Create a new hydrolysis system

1# long198600 I don’t know why you haven’t installed a hydrolysis tower, but it’s definitely necessary for a urea production plant – unless you are sure that there is no urea present in the ammonia solution. I wonder, long198600 and the other poster, do you use the carbon dioxide stripping process or an aqueous solution? ? What is the parsing load? ? What is the urea content in the analysis solution? ? Say it, and everyone will help you.

This post was last edited by Durian on 2009-6-14 20:30. We use the carbon dioxide stripping process, with hydrolyzers being employed. It’s the horizontal type, with baffle plates inside to increase the residence time; the effect is quite good.

Could you tell me the manufacturers that use horizontal hydrolyzers?

Please ask the durian moderator to explain: What is the actual effectiveness of your hydrolysis device? That is, what are the levels of ammonia and urea in the hydrolysis waste liquid?

Ningbo Far East’s low-pressure hydrolysis technology is excellent; it features mature technology and proven performance in practical applications, so it’s worth consulting about.

Specifically, what type of hydrolysis to use depends on the condition of the plant’s steam system. If there is excess high-pressure steam, it can be fed into Slam’s high-pressure hydrolysis. If there is an excess of medium-pressure steam, it can be sent for low-pressure hydrolysis.

We use a carbon dioxide stripping process; the separation capacity is 35 cubic meters per hour, and the urea content in the separation liquid is over 4000 PPm. All of this goes into the urea separation liquid recovery unit, from where it then enters the gas generation jacket to produce steam.

5# lxq700918: So far, its performance is satisfactory. We have analyzed the ammonia content in the waste liquid, which is around 1-3 PPm, while the urea level varies around 2 PPm. Our analysis volume is relatively high, and the analysis values sometimes fluctuate slightly, but the hydrolysis process runs very steadily. For hydrolysis, self-produced low-pressure steam at 0.33 MPa is used, while for hydrolysis as well steam at 2.2 MPa is employed.

There are two options for the problems on the 1st floor. One is to use the traditional Stamicarbon desorption-hydrolysis process, but the desorption tower and hydrolysis tower need to be redesigned based on the existing design, as the originally designed towers have many issues. The ammonia synthesis process on the first floor uses an atmospheric-pressure batch gas generator, which therefore requires a large amount of low-pressure steam. The newly designed desorption tower consumes less than 200 kilograms of steam per ton of ammonia-containing wastewater. The original design for Stamicarbon required 235–240 kilograms of low-pressure steam per ton of ammonia-containing wastewater; the key advantage of the optimized desorption-hydrolysis process is its energy efficiency, that is, it reduces steam consumption. The second approach is to use a single desorption-hydrolysis stripping tower; similarly, it is an optimization based on the single-tower processes used by Monsanto and some domestic companies. It is understood that in domestic production, the performance of the aforementioned process rarely meets the design specifications (ammonia and urea levels below 5 ppm); this is due to defects in the desorption and hydrolysis towers as well as in the overall process. Through optimizations of the tray technology and the process itself, it has been calculated that 40 kilograms of steam can be saved per ton of urea produced.

From the perspective of saving investment, I think it would be more appropriate to add a horizontal hydrolyzer. However, with the traditional Stamicarbon desorption-hydrolysis process, the desorption tower will need to be modified – the current single-stage desorption process needs to be changed to a two-stage one. Do any of you have any good suggestions? Thank you!