chloride The hazards of ammonia solutions depend on the concentration dilute ammonia solutions are usually – % by weight < mol L concentrated solutions are usually prepared at > % by weight A % by weight solution has a density of g cm , and a solution that has a lower density will be more concentrated The European Union classification of ammonia solutions is given in the table Concentration by weight w w Molarity Concentration mass volume w v Classification R Phrases – % – mol L – g L Irritant Xi R – % – mol L – g L Corrosive C R > % > mol L > g L Corrosive C Dangerous for the environment N R , R S Phrases S , S , S , S , S The ammonia vapour from concentrated ammonia solutions is severely irritating to the eyes and the respiratory tract, and these solutions should only be handled in a fume hood Saturated solutions can develop a significant pressure inside a closed bottle in warm weather, and the bottle should be opened with care this is not usually a problem for % solutions Ammonia solutions should not be mixed with halogens, as toxic and or explosive products are formed Prolonged contact of ammonia solutions with silver, mercury or iodide salts can also lead to explosive products such mixtures are often formed in qualitative inorganic analysis, and should be lightly acidified but not concentrated < % w v before disposal once the test is completed Laboratory use of anhydrous ammonia gas or liquid edit Anhydrous ammonia is classified as toxic T and dangerous for the environment N The gas is flammable autoignition temperature °C and can form explosive mixtures with air – % The permissible exposure limit PEL in the United States is ppm mg m , while the IDLH concentration is estimated at ppm Repeated exposure to ammonia lowers the sensitivity to the smell of the gas normally the odour is detectable at concentrations of less than ppm, but desensitised individuals may not detect it even at concentrations of ppm Anhydrous ammonia corrodes copper and zinc containing alloys, and so brass fittings should not be used for handling the gas Liquid ammonia can also attack rubber and certain plastics Ammonia reacts violently with the halogens Nitrogen triiodide, a primary high explosive, is formed when ammonia comes in contact with iodine Ammonia causes the explosive polymerisation of ethylene oxide It also forms explosive fulminating compounds with compounds of gold, silver, mercury, germanium or tellurium, and with stibine Violent reactions have also been reported with acetaldehyde, hypochlorite solutions, potassium ferricyanide and peroxides Synthesis and production edit See also Haber process This section is about industrial synthesis For synthesis in certain organisms, see section §?Biosynthesis below Production trend of ammonia between and Because of its many uses, ammonia is one of the most highly produced inorganic chemicals Dozens of

chemical plants worldwide produce ammonia Consuming more than % of all man made power, ammonia production is a significant component of the world energy budget Market research reports total ammonia production in is million tonnes and is predicted to increase by about million tonnes by China produced % of the worldwide production increasingly from coal as part of urea synthesis followed by India with %, Russia with %, and the United States with % About % or more of the ammonia produced is used for fertilizing agricultural crops Before the start of World War I, most ammonia was obtained by the dry distillation of nitrogenous vegetable and animal waste products, including camel dung, where it was distilled by the reduction of nitrous acid and nitrites with hydrogen in addition, it was produced by the distillation of coal, and also by the decomposition of ammonium salts by alkaline hydroxides such as quicklime, the salt most generally used being the chloride sal ammoniac thus NH Cl + CaO ? CaCl + Ca OH + NH Hydrogen for ammonia synthesis could also be produced economically by using the water gas reaction followed by the water gas shift reaction, produced by passing steam through red hot coke, to give a mixture of hydrogen and carbon dioxide gases, followed by removal of the carbon dioxide washing the gas mixture with water under pressure standard atmospheres , kPa or by using other sources like coal or coke gasification Modern ammonia producing plants depend on industrial hydrogen production to react with atmospheric nitrogen using a magnetite catalyst or over a promoted Fe catalyst under high pressure standard atmospheres , kPa and temperature °C to form anhydrous liquid ammonia This step is known as the ammonia synthesis loop also referred to as the Haber–Bosch process H + N ? NH Hydrogen required for ammonia synthesis could also be produced economically using other sources like coal or coke gasification or less economically from the electrolysis of water into oxygen + hydrogen and other alternatives that are presently impractical for large scale At one time, most of Europe's ammonia was produced from the Hydro plant at Vemork, via the electrolysis route Various renewable energy electricity sources are also potentially applicable As a sustainable alternative to the relatively inefficient electrolysis, hydrogen can be generated from organic wastes such as biomass or food industry waste , using catalytic reforming This releases hydrogen from carbonaceous substances at only % of energy used by electrolysis and may lead to hydrogen being produced from municipal wastes at below zero cost allowing for the tipping fees and efficient catalytic reforming, such as cold plasma Catalytic thermal reforming is possible in small, distributed even mobile plants, to take advantage of low value, stranded biomass biowaste or natural gas deposits Conversion of such wastes into ammonia solves the problem of hydrogen storage, as hydrogen can be released economically from ammonia on demand, without the need for high pressure or cryogenic storage It is also easier to store ammonia on board vehicles than to store hydrogen, as ammonia is less flammable than petrol or LPG Liquid ammonia as a solvent edit See also Inorganic nonaqueous solvent Liquid ammonia is the best known and most widely studied nonaqueous ionising solvent Its most conspicuous property is its ability to dissolve alkali metals to form highly coloured, electrically conductive solutions containing solvated electrons Apart from these remarkable solutions, much of the chemistry in liquid ammonia can be classified by analogy with related reactions in aqueous solutions Comparison of the physical properties of NH with those of water shows NH has the lower melting point, boiling point, density, viscosity, dielectric constant and electrical conductivity this is due at least in part to the weaker hydrogen bonding in NH and because such bonding cannot form cross linked networks, since each NH molecule has only one lone pair of electrons compared with two for each H O molecule The ionic self dissociation constant of liquid NH at - °C is about - mol •l- Solubility of salts edit Solubility g of salt per g liquid NH Ammonium acetate Ammonium nitrate Lithium nitrate Sodium nitrate Potassium nitrate Sodium fluoride Sodium chloride Sodium bromide Sodium iodide Sodium thiocyanate Liquid ammonia is an ionising solvent, although less so than water, and dissolves a range of ionic compounds, including many nitrates, nitrites, cyanides and thiocyanates Most ammonium salts are soluble and act as acids in liquid ammonia solutions The solubility of halide salts increases from fluoride to iodide A saturated solution of ammonium nitrate contains mol solute per mole of ammonia and has a vapour pressure of less than bar even at °C °F Solutions of metals edit See also Solvated electron Liquid ammonia will dissolve the alkali metals and other electropositive metals such as magnesium, calcium, strontium, barium, europium and ytterbium At low concentrations < mol l , deep blue solutions are formed these contain metal cations and solvated electrons, free electrons that are surrounded by a cage of ammonia molecules These solutions are very useful as strong reducing agents At higher concentrations, the solutions are metallic in appearance and in electrical conductivity At low temperatures, the two types of solution can coexist as immiscible phases Redox properties of liquid ammonia edit See also Redox E° V, ammonia E° V, water Li+ + e- ? Li - - K+ + e- ? K - - Na+ + e- ? Na - - Zn + + e- ? Zn - - NH + + e- ? ½ H + NH — Cu + + e- ? Cu + + Ag+ + e- ? Ag + + The range of thermodynamic stability of liquid ammonia solutions is very narrow, as the potential for oxidation to dinitrogen, E° N + NH + + e- ? NH , is only + V In practice, both oxidation to dinitrogen and reduction to dihydrogen are slow This is particularly true of reducing solutions the solutions of the alkali metals mentioned above are stable for several days, slowly decomposing to the metal amide and dihydrogen Most studies involving liquid ammonia solutions are done in reducing conditions although oxidation of liquid ammonia is usually slow, there is still a risk of explosion, particularly if transition metal ions are present as possible catalysts Ammonia's role in biological systems and human disease edit Main symptoms of hyperammonemia ammonia reaching toxic concentrations Ammonia is both a metabolic waste and a metabolic input throughout the biosphere It is an important source of nitrogen for living systems Although atmospheric nitrogen abounds more than % , few living creatures are capable of using this atmospheric nitrogen in its diatomic form, N gas Therefore, nitrogen fixation is required for the synthesis of amino acids, which are the building blocks of protein Some plants rely on ammonia and other nitrogenous wastes incorporated into the soil by decaying matter Others, such as nitrogen fixing legumes, benefit from symbiotic relationships with rhizobia that create ammonia from atmospheric nitrogen Biosynthesis edit In certain organisms, ammonia is produced from atmospheric nitrogen by enzymes called nitrogenases The overall process is called nitrogen fixation Although it is unlikely that biomimetic methods that are competitive with the Haber process will be developed, citation needed intense effort has been directed toward understanding the mechanism of biological nitrogen fixation The scientific interest in this problem is motivated by the unusual structure of the active site of the enzyme, which consists of an Fe MoS ensemble Ammonia is also a metabolic product of amino acid deamination catalyzed by enzymes such as glutamate dehydrogenase Ammonia excretion is common in aquatic animals In humans, it is quickly converted to urea, which is much less toxic, particularly less basic This urea is a major component of the dry weight of urine Most reptiles, birds, insects, and snails excrete uric acid solely as nitrogenous waste In physiology edit Ammonia also plays a role in both normal and abnormal animal physiology It is biosynthesised through normal amino acid metabolism and is toxic in