Ammonium Sulfate Solution

[NPKresults]

Hello All,

I am currently trying to come up with options for extracting the ammonium sulfate from a bi-product stream. Although it is possible to sell A.S. liquor, I would rather not have to worry about its demand. Basically, any information would be helpful, but I am specifically interested in moisture contents out of various unit operations as well as rough energy and capital cost estimates. Ideally I would like to have crystallized ammonium sulfate with less than 5% moisture. The stream will be about 130kg/hr @ 25 wt% A.S. I was thinking a crystallizer followed by a centrifuge, I have heard that post-centrifuge the moisture content is approximately 0.5%? Any thoughts would be appreciated.

Danny B

 

[djack77494]

Danny,
You might want to check into some fertilizer industry literature and websites. Ammonium sulfate is one of their products, and I'd think they'd have some good information on its preparation, specs, and usage.

 

[NPKresults]

Jack,

Thanks for your insight, I guess my question was too generalized. I am well aquanted with the specs and market for A.S. in the ag industry, and I am aware of some of the process options available, crystallization, compaction, centrifugation etc. What I was looking for was words of wisdom from someone who had experience in design and plant start-up for these processes and opinions on which was the more favorable. For my specific application I need to concentrate it to only 5% moisture. Would this require one crystallizer with a centrifuge? Would I need two centrifuges in series? Are any specific materials of construction known to be better or worse? How much A.S. can I expect to remain in the crystallizer liquor? etc.

 

[Leclerc]

By-product liquor will produce contaminated A/S crystals, especially colour, organic content, but also, possibly specific toxic and/or pathogenic compounds. Scope for some creative marketing!

That said, A/S crystals are relatively easy to de-water, and a single-stage centrifuge could easily be sufficient.

A 2 stage pusher centrifuge allows dewatering in the 1st stage, with an ability to wash the crystals in the second stage which reduces the contamination levels (present in the M/L and adhering to the crystal surface) considerably.