Nitrogen Industry
Nitrogen: requiring early stages of plant the growth to promote development of stems and leaves.
Phosphorous: early growth and accelerates seeding or fruit formation in later stages of growth.
Potassium 'K' for the development of starche of potatoes and grains, sugar of fruits and vegetables and fibrous material of plants an ample supply of potassium in soil sometimes it helps to prevent disease and lessens the effects of excessive nitrogen applications.
K along N & P: Primary nutrients considered essential for plant growth.
Ammonia Production (NH₃) :
End uses of NH₃
- Direct application as fertilizer
- Uses (for both fertilizer & plastics)
- Ammonium phosphates
- Nitric acid
- Ammonium nitrate
- Ammonium sulphate
- Acrylonitrile
Type of Nitrogen :
- Mixed Fertilizers (N, P, K) (expressed as wt% total N₂ P₂, O₅, K₂O (eg. 5-10-5)
- Chemical Nitrogen Fertilizers.
Method of production :
Based on pressure-catalytic reaction of N₂ and H₂.
Ammonia Production: Reactions, Flow Diagram, Production Process and Uses of Ammonia
Grades:
Fertilizer: Granular-coated (non hygroscopic dust such as phosphate rock or limestone (40-42%N)
Liquor: mixture of urea in NH₃ sol (45% total N, 30% NH₃, 15% urea)
Slow release: Contains low molecular weight urea polymers
End uses:
- Solid fertilizer (53%)
- Liquid fertilizer (31%)
- Formaldehyde resins
- Melamine etc.
Methods of Production:
1. Classification of Processes:
All process for synthetic NH₃ are based on the pressure catalytic reaction of N₂ and H₂. The principal variations is in the operating pressure.
2. Processes for NH₃ Production:
- Reference flow sheet 1. Figure
- Chemical Reaction:
Processes for NH₃ Production
Raw Materials:
- H₂ from synthesis gas.
- N₂ from air addition in synthesis gas process or from air liquefaction process.
Process Description:
- Ammonia synthesis gas ( 3 moles pure H₂; 1 mole pure N₂ ) is compressed to the operating pressure (100-1000 atoms, depending on conversion required) and it is sent to the filter to remove compression oil and additionally through a very high temperature guard converter. (Converts CO and CO₂ to CH₄ and removes traces of H₂O, H₂S, P and As). This is done by catalysts and suitable getter materials.
- Relatively cool gases is added along with the outside of converter tube walls to provide cooling. So that carbon steel can be used for the thick wall pressure vessels and internal tubes. Preheated gas flow next through the inside of the tube which contains promoted porous iron catalysts at 500-550° C. The NH₃ product with an 8-30% conversion.
- Depending on process condition is remove by condensation first with water cooling and then NH₃ refrigeration.
- Then unconverted N₂-H₂ mixture is re-circulated to allow an 85-90% yield.
Major Engineering Problems:
Catalyst Development:
The preparation and use of active catalyst for NH₃ synthesis has been the subject of years of research. Principle aim of course is to develop catalyst that will allow improved yield at lower temperature and pressure and thus lower production cost.
Process Design Modification:
The above considerations have resulted in number of design modification, particularly as to the pressure used which affects conversion. re-circulation rate and refrigeration. The modern trend is towards lower pressure and increased re-circulation level because of the relatively high cost of pressure vessels.
Process Flow Diagram ( Ammonia Production ):
Fig. 1. Ammonia Production Flowsheet
Uses of Ammonia ( NH₃ ):
- Agricultural industries are the major users of ammonia (NH₃), representing nearly 80% of ammonia produced in the United States. Ammonia (NH₃) is a very valuable source of nitrogen that is essential for plants growth. Depending on the particular crops being grown, up to 200 pounds of ammonia (NH₃) per acre may be applied for each growing season.
- Ammonia (NH₃) is used in the production of liquid fertilizers solutions which consists of ammonia, ammonium nitrate, urea (CH₄N₂O) and aqua ammonia. It is also used by the fertilizer industries to produce ammonium and nitrate salt.
- Ammonia (NH₃) and urea (CH₄N₂O) are used as a source of protein in livestock feeds for ruminating animals such as cattles, sheeps and goats. Ammonia (NH₃) can also be used as a pre-harvest cotton defoliant, in anti-fungal agent on certain fruits and as preservatives for the storage of high-moisture corns.
- Dissociated ammonia (NH₃) is used in such metal treating operation as nitriding, carbonitriding, bright annealing and furnace brazing, sintering, sodium hydride descaling and atomic hydrogen welding and other applications where protective atmospheres are required.