high concentrations The liver converts ammonia to urea through a series of reactions known as the urea cycle Liver dysfunction, such as that seen in cirrhosis, may lead to elevated amounts of ammonia in the blood hyperammonemia Likewise, defects in the enzymes responsible for the urea cycle, such as ornithine transcarbamylase, lead to hyperammonemia Hyperammonemia contributes to the confusion and coma of hepatic encephalopathy, as well as the neurologic disease common in people with urea cycle defects and organic acidurias Ammonia is important for normal animal acid base balance After formation of ammonium from glutamine, a ketoglutarate may be degraded to produce two molecules of bicarbonate, which are then available as buffers for dietary acids Ammonium is excreted in the urine, resulting in net acid loss Ammonia may itself diffuse across the renal tubules, combine with a hydrogen ion, and thus allow for further acid excretion Excretion edit Main article Excretion Ammonium ions are a toxic waste product of metabolism in animals In fish and aquatic invertebrates, it is excreted directly into the water In mammals, sharks, and amphibians, it is converted in the urea cycle to urea, because it is less toxic and can be stored more efficiently In birds, reptiles, and terrestrial snails, metabolic ammonium is converted into uric acid, which is solid, and can therefore be excreted with minimal water loss Reference ranges for blood tests, comparing blood content of ammonia shown in yellow near middle with other constituents In astronomy edit Ammonia occurs in the atmospheres of the outer gas planets such as Jupiter % ammonia and Saturn % ammonia Ammonia has been detected in the atmospheres of the gas giant planets, including Jupiter, along with other gases like methane, hydrogen, and helium The interior of Saturn may include frozen crystals of ammonia It is naturally found on Deimos and Phobos – the two moons of Mars Interstellar space edit Ammonia was first detected in interstellar space in , based on microwave emissions from the direction of the galactic core This was the first polyatomic molecule to be so detected The sensitivity of the molecule to a broad range of excitations and the ease with which it can be observed in a number of regions has made ammonia one of the most important molecules for studies of molecular clouds The relative intensity of the ammonia lines can be used to measure the temperature of the emitting medium The following isotopic species of ammonia have been detected NH , NH , NH D, NHD , and ND The detection of triply deuterated ammonia was considered a surprise as deuterium is relatively scarce It is thought that the low temperature conditions allow this molecule to survive and accumulate Since its interstellar discovery, NH has proved to be an invaluable spectroscopic tool in the study of the interstellar medium With a large number of transitions sensitive to a wide range of excitation conditions, NH has been widely astronomically detected – its detection has been reported in hundreds of journal articles Listed below is a sample of journal articles that highlights the range of detectors that have been used to identify ammonia The study of interstellar ammonia has been important to a number of areas of research in the last few decades Some of these are delineated below and primarily involve using ammonia as an interstellar thermometer Interstellar formation mechanisms edit Ball and stick model of the diamminesilver I cation, Ag NH + The interstellar abundance for ammonia has been measured for a variety of environments The NH H ratio has been estimated to range from - in small dark clouds up to - in the dense core of the Orion Molecular Cloud Complex Although a total of total production routes have been proposed, the principal formation mechanism for interstellar NH is the reaction NH + + e- ? NH + H• The rate constant, k, of this reaction depends on the temperature of the environment, with a value of × - at K The rate constant was calculated from the formula k a T B For the primary formation reaction, a × - and B - Assuming an NH + abundance of × - and an electron abundance of - typical of molecular clouds, the formation will proceed at a rate of × - cm- s- in a molecular cloud of total density cm- All other proposed formation reactions have rate constants of between and orders of magnitude smaller, making their contribution to the abundance of ammonia relatively insignificant As an example of the minor contribution other formation reactions play, the reaction H + NH ? NH + H has a rate constant of × - Assuming H densities of and NH H ratio of - , this reaction proceeds at a rate of × - , more than orders of magnitude slower than the primary reaction above Some of the other possible formation reactions are H- + NH + ? NH + H PNH + + e- ? P + NH Interstellar destruction mechanisms edit There are total proposed reactions leading to the destruction of NH Of these, were tabulated in extensive tables of the chemistry among C, N, and O compounds A review of interstellar ammonia cites the following reactions as the principal dissociation mechanisms NH + H + ? NH + + H NH + HCO+ ? NH + + CO with rate constants of × - and × - , respectively The above equations , run at a rate of × - and × - , respectively These calculations assumed the given rate constants and abundances of NH H - , H + H × - , HCO+ H × - , and total densities of n , typical of cold, dense, molecular clouds Clearly, between these two primary reactions, equation is the dominant destruction reaction, with a rate ~ , times faster than equation This is due to the relatively Because of its many uses, ammonia is one of the most highly produced inorganic chemicals There are numerous large scale ammonia production plants worldwide, producing a total of million tonnes of nitrogen equivalent to million tonnes of ammonia in China produced % of the worldwide production, followed by India with %, Russia with %, and the United States with % % or more of the ammonia produced is used for fertilizing agricultural crops Ammonia is also used for the production of plastics, fibers, explosives, nitric acid via the Ostwald process and intermediates for dyes and pharmaceuticals Contents hide History Modern ammonia producing plants Sustainable ammonia production See also References External links History edit Before the start of World War I, most ammonia was obtained by the dry distillation of nitrogenous vegetable and animal products by the reduction of nitrous acid and nitrites with hydrogen and also by the decomposition of ammonium salts by alkaline hydroxides or by quicklime, the salt most generally used being the chloride sal ammoniac Today, most ammonia is produced on a large scale by the Haber process with capacities of up to , metric tons per day Ammonia is manufactured on a large scale by Haber's process In this process,N and H gases are allowed to react at high pressure of bar a Modern ammonia producing plants edit Block flow diagram of the ammonia synthesis process A typical modern ammonia producing plant first converts natural gas i e , methane or LPG liquefied petroleum gases such as propane and butane or petroleum naphtha into gaseous hydrogen The method for producing hydrogen from hydrocarbons is referred to as Steam Reforming The hydrogen is then combined with nitrogen to produce ammonia via the Haber Bosch process Starting with a natural gas feedstock, the processes used in producing the hydrogen are The first step in the process is to remove sulfur compounds from the feedstock because sulfur deactivates the catalysts used in subsequent steps Sulfur removal requires catalytic hydrogenation to convert sulfur compounds in the feedstocks to gaseous hydrogen sulfide H + RSH ? RH + H S gas The gaseous hydrogen sulfide is then adsorbed and removed by passing it through beds of zinc oxide where it is converted to solid zinc sulfide H S + ZnO ? ZnS + H O Catalytic steam reforming of the sulfur free feedstock is then used to form hydrogen plus carbon monoxide CH + H O ? CO + H The next step then uses catalytic shift conversion to convert the carbon monoxide to carbon dioxide and more hydrogen CO + H O ? CO + H The carbon dioxide is then removed either by absorption in aqueous ethanolamine solutions or by adsorption in pressure swing adsorbers PSA using proprietary solid adsorption media The final step in producing the hydrogen is to use catalytic methanation to remove any small residual amounts of carbon monoxide or carbon dioxide from the hydrogen CO + H ? CH + H O CO + H ? CH + H O To produce the desired end product ammonia, the hydrogen is then catalytically reacted with nitrogen derived from process air to form anhydrous liquid ammonia This step is known as the ammonia synthesis loop also referred to as the Haber Bosch process H + N ? NH Due to the nature of the typically multi promoted magnetite catalyst used in the ammonia synthesis


abby-lane abby-rode abigail-clayton ada-tauler addie-juniper addison-cain adele-wiesenthal adeline-lange adeline-pollicina adriana-amante adrianna-laurenti adrianna-russo agnes agnes-ardant agnes-zalontai aimee-addison aisha-sun aja aleena-ferari alessandra-schiavo aletta-ocean alexandra-nice alexandria-cass alexa-parks alex-dane alex-foxe alexia-knight alexis-devell alexis-firestone alexis-greco alexis-payne alexis-x alex-storm alex-white aliana-love alice-springs alicia-alighatti alicia-monet alicia-rio alicyn-sterling alighiera-olena ali-moore aline-santos alissa-ashley allysin-chaynes alysin-embers alyssa-love alyssa-reece amanda-addams amanda-blake amanda-blue amanda-jane-adams amanda-rae amanda-stone amanda-tyler amber-hunt amberlina-lynn amber-lynn amber-michaels amber-peach amber-wild amber-woods ambrosia-fox amia-miley ami-rodgers amy-allison amy-brooke amy-rose amy-starz anastasia-christ anastasia-sands andrea-adams andrea-brittian andrea-lange andrea-true andy angel angela-baron angela-summers angel-barrett angel-cash angel-cruz angel-cummings angel-ducharme angelica-sin angelika-reschner angelina-brasini angelina-korrs angelina-valentine angel-kelly angel-long angel-west angie-knight anita-andic anita-blond anita-cannibal anita-dark anna-belle anna-malle anna-nikova anna-pierce anna-ventura anna-veruska anne-bie-warburg anne-libert anne-magle anne-sand annette-haven annie-sprinkle ann-kiray ann-marie-michelle antonia-dorian april-flowers april-may april-west arcadia-lake ariana-bali ariana-jollee arlana-blue ashley-anne ashley-brooks ashley-coda ashley-fires ashley-lauren ashley-long ashley-marie ashley-nicole ashley-perk ashley-renee ashley-robbins ashley-welles ashley-wells ashley-winger ashlyn-gere astrid-bone athena-star aubrey-nichols aurora aurora-snow autumn-bliss autumn-rayne ava-devine ava-lauren avalon ava-marteens avy-lee-roth bailey-monroe bambi-allen barbara-bourbon barbara-boutet barbara-dare barbara-doll barbara-moose barbarella barbie-angel barbie-doll barett-moore bea-fiedler beata beatrice-poggi beatrice-valle becky-savage becky-sunshine belinda-butterfield