ENERGY AND FUELS. Energy Sources of Industrial Sectors 29/03/18. Energy Uses in Industry

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1 Energy Sources of Industrial Sectors ENERGY AND FUELS KMU 392 March 28, 2018 Natural gas Petroleum, such as distillate and residual fuel oils and hydrocarbon gas liquids Electricity Renewable sources Coal and coal coke Energy Uses in Industry Most industries purchase electricity from electric utilities or independent power producers. Some industrial facilities generate electricity for use at their plants using fuels that they purchase or the residues from their industrial processes. A few produce electricity with solar photovoltaic systems located on their properties. Some of them sell some of the electricity that they generate. Heat in industrial processes and space heating in buildings Boiler fuel to generate steam or hot water for process heating and generating electricity Electricity is used for operating industrial motors and machinery, lights, computers, and office equipment and for facility heating, cooling, and ventilation equipment. 1

2 Nonrenewable Sources One major application involves raising the temperature of components in the manufacturing process, which is called process heating. Refining crude oil, where heat is used to separate various distillates, is an example of this. Another common use of energy in industry is to heat a boiler that generates steam or hot water. A few industries use a very large share of energy in the industrial sector. Petroleum refining Chemical industry (the paper and metal industries) Energy sources are classified as nonrenewable because they do not form or replenish in a short period of time. Renewable energy sources such as solar and wind replenish naturally in a short period of time. The four major nonrenewable energy sources are - Crude oil - Natural gas - Coal - Uranium (nuclear energy) Nonrenewable Sources Nonrenewable energy sources liquids gases solids. Crude oil is used to make liquid petroleum products such as gasoline, diesel fuel, and heating oil. Propane and other hydrocarbon gas liquids, such as butane and ethane, are found in natural gas and crude oil. Nonrenewable Sources All fossil fuels are nonrenewable, but not all nonrenewable energy sources are fossil fuels. Coal, crude oil, and natural gas are all considered fossil fuels because they were formed from the buried remains of plants and animals that lived millions of years ago. Uranium ore, a solid, is mined and converted to a fuel used at nuclear power plants. Uranium is not a fossil fuel, but it is classified as a nonrenewable fuel. 2

3 Solid fuels: Coal Coal is a combustible black or brownish-black sedimentary rock with a high amount of carbon and hydrocarbons. Coal is classified as a nonrenewable energy source because it takes millions of years to form. Coal types Anthracite contains 86% 97% carbon, and generally has the highest heating value of all ranks of coal. Anthracite is mainly used by the metals industry. Bituminous coal contains 45% 86% carbon. Bituminous coal is used to generate electricity and is an important fuel and raw material for making iron and steel. Subbituminous coal typically contains 35% 45% carbon, and it has a lower heating value than bituminous coal. Lignite contains 25% 35% carbon and has the lowest energy content of all coal ranks. Lignite coal deposits tend to be relatively young and were not subjected to extreme heat or pressure. Lignite is crumbly and has high moisture content, which contributes to its low heating value. Coal uses The most significant uses of coal are in electricity generation, steel production, cement manufacturing and as a liquid fuel. Steam coal - also known as thermal coal - is mainly used in power generation. Coking coal - also known as metallurgical coal - is mainly used in steel production. Coal uses Electric power Power plants make steam by burning coal, and the steam turns turbines (machines for generating rotary mechanical power) to generate electricity. Many industries and businesses have their own power plants, and some use coal to generate electricity, mostly in combined heat and power plants. 3

4 Coal uses Industry Blast furnace in a modern steel works The concrete and paper industries burn large amounts of coal to produce heat. The steel industry uses coal indirectly to make steel. The high temperatures created by burning coal coke give steel the strength and flexibility needed for bridges, buildings, and automobiles. Coal uses Converting coal into gas and liquids Coal can be turned into gases and liquids that can be used as fuels or processed into chemicals to make other products. These gases or liquids are sometimes called synthetic fuels or synfuels. Synthetic fuels are made by heating coal in large vessels. These fuels produce fewer air pollutants when burned than burning coal directly. Coal liquefaction Coal liquefaction Coal liquefaction is a process in which coal is converted into liquid fuels or petrochemicals. There are several processes used to accomplish this task, the two most common being the "indirect route" and the "direct route". The indirect route is composed of 2 steps: First, coal is gasified with steam and oxygen to produce a synthesis gas (syngas), which is then cleaned to rid of dust, tar, and acid gases. The second step reacts the synthesis gas with a catalyst in the Fischer-Tropsch process, which converts the syngas into a range of hydrocarbon fuels such as gasoline, diesel and methanol. In the direct route, coal is pulverized and reacted with a catalyst, then hydrogen is added under high pressures and temperatures in the presence of a solvent to produce a raw liquid fuel. This raw fuel requires refining in order to yield acceptable transportation fuels. 4

