1.  GUIDED BY: Prof. Mayank Dalal Submitted by: ۩ Singh Shubham. (140420105058)  2 nd YEAR- SCET, SURAT DEPARTMENT OF CHEMICAL ENGINEERING

2. CONTENTS UREA IUPAC nomenclature Introduction History Disadvantage Raw materials Manufacture a. Lab b. Industry Contents Properties Uses Safety

3. UREA  IUPAC NAME : UREA  Urea, also called carbamide, the diamide of carbonic acid.  Formula is H 2 NCONH 2.

4. IUPAC NOMENCLATURE The IUPAC name Of urea is Diaminomethanal and it is also known as are as follows : Carbamide Carbonyl diamide Carbonyldiaminel Diaminomethanone

5. Introduction  Urea (nh2conh2) or carbamide is an organic compound has two —nh2 groups joined by a carbonyl (c=o) functional group. Urea serves an important role in the metabolism of nitrogen containing compounds by animals and is the main nitrogen containing substance in the urine of mammals.  Urea was first discovered in urine in 1727 by Herman Boerhaave, though this discovery is often credited to Hilaire Rouelle.  Friedrich Wohler synthesized urea from an inorganic precursor in 1828. It was the first time that the molecule found in living organisms could be synthesized in the laboratory without biological starting materials. Due to this discovery, WOhler is considered as the father of organic chemistry by many scientists.  Urea has the highest nitrogen content available in a solid fertilizer (46%). It is easy to produce as prills or granules and easily transported in bulk or bags with no explosive hazard. It dissolves readily in water. It leaves no salt residue after use on crops and can often be used for foliar feeding.

6. HISTORY Urea was first discovered in urine in 1727 by the Dutch scientist Herman Boerhaave, though this discovery is often attributed to the French chemist Hilaire Rouelle. In 1828, the German chemist Friedrich Wöhler obtained urea artificially by treating silver cyanate with ammonium chloride: AgNCO + NH 4 Cl → (NH 2 ) 2 CO + AgCl This was the first time an organic compound was artificially synthesized from inorganic starting materials, without the involvement of living organisms.

7. DISADVANTAGE  When applied to a bare soil surface, urea hydrolyzes rapidly result into loss of significant quantity of ammonia by volatilization. Such losses vary from soil to soil and are greater for urea in a pellet form rather than in solution form.  It is phytotoxic due to rapid hydrolysis of urea in soils can cause injury to the seedlings by ammonia,  The fertilizer grade urea may contain toxic biuret which is formed during urea manufacture by an excessive temperature rise. Above 2% concentration of biuret in urea is harmful to plants.

8. RAW MATERIALS Urea is produced commercially from two raw materials:  Ammonia  Carbon dioxide  Large quantities of carbon dioxide are produced during the manufacture of ammonia from coal or from hydrocarbons such as natural gas and petroleum derived raw materials.

9. MANUFACTURE Raw materials  Basis: 1000kg prilled urea *Prilled is a term used in mining and manufacturing to refer to product that has been pelletized

10. LABORATORY PREPARATION Urea in the more general sense can be accessed in the laboratory by reaction of phosgene with primary or secondary amines, proceeding through an isocyanate intermediate. Non-symmetric ureas can be accessed by reaction of primary or secondary amines with an isocyanate. Also, urea is produced when phosgene reacts with ammonia: COCl2 + 4 NH3 → (NH2)2CO + 2 NH4Cl Urea is byproduct of converting alkyl halides to thiols via a S-alkylation of thiourea. Such reactions proceed via the intermediacy of isothiouronium salts: RX + CS(NH 2 ) 2 → RSCX(NH 2 ) 2 X RSCX(NH 2 ) 2 X + MOH → RSH + (NH 2 ) 2 CO + MX *In this reaction R is alkyl group, X is halogen and M is alkali metal.

