into duct ion to ammonia

8/8/2019 Into Duct Ion to Ammonia

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Objective

1. To get know the uses of Ammonia.

2. To know the properties of Ammonia.

3. To explain the industrial process in the manufacture of ammonia.

4. Get know about activity to prepare ammonium fertiliser.


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Introduction to Ammonia

Ammonia is a compound of nitrogen and hydrogen with the formula NH3. It is acolourless gas with a characteristic pungent odour. Ammonia contributes significantly to the

nutritional needs of terrestrial organisms by serving as a precursor to food and fertilizers.Ammonia, either directly or indirectly, is also a building block for the synthesis of manypharmaceuticals. Although in wide use, ammonia is both caustic and hazardous. In 2006,

worldwide production was estimated at 146.5 million tonnes. It is used in commercial cleaning

products.

Ammonia, as used commercially, is often called anhydrous ammonia. This termemphasizes the absence of water in the material. Because NH3 boils at -33 C, the liquid

must be stored under high pressure or at low temperature. Its heat of vaporization is,

however, sufficiently great that NH3 can be readily handled in ordinary beakers in a

fume hood. "Household ammonia" or "ammonium hydroxide" is a solution of NH3 in

water. The strength of such solutions is measured in units of baume (density), with 26degrees baume (about 30 weight percent ammonia at 15.5 C) being the typical high

concentration commercial product. Household ammonia ranges in concentration from 5to 10 weight percent ammonia. Ammonia, NH3, is used to manufacture nitric acid,

HNO3. Nitric acid, HNO3, is then used to manufacture explosives and nitrate fertilisers.

Ammonia has a triangular pyramidal geometry, and boiling points of 77.7*C and 33.5*C. In its

pure form ammonia was prepared in 1774 by Joseph Priestly, and its composition was determined in 1785

by Claude-Louis Berthollet. Ammonia has a chemical formula of NH3, and is sp3 hybridised. Ammonia is

highly polarised, due to the electronegativity of nitrogen, and as a result, has a large dipole moment.Ammonias polarisation allows it to dissociate in water forming hydroxide and ammonium ions:

NH3 (aq) + H2O (l)NH4 (aq) + OH (aq)

Ammonia solutions are basic, due to the hydroxide ions formed in solution.
http://en.wikipedia.org/wiki/Odourhttp://en.wikipedia.org/wiki/Odour


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Information

Uses of Ammonia

1. Ammonia is used in the production of liquid fertilizer solutions which consist ofammonia, ammonium nitrate, urea and aqua ammonia.It is also used by the fertilizerindustry to produce ammonium and nitrate salts.

2. Ammonia and urea are used as a source of protein in livestock feeds for ruminating

animals such as cattle, sheep and goats.Ammonia can also be used as a pre-harvest cottondefoliant, an anti-fungal agent on certain fruits and as preservative for the storage of

high-moisture corn.

3. Dissociated ammonia is used in such metal treating operations as nitriding,

carbonitriding, bright annealing, furnace brazing, sintering, sodium hydride descaling,atomic hydrogen welding and other applications where protective atmospheres are

required.

4. Ammonia is used in the manufacture of nitric acid; certain alkalies such as soda ash;

dyes; pharmaceuticals such as sulfa drugs, vitamins and cosmetics; synthetic textile fiberssuch as nylon, rayon and acrylics; and for the manufacture of certain plastics such as

phenolics and polyurethanes.

5. The petroleum industry utilizes ammonia in neutralizing the acid constituents of crude oil

and for protection of equipment from corrosion.Ammonia is used in the mining industryfor extraction of metals such as copper, nickel and molybdenum from their ores.

6. Ammonia is used in several areas of water and wastewater treatment, such as pH control,

in solution form to regenerate weak anion exchange resins, in conjunction with chlorine

to produce potable water and as an oxygen scavenger in boiler water treatment.