bella-donna bethany-sweet beverly-bliss beverly-glen biggi-stenzhorn bionca black-widow blond-cat blondi blue-angel bobbi-bliss bobbi-dean bobbie-burns bonnie-holiday brandee brandi-edwards brandy-alexandre brandy-dean brandy-lee brandy-smile brandy-wine bree-anthony breezy-lane brenda-basse briana-blair bridgette-belle bridgette-monet bridgette-monroe bridget-waters brigitte-lahaie brigitte-monnin brigitte-verbecq brittany brittany-stryker britt-corvin britt-morgan bronze brooke-bennett brooke-fields brooke-haven brooke-west brook-van-buuren buffy-davis bunnie-blake bunny-bleu bunny-hatton busty-belle cali-caramel calisyn-heart cameo cameron-love camila-sampaio camilla-rhodes camille-morgan camrie-foxxx candace-daley candi candida-royalle candie-evens candi-summers candy-apples candy-barr candy-hill candy-samples candy-stanton cara-lott caressa-savage carmel-nougat carmen-blonde carmen-de-la-torre carmen-moore carmen-rose carol-connors carol-cross carol-cummings carole-dubois carole-gire carole-pierac carol-titian carolyn-connoly carolyn-monroe carrie-cruise cassandra-leigh cassidy cassie-courtland cataline-bullock catherine-count catherine-crystal catherine-ringer catherine-tailleferre cathy-delorme cathy-menard cathy-stewart celeste-fox celine-gallone chanel-preston chanel-price chantal-virapin chanta-rose chantelle-stevens charisma charisma-cole charlie-latour charlie-waters charlotte-de-castille charmane-star chasey-lain chayse-manhattan chaz-vincent chelsea-sinclaire chennin-blanc cheri-janvier cheri-taylor cherry-hill chessie-moore cheyenne-hunter cheyenne-silver china-lee china-leigh china-moon chloe-cruize chloe-dior chloe-kez chloe-stevens chris-collins chris-jordan chris-petersen chrissie-beauchamp christa-abel christa-ludwig christie-ford christi-lake christina-berg christina-blond christina-evol christina-skye christine-black christine-chavert christine-neona christine-rigoler christy-canyon cicciolina cindi-stephens cindy-carver cindy-crawford cindy-more cindy-shepard cindy-wong cinthya-marinho clair-dia claire-robbins claude-janna claudia-jackson claudia-jamsson claudia-mehringer claudia-nero claudia-van-statt claudia-zante claudine-beccarie clea-carson cleo-nichole cleo-patra cody-lane cody-love cody-nicole coffee-brown colleen-brennan connie-bennett connie-peterson constance-money copper-penny coreena corey-everson corinne-lemoine corneliah cory-everson cory-wolf courtney courtney-cummz courtney-james cris-cassidy crissy-moran cris-taliana crystal-breeze crystal-dawn crystal-holland crystal-knight crystal-lake crystal-lovin crystal-sync csilla-kalnay cuban-bee cynara-fox cyndee-summers cynthia-black cynthia-brooks cynthia-hammers cynthia-lavigne dagmar-lost daisy-layne dallas-miko dana-dylan dana-lynn danica-rhea daniela-nanou daniela-schiffer daniele-troeger daniella daniella-schiffer danielle danielle-foxxx danielle-rodgers danny-ricci danyel-cheeks daphne daphne-rosen darby-lloyd-rains darla-crane darla-delovely davia-ardell dayton-rain debbie-northrup debbie-revenge debbie-van-gils debi-diamond debi-jointed debra-lynn deidra-hopkins deidre-holland delania-raffino delia-moore delphine-thail delta-force delta-white demi-moor denice-klarskov denise-derringer denise-dior denise-sloan desiree-cousteau desiree-foxx desiree-lane desiree-west deva-station devin-devasquez devinn-lane devon-shire dia diana-holt diana-kisabonyi diana-siefert diana-stevenson diane-dubois diane-richards diane-sloan diane-suresne dido-angel dillan-lauren dina-deville dina-jewel dina-pearl ditty-blue diva divinity-love djiana dolly-darkley dominique dominique-dewitt dominique-saint-claire donna-hart donna-marie dorle-buchner dorothy-lemay dorothy-onan drea drimla dru-berrymore dusty-rose dyanna-lauren ebony-ayes edina-blond edita-ungerova edwige-faillel eileen-wells elaine-southern elena-berkova elena-maria-ricci eleonore-melzer elisabeth-bure elis-black elise elise-di-medici elle-devyne elle-rio elodie-delage elsa-maroussia elza-brown emili-doll emily-evermoore emily-george emily-jewel emmanuelle-pareze envy-mi erica-boyer erica-eaton erica-havens erica-idol erica-lauren erika-bella erika-cool erika-heaven erika-lockett esme-monroe eva-allen eva-angel eva-dionisio eva-gross eva-kleber eva-lux eva-uettori eve-laurence evelyne-lang evie-delatosso fabiana-venturi faith-stevens fallon fanny-garreau fanny-steel faye-runaway flame flick-shagwell flore-soller flower france-lomay france-quenie francoise frankie-leigh gabriella gabriella-mirelba gabriella-vincze gail-force gail-palmer gail-sterling georgette-saunders georgia-peach georgina-spelvin gia-givanna gianna-lynn gili-sky gina-carrera gina-gianetti gina-janssen gina-lee gina-martell gina-valentino ginger-jay ginger-lee ginger-lynn ginny-noack giovanna gisela-schwarz giselle-monet gladys-laroche gloria-leonard gloria-todd golden-jade greta-carlson greta-milos guia-lauri-filzi gwenda-farnel hare-krane harley-raine hayley-jade hazel-young heather-deeley heather-ellis heather-hart heather-lere heather-lyn heather-manfield heather-thomas heather-torrance heather-wayne heather-young helen-madigan helen-thomas helga-sven helga-wild hillary-summers holly-hollywood holly-joy holly-page holly-ryder honey-winter hottie-hollie hyapatia-lee ida-fabry ildiko-smits illana-moor ines-ridere ingrid-choray isabella-dior isabella-soprano isabelle-allay isabelle-brell isabelle-marchall isobel-wren iveta ivette-blanche jackie-right jacqueline-lorians jacy-allen jada-stevens jade-east jade-hsu jade-marcela jade-summers jade-wong jahn-gold jamie-brooks jamie-james jamie-summers jana-irrova jana-mrazkova jane-baker jane-darling jane-iwanoff jane-lindsay jane-lixx janet-jacme janey-robbins jasmine-delatori jayden-simone jaylyn-rose jayna-woods jazella-moore jazmin-luna-gold jean-afrique jeanette-littledove jeanie-marie-sullivan jean-jennings jeanna-fine jeannie-pepper jenna-jameson jenna-jane jenna-presley jenna-wells jennifer-haussmann jennifer-janes jennifer-jordan jennifer-morante jennifer-noxt jennifer-stewart jennifer-welles jennifer-west jenny jenny-feeling jenny-fields jenny-wings jersey-jaxin jesie-st-james jesse-capelli jessica-bangkok jessica-bogart jessica-darlin jessica-fiorentino jessica-gabriel jessica-laine jessica-may jessica-road jessica-wylde jessi-foster jill-ferari jill-kelly joana-redgrave joan-devlon joanna-storm joanna-sweet jody-maxwell joelle-lequement joelle-petinot johnni-black jordana-james jordan-green jordan-nevaeh jordan-star josephine-carrington joslyn-james julia-chanel julia-dal-fuoco juliana-grandi julia-paes julia-parton julia-perrin julia-swen julia-thomas julie-meadows julie-rage julie-simone juliet-anderson juliet-graham juliette-carelton kacey-jordan kagney-linn-karter kaitlyn-ashley kalena-rios kami-andrews kamila-smith kandee-licks kandi-barbour kapri-styles kara-nox karen-summer kari-foxx karine-gambier karin-schubert karli-sweet karmen-kennedy karol-castro kascha kassi-nova kat kate-frost kate-jones kathia-nobili kathleen-gentry kathleen-white kathy-divan kathy-harcourt kathy-heart kathy-kash katie-cummings katja-love kat-langer katrina-isis katrina-kraven katy-borman katy-caro kaycee-dean kayla-kupcakes kay-parker k-c-valentine keama-kim keira-moon keisha keli-richards kelli-tyler kelly-adams kelly-blue kelly-broox kelly-hearn kelly-kay kelly-kline kelly-nichols kelly-royce kelly-skyline kendra-kay kenzi-marie keri-windsor ketthy-divan kianna-dior kiley-heart kim-alexis kimber-blake kimberly-carson kimberly-kane kimberly-kyle kim-de-place kim-holland kimi-gee kimkim-de kim-kitaine kimmie-lee kimmy-nipples kina-kara kira-eggers kira-red kirsty-waay kitty-langdon kitty-lynxxx kitty-marie kitty-shayne kitty-yung kora-cummings kris-lara krista-lane krista-maze kristara-barrington kristarah-knight kristi-klenot kristina-blonde kristina-king kristina-klevits kristina-soderszk kristine-heller kristin-steen krisztina-ventura krystal-de-boor krystal-steal kylee-karr kylee-nash kylie-brooks kylie-channel kylie-haze kylie-wylde kym-wilde kyoto-sun lachelle-marie lacy-rose lady-amanda-wyldefyre lady-stephanie laetitia-bisset lana-burner lana-cox lana-wood lara-amour lara-roxx lara-stevens lataya-roxx latoya laura-clair laura-lazare laura-lion laura-may laura-orsolya laura-paouck laura-zanzibar lauren-black laurence-boutin lauren-montgomery laurien-dominique laurien-wilde laurie-smith lauryl-canyon lauryn-may leah-wilde lea-magic lea-martini leanna-foxxx lee-caroll leigh-livingston leilani lenora-bruce leslie-winston lesllie-bovee letizia-bruni lexi-lane lexi-matthews lezley-zen lia-fire liliane-gray liliane-lemieuvre lili-marlene lily-gilder lily-labeau lily-rodgers lily-valentine linda-shaw linda-vale linda-wong linnea-quigley lisa-bright lisa-de-leeuw lisa-k-loring lisa-lake lisa-melendez lisa-sue-corey lise-pinson little-oral-annie liza-dwyer liza-harper lizzy-borden logan-labrent lois-ayres lola-cait long-jean-silver loni-bunny loni-sanders loona-luxx lorelei-lee lorelei-rand lorena-sanchez lori-alexia lori-blue lorrie-lovett luci-diamond lucie-doll lucie-theodorova lucy-van-dam lydia-baum lynn-franciss lynn-lemay lynn-ray lynn-stevens lynx-canon lysa-thatcher madelina-ray madison-parker magdalena-lynn maggie-randall mai-lin mandi-wine mandy-bright mandy-malone mandy-may mandy-mistery mandy-starr marcia-minor maren margit-ojetz margitta-hofer margo-stevens margot-mahler mariah-cherry marianne-aubert maria-tortuga marie-anne marie-christine-chireix marie-christine-veroda marie-claude-moreau marie-dominique-cabannes marie-france-morel marie-luise-lusewitz marie-sharp marilyn-chambers marilyne-leroy marilyn-gee marilyn-jess marilyn-martyn marilyn-star marina-hedman marion-webb marita-ekberg marita-kemper marlena marlene-willoughby marry-queen martine-grimaud martine-schultz maryanne-fisher mary-hubay mary-ramunno mary-stuart mascha-mouton maud-kennedy mauvais-denoir maxine-tyler maya-black maya-france megan-leigh megan-martinez megan-reece mei-ling melanie-hotlips melanie-scott melba-cruz melinda-russell melissa-bonsardo melissa-del-prado melissa-golden melissa-martinez melissa-melendez melissa-monet mercedes-dragon mercedes-lynn merle-michaels mesha-lynn mia-beck mia-lina mia-smiles michele-raven michelle-aston michelle-ferrari michelle-greco michelle-maren michelle-maylene michelle-monroe micki-lynn mika-barthel mika-tan mikki-taylor mimi-morgan mindy-rae ming-toy miranda-stevens miss-bunny miss-meadow miss-pomodoro missy missy-graham missy-stone missy-vega misti-jane mistress-candice misty-anderson misty-dawn misty-rain misty-regan mona-lisa mona-page moni monica-baal monica-swinn monika-peta monika-sandmayr monika-unco monique-bruno monique-cardin monique-charell monique-demoan monique-gabrielle monique-la-belle morgan-fairlane morrigan-hel moxxie-maddron mulani-rivera mysti-may nadege-arnaud nadia-styles nadine-bronx nadine-proutnal nadine-roussial nadi-phuket nanci-suiter nancy-hoffman nancy-vee natacha-delyro natalia-wood natalli-diangelo natascha-throat natasha-skyler naudia-nyce nessa-devil nessy-grant nesty nicki-hunter