11. MANUFACTURING PROCESS-INDUSTRIAL  Solidification Urea processes produce an aqueous solution containing 70-87% urea. The two most commonly employed methods for the production of solid urea are prilling and granulation. Prilling In prilling, molten urea that is almost anhydrous is forced through spray heads or spinner buckets. The droplets of urea fall through a countercurrent stream of air in which they solidify to form prills (pellets). This process has potentially greater pollution problems due to the production of a large volume of air laden with very fine dust that must be processed. Many recovery systems have been tried for this process, but all with limited success. Granulation Granulation is now superceding prilling as the method of choice for urea solidification. In this process, granules are usually formed by the successively spraying and drying (layering) of concentrated urea solution onto recycled granules, in a rotating drum For both the prilling and granulation processes, formaldehyde (0.2-0.5%) is often added to the urea melt prior to solidification. This is to condition the finished product, improving the particle crushing strength and reducing caking during storage, without lowering the nitrogen content. The addition of formaldehyde to the pre-solidified urea has also been used to reduce dust formation in both processes

12. MANUFACTURE -INDUSTRIAL  Emissions For every tonne of urea produced, 0.3 tonnes of water are formed. This water is usually discharged from the urea concentration and evaporation section of the plant. Removal of ammonia and urea from wastewaters can be a problem as it is difficult to remove one in the presence of the other. One method used to overcome this problem is the hydrolysis of urea to ammonium carbamate, which is decomposed to ammonia and carbon dioxide. These gases can then be stripped from the wastewaters. Urea plants are in operation that produce wastewaters with ammonia and urea levels below 1ppm. This water can then be used as boiler feed water. The solidification of urea results in the formation of particulate matter, particularly the prilling process. Of greater concern, however, are one-off accidental releases of ammonia, often due to equipment failure.

14. CONTENTS OF UREA:  PRILLED UREA

15.  GRANULAR UREA

16. PROPERTIES Molecular formula : CH4N2O Molecular weight : 60.06gm/mole Appearance : White granules Odour : Odourless Bulk density : 673-721kg/m3 Angle of repose : 300 Melting point : 132-1350C Density : 1.32gm/ml Solubility : Solubility in water, ethanol, glycerol Moisture : 1% by wt. (Max.)

17. INDUSTRIAL USES Adhesives and sealant chemicals Agricultural chemicals (non-pesticidal) Dyes Fuels and fuel additives Functional fluids (closed systems) Intermediates Oxidizing/reducing agents Paint additives and coating additives not described by other categories Pigments Processing aids, not otherwise listed Processing aids, specific to petroleum production Solids separation agents Explosives

18. MEDICAL USE Urea-containing creams are used as topical dermatological products to promote rehydration of the skin. 40% urea preparations may also be used for nonsurgical debridement of nails. urea injection is used to perform abortion. Certain types of instant cold packs (or ice packs) contain water and separated urea crystals.

19. CONSUMER USE Automotive Care Products Building/Construction Materials - Wood and Engineered Wood Products Cleaning and Furnishing Care Products Fuels and Related Products Furniture and Furnishings not covered elsewhere Ink, Toner, and Colorant Products Laundry and Dishwashing Products Lawn and Garden Care Products Paints and Coatings Paper Products Personal Care Products

20. SAFETY Urea can be irritating to skin, eyes, and the respiratory tract. Repeated or prolonged contact with urea in fertilizer form on the skin may cause dermatitis. High concentrations in the blood can be damaging. Ingestion of low concentrations of urea, such as are found in typical human urine, are not dangerous with additional water ingestion within a reasonable time-frame. Many animals (e.g., dogs) have a much more concentrated urine and it contains a higher urea amount than normal human urine; this can prove dangerous as a source of liquids for consumption in a life-threatening situation (such as in a desert).

21. SAFETY Urea can cause algal blooms to produce toxins, and its presence in the runoff from fertilized land may play a role in the increase of toxic blooms. The substance decomposes on heating above melting point, producing toxic gases, and reacts violently with strong oxidants, nitrites, inorganic chlorides, chlorites and perchlorates, causing fire and explosion

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