5 Coal liquefaction Coal and the environment Several principal emissions result from coal combustion: Sulfur dioxide (SO2), which contributes to acid rain and respiratory illnesses Nitrogen oxides (NOx), which contribute to smog and respiratory illnesses Particulates, which contribute to smog, haze, and respiratory illnesses and lung disease Carbon dioxide (CO2), which is the primary greenhouse gas produced from the burning of fossil fuels (coal, oil, and natural gas) Mercury and other heavy metals, which have been linked to both neurological and developmental damage in humans and other animals Fly ash and bottom ash, which are residues created when coal is burned at power plants Oil and Petroleum Products Crude oil is a mixture of hydrocarbons that formed from plants and animals that lived millions of years ago. Crude oil is a fossil fuel, and it exists in liquid form in underground pools or reservoirs, in tiny spaces within sedimentary rocks, and near the surface in tar (or oil) sands. Petroleum products are fuels made from crude oil and other hydrocarbons contained in natural gas. Petroleum products can also be made from coal, natural gas, and biomass. 5

6 After crude oil is removed from the ground, it is sent to a refinery where different parts of the crude oil are separated into useable petroleum products. These petroleum products include gasoline, distillates such as diesel fuel and heating oil, jet fuel, petrochemical feedstocks, waxes, lubricating oils, and asphalt. Crude oil and other liquids produced from fossil fuels are refined into petroleum products that people use for many different purposes. How does oil affect the environment? Finding, producing, and moving crude oil may have negative effects on the environment. Technological advances in exploration, production, and transportation of oil Hydraulic fracturing (large amounts of water and wastewater due to hazardous chemical use) Oil spills (accidents, soil and water contamination, fires) Hydrocarbon Gas Liquids Hydrocarbons are molecules of carbon and hydrogen in various combinations. Hydrocarbon gas liquids (HGL) are hydrocarbons that occur as gases at atmospheric pressure and as liquids under higher pressures. HGL can also be liquefied by cooling. The specific pressures and temperatures at which the gases liquefy vary by the type of HGL. HGL may be described as being light or heavy according to the number of carbon atoms and hydrogen atoms in an HGL molecule. Propane, ethane, butane, and other hydrocarbon gas liquids that are produced at natural gas processing plants and oil refineries. The petrochemical industry uses HGL as feedstock for making many products. Propane, a heavily consumed HGL, is also used in homes for space heating and water heating, for clothes drying, for cooking, for heating greenhouses and livestock housing, for drying crops, and as a transportation fuel. 6

7 HGLs are categorized as Alkanes, or paraffins Ethane C2H6 Propane C3H8 Butanes: normal butane and isobutane C4H10 Natural gasoline or pentanes plus C5H12 and heavier Alkenes, or olefins Ethylene C2H4 Propylene C3H6 Butylene and isobutylene C4H8 Hydrocarbon gas liquids have many uses Feedstock in petrochemical plants to make chemicals, plastics, and synthetic rubber Fuels for heating, cooking, and drying Fuels for transportation Additives for motor gasoline production Diluent (a diluting or thinning agent) for transportation of heavy crude oil Natural gas Hydrocarbon gas liquids, uses, products, and consumers Natural gas occurs deep beneath the earth's surface. Natural gas consists mainly of methane, a compound with one carbon atom and four hydrogen atoms. Natural gas also contains small amounts of hydrocarbon gas liquids and non-hydrocarbon gases. 7

8 Liquefied natural gas (LNG) Liquefied natural gas (LNG) is natural gas that has been cooled to a liquid state, at about -160C, for shipping and storage. The volume of natural gas in its liquid state is about 600 times smaller than its volume in its gaseous state. Liquefying natural gas is a way to move natural gas long distances when pipeline transport is not feasible Natural gas uses The electric power sector uses natural gas to generate electricity. The industrial sector uses natural gas as a fuel for process heating and for combined heat and power systems and as a raw material (feedstock) to produce chemicals, fertilizer, and hydrogen The residential sector uses natural gas to heat buildings and water, to cook, and to dry clothes. A relatively small amount of natural gas is used as vehicle fuel in the form of compressed natural gas and liquefied natural gas. Purification of natural gas If the water present in most fuel gas is not removed, high corrosion will occur in the transmission lines, and trouble may also result from the formation of hydrates, which can cause line stoppages. The freezing of valves and regulators in cold weather may also cause difficulties. Hydrogen sulfide and other sulfur compounds are objectionable in natural gas because they cause corrosion and also form air-polluting compounds when burned. Carbon dioxide in the gas is objectionable because it lowers the heating value of the gas. Methods for the dehydration of gas: compression, treatment with drying substances (glycol, silica gel) adsorption, refrigeration 8