7. Ammonia is used in stack emission control systems to neutralize sulfur oxides from

combustion of sulfur-containing fuels, as a method of NOx control in both catalytic and

non-catalytic applications and to enhance the efficiency of electrostatic precipitators for

particulate control.

8. Ammonia is used in the rubber industry for the stabilization of natural and synthetic latex

to prevent premature coagulation.

9. Ammonia is used by the leather industry as a curing agent, as a slime and mold

preventative in tanning liquors and as a protective agent for leathers and furs in storage


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Properties of Ammonia Gas

Ammonia is a chemical consisting of one atom of nitrogen and three atoms of hydrogen. It is

designated in chemical notation as NH3. Ammonia is extremely soluble in water and is frequently used as

a water solution called aqua ammonia. Ammonia chemically combines with water to form ammonium

hydroxide. Household ammonia is a diluted water solution containing 5 to 10 percent ammonia. On theother hand, anhydrous ammonia is essentially pure (over 99 percent) ammonia. "Anhydrous" is a Greek

word meaning "without water;" therefore, anhydrous ammonia in ammonia without water.

Refrigerant grade anhydrous ammonia is a clear, colorless liquid or gas, free from visible

impurities. It is at least 99.95 percent pure ammonia. Water cannot have a content above 33 parts per

million (ppm) and oil cannot have a content above 2 ppm. Preserving the purity of the ammonia is

essential to ensure proper function of the refrigeration system.

Physical Propertiess

Anhydrous ammonia is a clear liquid that boils at a temperature of -28F. Inrefrigeration systems, the liquid is stored in closed containers under pressure. When the pressure

is released, the liquid evaporates rapidly, generally forming an invisible vapor or gas. The rapid

evaporation causes the temperature of the liquid to drop until it reaches the normal boiling point

of -28F, a similar effect occurs when water evaporates off the skin, thus cooling it. This is whyammonia is used in refrigeration systems.

Liquid anhydrous ammonia weighs less than water. About eight gallons of ammoniaweighs the same as five gallons of water.

Liquid and gas ammonia expand and contract with changes in pressure and temperature.

For example, if liquid anhydrous ammonia is in a partially filled, closed container it is heatedfrom 0F to 68F, the volume of the liquid will increase by about 10 percent. If the tank is 90

percent full at 0F, it will become 99 percent full at 68F. At the same time, the pressure in thecontainer will increase from 16 pounds per square inch (psi) to 110 psi.

Liquid ammonia will expand by 850 times when evaporating:

Anhydrous ammonia gas is considerably lighter than air and will rise in dry air. However,

because of ammonias tremendous affinity for water, it reacts immediately with the humidity in

the air and may remain close to the ground.

The odor threshold for ammonia is between 5 - 50 parts per million (ppm) of air. The

permissible exposure limit (PEL) is 50 ppm averaged over an 8 hour shift. It is recommendedthat if an employee can smell it they ought to back off and determine if they need to be using

respiratory protection.


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Summary of properties:

Boiling Point -28F

Weight per gallon of liquid at -28F 5.69 pounds

Weight per gallon of liquid at 60F 5.15 poundsSpecific gravity of the liquid (water=1) 0.619

Specific gravity of the gas (air=1) 0.588

Flammable limits in air 16-25%

Ignition temperature 1204F

Vapor pressure at 0F 16 psi



One cubic foot of liquid at 60F expands to 850 cubic foot of gas

Chemical Properties Anhydrous ammonia is easily absorbed by water. At 68F, about 700

volumes of vapor can be dissolved in one volume of water to make a solution containing 34 percent

ammonia by weight. Ammonia in water solution is called aqua ammonia or ammonium hydroxide.

Ammonia, especially in the presence of moisture, reacts with and corrodes copper, zinc, and

many alloys. Only iron, steel, certain rubbers and plastics, and specific nonferrous alloys resistant to

ammonia should be used for fabrications of anhydrous ammonia containers, fittings, and piping.

Ammonia will combine with mercury to form a fulminate which is an unstable explosive

compound.

