?what is urea

Specifications of urea
Melting point: 133 to 135 degrees Celsius
Density: 2.13 grams per cubic centimeter
Solvents: water, glycerol, ethanol and acetonitrile
Chemical formula of urea: CO (NH2) 2
Urea is also called carbamide. This amide has two amine groups attached to a carbonyl functional group. Urea plays an important role in the metabolism of nitrogen-containing compounds in animals. Urea is the main substance in nitrogen in mammalian urine.

Pure solid urea is colorless and highly soluble in water and non-toxic. This chemical compound is soluble in water and insoluble in acid and alkali.
It is widely used in fertilizers as a source of nitrogen and is an important raw material in the chemical industry. This compound can be made from minerals. In the laboratory, pure urea can be produced without biological raw materials. The most common urea impurity is biorite, which reduces plant growth.

Applications of urea in various industries
It is mainly used in the production of solid fertilizers, liquid fertilizers, animal feed supplements, plastics and adhesives. Nitrogen is one of the essential and important substances for plant growth and one of the best sources to provide this element in plants is urea. Among nitrogenous compounds, urea has the highest production volume among different materials. The use of this substance is constantly increasing and is considered as the top nitrogen fertilizer in the world.

Urea in agriculture:
More than 90% of the industrial production of this substance in the world is used as nitrogen-releasing fertilizer. Many soil bacteria contain the enzyme urease, which catalyzes their conversion to ammonia (NH3) or ammonium ions (NH + 4) and ionic carbonate (HCO-3). Therefore, urea fertilizers are rapidly converted to ammonium in the soil.
Urea in the chemical industry:
This compound is the raw material for the construction of two main classes of materials:
Urea-formaldehyde resins
Urea – Melamine – Formaldehyde used in marine boards

Urea in explosives:
It can be used to make urea nitrate, an explosive that is used industrially as part of some explosives. It stabilizes nitrocellulose explosives.

Urea in automotive systems:
Used to reduce NOx pollutants in exhaust gases.
In a catalytic converter, ammonia from urea hydrolysis reacts with the release of nitrous oxide and is converted to nitrogen and water.
Cars that use these catalytic converters need to prepare diesel exhaust liquids, a solution of urea in water.

Laboratory use of urea:
It is a powerful protein repellent at concentrations up to 10M. This property is used to increase the solubility of some proteins.

Medical use of urea:
Creams containing medicinal urea are used as topical skin products to strengthen the body. It has also been studied as a diuretic.

Other uses of urea:
Other uses for this material include:
Use of medicinal urea in cosmetic products (skin moisturizing cream, hair conditioner and shampoo as well as trimmers)
Production of urea formaldehyde resin and formaldehyde urea melamine and urea nitrate
In fire extinguishers as a fire resistant agent
As a yeast nutrient for fermenting sugars to ethanol
Anti-corrosion alternative to antifreeze salt
Rich source of hydrogen in fuel cells
Reduction of nitrogen oxide pollutants
Application of medicinal urea in teeth whitening products
As a synthetic protein
Dyeing and printing fabrics
Diagnosis of kidney function
In the cultivation of cereals and cotton
Dishwashing Liquid
humidity absorber
Animal feed
Gardening

Steps of urea production:
Industrial production of carbamide is only from ammonia and carbon dioxide. Because carbon dioxide is produced as a by-product in the production of hydrogen from natural gas or crude oil for use in ammonia synthesis, the urea production unit is often connected to an ammonia synthesis unit.

In the first stage, ammonia and carbon dioxide are composed of ammonium carbamate:
CO2 (g) + 2NH3 (l) → NH2COONH4 (l)

At high pressures this reaction is minor. Ammonium carbamate and water are in balance:
NH2COONH4 (l) ↔ H2NCONH2 (l) + H2O (l)
At a molar ratio of ammonia to carbon dioxide of 4 to 1, a temperature of 200 ° C and a pressure of 200 bar, about 70% of carbon dioxide will be converted to urea.

Unconverted and unreacted ammonium carbamates should be removed from the resulting reaction mixture (aqueous solution of urea, ammonium carbamate and ammonia). Numerous industrial processes for the production of this chemical compound differ, especially in terms of the method of separation and recovery of ammonia carbon dioxide. Minimizing the energy consumption of these large production units is of great importance

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Production by one-pass method
In the first factories built using the “one-pass” process, a mixture of ammonia and carbon dioxide from the pressure release and thermal decomposition of ammonium carbamate was converted to ammonium nitrate or sulfate, and carbon dioxide was emitted.

