractions” are on the bottom; light fractions are on the top. This difference in weights allows the separation of the various petrochemicals. Modern separation involves piping oil through hot furnaces. The resulting liquids and vapors are discharged into distillation towers. Inside the towers, the liquids and vapors separate into fractions according to weight and boiling point. The lightest fractions, including gasoline and liquid petroleum gas (LPG), vaporize and rise to the top of the tower, where they condense back to liquids.
Medium weight liquids, including kerosene and diesel oil distillates, stay in the middle. Heavier liquids, called gas oils, separate lower down, while the heaviest fractions with the highest boiling points settle at the bottom. Fluid Catalytic Cracking Distillation Column Photo courtesy of Chevron. Refining Workers Overlooking a Refinery Photo courtesy of Chevron. Conversion Cracking and rearranging molecules takes a heavy, low-valued feedstock — often itself the output from an earlier process — and change it into lighter, higher-valued output such as gasoline.
This is where refining’s fanciest footwork takes place — where fractions from the distillation towers are transformed into streams (intermediate components) that eventually become finished products. The most widely used conversion method is called cracking because it uses heat and pressure to “crack” heavy hydrocarbon molecules into lighter ones. A cracking unit consists of one or more tall, thick-walled, bullet-shaped reactors and a network of furnaces, heat exchangers, and other vessels. Cracking and coking are not the only forms of conversion.
Other refinery processes, instead of splitting molecules, rearrange them to add value. Alkylation, for example, makes gasoline components by combining some of the gaseous byproducts of cracking. The process, which essentially is cracking in reverse, takes place in a series of large, horizontal vessels and tall, skinny towers that loom above other refinery structures. Reforming uses heat, moderate pressure, and catalysts to turn naphtha, a light, relatively low-value fraction, into high-octane gasoline components. Treatment The finishing touches occur during the final treatment.
To make gasoline, refinery technicians carefully combine a variety of streams from the processing units. Among the variables that determine the blend are octane level, vapor pressure ratings and special considerations, such as whether the gasoline will be used at high altitudes. Storage Both the incoming crude oil and the outgoing final products need to be stored. These liquids are stored in large tanks on a tank farm near the refinery. Pipelines then carry the final products from the tank farm to other tanks all across the country.
All of these activities are required to make the gasoline that powers our cars, the diesel fuel that brings our food to market, and the jet fuel that flies our planes. These provide us with the energy we need to get from place to place quickly and comfortably. Tank Farm Near a Refinery Photo courtesy of Chevron. back to top Oil & the Environment How Does Oil Impact the Environment? Products from oil (petroleum products) help us do many things. We use them to fuel our airplanes, cars, and trucks, to heat our homes, and to make products like medicines and plastics.
Even though petroleum products make life easier — finding, producing, moving, and using them can harm the environment through air and water pollution. Emissions and Byproducts Are Produced from Burning Petroleum Products Petroleum products give off the following emissions when they are burned as fuel: •Carbon dioxide (CO2) •Carbon monoxide (CO) •Sulfur dioxide (SO2) •Nitrogen oxides (NOX) and Volatile Organic Compounds (VOC) •Particulate matter (PM) •Lead and various air toxics such as benzene, formaldehyde, acetaldehyde, and 1,3-butadiene may be emitted when some types of petroleum are burned
Nearly all of these byproducts have negative impacts on the environment and human health: •Carbon dioxide is a greenhouse gas and a source of global warming. 1 •SO2 causes acid rain, which is harmful to plants and to animals that live in water, and it worsens or causes respiratory illnesses and heart diseases, particularly in children and the elderly. •NOX and VOCs contribute to ground-level ozone, which irritates and damages the lungs. •PM results in hazy conditions in cites and scenic areas, and, along with ozone, contributes to asthma and chronic bronchitis, especially in children and the elderly.
Very small, or “fine PM” is also thought to cause emphysema and lung cancer. •Lead can have severe health impacts, especially for children, and air toxics are known or probable carcinogens. Laws Help Reduce Pollution from Oil No Dumping/Drains to River Sign Source: Stock photography (copyrighted) Fish Swimming Through “Rigs-to-Reefs” Project Source: U. S. Department of the Interior, Minerals Management Service (Public Doman) Over the years, new technologies and laws have helped to reduce problems related to petroleum products.