Anhydrous ammonia is classified by the Department of Transportation as nonflammable. However,

ammonia vapor in high concentrations (16 to 25 percent by weight in air) will burn. It is unlikely that

such concentrations will occur except in confined spaces or in the proximity of large spills. The fire

hazard from ammonia is increased by the presence of oil or other combustible materials.

Anhydrous ammonia is an alkali

Structure of Ammonia


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Manufacture of ammonia

Ammonnia, NH3 is manufactured on a large scale in factories through the HaberProcess. There are three main stages in the manufacture of ammonia. The Haber process is

the third stage and uses a catalyst.

The three main stages in ammonia synthesis

a) Conversion of methane and steam to hydrogen and carbon monoxide

b) Removal of the carbon monoxideand the production of a mixture of hydrogen and nitrogen

c) Synthesis of ammonia in the Haber process

The process combines nitrogen gas, N2, from the air with hydrogen gas, H2, derived

mainly from natural gas to form ammonia, NH3. The two gases are mixed in the ratioof 1:3 volumes.

The hydrogen gas is obtained from methane CH4, a type of natural gas, while nitrogen

gas is obtained from air by fractional distillation of liquified air. The gas mixture is passed over

iron (catalyst) at a temperature of 450 5500C to speed up the rate of reaction and compressed

under a pressure of 200 500 atmospheres.


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THE MANUFACTURE OF AMMONIA, NH3 THROUGH HABER PROCESS

THE MANUFACTURE OF NITROGENOUS FERTILISERS

a) Ammonium Sulphate

Ammonia reacts with sulphuric acid by neutralisation to produce ammonium sulphate

2NH3+H2SO4 (NH4)2SO4

Ammonium sulphate

b) Ammonium nitrate

Ammonia reacts with nitric acid by neutralisation to produce ammonium nitrate.

The chemical compound ammonium nitrate, the nitrate of ammonia with the chemical formulaNH4NO 3, is a white crystalline solid at room temperature and standard pressure. It is commonly

used in agriculture as a high-nitrogen fertiliser, and it has also been used as an oxidizing agent in

explosives, including improvised explosive devices. It is the main component of ANFO, a verypopular explosive.

Ammonium nitrate is used in instant cold packs, as hydrating the salt is an endothermic process.

c) Urea

Urea or carbamide is an organic compound with the chemical formula (N2)2CO. The molecule

has two amine (-NH2) groups joined by a carbonyl (C=O) functional group.

The terms urea and carbamide are also used for a class of chemical compounds sharing

the same functional group RR'N-CO-NRR', namely a carbonyl group attached to two organicamine residues. Examples include carbamide peroxide, allantoin, and hydantoin. Ureas are

closely related to biurets and related in structure to amides, carbamates, diimides, carbodiimides,

and thiocarbamides.


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Preparation of Ammonium Sulphate

Ammonium sulfate is made by reacting synthetic ammonia (or by-product ammonia from

coke-ovens) with sulphuric acid

2 NH3 + H2SO4 (NH4)2SO4

A mixture of ammonia gas and water vapor is introduced into a reactor that contains a saturated

solution of ammonium sulphate and about 2 to 4% of free sulfuric acid at 60 C. Concentrated

sulfuric acid is added to keep the solution acidic, and to retain its level of free acid. The heat ofreaction keeps reactor temperature at 60 C.

Dry, powdered ammonium sulphate may be formed by spraying sulphuric acid into a reaction

chamber filled with ammonia gas. The heat of reaction evaporates all water present in the

system, forming a powdery salt.

Ammonium sulphate also is manufactured from gypsum (CaSO42H2O). Finely divided gypsum

is added to an ammonium carbonate solution. Calcium carbonate precipitates out, leaving

ammonium sulfate in the solution.

(NH4)2CO3 + CaSO4 (NH4)2SO4 + CaCO3

Ammonium sulfate occurs naturally as the rare mineral mascagnite in volcanic fumaroles and

due to coal fires on some dumps.