In modern factories, complete recovery of carbon dioxide and ammonia takes place, so that the efficiency of ammonia reaches 99%. Because significant product loss occurs at the next tablet-making stage, the actual reaction efficiency goes even higher. Current methods include the following:

Restore the solution
Extraction processes (descaling or removal)
Urea production by solution recovery method:
In this method, the pressure of the synthesis solution is gradually released after leaving the reactor, gradually releasing ammonia and carbon dioxide, under their own pressure in an adsorbent device, in water or vice versa in the mother urea solution. To be. The adsorption solution pressure is increased step by step to restore the synthesis pressure. By this type of reverse compression absorption, a concentrated solution of carbamate containing a small amount of water is produced, thereby balancing the formation of urea. In those recovery processes where the first stage of decomposition is performed at a pressure of 60 to 80 bar, less heat is required.
Production of urea by extraction method
In extraction processes, the solution is injected into a layered evaporator after leaving the reactor. In this device, the downstream solution is inverted in contact with all the carbon dioxide required by the process. The gases leaving the upper part of the evaporator, together with part of the primary ammonia, are partially condensed in a compressed solution introduced from the low-pressure decomposer part, and the result is a mixture of liquid and gas. Becomes a reactor.

Because about 85% of carbamate decomposes in the sediment chamber, a low-pressure decomposition unit is sufficient to complete the separation operation. The heat generated in the high pressure condenser is converted to steam and used to operate the low pressure decomposer. Ammonia can also be used instead of carbon dioxide precipitation. Sedimentation processes are somewhat more energy efficient than recovery processes with high pressure decomposers.

Urea production process
Feed pressure boosting unit: In the ammonia and CO2 gas phase, which is first compressed as the main feed for urea synthesis and then sent to the urea synthesis unit.
Urea synthesis unit: In this section, ammonia and CO2 are converted to urea under temperature and pressure conditions.
Evaporation and purification unit: At this stage, the purity of the urea output from the synthesis section to be sent to the granulation unit increases.
Granulation unit: In this unit, the final product of urea is solid granulated and granulated and finally stored in 3 special warehouses (with a capacity of 50,000 tons for each warehouse).

Bort value:
By heating urea, biuret is formed:
H2NCONH2 → H2NCONHCONH2 + NH3
The presence of this substance is harmful to some plants. Therefore, the amount of biuret in this material should be kept low (commercial carbamide contains 0.3-1% of biuret).

Risks of urea (MSDS urea)
It can irritate the skin, eyes and respiratory system. Frequent or prolonged skin contact with urea fertilizers can cause dermatitis. Pure urea with high concentrations in the blood can be harmful. The presence of small amounts of this substance is not as dangerous as the amount of urea in human urine. Swallowing small amounts of this chemical with plenty of water for an acceptable amount of time is not dangerous.

The amount of this substance in the urine of animals is higher than that of humans, and this amount can be dangerous. This compound can cause algal blooms and lead to the production of toxins. The presence of this substance in the reputation of fertilizer fields can play an important role in increasing the algal bloom.

Urea decomposes at temperatures above the melting point, while producing toxic gases that react strongly with strong oxidants, nitrites, mineral chlorides, chlorites, and perchlorates, causing fires and explosions.

Urea Safety Guide
Substances are usually divided into three categories in terms of toxicity, including high, medium and low toxicity. The type of contact with the material from a safety point of view depends on the toxicity and physical shape of the material. The most dangerous way for toxins to enter the body is the respiratory system, so proper ventilation systems must be set up. In conditions of moderate toxicity, the use of ordinary masks works and the presence of ventilation systems along with personal protective equipment can be more effective. In low toxicity conditions, the risk is eliminated.
Urea in contact with the skin surface of the feet of the eye causes itching and has respiratory complications, so it is better to avoid constant contact with the skin because it will cause swelling in the skin. In addition, its high concentration in the blood can damage organs. The body becomes. Heating urea above the melting point causes it to decompose and produce toxic fumes. Urea is normally non-flammable, but mixing it with strong oxidants such as nitride can cause an explosion

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What is urea fertilizer?
Urea, first discovered in 1773 by a French chemist, has many uses in agriculture and is known by various names such as white manure, sugar manure and… in agricultural communities. This manure is actually one of the types of nitrogen fertilizers. And it is consumed all over the world as one of the most widely used and of course the cheapest chemical fertilizers that supply nitrogen. Urea fertilizer is soluble in water and hydrolyzed in soil to ammonia and dioxide.

Urea fertilizer contains 46% nitrogen and is also known as 46% urea. The melting temperature of urea is 132 to 135 ° C and the density of urea fertilizer is 1.32 g / cm3. The solubility of urea fertilizer in water is 108 g per 100 ml of water at 20 ° C.

It should be noted that in order to store urea fertilizer, it should be noted that urea fertilizer should not be stored in humid places that do not have proper ventilation. Because the presence of moisture along with urea fertilizer, in addition to chemical effects, also causes clumps of urea fertilizer.

Urea fertilizer is a white solid compound with the molecular formula CH4N2O.
This fertilizer, when produced, is in a prill state and has a desirable quality and turns into granules to increase its quality and efficiency.
The difference between granular and peril urea fertilizers is in grain size, but they do not differ much in terms of application.
Urea fertilizer is mostly used for agriculture, but its industrial type can be used in the production of car catalysts and ammunition.