As with any industry, the Government monitors how oil is produced, refined, stored, and sent to market to reduce the impact on the environment. Since 1990, fuels like gasoline and diesel fuel have also been improved so that they produce less pollution when we use them. Reformulated Fuels Because a lot of air pollution comes from cars and trucks, many environmental laws have been aimed at changing the make-up of gasoline and diesel fuel so that they produce fewer emissions. These “reformulated fuels” are much cleaner-burning than gasoline and diesel fuel were in 1990.
Technology Helps Reduce Drilling’s “Footprint” Exploring and drilling for oil may disturb land and ocean habitats. New technologies have greatly reduced the number and size of areas disturbed by drilling, sometimes called “footprints. “2 Satellites, global positioning systems, remote sensing devices, and 3-D and 4-D seismic technologies make it possible to discover oil reserves while drilling fewer wells. The use of horizontal and directional drilling makes it possible for a single well to produce oil from a much bigger area. Today’s production ootprints are also smaller those 30 years ago because of the development of movable drilling rigs and smaller “slimhole” drilling rigs. When the oil in a well becomes uneconomic to produce, the well must be plugged below ground, making it hard to tell that it was ever there. As part of the “rigs-to-reefs” program, some old offshore rigs are tipped over and left on the sea floor to become artificial reefs that attract fish and other marine life. Within six months to a year after a rig is toppled, it becomes covered with barnacles, coral, sponges, clams, and other sea creatures.
If oil is spilled into rivers or oceans, it can harm wildlife. When we talk about “oil spills,” people usually think about oil that leaks from a ship that is involved in an accident. The amount of oil spilled from ships dropped significantly during the 1990s partly because new ships were required to have a “double-hull” lining to protect against spills. The Greatest Share of Oil in the Sea Comes from Natural Seeps While oil spills from ships are the most well-known source of oil in ocean water, more oil actually gets into water from natural oil seeps coming from the ocean floor.
Leaks also happen when we use petroleum products on land. For example, gasoline sometimes drips onto the ground when people are filling their gas tanks, when motor oil gets thrown away after an oil change, or when fuel escapes from a leaky storage tank. When it rains, the spilled products get washed into the gutter and eventually flow to rivers and into the ocean. Another way that oil sometimes gets into water is when fuel is leaked from motorboats and jet skis. When a leak in a storage tank or pipeline occurs, petroleum products can also get into the ground, and the ground must be cleaned up.
To prevent leaks from underground storage tanks, all buried tanks are supposed to be replaced by tanks with a double lining. Natural Gas Natural Gas Basics How Was Natural Gas Formed? The main ingredient in natural gas is methane, a gas (or compound) composed of one carbon atom and four hydrogen atoms. Millions of years ago, the remains of plants and animals (diatoms) decayed and built up in thick layers. This decayed matter from plants and animals is called organic material — it was once alive. Over time, the sand and silt changed to rock, covered the organic material, and trapped it beneath the rock.
Pressure and heat changed some of this organic material into coal, some into oil (petroleum), and some into natural gas — tiny bubbles of odorless gas. Source: U. S. Energy Information Administration (Public Domain) In some places, gas escapes from small gaps in the rocks into the air; then, if there is enough activation energy from lightning or a fire, it burns. When people first saw the flames, they experimented with them and learned they could use them for heat and light. How Do We Get Natural Gas? Operators Preparing a Hole for the Explosive Charges Used in Seismic Exploration
Source: Stock photography (copyrighted) The search for natural gas begins with geologists, who study the structure and processes of the Earth. They locate the types of rock that are likely to contain gas and oil deposits. Today, geologists’ tools include seismic surveys that are used to find the right places to drill wells. Seismic surveys use echoes from a vibration source at the Earth’s surface (usually a vibrating pad under a truck built for this purpose) to collect information about the rocks beneath. Sometimes it is necessary to use small amounts of dynamite to provide the vibration that is needed.
Scientists and engineers explore a chosen area by studying rock samples from the earth and taking measurements. If the site seems promising, drilling begins. Some of these areas are on land but many are offshore, deep in the ocean. Once the gas is found, it flows up through the well to the surface of the ground and into large pipelines. Some of the gases that are produced along with methane, such as butane and propane (also known as “by-products”), are separated and cleaned at a gas processing plant. The by-products, once removed, are used in a number of ways. For example, propane can be used for cooking on gas grills.
