Skip to content

THE UREA MANUFACTURING PROCESS

PROCESSES INVOLVED IN UREA MANUFACTURING

Urea popularly known as Carbamide is an organic chemical compound. Mostly it is manufactured to be stored as a solid, commonly in shape and form of pills and granules. They are highly soluble in water; hence it is easier to form their solutions at varying concentration. It can also be stored in solution after preparation of required. The nitrogen content is high.

Naturally, urea is produced in the human body and disposed of by the kidney as a natural cyclic process during excretion. In history was a significant chemical compound because it was the first organic chemical which is naturally found in the human body to be synthesized using inorganic chemicals in a laboratory by Friedrich Wöhler.  Because of this accomplishment, some people refer to Friedrich as the father of organic chemistry.

Urea is used in industries such as Plastic, Textile, Coatings, Adhesive industries. The most popular and common use of urea is fertilizer productions; this is not because of it high nitrogen contents(46%), urea readily dissolves in water and leaves no salt residues on crops and in soil. It is also used for foliar feeding. The main disadvantage of using urea as a fertilizer is its biuret component which forms during the urea manufacturing. Biuret becomes harmful to plant if its concentration exceeds 2% particularly germinating seeds and also is poisonous to animals. Controlling the concentration by optimizing equipment design and the temperature is a major industrial problem in urea manufacturing which demands continuous research.

The  Manufacturing Process 

Ammonia and carbon dioxide are the raw materials for the urea manufacturing process; usually, urea is manufactured in an ammonia plant because it yields ammonia as a product and carbon dioxide as a byproduct and this carbon dioxide can be recycled directly into the process. 

The chemical reactions involved in the process:

The reaction of Ammonia and Carbon Dioxide to form Ammonium Carbamate.

2NH3 + CO2 → NH2COONH42NH3+CO2→NH2COONH4

Decomposition of Ammonium Carbonate to form Urea and Water.

NH2COONH4 → H2O + NH2CONH2 (urea)NH2COONH4→H2O+NH2CONH2(urea)

Note: both reaction equations above are reversible.

Liquified ammonia is pumped, and a compressed carbon dioxide is a feed into a reaction chamber. The reactor is the heart of the process because all the reaction happens in the reaction chamber. The reactor is maintained at 14Mpa pressure and 170-190°C for the first reaction to occur. The reaction of ammonia and carbon dioxide is highly exothermic. Most of the heat released is utilized in the form of process steam wherever it is needed in to process.

The product from the first reaction flow into a decomposer where the second reaction occurs, and it is an endothermic reaction. It requires a certain energy to begin. Biuret is also formed as a result of decomposition of ammonium carbamate if temperature rise is excessive.

The conversion of the reactants to urea can be increased by increasing the amount of carbon dioxide, if carbon dioxide is present in excess then the conversion can be as high as 85% per pass but optimizing for the proper temperature, pressure and design is a challenge in itself hence usually per pass conversion are kept around 50%. The unreacted materials are recycled, resulting in overall conversion of over 99%. This minimizes the effects on the environment.

The major impurity in urea is water and also unreacted ammonia, carbon dioxide and ammonium carbamate. These are removed using distillation tower and evaporator. The essential condition is to keep the temperature high and pressure low during stages of separation. At these conditions, the ammonium carbamate will be decomposed back to ammonia and carbon dioxide also some carbon dioxide and ammonia will flash off. The primary process which happens in the evaporator is that of concentration. During concentration, optimum temperature should be maintained so that the urea remains in molten state and crystals are not formed inside the evaporator.

The molten urea is passed through nozzles inside the prilling tower. Compressed air is passed in the tower so that its flow is counter-current with respect to that of molten urea. The urea gets solidified in the prilling tower, and air helps in shaping it in the form of prills or granules. The urea is then stored and ready to be sold.

34 thoughts on “THE UREA MANUFACTURING PROCESS”

  1. I just wanted to make a brief remark so as to thank you for all the superb solutions you are placing at this site. My extended internet investigation has at the end been paid with reliable ideas to talk about with my neighbours. I ‘d repeat that we site visitors are very fortunate to live in a great site with many lovely people with beneficial methods. I feel really blessed to have seen the web site and look forward to plenty of more pleasurable times reading here. Thanks a lot once more for a lot of things.

  2. I actually wanted to make a brief note to be able to appreciate you for some of the great concepts you are placing at this site. My prolonged internet search has finally been rewarded with extremely good facts and techniques to write about with my pals. I would repeat that many of us visitors actually are quite blessed to dwell in a fantastic place with many marvellous professionals with very helpful basics. I feel somewhat fortunate to have encountered the webpages and look forward to plenty of more exciting moments reading here. Thanks a lot once more for all the details.

  3. I am also writing to make you understand of the magnificent discovery my cousin’s child had checking your webblog. She even learned so many details, not to mention what it is like to possess an amazing coaching character to make the rest completely know just exactly chosen problematic topics. You truly exceeded people’s expectations. I appreciate you for showing the good, dependable, edifying and even unique thoughts on the topic to Mary.

  4. My husband and i felt now relieved when Jordan managed to carry out his analysis through the precious recommendations he came across through the web pages. It is now and again perplexing to simply happen to be freely giving instructions that many other people may have been selling. And now we discover we have got you to give thanks to because of that. The most important explanations you have made, the easy blog menu, the friendships you can aid to promote – it is mostly amazing, and it’s really leading our son and the family recognize that the situation is excellent, and that’s rather pressing. Many thanks for everything!

  5. I and my buddies have already been taking note of the great recommendations from your web page while all of the sudden I got an awful feeling I never expressed respect to the site owner for those tips. All of the guys are actually totally glad to read through them and have pretty much been enjoying those things. We appreciate you truly being very kind as well as for opting for certain excellent information most people are really wanting to learn about. Our sincere regret for not saying thanks to you earlier.

  6. I’m also writing to let you understand what a superb discovery my wife’s girl encountered visiting your web site. She even learned many things, which include what it is like to possess a very effective helping character to get the others easily master a variety of specialized issues. You actually surpassed our own expected results. Thanks for supplying those warm and friendly, safe, edifying and in addition unique tips about your topic to Jane.

  7. Thank you so much for giving everyone remarkably terrific opportunity to read critical reviews from this blog. It’s always very kind plus jam-packed with a great time for me and my office mates to search your web site at minimum thrice in a week to learn the fresh stuff you have. And indeed, I am also always impressed with your unbelievable creative ideas you serve. Selected 2 facts in this posting are in fact the most efficient I have ever had.

Leave a Reply

Your email address will not be published. Required fields are marked *