- Ammonia (NH₃) is used in the manufacture of nitric acid (HNO₃) ; certain alkalies such as soda ash; dyes; pharmaceuticals such as sulfa drug, vitamins and cosmetics; synthetic textile fibers such as nylons, rayons and acrylics, and for the manufacturing of certain plastics such as phenolics and polyurethanes.
- The petroleum industry utilizes ammonia (NH₃) in neutralizing the acid constituents of crude oil and for prtection of equipments from corrosion. Ammonia (NH₃) is used in the mining industry for extraction of metals such as copper, nickel and olybdenum from their ores.
- Ammonia (NH₃) is used in several areas of water and wastewater treatments, such as pH control, in solution form to regenerate weak anion exchange resin, in conjunction with chlorine (Cl) to produce potable water and as an oxygen scavenger in boiler water treatment.
- Ammonia (NH₃) is used in stack emission control system to neutralize sulfur oxides from combustion of sulfur-containing fuels, as a method of NOx control in both catalytic and non-catalytic application and to enhance the efficiency of electrostatic precipitator for particulate control.
- Annonia (NH₃) is used as the developing agent in photochemical processes such as white printings, blue printings and in the diazo duplication processes.
- Ammonia (NH₃) is a widely used refrigerant in industrial refrigeration systems found in the food, beverage, petro-chemical and cold storage industries.
- Ammonia (NH₃) is used in the rubber industries for the stabilization of natural and synthetic latex to prevent premature coagulation.
- The pulp and paper industry uses ammonia (NH₃) for pulping wood and as a casein dispersant in the coating of paper.
- The food and beverage industry uses ammonia (NH₃) as a source of nitrogen needed for yeast and microorganisms.
- The decomposition of ammonia (NH₃) serves as a source of hydrogen for some fuel cell and other applications.
- Ammonia (NH₃) is used by the leather industries as a curing agent, as a slime and mold preventative in tanning liquors and as a protective agent for leathers and furs in storage.
- Abundant nitrogen (N2) in the air is commercially fixed by reaction with low cost hydrogen to give ammonia (NH₃) . this low cost chemicals is used for supplying:
* Most nitrogen chemical compounds.
FAQs
What is Ammonia?
Ammonia is one of the most widely produced chemicals. In pure form, it is known as anhydrous ammonia. Ammonia is also produced in the human body and is commonly found in nature. It is essential in the body as a building block for making proteins and other complex molecules. In nature, ammonia occurs in soil from bacterial processes. It is also produced when plants, animals and animal wastes decays.
What are the properties of Ammonia?
Ammonia is a colorless highly irritating gas with a sharp suffocating odor. It dissolves easily in water to form ammonium hydroxide solution which can cause irritation and burns. Ammonia gas is easily compressed and forms a clear, colorless liquid under pressure. It is usually shipped as a compressed liquid in steel cylinders. Ammonia is not highly flammable, but containers of ammonia may explode when exposed to heat.
How is Ammonia used?
About 80% of the ammonia produced in industries is used in agriculture as fertilizer. Ammonia is also used as a refrigerant gas, to purify water supplies, and in the manufacture of plastics, explosives, fabrics, pesticides, dyes and other chemicals. It is found in many household and industrial-strength cleaning solutions. Cleaning solutions for industrial use contain higher concentrations of ammonia and can quickly cause irritation and burns.
How can people be exposed to Ammonia?
Most people are exposed to ammonia from breathing its gas or vapors. Since ammonia exists naturally and is also present in cleaning products, exposure may occur from these sources. The widespread use of ammonia on farms and in industrial and commercial locations means that exposure can also occur from aammonia on farms and in industrial and commercial locations means that exposure can also occur from an accidental release or from a deliberate terrorist attack. Ammonia gas is lighter than air and will rise, so that generally it does not settle in low-lying areas. However, in the presence of moisture, ammonia can form vapors that are heavier than air. These vapors can spread along the ground or other low-lying areas.
How docs ammonia act in the body?
When ammonia enters the body as a result of breathing, swallowing or skin contact, it reacts with water to produce ammonium hydroxide. This chemical is very corrosive and damages cells in the body on contact.
Is ammonia a liquid or a gas?
Ammonia quickly turns to a gas when exposed to air. But ammonia is easily and indefinitely stored as a liquid at about 150 PSI, a very low pressure which doesn't require special high pressure tanks like hydrogen.