9 Carbon Dioxide and Sulfur Removal Processes Gases containing H 2 S or both H 2 S and CO 2 are commonly referred to as sour gases or acid gases in the hydrocarbon processing industries. Process industries produce chemicals by chemical reactions using a catalyst. Most catalyst poisoned by sulphur and thus affects the conversion rate. Hydrogen sulphide should be removed before the process gas enters into the manufacturing units. Sulphur removal methods for gases with chemical reactions: The Girbotol process uses NH2 compound to react with hydrogen sulphide 2RNH2 + H2S (RNH3)2S Phosphate (Shell) process uses K3PO4 K3PO4 + H2S KHS + K2HPO4 Iron oxide reagent application to the sulphur containing gas reacts as Fe2O3.xH2O + 3H2S Fe2S3 + (x+3) H2O Sulphur removal methods for gases with chemical reactions: By oxidation with air iron oxide regenerated 2Fe2S3 + 3O2 +xh2o 2Fe2O3.xH2O +6S Seaboard developed by the application sodium carbonate Na2CO3 + H2S NaHCO3 + NaHS Lime the Ca(OH)2 process work by the reactions Ca(OH)2 + H2S CaS + 2H2O Other gaseous fuels Coke oven gas: Coke-oven gas is a coproduct of pyrolysis. Coke oven gas is separated from the ammonia liquor and the coal tar. Some of the gas may be used for underfiring the coke ovens themselves. Caustic Soda the NaOH reagent treatment system 2NaOH +H2S Na2S + 2H2O 9

10 Other gaseous fuels Other gaseous fuels Producer gas: Producer gas is the mixture of gases produced by the gasification of organic material such as biomass at relatively low temperatures. Producer gas is composed of carbon monoxide (CO), hydrogen (H2), carbon dioxide (CO2) and typically a range of hydrocarbons such as methane (CH4) with nitrogen from the air. Producer gas can be burned as a fuel Water gas: Water gas is often called blue-gas because of the color of the flame when it is burned. It is produced by the reaction of steam on incandescent coal or coke at temperatures above 1000C. The following reactions occur: C + H 2 O CO + H 2 C + 2H 2 O CO 2 + 2H 2 Other gaseous fuels Synthetic natural gas: Synthetic natural gas is a type of gas created from coal that serves as a substitute for natural gas and is suitable for transmission in natural gas pipelines. This natural gas substitute must have a minimum of 95% methane in it. Other gaseous fuels Liquified petroleum gases: LPG describes flammable hydrocarbon gases including propane, butane and mixtures of these gases. LPG, liquefied through pressurisation, comes from natural gas processing and oil refining. LPG is used as heating, cooking and auto fuel. 10

11 29/03/18 Nuclear Energy (Alternative energy sources) A nuclear reactor produces and controls the release of energy from splitting the atoms of uranium. Uranium is the most common fuel used in commercial nuclear power plants. Uranium has three isotopes: uranium-238 (99.275%) uranium-235 (0.720% èenriched to 3%) uranium-234 (0.006%) Uranium dioxide in powder and pellet form Yellow cake Uranium fuel rods 11

12 Uranium-fuelled nuclear power is a clean and efficient way of boiling water to make steam which drives turbine generators. The reactor core sits inside a steel pressure vessel, so that water around it remains liquid even at the operating temperature of over 320 C. Steam is formed either above the reactor core or in separate pressure vessels, and this drives the turbine to produce electricity. The steam is then condensed and the water recycled. Components of a nuclear reactor There are several components common to most types of reactors: Fuel Uranium is the basic fuel. Usually pellets of uranium oxide (UO2) are arranged in tubes to form fuel rods. The rods are arranged into fuel assemblies in the reactor core. In a 1000 MW class reactor there might be 51,000 fuel rods with over 18 million pellets. Moderator Material in the core which slows down the neutrons released from fission so that they cause more fission. It is usually water, but may be heavy water or graphite. Control rods These are made with neutron-absorbing material such as cadmium, hafnium or boron, and are inserted or withdrawn from the core to control the rate of reaction, or to halt it. Secondary control systems involve other neutron absorbers, usually boron in the coolant. Coolant A fluid circulating through the core so as to transfer the heat from it. In light water reactors the water moderator functions also as primary coolant. 12

13 Pressure vessel or pressure tubes Usually a robust steel vessel containing the reactor core and moderator/coolant, but it may be a series of tubes holding the fuel and conveying the coolant through the surrounding moderator. Steam generator Part of the cooling system of pressurized water reactors where the high-pressure primary coolant bringing heat from the reactor is used to make steam for the turbine, in a secondary circuit. Containment The structure around the reactor and associated steam generators which is designed to protect it from outside intrusion and to protect those outside from the effects of radiation in case of any serious malfunction inside. It is typically a metre-thick concrete and steel structure. Four conditions for a stable natural nuclear reactor: 1. The natural uranium ore must have a high uranium content and must have a thickness and geometry that increase the probability of spontaneous, natural fission in uranium-238 inducing a self-sustaining fission reaction in uranium The uranium must contain significant amount of fissionable uranium There must be a moderator, something that can slow down the neutrons produced when uranium fissions. 4. There must not be significant amounts of neutronabsorbing elements (such as silver or boron), which would inhibit a self-sustaining nuclear reaction, in the vicinity of the uranium. Nuclear Power in the World Today The first commercial nuclear power stations started operation in the 1950s. Nuclear energy now provides about 11% of the world's electricity from about 450 power reactors. Nuclear is the world's second largest source of lowcarbon power (>30% of the total in 2015). 50 countries utilise nuclear energy in about 225 research reactors. In addition to research, these reactors are used for the production of medical and industrial isotopes, as well as for training. 13