Fossil fuels Environmental Science Test 4 Fossil Fuels are forms of stored solar energy it is a fuel derived from biological material that became fossilized millions of years ago o Plants through photosynthesis o Oil natural gas peat and coal Oil Formed from incompletely decomposed organic matter converted by chemical reactions Provide 87 of energy consumed worldwide o Hypothesized that crude oil and natural gas are derived from organic materials mostly plants that were buried with marine or lake sediments in depositional basins o Fossil fuels are found primarily along plate boundaries Exceptions to this include texas gulf of mexico North Dakota and Crude oil and natural gas the North Sea o Conventional and continuous oil and gas present in the rocks Resources are the total amount of oil and gas present in the rocks Reserves are that portions of the resource that is identified and is currently available to be legally extracted at a profit Continuous oil resources are regional in extent occurring in broad geological basins Bakken formation in North Dakota for example o Source rock Fine grained organic rick sediment At least 500 m depth Subjected to increased heat and pressure Initiates the chemical transformation Elevated pressure causes sediment to be compressed o Reservoir rock Coarser grained and relatively porous For example sandstone and porous limestone Porous rocks are rocks that have holes in them similar to a sponge These small holes allow oil and natural gas to pass threw the rock and rise until it reaches a none porous rock Porosity is the measure of a rocks ability to hold a fluid It is normally expressed as a percentage of the total rock which is taken up by pore space Permeability of a rock is the measure of the resistance to the flow of fluid through the rock High permeability means fluid passes through the rock easily o Coal bed gas a natural gas extracted from coal beds The gases that are typically found in coal bed are methane and small traces of ethane nitrogen carbon dioxide and a few other gases o Pros and Cons of coal Pros Abundant supply Relatively inexpensive Continuous power Can be made low carbon Can be converted to liquid or gas Cons Nonrenewable Largest contributor to global warming Highest transportation costs High level of radiation Severe environmental social and health and safety impacts of coal mining Trap o Cap rock often shale blocks natural upward migration of the oil and gas often form in anticlines or faults o Types of traps Structural traps are formed as a result of geological structures like folds and faults Fault traps form when an impermeable layer above and a fault zone impede the flow of oil Drilling o Derrick a tall framework over a drill hole used to support equipment and lower or hoist lengths of the drill pipe o Bit a drill bit is the device attached to the end of the drill string that breaks apart cuts and crushes the rock formations when drilling o BOP or Blowout preventer the second line of defense for the workers and the well to prevent a blowout It is a large valve that is able to seal off at the surface of a well that is being worked on or drilled over o Pipe Drill pipe is normally 30ft ling and can have a diameter of 4 inched to over 14 inches One length of 8 inch pipe weighs over 1 ton Petroleum production o Proven oil reserves Portion of total resources that has been identified and can be extracted at a profit Majority are located in the middle east o Primary production Natural pressure drives oil to the surface Recovers less than 5 of petroleum in reservoir o Secondary production Involves pumping oil from wells Recovers only 25 of petroleum in reservoir o Enhanced recovery Increases the amount recovered to about 60 Steam water or chemicals injected into the reservoir o Proven oil reserves estimates some say oil and natural gas will last only a few decades 30 years ago 1 6 trillion bbls Today 2 2 trillion bbls Tar sands o Is sedimentary rocks or sands impregnated with tar oil asphalt or bitumen Recovered by mining sands and washing the oil out with hot water Found in Alberta Canada Strip mined 2014 production greater than 2 mill bbls day and will double by 2024 Waste disposal similar problem as with shale but greater volume of waste produced Inherently dirty process Transportation via rail and pipeline Oil shale o Fine grained sedimentary rock containing organic matter kergen When heated to 500 c oil sale yields oil Destructive distillation Oil from shale called synfuel o Recovery performed on both surface and subsurface Disposal of waste a problem because shale must be retorted crushed and heated Volume of waste 20 to 30 greater than original volume o Oil shale mining may develop as oil process rise o Fracking which is also called hydraulic fracturing is the process of extracting natural gas from shale rock layers deep within the earth How oil and gas deposits form o Dead marine animals settle to the ocean floor and are covered with o Methane hydrate is methane that has been trapped in ice that was formed o Heat and pressure build Over millions of years a chemical change takes sediment restricting oxygen from dead marine animals place leaving oil and gas o Oil and gas move toward the surface some getting trapped below dense rock Keystone XL Pipeline a pipeline that would trek over 2000 miles from Albrta Canada to the Gulf of Texas carrying tar sand oil There is already parts of the pipeline finished and the XL pipeline has still yet to be approved due to controversies A bushel of corn produces 2 8 gallons of ethanol and 17 to 18 pounds of dried Distillers byproducts are a higher protein feed than corn that can be fed either wet Ethanol is an alcohol the same one found in an alcoholic beverage Ethanol is made by converting starches and sugars from plant material into alcohol and carbon dioxide Ethanol as fuel distillers byproducts or dry Energy efficiency Pros and cons of ethanol as fuel o Pros Greenhouse gas reduction Positive net energy balance o Cons Its biodegradable It produces usable byproducts The use of corn as fuel could create higher food prices Would reduce MPG when used in cars Absorbs water and is corrosive making it hard to transport Shorter shelf and tank life than other fuels Streams and Groundwater Water supply use and management o Unique properties of water Universal solvent It can dissolve in almost anything Common salts and crustal minerals have ionic bonds that are weaker than the covalent bonds of the