nicky-reed nicole-berg nicole-bernard nicole-black nicole-grey nicole-london nicole-parks nicole-scott nicole-taylor nicolette-fauludi nicole-west nika-blond nika-mamic niki-cole nikita-love nikita-rush nikki-charm nikki-grand nikki-king nikki-knight nikki-randall nikki-rhodes nikki-santana nikki-steele nikki-wilde niko nina-cherry nina-deponca nina-hartley nina-preta oana-efria obaya-roberts olesja-derevko olga-cabaeva olga-conti olga-pechova olga-petrova olivia-alize olivia-del-rio olivia-flores olivia-la-roche olivia-outre ophelia-tozzi orchidea-keresztes orsolya-blonde paige-turner paisley-hunter pamela-bocchi pamela-jennings pamela-mann pamela-stanford pamela-stealt pandora paola-albini pascale-vital pat-manning pat-rhea patricia-dale patricia-diamond patricia-kennedy patricia-rhomberg patrizia-predan patti-cakes patti-petite paula-brasile paula-harlow paula-morton paula-price paula-winters pauline-teutscher penelope-pumpkins penelope-valentin petra-hermanova petra-lamas peyton-lafferty phaedra-grant pia-snow piper-fawn pipi-anderson porsche-lynn porsha-carrera precious-silver priscillia-lenn purple-passion queeny-love rachel-ashley rachel-love rachel-luv rachel-roxxx rachel-ryan rachel-ryder racquel-darrian rane-revere raven reagan-maddux rebecca-bardoux regan-anthony regine-bardot regula-mertens reina-leone reka-gabor renae-cruz renee-foxx renee-lovins renee-morgan renee-perez renee-summers renee-tiffany rhonda-jo-petty rikki-blake riley-ray rio-mariah rita-ricardo roberta-gemma roberta-pedon robin-byrd robin-cannes robin-everett robin-sane rochell-starr rosa-lee-kimball rosemarie roxanne-blaze roxanne-hall roxanne-rollan ruby-richards sabina-k sabre sabrina-chimaera sabrina-dawn sabrina-jade sabrina-johnson sabrina-love-cox sabrina-mastrolorenzi sabrina-rose sabrina-scott sabrina-summers sacha-davril sahara sahara-sands sai-tai-tiger samantha-fox samantha-ryan samantha-sterlyng samantha-strong samueline-de-la-rosa sandra-cardinale sandra-de-marco sandra-kalermen sandra-russo sandy-lee sandy-pinney sandy-reed sandy-samuel sandy-style sandy-summers sara-brandy-canyon sara-faye sarah-bernard sarah-cabrera sarah-hevyn sarah-mills sarah-shine sara-sloane sasha sasha-hollander sasha-ligaya sasha-rose satine-phoenix satin-summer savannah-stern savanna-jane scarlet-scarleau scarlet-windsor seka selena serena serena-south severine-amoux shana-evans shanna-mccullough shannon-kelly shannon-rush shantell-day sharon-da-vale sharon-kane sharon-mitchell shaun-michelle shawna-sexton shawnee-cates shay-hendrix shayne-ryder sheena-horne sheer-delight shelby-star shelby-stevens shelly-berlin shelly-lyons sheri-st-clair sheyla-cats shonna-lynn shyla-foxxx shy-love sierra-sinn sierra-skye sigrun-theil silver-starr silvia-bella silvia-saint silvie-de-lux silvy-taylor simone-west sindee-coxx sindy-lange sindy-shy siobhan-hunter skylar-knight skylar-price skyler-dupree smokie-flame smoking-mary-jane solange-shannon sonya-summers sophia-santi sophie-call sophie-duflot sophie-evans sophie-guers stacey-donovan stacy-lords stacy-moran stacy-nichols stacy-silver stacy-thorn starla-fox starr-wood stefania-bruni stella-virgin stephanie-duvalle stephanie-rage stephanie-renee stevie-taylor summer-knight summer-rose sunny-day sunset-thomas sunshine-seiber susan-hart susanne-brend susan-nero susi-hotkiss suzanne-mcbain suzan-nielsen suzie-bartlett suzie-carina suzi-sparks sweet-nice sweety-pie sybille-rossani sylvia-benedict sylvia-bourdon sylvia-brand sylvia-engelmann syreeta-taylor syren-de-mer syvette szabina-black szilvia-lauren tai-ellis taija-rae taisa-banx talia-james tamara-lee tamara-longley tamara-n-joy tamara-west tami-white tammy tammy-lee tammy-reynolds tania-lorenzo tantala-ray tanya-danielle tanya-fox tanya-foxx tanya-lawson tanya-valis tara-aire tasha-voux tatjana-belousova tatjana-skomorokhova tawnee-lee tawny-pearl tayla-rox taylor-wane teddi-austin teddi-barrett tera-bond tera-heart tera-joy teresa-may teresa-orlowski teri-diver teri-weigel terri-dolan terri-hall tess-ferre tess-newheart thais-vieira tia-cherry tianna tiara tiffany-blake tiffany-clark tiffany-duponte tiffany-rayne tiffany-rousso tiffany-storm tiffany-towers tiffany-tyler tiger-lily tigr timea-vagvoelgyi tina-blair tina-burner tina-evil tina-gabriel tina-loren tina-marie tina-russell tish-ambrose tommi-rose tonisha-mills topsy-curvey tori-secrets tori-sinclair tori-welles tracey-adams traci-lords traci-topps traci-winn tracy-duzit tracy-love tracy-williams tricia-devereaux tricia-yen trinity-loren trisha-rey trista-post trixie-tyler ultramax ursula-gaussmann ursula-moore uschi-karnat valentina valerie-leveau valery-hilton vanessa-chase vanessa-del-rio vanessa-michaels vanessa-ozdanic vanilla-deville velvet-summers veri-knotty veronica-dol veronica-hart veronica-hill veronica-rayne veronica-sage veronika-vanoza via-paxton vicky-lindsay vicky-vicci victoria-evans victoria-gold victoria-knight victoria-luna victoria-paris victoria-slick victoria-zdrok viper virginie-caprice vivian-valentine vivien-martines wendi-white wendy-divine whitney-banks whitney-fears whitney-wonders wonder-tracey wow-nikki xanthia-berstein yasmine-fitzgerald yelena-shieffer yvonne-green zara-whites zsanett-egerhazi zuzie-boobies

reaction, only very low levels of oxygen containing especially CO, CO and H O compounds can be tolerated in the synthesis hydrogen and nitrogen mixture gas Relatively pure nitrogen can be obtained by Air separation, but additional oxygen removal may be required Hydrogen storage From Wikipedia, the free encyclopedia Utility scale underground liquid hydrogen storage Methods of hydrogen storage for subsequent use span many approaches, including high pressures, cryogenics, and chemical compounds that reversibly release H upon heating Underground hydrogen storage is useful to provide grid energy storage for intermittent energy sources, like wind power, as well as providing fuel for transportation, particularly for ships and airplanes Most research into hydrogen storage is focused on storing hydrogen as a lightweight, compact energy carrier for mobile applications Liquid hydrogen or slush hydrogen may be used, as in the Space Shuttle However liquid hydrogen requires cryogenic storage and boils around K - °C or - °F Hence, its liquefaction imposes a large energy loss as energy is needed to cool it down to that temperature The tanks must also be well insulated to prevent boil off but adding insulation increases cost Liquid hydrogen has less energy density by volume than hydrocarbon fuels such as gasoline by approximately a factor of four This highlights the density problem for pure hydrogen there is actually about % more hydrogen in a liter of gasoline grams hydrogen than there is in a liter of pure liquid hydrogen grams hydrogen The carbon in the gasoline also contributes to the energy of combustion Compressed hydrogen, by comparison, is stored quite differently Hydrogen gas has good energy density by weight, but poor energy density by volume versus hydrocarbons, hence it requires a larger tank to store A large hydrogen tank will be heavier than the small hydrocarbon tank used to store the same amount of energy, all other factors remaining equal Increasing gas pressure would improve the energy density by volume, making for smaller, but not lighter container tanks see hydrogen tank Compressed hydrogen costs % of the energy content to power the compressor Higher compression without energy recovery will mean more energy lost to the compression step Compressed hydrogen storage can exhibit very low permeation Contents hide Automotive Onboard hydrogen storage Established technologies Compressed hydrogen Liquid hydrogen Proposals and research Chemical storage Metal hydrides Non metal hydrides Carbohydrates Synthesized hydrocarbons Liquid organic hydrogen carriers LOHC Ammonia Amine borane complexes Imidazolium ionic liquids Phosphonium borate Carbonite substances Metal organic frameworks Encapsulation Physical storage Cryo compressed Carbon nanotubes Clathrate hydrates Glass capillary arrays Glass microspheres Stationary hydrogen storage Underground hydrogen storage Power to gas See also References External links Automotive Onboard hydrogen storage edit Timeline Targets assume a kg hydrogen storage system Targets were set by the FreedomCAR Partnership in January between the United States Council for Automotive Research USCAR and U S DOE Targets assume a kg H storage system The targets were not reached in The targets were revised in to reflect new data on system efficiencies obtained from fleets of test cars The ultimate goal for volumetric storage is still above the theoretical density of liquid hydrogen It is important to note that these targets are for the hydrogen storage system, not the hydrogen storage material System densities are often around half those of the working material, thus while a material may store wt% H , a working system using that material may only achieve wt% when the weight of tanks, temperature and pressure control equipment, etc , is considered In , only two storage technologies were identified as being susceptible to meet DOE targets MOF exceeds target for volumetric capacity, while cryo compressed H exceeds more restrictive targets for both gravimetric and volumetric capacity see slide in Established technologies edit net storage density of hydrogen Compressed hydrogen edit Compressed hydrogen is the gaseous state of the element hydrogen which is kept under pressure Compressed hydrogen in hydrogen tanks at bar , psi and bar , psi is used for hydrogen tank systems in vehicles, based on type IV carbon composite technology Car manufacturers have been developing this solution, such as Honda or Nissan Liquid hydrogen edit BMW has been working on liquid tank for cars, producing for example the BMW Hydrogen Proposals and research edit Hydrogen storage technologies can be divided into physical storage, where hydrogen molecules are stored including pure hydrogen storage via compression and liquefication , and chemical storage, where hydrides are stored Chemical storage edit Chemical storage could offer high storage performance due to the strong interaction However, the regeneration of storage material is still an issue A large number of chemical storage systems are under investigation, which involve hydrolysis reactions, hydrogenation dehydrogenation reactions, ammonia borane and other boron hydrides, ammonia, and alane etc Metal hydrides edit Metal hydride hydrogen storage Metal hydrides, such as MgH , NaAlH , LiAlH , LiH, LaNi H , TiFeH and palladium hydride, with varying degrees of efficiency, can be used as a storage medium for hydrogen, often reversibly Some are easy to fuel liquids at ambient temperature and pressure, others are solids which could be turned into pellets These materials have good energy density by volume, although their energy density by weight is often worse than the leading hydrocarbon fuels Most metal hydrides bind with hydrogen very strongly As a result, high temperatures around °C °F – °C °F are required to release their hydrogen content This energy cost can be reduced by using alloys which consists of a strong hydride former and a weak one such as in LiNH , LiBH and NaBH These are able to form weaker bonds, thereby requiring less input to release stored hydrogen However, if the interaction is too weak, the pressure needed for rehydriding is high, thereby eliminating any energy savings The target for onboard hydrogen fuel systems is roughly < °C for release and < bar for recharge – kJ mol H An alternative method for reducing dissociation temperatures is doping with activators This has been successfully used for aluminium hydride but its complex synthesis makes it undesirable for most applications as it is not easily recharged with hydrogen Currently the only hydrides which are capable of achieving the wt % gravimetric goal for see chart above are limited to lithium, boron and aluminium based compounds at least one of the first row elements or Al must be added Research is being done to determine new compounds which can be used to meet these requirements Proposed hydrides for use in a hydrogen economy include simple hydrides of magnesium or transition metals and complex metal hydrides, typically containing sodium, lithium, or calcium and aluminium or boron Hydrides chosen for storage applications provide low reactivity high safety and high hydrogen storage densities Leading candidates are lithium hydride, sodium borohydride, lithium aluminium hydride and ammonia borane A French company McPhy Energy is developing the first industrial product, based on magnesium hydride, already sold to some major clients such as Iwatani and ENEL New Scientist stated that Arizona State University is investigating using a borohydride solution to store hydrogen, which is released when the solution flows over a catalyst made of ruthenium Researchers at University of Pittsburgh and Georgia Tech performed extensive benchmarking simulations on mixtures of several light metal hydrides to predict possible reaction thermodynamics for hydrogen storage Beyond research, Fuel Cell Company Intelligent Energy has released a small Fuel Cell portable power product 'UPP' which uses metal hydride as the storage media See http www beupp com technical specification Non metal hydrides edit The Italian catalyst manufacturer Acta has proposed using hydrazine as an alternative to hydrogen in fuel cells As the hydrazine fuel is liquid at room temperature, it can be handled and stored more easily than hydrogen By storing it in a tank full of a double bonded carbon oxygen carbonyl, it reacts and forms a safe solid called hydrazone By then flushing the tank with warm water, the liquid hydrazine hydrate is released Hydrazine breaks down in the cell to form nitrogen and hydrogen which bonds with oxygen, releasing water Carbohydrates edit Carbohydrates polymeric C H O releases H in a bioreformer mediated by the enzyme cocktail—cell free synthetic pathway biotransformation Carbohydrate provides high hydrogen storage densities as a liquid with mild pressurization and cryogenic constraints It can also be stored as a solid powder Carbohydrate is the most abundant renewable bioresource in the world In May biochemical engineers from the Virginia Polytechnic Institute and State University and biologists and chemists from the Oak Ridge National Laboratory announced a method of producing high yield pure hydrogen from starch and water In , they demonstrated to produce nearly moles of hydrogen per glucose unit from cellulosic materials and water Thanks to complete conversion and modest reaction conditions, they propose to use carbohydrate as a high energy density hydrogen carrier with a density of wt% Synthesized hydrocarbons edit An alternative to hydrides is to use regular hydrocarbon fuels as the hydrogen carrier Then a small hydrogen reformer would extract the hydrogen as needed by the fuel cell However, these reformers are slow to react to changes in demand and add a large incremental cost to the vehicle powertrain Direct methanol fuel cells do not require a reformer, but provide a lower energy density compared to conventional fuel cells, although this could be counterbalanced with the much better energy densities of ethanol and methanol over hydrogen Alcohol fuel is a renewable resource Solid oxide fuel cells can operate on light hydrocarbons such as propane and methane without a reformer, or can run on higher hydrocarbons with only partial reforming, but the high temperature and slow startup time of these fuel cells are problematic for automotive applications Liquid organic hydrogen carriers LOHC edit Reversible hydrogenation of N Ethylcarbazole Unsaturated organic compounds can store huge amounts of hydrogen These Liquid Organic Hydrogen Carriers LOHC are hydrogenated for storage and dehydrogenated again when the energy hydrogen is needed Researches on LOHC was concentrated in cycloalkanes at early stage, with its relatively higher hydrogen capacity wt % and production of COx free hydrogen Heterocyclic aromatic compounds or N Heterocycles are also appropriate for this task A compound that stands in the focus of the current LOHC research is N ethylcarbazole NEC but many others do exist, e g dibenzyltoluene which is already industrially used as a heat transfer fluid More recently, formic acid FA has been suggested as a promising hydrogen storage material with a wt% hydrogen capacity Using LOHCs relatively high gravimetric storage densities can be reached about wt % and the overall energy efficiency is higher than for other chemical storage options such as producing methane from the hydrogen Cycloalkanes The candidate cycloalkanes reported by far include cyclohexane, methyl cyclohexane and decalin The dehydrogenation of cycloalkanes is highly endothermic KJ mol H , which means this process requires high temperature Dehydrogenation of decalin is the most thermodynamically favored among three cycloalkanes, and methyl cyclohexane is second because of the presence of methyl group Researches on catalysts development for dehydrogenation of cycloalkanes have continued for decades Nickel Ni , Molybdenum Mo and Platinum Pt based catalysts are highly investigated for dehydrogenation However, coking is still a big challenge for catalyst’s stability N Heterocycles Both hydrogenation and dehydrogenation of LOHCs requires catalysts It was demonstrated that replacing hydrocarbons by hetero atoms, like N, O etc improves reversible de hydrogenation properties The hydrogenation temperature of cyclohexane is highly dependent on N content in cyclohexane, which hydrogen release temperature drops sufficiently with the presence of N atoms in the rings or ring substituents Among all the N heterocycles, the saturated unsaturated pair of dodecahydro N ethylcarbazole H NEC and NEC has been considered as a promising candidate for hydrogen storage, which has fairly large hydrogen content wt% Figure on the top rights shows dehydrogenation and hydrogenation of H NEC and NEC pair The sufficient catalyst for NEC to H NEC is Ru and Rh based, which selectivity can reach % at MPa and °C °C Although N Heterocyles optimized the unfavorable thermodynamic properties of cycloalkanes, it still facing a lot issues, such as cost toxicity and kinetic barrier etc Formic acid In researchers of EPFL, Switzerland, reported the use of formic acid as a hydrogen storage material Carbon monoxide free hydrogen has been generated in a very wide pressure range – bar A homogeneous catalytic system based on water soluble ruthenium catalysts selectively decompose HCOOH into H and CO in aqueous solution This catalytic system overcomes the limitations of other catalysts e g poor stability, limited catalytic lifetimes, formation of CO for the decomposition of formic acid making it a viable hydrogen storage material And the co product of this decomposition, carbon dioxide, can be used as hydrogen vector by hydrogenating it back to formic acid in a second step The catalytic hydrogenation of CO has long been studied and efficient procedures have been developed Formic acid contains g L- hydrogen at room temperature and atmospheric pressure By weight, pure formic acid stores wt% hydrogen Pure formic acid is a liquid with a flash point °C cf gasoline - °C, ethanol °C % formic acid is not flammable Ammonia edit Further information Ammonia production Ammonia NH releases H in an appropriate catalytic reformer Ammonia provides high hydrogen storage densities as a liquid with mild pressurization and cryogenic constraints It can also be stored as a liquid at room temperature and pressure when mixed with water Ammonia is the second most commonly produced chemical in the world and a large infrastructure for making, transporting, and distributing ammonia exists Ammonia can be reformed to produce hydrogen with no harmful waste, or can mix with existing fuels and under the right conditions burn efficiently Pure ammonia burns poorly at the atmospheric pressures found in natural gas fired water heaters and stoves Under compression in an automobile engine it is a suitable fuel for slightly modified gasoline engines Ammonia is a toxic gas at normal temperature and pressure and has a potent odor In September chemists from the Technical University of Denmark announced a method of storing hydrogen in the form of ammonia saturated into a salt tablet They claim it will be an inexpensive and safe storage method Amine borane complexes edit Main article Amine borane complex Prior to , several compounds were investigated for hydrogen storage including complex borohydrides, or aluminohydrides, and ammonium salts These hydrides have an upper theoretical hydrogen yield limited to about % by weight Amongst the compounds that contain only B, N, and H both positive and negative ions , representative examples include amine boranes, boron hydride ammoniates, hydrazine borane complexes, and ammonium octahydrotriborates or tetrahydroborates Of these, amine boranes and especially ammonia borane have been extensively investigated as hydrogen carriers During the s and s, the U S Army and Navy funded efforts aimed at developing hydrogen deuterium gas generating compounds for use in the HF DF and HCl chemical lasers, and gas dynamic lasers Earlier hydrogen gas generating formulations used amine boranes and their derivatives Ignition of the amine borane s forms boron nitride BN and hydrogen gas In addition to ammonia borane H BNH , other gas generators include diborane diammoniate, H B NH BH Imidazolium ionic liquids edit In Dupont and others reported hydrogen storage materials based on imidazolium ionic liquids Simple alkyl aryl methylimidazolium N bis trifluoromethanesulfonyl imidate salts that possess very low vapour pressure, high density, and thermal stability and are not inflammable can add reversibly – hydrogen atoms in the presence of classical Pd C or Ir nanoparticle catalysts and can be used as alternative materials for on board hydrogen storage devices These salts can hold up to g L- of hydrogen at atmospheric