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DISCUSSION

The most familiar compound composed of the elements nitrogen and hydrogen, NH3. It

is formed as a result of the decomposition of most nitrogenous organic material, and itspresence is indicated by its pungent and irritating odor.

Ammonia has a wide range of industrial and agricultural applications. Examples of its use

are the production of nitric acid and ammonium salts, particularly the sulfate, nitrate, carbonate,

and chloride, and the synthesis of hundreds of organic compounds including many drugs,plastics, and dyes. Its dilute aqueous solution finds use as a household cleansing agent.

Anhydrous ammonia and ammonium salts are used as fertilizers, and anhydrous ammonia

also serves as a refrigerant, because of its high heat of vaporization and relative ease ofliquefaction.

The physical properties of ammonia are analogous to those of water and hydrogen

fluoride in that the physical constants are abnormal with respect to those of the binary hydrogen

compounds of the other members of the respective periodic families. These abnormalitiesmay be related to the association of molecules through intermolecular hydrogen bonding.

Ammonia is highly mobile in the liquid state and has a high thermal coefficient of

expansion.Most of the chemical reactions of ammonia may be classified under three chief

groups: (1) addition reactions, commonly called ammonation; (2) substitution reactions,commonly called ammonolysis; and (3) oxidation-reduction reactions.

Ammonation reactions include those in which ammonia molecules add to other

molecules or ions. Most familiar of the ammonation reactions is the reaction with water to formammonium hydroxide. The strong tendency of water and ammonia to combine is evidenced

by the very high solubility of ammonia in water. Ammonia reacts readily with strong acids toform ammonium salts. Ammonium salts of weak acids in the solid state dissociate readily

into ammonia and the free acid. Ammonation occurs with a variety of molecules capable ofacting as electron acceptors (Lewis acids), such as sulfur trioxide, sulfur dioxide, silicon

tetrafluoride, and boron trifluoride. Included among ammonation reactions is the formation

of complexes (called ammines) with many metal ions, particularly transition metal ions.Ammonolytic reactions include reactions of ammonia in which an amide group (NH2), an

imide group), or a nitride group replaces one or more atoms or groups in the reacting

molecule.

Oxidation-reduction reactions may be subdivided into those which involve a change in

the oxidation state of the nitrogen atom and those in which elemental hydrogen is liberated. Anexample of the first group is the catalytic oxidation of ammonia in air to form nitric oxide. In

the absence of a catalyst, ammonia burns in oxygen to yield nitrogen. Another example is thereduction with ammonia of hot metal oxides such as cupric oxide.


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The physical and chemical properties of liquid ammonia make it appropriate for use as a

solvent in certain types of chemical reactions. The solvent properties of liquid ammonia are,

in many ways, qualitatively intermediate between those of water and of ethyl alcohol. This isparticularly true with respect to dielectric constant; therefore, ammonia is generally superior

to ethyl alcohol as a solvent for ionic substances but is inferior to water in this respect. On

the other hand, ammonia is generally a better solvent for covalent substances than is water.

The Haber-Bosch synthesis is the major source of industrial ammonia. In a typicalprocess, water gas (CO, H2, CO2) mixed with nitrogen is passed through a scrubber cooler to

remove dust and undecomposed material. The CO2 and CO are removed by a CO2 purifier and

ammoniacal cuprous solution, respectively. The remaining H2 and N2 gases are passed over acatalyst at high pressures (up to 1000 atm or 100 megapascals) and high temperatures

(approx. 1300F or 700C). Other industrial sources of ammonia include its formation as a

by-product of the destructive distillation of coal, and its synthesis through the Cyanamidprocess. In the laboratory, ammonia is usually formed by its displacement from ammonium

salts (either dry or in solution) by strong bases. Another source is the hydrolysis of metal

nitrides.

Ammonia is commercially produced by the Haber-Bosch process, which is alsosometimes referred to as the Haber-Ammonia Process or Synthetic Ammonia Process. Fritz

Haber, the German physical chemist, created the process in 1909, and it was further developed

by Carl Bosch to make it economically viable. Both chemists won the Nobel prize for their workin this field; Haber in 1918 for its development, and Bosch in 1931 for creating high-pressure

conditions which obtained a higher yield, economically.

