T
he MicroMist Scrubber technology is ideally suited for stringent ammonia and PM emissions regulations from urea granulators and prilling towers in the fertilizer industry.
Increasingly, more stringent regulations are being imposed on the production of fertilizer, more specifically urea, that require advance scrubbing for multiple pollutants. Emission of submicron particulate is very light refractive and therefore produces a visible plume that may trail on for many miles. Using the MicroMist design, allows for combined or segregated scrubbing of the multi-pollutants in one unit. Often, the air permit for the plant hinges on the ability of the APC device to meet and exceed the necessary regulations. In essence, if the APC equipment is not performing, fines and possible shut down will occur.
Most plants have used “traditional” Venturi scrubbers or multi-stage mesh pad style scrubbers. Traditional Venturi scrubbers may be satisfactory, but to meet today’s and future emission limits, they require high pressure drop (fan kW) presenting for long term OPEX. The mesh pad designs work very well when clean, but will gradually plug and require down time for removal of the pads, high pressure washing and reassembly, causing unnecessary down time. Viewing the cut away of the MicroMist design shows large passages and no points of plugging.
Combined scrubbing of urea + ammonia nitrate (AN) or ammonia sulfate (AS) can be accomplished with our multi stage approach as well as separately. Typically the urea is cycled up to ~45% concentration and returned to the process while the ammonia salt is scrubbed with acid and separated from the gas stream.
Prill towers have long been a visual nuisance. The choices here are to duct the gases to the ground and scrub before being exhausted to atmosphere. This will require an induced draft fan (often quite large), ducting to convey the gases and a stack. EnviroCare has designed a top-of-the-tower scrubber with no induced draft fan to meet <<50 mg/dNm3 dust emissions. Optional ammonia scrubbing can be integrated into the design.
Keys to the EnviroCare approach:
- Very low emissions for both urea and ammonia
- Low pressure drop
- Open design, no plugging
- Can be delivered in “modules” for ease of assembly at site
- On site support