Dry natural gas is also known as consumer-grade natural gas. In addition to natural gas production, the U. S. gas supply is augmented by imports, withdrawals from storage, and by supplemental gaseous fuels. Most of the natural gas consumed in the United States is produced in the United States. Some is imported from Canada and shipped to the United States in pipelines. Increasingly, natural gas is also being shipped to the United States as liquefied natural gas (LNG). We can also use machines called “digesters” that turn today’s organic material (plants, animal wastes, etc. into natural gas. This process replaces waiting for millions of years for the gas to form naturally. back to top Getting Natural Gas to Users Natural Gas Is Often Stored Before It Is Delivered Natural gas is moved by pipelines from the producing fields to consumers. Because natural gas demand is greater in the winter, it is stored along the way in large underground storage systems, such as old oil and gas wells or caverns formed in old salt beds. The gas remains there until it is added back into the pipeline when people begin to use more gas, such as in the winter to heat homes.
When the gas gets to the communities where it will be used (usually through large pipelines), it flows into smaller pipelines called “mains. ” Very small lines, called “services,” connect to the mains and go directly to homes or buildings where it will be used. Natural Gas Can Also Be Stored and Transported as a Liquid LNG Transport Barge Unloading Source: Stock photography (copyrighted) When chilled to very cold temperatures, approximately -260°F, natural gas changes into a liquid and can be stored in this form.
Because it takes up only 1/600th of the space that it would in its gaseous state, liquefied natural gas (LNG) can be loaded onto tankers (large ships with several domed tanks) and moved across the ocean to other countries. When this LNG is received in the United States, it can be shipped by truck to be held in large chilled tanks close to users or turned back into gas when it’s ready to put in the pipelines. back to top What is Liquefied Natural Gas? Liquefied natural gas (LNG) is natural gas that has been cooled to about -260°F for shipment and/or storage as a liquid. The volume of the liquid is bout 600 times smaller than in its gaseous form. In this compact form, natural gas can be shipped in special tankers to receiving terminals in the United States and other importing countries. At these terminals, the LNG is returned to a gaseous form and transported by pipeline to distribution companies, industrial consumers, and power plants. Liquefying natural gas provides a means of moving it long distances where pipeline transport is not feasible, allowing access to natural gas from regions with vast production potential that are too distant from end-use markets to be connected by pipeline. ack to top Uses of Natural Gas Data for this graph Natural Gas Is a Major Energy Source for the United States About 25% of energy used in the United States came from natural gas in 2009. The United States used 22. 84 trillion cubic feet (Tcf) of natural gas in 2009. How Natural Gas Is Used Natural gas is used to produce steel, glass, paper, clothing, brick, electricity and as an essential raw material for many common products. Some products that use natural gas as a raw material are: paints, fertilizer, plastics, antifreeze, dyes, photographic film, medicines, and explosives.
Slightly more than half of the homes in the United States use natural gas as their main heating fuel. Natural gas is also used in homes to fuel stoves, water heaters, clothes dryers, and other household appliances. The major consumers of natural gas in the United States in 2009 included: •Electric power sector — 6. 9 trillion cubic feet (Tcf) •Industrial sector — 6. 1 Tcf •Residential sector — 4. 8 Tcf •Commercial sector — 3. 1 Tcf Where Natural Gas Is Used Natural gas is used throughout the United States, but the top natural gas consuming States in 2008 were: •Texas •California •Louisiana •New York •Illinois •Florida ack to top Natural Gas & the Environment Pipeline Across Alaskan Lands Source: Stock photography (copyrighted) Natural Gas Use Contributes to Air Pollution Natural gas burns more cleanly than other fossil fuels. It has fewer emissions of sulfur, carbon, and nitrogen than coal or oil, and when it is burned, it leaves almost no ash particles. Being a cleaner fuel is one reason that the use of natural gas, especially for electricity generation, has grown so much. However, as with other fossil fuels, burning natural gas produces carbon dioxide which is a greenhouse gas. Greenhouse gases contribute to the “greenhouse effect. 1 As with other fuels, natural gas also affects the environment when it is produced, stored, and transported. Because natural gas is made up mostly of methane (another greenhouse gas), small amounts of methane can sometimes leak into the atmosphere from wells, storage tanks, and pipelines. The natural gas industry is working to prevent any methane from escaping. Technology Helps Reduce Drilling’s “Footprint” Exploring and drilling for natural gas will always have some impact on land and marine habitats. But new technologies have greatly reduced the number and size of areas disturbed by drilling, sometimes called “footprints. Plus, the use of horizontal and directional drilling make it possible for a single well to produce gas from much bigger areas than in the past. Natural gas pipelines and storage facilities have a good safety record. This is important because when natural gas leaks it can cause explosions. Since raw natural gas has no odor, natural gas companies add a smelly substance to it so that people will know if there is a leak. If you have a natural gas stove, you may have smelled this “rotten egg” smell of natural gas when the pilot light has gone out. Uranium (nuclear)
Uranium (nuclear) Basics The sun is basically a giant ball of hydrogen gas undergoing fusion into helium gas and giving off vast amounts of energy in the process. Source: NASA (Public Domain) How Fission Splits the Uranium Atom Source: National Energy Education Development Project (Public Domain) Nuclear Energy Is Energy from Atoms Nuclear energy is energy in the nucleus (core) of an atom. Atoms are tiny particles that make up every object in the universe. There is enormous energy in the bonds that hold atoms together. Nuclear energy can be used to make electricity.