Production of urea fertilizer
77-72% urea solutions prepared by the above processes, after pre-treatment (for example with the help of activated carbon to remove oil) are evaporated under vacuum to perform crystallization or in layered evaporators, Evaporate to form molten carbamide (132.7 ° C). Usually pure molten urea or molten crystals will form tablets or granular urea will be produced. Urea fertilizers with 46% nitrogen are widely used for agricultural purposes.

This chemical compound is produced for use as fertilizer, mainly in the form of small round grains (tablets) and is subjected to post-operation to prevent the grains from sticking together. This material is easily stored in cakes due to storage. This behavior can be improved by post-treatment with formaldehyde.

Specifications of urea chemical fertilizer:
This fertilizer has an organic compound that has the following characteristics:
This fertilizer can be said to have replaced ammonium nitrate.
Urea has 46% of nitrons.
It is used to add animal feed and fertilizer.
It is the most widely used fertilizer.
Urea is produced by the reaction between liquid ammonia and carbon dioxide.
This fertilizer is highly effective in Asia due to its numerous rice fields. Urea fertilizer is one of the most widely used along with various types of agricultural fertilizers.

Introduction of urea chemical fertilizers:
Urea is one of the chemical fertilizers that farmers use extensively for soil fertility and plant growth in Iran. In general, this fertilizer can be divided into three types:
Urea fertilizer: This type of fertilizer contains 26% nitrogen. This fertilizer is suitable for grasses because of its acidity.
Sulfur urea fertilizer: This fertilizer has 35% nitrogen. Acidic and recommended for light soils. Its price is reasonable and resistant to washing.
Urea fertilizer: 46% nitrogen is suitable for most soils. This type of fertilizer is not acidic.

Benefits of urea chemical fertilizer:
Improves product performance.
Urea reduces environmental pollutants.
The presence of 46% nitrogen in urea helps reduce transportation costs.
Urea does not catch fire.
Urea is used in both soluble and solid forms.

46%urea (containing 46% nitrogen)

– Urea 46% peril
Urea 46% granules
– Urea fertilizer with sulfur coating
Package of 50 kg bag and one ton jumbo and bulk

Urea and urea granule units:
Urea fertilizer is the most important nitrogen fertilizer in the world. This fertilizer is produced from a combination of ammonia with carbon dioxide, both of which are produced from integrated ammonia production units. The urea produced is initially in the form of a concentrated liquid. After concentrating and separating the urea water in the Peril tower, it turns into a white powder called peril fertilizer. Since the quality of Pril urea fertilizer is not desirable and there is no world market, so the construction of a unit to convert molten urea produced to granular urea quality product was put on the agenda. Granular urea was shipped through the company’s wharf facilities and exported.
In the application of fertilizers, the granular shape of the fertilizer is preferable to its peril shape, because due to the narrower particle size in the granular type, it is easier to distribute and disperse, and this is a point for the mechanical application.
Chemical urea fertilizer, the main component of which is urea, must first be prepared in the form of urea granules. Urea granules are a viscous material that has better resistance to air humidity and is also larger in size. Therefore, researchers have realized that the extraction of urea chemical fertilizer from urea granules will have better results. In fact, the particle size in urea granular type is narrower than its peril type, which makes it easier to disperse and disperse. In fact, the process of production and ultimately absorption by the plant in this form and type is easier and more practical.

Urea phosphate fertilizer:
This fertilizer has high purity and excellent solubility. Its acidic nature helps to absorb nitrogen, phosphorus as well as other soil micronutrients or fertilizer solution. Phosphorus in this solution is a unique starter to increase root growth and accelerate spring growth in ornamental trees. This product is suitable for calcareous and alkaline soils and when used with hard water (high in calcium and magnesium) prevents the formation of sediment in the irrigation system and in many cases to open the drippers in the drip irrigation system. It is also used to neutralize bicarbonate.
Total nitrogen 18%
Usable phosphorus 44%
This fertilizer is a very good source for a variety of plants, including saffron and citrus. In saffron cultivation, granular fertilizer is usually spread on the soil after flower harvest and before the second stage irrigation. In citrus, fertilizer is usually added to the soil in three stages, and the amount of fertilizer given to the tree in different stages is almost the same. Fertilization can be done with both liquid and solid fertilizers. Urea fertilizer has many properties. This fertilizer is widely used in agriculture today and for this reason it has been considered.
Export urea fertilizer:
Due to the fact that urea fertilizer in Iran has a lower price than other countries, many countries want to buy it.
Export urea fertilizer is packed in 50 kg bags and placed on a pallet to be very stylish and safe for the buyer.
Export urea fertilizer is one of the goods that are sent to all parts of the world and can make a good profit in this way.