pressure Phosphonium borate edit In researchers of University of Windsor reported on reversible hydrogen storage in a non metal phosphonium borate frustrated Lewis pair Phosphino borane hydrogenstorage The phosphino borane on the left accepts one equivalent of hydrogen at one atmosphere and °C and expels it again by heating to °C The storage capacity is wt% still rather below the to wt% required for practical use Carbonite substances edit Research has proven that graphene can store hydrogen efficiently After taking up hydrogen, the substance becomes graphane After tests, conducted by dr André Geim at the University of Manchester, it was shown that not only can graphene store hydrogen easily, it can also release the hydrogen again, after heating to °C Metal organic frameworks edit Metal organic frameworks represent another class of synthetic porous materials that store hydrogen and energy at the molecular level MOFs are highly crystalline inorganic organic hybrid structures that contain metal clusters or ions secondary building units as nodes and organic ligands as linkers When guest molecules solvent occupying the pores are removed during solvent exchange and heating under vacuum, porous structure of MOFs can be achieved without destabilizing the frame and hydrogen molecules will be adsorbed onto the surface of the pores by physisorption Compared to traditional zeolites and porous carbon materials, MOFs have very high number of pores and surface area which allow higher hydrogen uptake in a given volume Thus, research interests on hydrogen storage in MOFs have been growing since when the first MOF based hydrogen storage was introduced Since there are infinite geometric and chemical variations of MOFs based on different combinations of SBUs and linkers, many researches explore what combination will provide the maximum hydrogen uptake by varying materials of metal ions and linkers In , chemists at UCLA and the University of Michigan have achieved hydrogen storage concentrations of up to wt% in MOF at a low temperature of K In , researchers at University of Nottingham reached wt% at bar , psi and K with MOF NOTT Most articles about hydrogen storage in MOFs report hydrogen uptake capacity at a temperature of K and a pressure of bar because such condition is commonly available and the binding energy between hydrogen and MOF is large compare to the thermal vibration energy which will allow high hydrogen uptake capacity Varying several factors such as surface area, pore size, catenation, ligand structure, spillover, and sample purity can result different amount of hydrogen uptake in MOFs Encapsulation edit Cella Energy technology is based around the encapsulation of hydrogen gas and nano structuring of chemical hydrides in small plastic balls, at room temperature and pressure Physical storage edit Cryo compressed edit Cryo compressed storage of hydrogen is the only technology that meets DOE targets for volumetric and gravimetric efficiency see CcH on slide in Furthermore, another study has shown that cryo compressed exhibits interesting cost advantages ownership cost price per mile and storage system cost price per vehicle are actually the lowest when compared to any other technology see third row in slide of For example, a cryo compressed hydrogen system would cost $ per mile including cost of fuel and every associated other cost , while conventional gasoline vehicles cost between $ and $ per mile Like liquid storage, cryo compressed uses cold hydrogen K and slightly above in order to reach a high energy density However, the main difference is that, when the hydrogen would warm up due to heat transfer with the environment boil off , the tank is allowed to go to pressures much higher up to bars versus a couple of bars for liquid storage As a consequence, it takes more time before the hydrogen has to vent, and in most driving situations, enough hydrogen is used by the car to keep the pressure well below the venting limit Consequently, it has been demonstrated that a high driving range could be achieved with a cryo compressed tank more than miles , km were driven with a full tank mounted on an hydrogen fueled engine of Toyota Prius Research is still on its way in order to study and demonstrate the full potential of the technology As of , the BMW Group has started a thorough component and system level validation of cryo compressed vehicle storage on its way to a commercial product Carbon nanotubes edit Carbon nanotubes Hydrogen carriers based on nanostructured carbon such as carbon buckyballs and nanotubes have been proposed However, since Hydrogen usually amounts up to ~ wt % at K which is far from the value set by US department of Energy wt % at nearly ambient conditions , it makes carbon materials poor candidates for hydrogen storage Clathrate hydrates edit H caged in a clathrate hydrate was first reported in , but requires very high pressures to be stable In , researchers from Delft University of Technology and Colorado School of Mines showed solid H containing hydrates could be formed at ambient temperature and s of bar by adding small amounts of promoting substances such as THF These clathrates have a theoretical maximum hydrogen densities of around wt% and kg m Glass capillary arrays edit A team of Russian, Israeli and German scientists have collaboratively developed an innovative technology based on glass capillary arrays for the safe infusion, storage and controlled release of hydrogen in mobile applications The C En technology has achieved the United States Department of Energy DOE targets for on board hydrogen storage systems DOE targets can be achieved using flexible glass capillaries and cryo compressed method of hydrogen storage Glass microspheres edit Hollow glass microspheres HGM can be utilized for controlled storage and release of hydrogen Stationary hydrogen storage edit Unlike mobile applications, hydrogen density is not a huge problem for stationary applications As for mobile applications, stationary applications can use established technology Compressed hydrogen CGH in a hydrogen tank Liquid hydrogen in a LH cryogenic hydrogen tank Industrial gases are a group of gases that are specifically manufactured for use in a wide range of industries, which include oil and gas, petrochemicals, chemicals, power, mining, steelmaking, metals, environmental protection, medicine, pharmaceuticals, biotechnology, food, water, fertilizers, nuclear power, electronics and aerospace Their production is a part of the wider chemical Industry where industrial gases are often seen as speciality chemicals The principal gases provided are nitrogen, oxygen, carbon dioxide, argon, hydrogen, helium and acetylene although a huge variety of gases and mixtures are available in gas cylinders The industry producing these gases is known as the industrial gases industry, which is seen as also encompassing the supply of equipment and technology to produce and use the gases Whilst most industrial gas is usually only sold to other industrial enterprises retail sales of gas cylinders and associated equipment to tradesmen and the general public are available through gas local agents and typically includes products such as balloon helium , dispensing gases for beer kegs, welding gases and welding equipment, LPG and medical oxygen Very small scale gas supply is not confined to just the industrial gas companies A wide variety of hand carried small gas containers, which may be called cylinders, bottles, cartridges, capsules or canisters are available to supply LPG, butane, propane, carbon dioxide or nitrous oxide Examples are whippets, powerlets, campingaz and sodastream Contents hide Early history of gases Gas production technology Gas distribution Mode of Gas supply Gas delivery What defines an industrial gas Gases Elemental gases Important liquefied gases Other common industrial gases Industrial gas applications Companies See also References Early history of gases edit A soda siphon, circa The first gas from the natural environment used by man was almost certainly air when it was discovered that blowing on or fanning a fire made it burn brighter Man also used the warm gases from a fire to smoke food Steam from boiling water has also been used by man in cooking foods Carbon dioxide has been known from ancient times as the byproduct of fermentation, particularly for beverages, which was first documented dating from – BCE in Jiahu, China Natural gas was used by the Chinese in about B C when they discovered the potential to transport gas seeping from the ground in crude pipelines of bamboo to where it was used to boil sea water Sulfur dioxide was first used by the Romans in winemaking

when it was discovered that if you burn candles made of sulfur inside empty wine vessels it would keep them fresh and prevent them gaining a vinegar smell Acetylene welding on cylinder water jacket, Lit carbide lamp However until the advent of scientific method and the science of chemistry, none of these gases would have been positively identified or understood The history of chemistry tells us that a number of gases were identified and either discovered or first made in relatively pure form during the Industrial Revolution of the th and th centuries by notable chemists in their laboratories The timeline of attributed discovery for various gases are carbon dioxide , hydrogen , nitrogen , nitrous oxide , oxygen , ammonia , chlorine , methane , hydrogen sulfide , carbon monoxide , hydrogen chloride , acetylene , helium fluorine , argon , krypton, neon and xenon and radon Carbon dioxide, hydrogen, nitrous oxide, oxygen, ammonia, chlorine, sulfur dioxide and manufactured fuel gas were already being used during the th century, and mainly had uses in food, refrigeration, medicine, and for fuel and gas lighting For example, carbonated water was being made from and commercially from , chlorine was first used to bleach textiles in and nitrous oxide was first used for dentistry anaethesia in At this time gases were often generated for immediate use by chemical reactions A notable example of a generator is Kipps apparatus which was invented in and could be used to generate gases such as hydrogen, hydrogen sulfide, chlorine, acetylene and carbon dioxide by simple gas evolution reactions Acetylene was manufactured commercially from and acetylene generators were used from about to produce gas for gas cooking and gas lighting, however electricity took over as more practical for lighting and once LPG was produced commercially from , the use of acetylene for cooking declined Once gases had been discovered and produced in modest quantities, the process of industrialisation spurred on innovation and invention of technology to produce larger quantities of these gases Notable developments in the industrial production of gases include the electrolysis of water to produce hydrogen in and oxygen from , the Brin process for oxygen production which was invented in the , the chloralkali process to produce chlorine in and the Haber Process to produce ammonia in