But first the energy must be released. It can be released from atoms in two ways: nuclear fusion and nuclear fission. In nuclear fission, atoms are split apart to form smaller atoms, releasing energy. Nuclear power plants use this energy to produce electricity. In nuclear fusion, energy is released when atoms are combined or fused together to form a larger atom. This is how the sun produces energy. Fusion is the subject of ongoing research, but it is not yet clear that it will ever be a commercially viable technology for electricity generation. Nuclear Fuel — Uranium
The fuel most widely used by nuclear plants for nuclear fission is uranium. Uranium is nonrenewable, though it is a common metal found in rocks all over the world. Nuclear plants use a certain kind of uranium, referred to as U-235. This kind of uranium is used as fuel because its atoms are easily split apart. Though uranium is quite common, about 100 times more common than silver, U-235 is relatively rare. Most U. S. uranium is mined in the Western United States. Once uranium is mined, the U-235 must be extracted and processed before it can be used as a fuel.
During nuclear fission, a small particle called a neutron hits the uranium atom and splits it, releasing a great amount of energy as heat and radiation. More neutrons are also released. These neutrons go on to bombard other uranium atoms, and the process repeats itself over and over again. This is called a chain reaction. back to top Nuclear Power Plants Nuclear Power Plants Generate About One-Fifth of U. S. Electricity Nuclear power accounted for about 20% of the total net electricity generated in the United States in 2008, about as much as the electricity used in California, Texas, and New York, the three States with the most people.
In 2008, there were 66 nuclear power plants (composed of 104 licensed nuclear reactors) throughout the United States. Most of the reactors are east of the Mississippi. The last new reactor to enter commercial service in the United States was the Tennessee Valley Authority’s Watts Bar 1 in Tennessee in 1996. In 2008, TVA resumed construction on Watts Bar 2, which was about 80% complete when its construction was stopped in 1988. It is now expected to be completed in 2012. Nuclear reactors look like large concrete domes from the outside. Not all nuclear power plants have cooling towers.
Source: Stock photography (copyrighted) Nuclear Power Comes from Fission Most power plants, including nuclear plants, use heat to produce electricity. They rely on steam from heated water to spin large turbines, which generate electricity. Instead of burning fossil fuels to produce the steam, nuclear plants use heat given off during fission. In nuclear fission, atoms are split apart to form smaller atoms, releasing energy. Fission takes place inside the reactor of a nuclear power plant. At the center of the reactor is the core, which contains the uranium fuel. The uranium fuel is formed into ceramic pellets.
The pellets are about the size of your fingertip, but each one produces roughly the same amount of energy as 150 gallons of oil. These energy-rich pellets are stacked end-to-end in 12-foot metal fuel rods. A bundle of fuel rods, sometimes hundreds, is called a fuel assembly. A reactor core contains many fuel assemblies. The heat given off during fission in the reactor core is used to boil water into steam, which turns the turbine blades. As they turn, they drive generators that make electricity. Afterward, the steam is cooled back into water in a separate structure at the power plant called a cooling tower.