So how did the Haber-Bosch process come about?

At the end of the 19th century, Chilean nitrates, were the major source of nitrates at the time. It

was clear, that this source would not be able to meet future demands. It was also realised that in the event

of a war, any nation cut off from the Chilean supply, would not be able to make adequate amounts of

munitions. Germany (Habers native country) was in particular dependent on this source of nitrogen

compounds, to manufacture explosives. Following the allied block of the South American ports, thissupply was well and truly cut off. An alternative method of producing nitrates was needed. Haber

promptly got to work on the problem. In World War 1, had Haber not invented the process, Germany

would have been forced to surrender years earlier than it did. As a result the Haber-Bosch process

indirectly, cost thousands of people their lives.


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Below is a diagram of a modern ammonia production site:

HISTORY

The Romans called the ammonium chloride deposits they collected from near the Temple of

JupiterAmu n (Greek Ammon) in ancient Libya 'sal ammoniacus' (salt of Amun)

because of proximity to the nearby temple. Salts of ammonia have been known from veryearly times; thus the term Hammoniacus sal appears in the writings ofPliny, although it is

not known whether the term is identical with the more modernsal-ammoniac.

In the form of sal-ammoniac, ammonia was known to the Arabic alchemists as early as the

8th century, first mentioned by Geber (Jabir ibn Hayyan), and to the European alchemists

since the 13th century, being mentioned by Albertus Magnus. It was also used by dyers in theMiddle Ages in the form of fermented urine to alter the colour of vegetable dyes. In the 15th

century, Basilius Valentinus showed that ammonia could be obtained by the action of alkalison sal-ammoniac. At a later period, when sal-ammoniac was obtained by distilling the hoofs

and horns of oxen and neutralizing the resulting carbonate with hydrochloric acid, the name

"spirit of hartshorn" was applied to ammonia.

Gaseous ammonia was first isolated by Joseph Priestley in 1774 and was termed by him

alkaline air; however it was acquired by the alchemist Basil Valentine. Eleven years later in

1785, Claude Louis Berthollet ascertained its compositionGaseous ammonia was first isolated by Joseph Priestley in 1774 and was termed by him alkaline

air; however it was acquired by the alchemist Basil Valentine. Eleven years later in

1785, Claude Louis Berthollet ascertained its composition.


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The Haber process to produce ammonia from the nitrogen in the air was developed by

Fritz Haber and Carl Bosch in 1909 and patented in 1910. It was first used on an industrial scaleby the Germans during World War I, following the allied blockade that cut off the supply of

nitrates from Chile. The ammonia was used to produce explosives to sustain their war effort.

Prior to the advent of cheap natural gas, hydrogen as a precursor to ammonia production

was produced via the electrolysis of water. The Vemork 60 MW hydroelectric plant in Norwayconstructed in 1911 was used purely for this purpose and up until the second world war

provided the majority of Europe's ammonia.


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DISCUSSION

It was developed immediately prior to World War I by Fritz Haber and Carl Bosch,German chemists. Haber won the Nobel Prize for Chemistry in 1918 for his discoveries, while

Bosch shared a Nobel Prize with Friedrich Bergius in 1931 for his work on high-pressurechemical reactions. At first a German national secret, the chemistry and techniques behind theeffective synthesis of ammonia spread to the rest of the world in the 20s and 30s.

Ammonia is important because it is the primary ingredient in artificial fertilizers, without

which modern-day agricultural yields would be impossible. Sometimes called the "Haber

Ammonia process", the Haber-Bosch process was the first industrial chemical process tomake use of extremely high pressures (200 to 400 atmospheres). In addition to high

pressures, high temperatures (750 to 1200 degrees Fahrenheit or 400 to 650 degrees Celsius)

are used. The efficiency of the reaction is a function of pressure and temperature - greater

yields are produced at higher pressures and lower temperatures.