The development of uses in refrigeration also enabled advances in air conditioning and the liquefaction of gases Carbon dioxide was first liquefied in The first Vapor compression refrigeration cycle using ether was invented in and a similar cycle using ammonia was invented in and another with sulfur dioxide in Liquid oxygen and Liquid nitrogen were both first made in Liquid hydrogen was first made in and liquid helium in LPG was first made in A patent for LNG was filed in with the first commercial production in Although no one event marks the beginning of the industrial gas industry, many would take it to be the s with the construction of the first high pressure gas cylinders Initially cylinders were mostly used for carbon dioxide in carbonation or dispensing of beverages In refrigeration compression cycles were further developed to enable the liquefaction of air, most notably by Carl von Linde allowing larger quantities of oxygen production and in the discovery that large quantities of acetylene could be dissolved in acetone and rendered nonexplosive allowed the safe bottling of acetylene A particularly important use was the development of welding and metal cutting done with oxygen and acetylene from the early s As production processes for other gases were developed many more gases came to be sold in cylinders without the need for a gas generator Gas production technology edit Distillation column in a cryogenic air separation plant Air separation plants refine air in a separation process and so allow the bulk production of nitrogen and argon in addition to oxygen these three are often also produced as cryogenic liquid To achieve the required low distillation temperatures, an Air Separation Unit ASU uses a refrigeration cycle that operates by means of the Joule–Thomson effect In addition to the main air gases, air separation is also the only practical source for production of the rare noble gases neon, krypton and xenon Cryogenic technologies also allow the liquefaction of natural gas, hydrogen and helium In natural gas processing, cryogenic technologies are used to remove nitrogen from natural gas in a Nitrogen Rejection Unit a process that can also be used to produce helium from natural gas if the natural gas fields contain sufficient helium to make this economic The larger industrial gas companies have often invested in extensive patent libraries in all fields of their business, but particularly in cryogenics The other principal production technology in the industry is Reforming Steam reforming is a chemical process used to convert natural gas and steam into a syngas containing hydrogen and carbon monoxide with carbon dioxide as a byproduct Partial oxidation and autothermal reforming are similar processes but these also require oxygen from an ASU Synthesis gas is often a precursor to the chemical synthesis of ammonia or methanol The carbon dioxide produced is an acid gas and is most commonly removed by amine treating This separated carbon dioxide can potentially be sequestrated to a carbon capture reservoir Air Separation and hydrogen reforming technologies are the cornerstone of the industrial gases industry and also form part of the technologies required for many fuel gasification including IGCC , cogeneration and Fischer Tropsch gas to liquids schemes Hydrogen has many production methods and is touted as a carbon neutral alternative fuel to hydrocarbons, whilst liquid hydrogen is used by NASA in the Space Shuttle as a rocket fuel see hydrogen economy for more information on hydrogens uses Simpler gas separation technologies, such as membranes or molecular sieves used in pressure swing adsorption or vacuum swing adsorption are also used to produce low purity air gases in nitrogen generators and oxygen plants Other examples producing smaller amounts of gas are chemical oxygen generators or oxygen concentrators In addition to the major gases produced by air separation and syngas reforming, the industry provides many other gases Some gases are simply byproducts from other industries and others are sometimes bought from other larger chemical producers, refined and repackaged although a few have their own production processes Examples are that hydrogen chloride can be produced by burning hydrogen in chlorine, nitrous oxide is produced by thermal decomposition of ammonium nitrate when gently heated electrolysis is used for the production of fluorine Electrical Corona discharge is used to produce ozone from air or oxygen Related services and technology can be supplied such as vacuum, which is often provided in hospital gas systems purified compressed air or refrigeration Another unusual system is the inert gas generator Some industrial gas companies may also supply related chemicals, particularly liquids such as bromine and ethylene oxide Gas distribution edit Mode of Gas supply edit Compressed hydrogen tube trailer Most materials that are gaseous at ambient temperature and pressure are supplied as compressed gas A gas compressor is used to compress the gas into storage pressure vessels such as gas canisters, gas cylinders or tube trailers through piping systems Gas cylinders are by far the most common gas storage and large numbers are produced at a cylinder fill facility However a few gases are vapours that can be liquefied at ambient temperature under pressure alone, so they can also be supplied as a liquid in an appropriate container This phase change also makes these gases useful as ambient refrigerants and the most significant industrial gases with this property are ammonia R , propane R , butane R and sulphur dioxide R Chlorine also has this property but is too toxic, corrosive and reactive to ever have been used as a refrigerant Some other gases exhibit this phase change if the ambient temperature is low enough this includes ethylene R , carbon dioxide R , ethane R , nitrous oxide R A and sulfur hexafluoride however these can only be liquefied under pressure if kept below their critical temperatures which are °C for C H °C for CO °C for C H °C for N O °C for SF All of these substances are also be provided as a Gas not a vapor at the bar pressure in a gas cylinder because that pressure is above their critical pressure Other gases can only be supplied as liquid if also cooled All gases can potentially be used as a refrigerant around the temperatures at which they are liquid for example nitrogen R and methane R are used as refrigerant at cryogenic temperatures Exceptionally carbon dioxide can be produced as a cold solid known as dry ice, which sublimes as it warms in ambient conditions, the properties of carbon dioxide are such that it cannot be liquid at a pressure below its triple point of bar Acetylene is also supplied differently Since it is so unstable and explosive, this is supplied as a gas dissolved in acetone within a packing mass in a cylinder Acetylene is also the only other common industrial gas that sublimes at atmospheric pressure Gas delivery edit Photos Gas Cabinet Inventory The major industrial gases can be produced in bulk and delivered to customers by pipeline, but can also be packaged and transported Most gases are sold in gas cylinders and some sold as liquid in appropriate containers e g Dewars or as bulk liquid delivered by truck The industry originally supplied gases in cylinders to avoid the need for local gas generation but for large customers such as steelworks or oil refineries, a large gas production plant may be built nearby typically called an on site facility to avoid using large numbers of cylinders manifolded together Alternatively, an industrial gas company may supply the plant and equipment to produce the gas rather than the gas itself An industrial gas company may also offer to act as plant operator under an operations and maintenance contract for a gases facility for a customer, since it usually has the experience of running such facilities for the production or handling of gases for itself Some materials are dangerous to use as a gas for example, fluorine is highly reactive and industrial chemistry requiring fluorine often uses hydrogen fluoride or hydrofluoric acid instead Another approach to overcoming gas reactivity is to generate the gas as and when required, which is done, for example, with ozone The delivery options are therefore local gas generation, pipelines, bulk transport truck, rail, ship , and packaged gases in gas cylinders or other containers Bulk liquid gases are often transferred to end user storage tanks Gas cylinders and liquid gas containing vessels are often used by end users for their own small scale distribution systems Toxic or flammable gas cylinders are often stored by end users in gas cabinets for protection from external fire or from any leak What defines an industrial gas edit Industrial gas is a group of materials that are specifically manufactured for use in industry and are also gaseous at ambient temperature and pressure They are chemicals which can be an elemental gas or a chemical compound that is either organic or inorganic, and tend to be low molecular weight molecules They could also be a mixture of individual gases They have value as a chemical whether as a feedstock, in process enhancement, as a useful end product, or for a particular use as opposed to having value as a simple fuel The term industrial gases is sometimes narrowly defined as just the major gases sold, which are nitrogen, oxygen, carbon dioxide, argon, hydrogen, acetylene and helium Many names are given to gases outside of this main list by the different industrial gas companies, but generally the gases fall into the categories specialty gases , medical gases , fuel gases or refrigerant gases However gases can also be known by their uses or industries that they serve, hence welding gases or breathing gases , etc or by their source, as in air gases or by their mode of supply as in packaged gases The major gases might also be termed bulk gases or tonnage gases In principle any gas or gas mixture sold by the industrial gases industry probably has some industrial use and might be termed an industrial gas In practice, industrial gases are likely to be a pure compound or precise mixture, packaged or in small quantities, but with high purity or tailored to a specific use e g oxyacetylene Lists of the more significant gases are listed in The Gases below There are cases when a gas is not usually termed an industrial gas principally where the gas is processed for later use of its energy rather than manufactured for use as a chemical substance or preparation The oil and gas industry is seen as distinct So, whilst it is true that natural gas is a gas used in industry often as a fuel, sometimes as a feedstock, and in this generic sense is an industrial gas this term is not generally used by industrial enterprises for hydrocarbons produced by the petroleum industry directly from natural resources or in an oil refinery This includes LPG The petrochemical industry is also seen as distinct So petrochemicals chemicals derived from petroleum such as