The water can be used again and again. Types of Nuclear Reactors Diagram of a Boiling Water Nuclear Reactor Source: U. S. Nuclear Regulatory Commission Diagram of a Pressurized Nuclear Reactor System Source: U. S. Nuclear Regulatory Commission Nuclear reactors are large machines that contain and control nuclear chain reactions, while releasing heat at a controlled rate. A nuclear power plant uses the heat supplied by the nuclear reactor to turn water into steam, which drives turbine-generators that generate electricity. There Are Two Types of U. S. Reactors
Just as there are different approaches to designing and building airplanes and automobiles, engineers have developed different types of nuclear power plants. Two types are used in the United States: boiling-water reactors and pressurized-water reactors. Boiling-Water Reactors In a boiling-water reactor, the water heated by the reactor core turns directly into steam in the reactor vessel and is then used to power the turbine-generator. Pressurized-Water Reactors In a pressurized-water reactor, the water heated by the reactor core is kept under pressure so that it does not turn to steam at all — it remains liquid.
This hot radioactive water flows through a piece of equipment called a steam generator. A steam generator is a giant cylinder with thousands of tubes in it that the hot radioactive water can flow through and heat up. Outside these hot tubes in the steam generator is nonradioactive water (or clean water), which eventually boils and turns to steam . The radioactive water flows back to the reactor core, where it is reheated and then sent back to the steam generator. The clean water may come from one of several sources including oceans, lakes, or rivers. back to top
Getting (Producing) Uranium The fuel most widely used by nuclear plants for nuclear fission is uranium. In nuclear fission atoms are split apart to form smaller atoms, releasing energy. Nuclear power plants use the heat from nuclear fission to produce electricity. Uranium Is Found in Nature but Must Be Processed into Fuel Uranium is nonrenewable, though it is a common metal found in rocks all over the world. Uranium occurs in nature in combination with small amounts of other elements. Nuclear plants use a certain kind of uranium, U-235, as fuel because its atoms are easily split apart.
Though uranium is quite common, about 100 times more common than silver, U-235 is relatively rare. Economically recoverable uranium deposits have been discovered principally in the western United States, Australia, Canada, Africa, and South America. Once uranium is mined, the U-235 must be extracted and processed before it can be used as a fuel. Mined uranium ore typically yields one to four pounds of uranium concentrate (U3O8 or “yellowcake”) per ton, or 0. 05% to 0. 20% U3O8. The Nuclear Fuel Cycle describes uranium processing in more detail.
Typical Conventional Uranium Mill Source: U. S. Energy Information Administration, Office of Coal, Nuclear, Electric and Alternate Fuels (Public Domain) Most of Our Uranium Is Imported Owners and operators of U. S. civilian nuclear power reactors purchased the equivalent of 53 million pounds of uranium during 2008. Uranium delivered to U. S. reactors in 2008 came from six continents: •14% of delivered uranium came from the United States •86% of delivered uranium was of foreign-origin: o42% was from Australia and Canada o33% originated in Kazakhstan, Russia and Uzbekistan 11% came from Brazil, Czech Republic, Namibia, Niger, South Africa, and the United Kingdom Nuclear Power & the Environment Dry Storage Cask Some canisters are designed to be placed vertically in robust above-ground concrete or steel structures. Source: U. S. Nuclear Regulatory Commission Nuclear Power Plants Produce No Carbon Dioxide Unlike fossil fuel-fired power plants, nuclear reactors do not produce air pollution or carbon dioxide while operating. However, the processes for mining and refining uranium ore and making reactor fuel require large amounts of energy.
Nuclear power plants have large amounts of metal and concrete, which also require large amounts of energy to manufacture. If fossil fuels are used to make the electricity and manufacture the power plant materials, then the emissions from burning those fuels could be associated with the electricity that nuclear power plants generate. Nuclear Energy Produces Radioactive Waste The main environmental concerns for nuclear power are radioactive wastes such as uranium mill tailings, spent (used) reactor fuel, and other radioactive wastes.
These materials can remain radioactive and dangerous to human health for thousands of years. They are subject to special regulations that govern their handling, transportation, storage, and disposal to protect human health and the environment. The U. S. Nuclear Regulatory Commission regulates the operation of nuclear power plants. Radioactive wastes are classified as low-level and high-level. The radioactivity in these wastes can range from just above natural background levels, as in mill tailings, to much higher levels, such as in spent reactor fuel or the parts inside a nuclear reactor.