In the first decade of the 20th century, the artificial synthesis of nitrates was being

researched

because the world's supply of fixed nitrogen was declining rapidly relative to the demand.While nitrogen in its inactive, atmospheric gas form is very plentiful, agriculturally useful

"fixed" nitrogen compounds were harder to come by at that time in history. Agricultural

operations require liberal amounts of fixed nitrogen to produce good yields. At the turn of the

century, all the world's developed countries were required to mass import nitrates from thelargest available source - Chilean saltpeter (NaNO3). Many scientists started worrying about

the declining supply of nitrogen compounds.

The Haber-Bosch process provided a solution to the shortage of fixed nitrogen. Using

extremely high pressures and a catalyst composed mostly of iron, critical chemicals used inboth the production of fertilizers and explosives were made highly accessible to German

industry, making it possible for them to continue fighting WWI effectively. As the Haber-

Bosch process branched out in global use, it became the primary procedure responsible forthe production of fertilizer to feed the world's population. Without it, billions of people might

not exist. Today, the Haber-Bosch process is used to produce more than 500 million tons (453

billion kilograms) of artificial fertilizer per year; roughly 1% of the world's energy is used forit, and it sustains about 40% of our planetary population.


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Ammonia, chemicalsymbol NH3, can take the form of a strong smelling liquid or gas. Most

popularly, consumer and commercial products use the alkaline substance to clean grime or

fertilize crops. Even in low concentrations, inhaling ammonia or getting the solution on your skincan cause burning, fainting, or death, so always use caution when handling this chemical.

Ammonia has one nitrogenatom and threehydrogen atoms tightly bonded. A tiny amount of

ammonia forms when organic matter decomposes, so the gas can be found naturally in our

atmosphere. Most of the ammonia used is produced through artificial means, however, bybonding the four atoms together by sheer force. Then the gas can be pressurized to form a liquid

for easy distribution to manufacturing plants.

As a gas, ammonia is lighter than air, so it won't pool indoors like other dangerous gases, such as

propane. While it has a very pungent, distinctive odor, it's clear and difficult to combust unlesshighly concentrated. This makes ammonia safer than other chemicals for household use, as most

people will recognize the smell and leave a toxic area to prevent fainting.

Since ammonia gets easily incorporated into water as a solution, it's used in many cleaners.

Many window sprays, oven foam, toilet bowl cleansers, wax removers, and other householdcleaners contain around 5-10% ammonia. Different types of cleaners should never be mixed in

the same application. For example, ammonia and bleach form a very dangerous gas, called

chloramine, that shouldn't be inhaled.

Commercial cleansers, with 25-30% ammonia, are extremely dangerous due to their corrosivity.Under careful oversight, liquid ammonia is also used to etch metal like aluminum and copper,

refrigerate rooms or trucks, and dissolve other elements inchemistry labs. Most of the ammonia

we produce goes to fertilizing crops by providing absorbable nitrogen to plants. Manufacturers of

plastics, pesticides, and dyes use the liquid at some point in their synthesizing process.
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Reference

http://www.chm.bris.ac.uk/webprojects2001/prime/

http://en.wikipedia.org/wiki/Ammonia

http://www.osha.gov/SLTC/etools/ammonia_refrigeration/ammonia/index.html

http://www.rmtech.net/uses_of_ammonia.htm

http://www.hillakomem.com/tag/ammonium-carbamate
http://www.chm.bris.ac.uk/webprojects2001/prime/http://en.wikipedia.org/wiki/Ammoniahttp://www.rmtech.net/uses_of_ammonia.htmhttp://www.hillakomem.com/tag/ammonium-carbamatehttp://www.chm.bris.ac.uk/webprojects2001/prime/http://en.wikipedia.org/wiki/Ammoniahttp://www.rmtech.net/uses_of_ammonia.htmhttp://www.hillakomem.com/tag/ammonium-carbamate

into duct ion to ammonia

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