ethylene are also generally not described as industrial gases Sometimes the chemical industry is thought of as distinct from industrial gases so materials such as ammonia and chlorine might be considered chemicals especially if supplied as a liquid instead of or sometimes as well as industrial gases Very small scale gas supply of hand carried containers is sometimes not considered to be industrial gas as the use is considered personal rather than industrial and suppliers are not always gas specialists These demarcations are based on perceived boundaries of these industries although in practice there is some overlap , and an exact scientific definition is difficult To illustrate overlap between industries Manufactured fuel gas such as town gas would historically have been considered an industrial gas Syngas is often considered to be a petrochemical although its production is a core industrial gases technology Similarly, projects harnessing Landfill gas or biogas, Waste to energy schemes, as well as Hydrogen Production all exhibit overlapping technologies Helium is an industrial gas, even though its source is from natural gas processing Any gas is likely to be considered an industrial gas if it is put in a gas cylinder except perhaps if it is used as a fuel Propane would be considered an industrial gas when used as a refrigerant, but not when used as a refrigerant in LNG production, even though this is an overlapping technology Gases edit Elemental gases edit Diatomic molecule Bromine and Iodine are not gases Noble gas The known chemical elements which are, or can be obtained from natural resources and which are gaseous are hydrogen, nitrogen, oxygen, fluorine, chlorine, plus the noble gases and are collectively referred to by chemists as the elemental gases These elements are all primordial apart from the noble gas radon which is a trace radioisotope but which does occur naturally, albeit only from radioactive decay It is not known if any synthetic elements with atomic number above are gases The elements which are stable two atom homonuclear molecules at standard temperature and pressure STP , are hydrogen H , nitrogen N and oxygen O , plus the halogens fluorine F and chlorine Cl The noble gases are all monatomic In the industrial gases industry the term elemental gases or sometimes less accurately molecular gases is used to distinguish these gases from molecules that are also chemical compounds These elements are all nonmetals Radon is chemically stable, but it is radioactive and does not have a stable isotope Its uses are due to its radioactivity rather than its chemistry and it requires specialist handling outside of industrial gas industry norms It can however be produced as a by product of uraniferous ores processing Radon is a trace naturally occurring radioactive material NORM encountered in the air processed in an ASU Chlorine is the only elemental gas that is technically a vapor since STP is below its critical temperature whilst bromine and mercury are liquid at STP, and so their vapor exists in equilibrium with their liquid at STP Air gases nitrogen N oxygen O argon Ar Noble gases helium He neon Ne argon Ar krypton Kr xenon Xe radon Rn The other Elemental gases hydrogen H chlorine Cl vapor fluorine F A self pressurising dewar silver, foreground being filled with liquid nitrogen from a large storage tank white, background Important liquefied gases edit This list shows the most important liquefied gases Produced from air liquid nitrogen LIN liquid oxygen LOX liquid argon LAR Produced from hydrocarbon feedstock liquid hydrogen liquid helium Liquefied natural gas LNG Liquefied petroleum gas LPG Other liquid carbon dioxide Other common industrial gases edit This list shows the other most common gases sold by industrial gas companies Compound gases ammonia NH carbon dioxide CO carbon monoxide CO hydrogen chloride HCl nitrous oxide N O nitrogen trifluoride NF sulfur dioxide SO sulfur hexafluoride SF Hydrocarbon gases methane CH acetylene C H ethane C H ethene C H propane C H propene C H butane C H butene C H Significant gas mixtures air breathing gases forming gas welding shielding gas synthesis gas Mixed Refrigerant used in LNG cycles There are many gas mixtures possible! Industrial gas applications edit A scuba diver in recreational diving gear The uses of industrial gases are very diverse The following is a small list of areas of use aerosol propellants airgun paintball beer widget calibration gas Coolant Cryogenics Cutting and welding dielectric gas Environmental protection Fire fighting gaseous fire suppression Food processing & packaging gas gas discharge lamp Metrology & measurement Laboratory and instrumentation Gases for safety and inerting Glass, ceramics, other minerals Lifting gas Medical gases Metallurgy Refrigerators rocket propellant Rubber, plastics, paint Semiconductor industry in Semiconductor fabrication plants soda fountain Water treatment Industrial water treatment Underwater diving Companies edit AGA AB part of The Linde Group Airgas Air Liquide Air Products & Chemicals BASF BOC part of The Linde Group Critical Systems Inc The Linde Group formerly Linde AG Messer Group MOX Linde Gases Praxair Matheson Tri Gas part of Taiyo Nippon Sanso Corporation See also edit Air separation Energy technology is an interdisciplinary engineering science having to do with the efficient, safe, environmentally friendly and economical extraction, conversion, transportation, storage and use of energy, targeted towards yielding high efficiency whilst skirting side effects on humans, nature and the environment For people, energy is an overwhelming need and as a scarce resource it has been an underlying cause of political conflicts and wars The gathering and use of energy resources can be harmful to local ecosystems and may have global outcomes Contents hide Interdisciplinary fields Electrical engineering Thermodynamics Thermal and chemical energy Nuclear energy Renewable energy Solar power Wind power Geothermal Hydropower Bioenergy Enabling technologies See also References Interdisciplinary fields edit As an interdisciplinary science Energy technology is linked with many interdisciplinary fields in sundry, overlapping ways Physics, for thermodynamics and nuclear physics Chemistry for fuel, combustion, air pollution, flue gas, battery technology and fuel cells Electrical engineering Engineering, often for fluid energy machines such as combustion engines, turbines, pumps and compressors Geography, for geothermal energy and exploration for resources Mining, for petrochemical and fossil fuels Agriculture and forestry, for sources of renewable energy Meteorology for wind and solar energy Water and Waterways, for hydropower Waste management, for environmental impact Transportation, for energy saving transportation systems Environmental studies, for studying the effect of energy use and production on the environment, nature and climate change Lighting Technology , for Interior and Exterior Natural as well as Artificial Lighting Design, Installations, and Energy Savings Energy Cost Benefit Analysis , for Simple Payback and Life Cycle Costing of Energy Efficiency Conservation Measures Recommended Electrical engineering edit High voltage lines for the long distance transportation of electrical energy Electric power engineering deals with the production and use of electrical energy, which can entail the study of machines such as generators, electric motors and transformers Infrastructure involves substations and transformer stations, power lines and electrical cable Load management and power management over networks have meaningful sway on overall energy efficiency Electric heating is also widely used and researched Thermodynamics edit Main article Thermodynamics Thermodynamics deals with the fundamental laws of energy conversion and is drawn from theoretical Physics Thermal and chemical energy edit A grate for a wood fire Thermal and chemical energy are intertwined with chemistry and environmental studies Combustion has to do with burners and chemical engines of all kinds, grates and incinerators along with their energy efficiency, pollution and operational safety Exhaust gas purification technology aims to lessen air pollution through sundry mechanical, thermal and chemical cleaning methods Emission control technology is a field of process and chemical engineering Boiler technology deals with the design, construction and operation of steam boilers and turbines also used in nuclear power generation, see below , drawn from applied mechanics and materials engineering Energy conversion has to do with internal combustion engines, turbines, pumps, fans and so on, which are used for transportation, mechanical energy and power generation High thermal and mechanical loads bring about operational safety worries which are dealt with through many branches of applied engineering science Nuclear energy edit A steam turbine Nuclear technology deals with nuclear power production from nuclear reactors, along with the processing of nuclear fuel and disposal of radioactive waste, drawing from applied nuclear physics, nuclear chemistry and radiation science Nuclear power generation has been politically controversial in many countries for several decades but the electrical energy produced through nuclear fission is of worldwide importance There are high hopes that fusion technologies will one day replace most fission reactors but this is still a research area of nuclear physics Renewable energy edit Main article Renewable energy Solar photovoltaic panels at a military base in the US Renewable energy has many branches Solar power edit Main article Solar power Photovoltaic power draws electricity from solar radiation through solar cells, either locally or in large photovoltaic power plants and uses semiconductor technology Solar heating uses solar panels which gather heat from sunlight to heat buildings and water Solar thermal power produces electricity by converting solar heat Wind power edit Wind turbines on Inner Mongolian grassland Main article Wind power Wind turbines draw energy from atmospheric currents and are designed using aerodynamics along with knowledge taken from mechanical and electrical engineering Geothermal edit Main article Geothermal Where it can be had, geothermal energy is used for heating and electricity Hydropower edit Building of Pelton water turbines in Germany Main article Hydropower Hydropower draws mechanical energy from rivers, ocean waves and tides Civil engineering is used to study and build dams, tunnels, waterways and manage coastal resources through hydrology and geology A low speed water turbine spun by flowing water can power an electrical generator to produce electricity Bioenergy edit Main article Bioenergy Bioenergy deals with the gathering, processing and use of biomasses grown in biological manufacturing, agriculture and forestry from which power plants can draw burning fuel Ethanol, methanol both controversial or hydrogen for fuel cells can be had from these technologies