The radioactivity of nuclear waste decreases with the passage of time through a process called radioactive decay. The amount of time necessary to decrease the radioactivity of radioactive material to one-half the original level is called the radioactive half-life of the material. Radioactive waste with a short half-life is often stored temporarily before disposal in order to reduce potential radiation doses to workers who handle and transport the waste, as well as to reduce the radiation levels at disposal sites.
By volume, most of the waste related to the nuclear power industry has a relatively low-level of radioactivity. Uranium mill tailings contain the radioactive element radium, which decays to produce radon, a radioactive gas. Most uranium mill tailings are placed near the processing facility or mill where they come from, and are covered with a barrier of a material such as clay to prevent radon from escaping into the atmosphere and then a layer of soil, rocks, or other materials to prevent erosion of the sealing barrier.
The other types of low level radioactive waste are the tools, protective clothing, wiping cloths, and other disposable items that get contaminated with small amounts of radioactive dust or particles at nuclear fuel processing facilities and power plants. These materials are subject to special regulation that govern their handling, storage, and disposal so they will not come in contact with the outside environment. High-level radioactive waste consists of “irradiated” or used nuclear reactor fuel (i. e. , fuel that has been used in a reactor to produce electricity).
The used reactor fuel is in a solid form consisting of small fuel pellets in long metal tubes. Spent Reactor Fuel Storage and Power Plant Decommissioning Spent reactor fuel assemblies are highly radioactive and must initially be stored in specially designed pools resembling large swimming pools, where water cools the fuel and acts as a radiation shield, or in specially designed dry storage containers. An increasing number of reactor operators now store their older spent fuel in dry storage facilities using special outdoor concrete or steel containers with air cooling.
There is currently no permanent disposal facility in the United States for high-level nuclear waste. High-level waste is being stored at nuclear plants. When a nuclear power plant stops operating, the facility must be decommissioned. This involves safely removing the plant from service and reducing radioactivity to a level that permits other uses of the property. The Nuclear Regulatory Commission has strict rules governing nuclear power plant decommissioning that involve cleanup of radioactively contaminated plant systems and structures, and removal of the radioactive fuel.
Nuclear Reactors and Power Plants Have Complex Safety and Security Features An uncontrolled nuclear reaction in a nuclear reactor can potentially result in widespread contamination of air and water with radioactivity for hundreds of miles around a reactor. The risk of this happening at nuclear power plants in the United States is considered to be very small due to the diverse and redundant barriers and numerous safety systems at nuclear power plants, the training and skills of the reactor operators, testing and maintenance activities, and the regulatory requirements and oversight of the Nuclear Regulatory Commission.
A large area surrounding nuclear power plants is restricted and guarded by armed security teams. U. S. reactors have containment vessels that are designed to withstand extreme weather events and earthquakes. Why is peat non renewable? Peat is non-renewable because it is a type of rock/mineral which can take eons to grow back, classifying this as non-renewable. Fossil Fuels and Minerals Earth’s Non-Renewable Resources Share Article | Jan 21, 2010 Jeri Schott Fossil fuels and minerals are derivatives of the earth. Both provide convenience and improve living standards for the earth’s 6 billion and growing inhabitants.
Ironically, both elements are nonrenewable resources in that reproduction is much slower than consumption. Beyond origin and nonrenewable status, fossil fuels and minerals are quite distinguishable in formation and use. Fossil Fuels Fossil fuels are components created from pressurized, compacted, heated remains of plants. Oil, peat, and gas are common outputs of decayed, aged plant material. Peat is a valuable energy source. It provides energy as peat but also converts to various levels of coal through the coalification process. The most desirable coal types contain high levels of carbon and take the most time to form.
How Peat Becomes Coal The process of coalification is natural and slow. It requires first that plant remains, or the organic layer, disappears. The remaining natural material, peat, is then covered by sediment over time. The sediment forms layers, typical of the earth’s basic cycle, which presses down on the peat. The organic layer loses water and decreases in size. As it is crushed down, it becomes more concentrated and the heat exposure rises. The heat and compaction create carbon bearing coal, a very heavily relied upon nonrenewable resource.
The process is reminiscent of a trash compactor except instead of a bundle of trash, a layer of coal is formed. Mineral Ores Minerals are solid deposits found in the earth. Ores are the valued portion of a deposit. Minerals are desirable based on the metals they contain or the properties they offer. Metals such as gold and bronze have served as weapons, tools, and money over thousands of years. Minerals are also known as gems and appear in necklaces, bracelets, and on wedding bands. The diamond ore is a nonrenewable resource of the hardest substance. It is treasured for beauty and resilience.
The mineral is used on the industrial front in saws and as a heat conductor. Diamond Formation Diamonds are formed deep within the earth and eventually wind up as placer deposits. A placer deposit is one of six methods forming minerals. Diamonds originate at the center of the earth given a great amount of heat and pressure. The source rock, kimberlite, is spit up to the surface and sometimes carried off by water, deposited in a sandy basin or alluvial area. The placer deposit is soon discovered in a process similar to panning for gold. (Note: Placer mining is not the only way to diamond mine. Diamond, or “indestructible” in Greek, is 100% carbon mineral. The properties of a diamond, if renewable, make it a theoretically clean energy resource. Peat has become a mainly non-renewable natural resource within the UK and Republic of Ireland and significant demand has depleted the source of supply. In the Republic of Ireland 95% of peat is burnt in electricity power stations. On a global scale it may be considered more renewable but importing peat into the UK and Eire from abroad, over longer distances, involves the consumption of large amounts of non-renewable fossil fuels and should not be encouraged.
The use of peat as a domestic fuel and as construction material can be traced back thousands of years. However, the scale of use was comparatively low, contained within small communities and had little environmental impact. It is only over the last forty years that its properties as a growing and packaging medium for the horticultural, agricultural and related industries has led to extraction and use on a massive scale. (Originally use in horticulture was to find a use for the waste peat overlying burnable peat).
The consequent impact on peat reserves, the wildlife they support, the landscape quality and wider environmental considerations has been irreparable in some cases. The Chartered Institution of Water and Environmental Management (CIWEM) is an independent professional body representing over 12,000 environmental professionals. CIWEM’s agreed purpose is to develop and promote better and integrated management of the environment; to foster a deeper understanding of water and environmental issues and to enhance the quality of people’s lives.
This is achieved through CIWEM’s Royal Charter, education, training and professional development; dissemination of information; conferences and events; research and publications; contact with Government agencies and other bodies, partnerships with other organisations and the publication of Policy Position Statements (PPS). The purpose of this PPS is to promote this lnstitution’s views on the environmental damage caused by the unsustainable extraction and the use of peat and to encourage the use of alternative renewable resources. CIWEM believes that, wherever practicable, we should maximise the use of renewable resources.
Peat extraction may involve the destruction of natural habitats and peat reserves which are often valuable sites of scientific interest. CIWEM supports the protection of such sites. CIWEM welcomes the efforts of the Peat Producers Association (PPA) to establish codes of operation to minimise the damage to the environment. Restoration of damaged sites to a natural habitat should be a requirement of the industry the PPA represents. CIWEM recognises that to be efficient and economic, a significant amount of plant production requires a non-soil based growing medium. At present peat often provides the best option for such a medium.
This view is supported by the research and development conducted on the use of peat and other materials as a growing medium by respected horticulture research establishments. The use of peat as a mulch, for the improvement of soil structure, or as a packaging material cannot be supported as there are alternative waste or renewable materials for this purpose. In the interests of sustainability and environmental protection, and renewable alternatives (preferably locally sourced) should be sought to replace peat as a plant growing medium. CIWEM recognises the contribution ade in the UK by the Ministry of Agriculture, Fisheries and Food (MAFF), Horticulture Research International, the Horticultural Development Council and producers to develop alternatives. This Institution believes that the building of a fund of knowledge on the use of any alternative must be continued and the further research and development in this area are necessary. Conclusions CIWEM calls on those industries which use peat, for whatever purpose, to find renewable alternative resources. To assist those industries the Institution urges continued research into the development of environmentally acceptable alternatives to peat.
CIWEM urges the urgent restoration of damaged peat reserves and that those companies which extract peat contribute to the cost of such restoration. CIWEM urges the Government to protect those peat reserves that are deemed to be scientifically and/or environmentally important through existing legislation or new legislation where current measures do not provide the proper protection. CIWEM urges MAFF to engage in a public awareness campaign which will lead to a better understanding of all the issues relating to the use of peat and the environmental damage commercial extraction is causing.
