System and method for production of granular ammonium sulfate

Abstract

A system for the production of ammonium sulfate granules including a pipe cross reactor (PCR) configured to contact concentrated sulfuric acid with anhydrous ammonia to produce a PCR product comprising ammonium sulfate; and a granulator fluidly connected to the PCR, whereby PCR product extracted from the PCR can be introduced into the granulator, an inlet for ammonium sulfate seed material, an ammonia sparger configured to spray liquid anhydrous ammonia onto a bed of ammonium sulfate granules within the granulator, and a granulator product outlet configured for extraction of granulator product comprising ammonium sulfate granules from the granulator. A method of producing ammonium sulfate granules is also provided.

What is claimed is: 
     
       1. A system for the production of ammonium sulfate granules, the system comprising:
 a pipe cross reactor (PCR) having an inlet flange and a discharge section opposite the inlet flange, wherein the inlet flange defines an interior surface of the PCR, wherein the interior surface comprises a first opening, a second opening, and a third opening, 
 wherein the first opening is configured to contact such that concentrated sulfuric acid with anhydrous is emitted thereform into the PCR, the second opening is coupled to a nozzle configured to emit ammonia, and the third opening is configured such that water is emitted therefrom into the PCR to produce a PCR product comprising ammonium sulfate; and 
 a granulator fluidly connected to the PCR, whereby PCR product extracted from the PCR can be introduced into the granulator, and comprising an inlet for ammonium sulfate seed material, an ammonia sparger configured to spray liquid anhydrous ammonia onto a bed of into the granulator to contact ammonium sulfate granules within the granulator, and a granulator product outlet configured for to allow extraction of granulator product comprising ammonium sulfate granules from the granulator; 
 wherein the pipe cross reactor comprises a discharge section is located internal to the granulator, and configured to introduce the PCR product ammonium sulfate thereto. 
 
     
     
       2. The system of  claim 1  wherein the PCR is constructed to be resistant to the concentrated sulfuric acid introduced thereto. 
     
     
       3. The system of  claim 1  wherein a reactant contact surface of the PCR is constructed of acid resistant material. 
     
     
       4. The system of  claim 1  wherein the PCR is fluidly connected to the granulator via a PCR product sparger configured to spray the PCR product into the granulator via a plurality of PCR product sparger nozzles. 
     
     
       5. The system of  claim 4  wherein the ammonia sparger is located below the PCR product sparger. 
     
     
       6. The system of  claim 1  wherein the granulator is a rotary granulator. 
     
     
       7. The system of  claim 1  further comprising a dryer fluidly connected to the granulator, whereby granulator product can be introduced into the dryer, and configured to reduce the moisture content thereof of the granulator product. 
     
     
       8. The system of  claim 7  wherein the dryer is a rotary dryer. 
     
     
       9. The system of  claim 7  wherein the dryer is configured to provide a dried ammonium sulfate product comprising less than about 4 weight percent moisture. 
     
     
       10. The system of  claim 9  wherein the dryer operates with less than about 0.08 MMBTU of fuel gas per ton of granulator product introduced thereto. 
     
     
       11. The system of  claim 7  wherein the dryer is a co-current flow dryer, wherein combustion air and fuel gas introduced thereto flow co-currently with the flow of granulator product therethrough. 
     
     
       12. The system of  claim 7  further comprising one or more sizing screens configured to separate on-size ammonium sulfate granules having a largest dimension within a desired range from undersized ammonium sulfate granules having a largest dimension below the desired range and oversized ammonium sulfate granules having a largest smallest dimension above the desired range. 
     
     
       13. The system of  claim 12  further comprising one or more recycle lines configured to recycle at least a portion of the undersized ammonium sulfate granules, at least a portion of the oversized ammonium sulfate granules, a portion of the on-size ammonium sulfate granules, or a combination thereof, to the granulator as seed material. 
     
     
       14. The system of  claim 12  wherein the on-size ammonium sulfate granules have a size guide number (SGN) in the range of from about 280 to about 350. 
     
     
       15. The system of  claim 12  further comprising a product cooler/deduster fluidly connected to the one or more sizing screens, whereby at least a portion of the on-size ammonium sulfate granules can be introduced thereto, thus producing configured to produce a dedusted ammonium sulfate product, and a product cooler offgas. 
     
     
       16. The system of  claim 15  wherein the product cooler/deduster is configured to contact the on-size ammonium sulfate granules introduced thereto with a deduster. 
     
     
       17. The system of  claim 16  wherein the deduster is non-aqueous. 
     
     
       18. The system of  claim 15  further comprising a dryer cyclone fluidly connected to the dryer whereby at least a portion of a dryer vent gas can be introduced thereto, and configured to separate solids therefrom, thus producing a dryer cyclone offgas and a dryer cyclone separated solids stream. 
     
     
       19. The system of  claim 18  further comprising a recycle line configured to introduce solids separated via the dryer cyclone into the granulator as at least a portion of the seed material. 
     
     
       20. The system of  claim 18  further comprising one or more elevators configured to transport ammonium sulfate granules throughout the system, and further comprising a dust cyclone configured to separate dust comprising ammonium sulfate from gas introduced thereto from the one or more elevators, from the one or more sizing screens, or from a combination thereof, thus producing a dust cyclone offgas, and a dust cyclone separated solids stream. 
     
     
       21. The system of  claim 20  further comprising a recycle line configured to introduce solids separated via the dust cyclone into the granulator as at least a portion of the seed material. 
     
     
       22. The system of  claim 20  further comprising at least one scrubber selected from the group consisting of:
 granulator scrubbers fluidly connected with the granulator, and configured to scrub unreacted ammonia from a vapor comprising unreacted ammonia extracted from the granulator, thus producing a granulator scrubber spent scrubber liquor comprising ammonia, and a granulator scrubber vent gas; 
 dryer primary scrubbers configured to scrub one or more components from at least a portion of the dryer cyclone offgas, thus providing a dryer primary scrubber spent scrubber liquor, and a dryer primary scrubber tailgas; 
 recycle cooler-granulator primary scrubbers configured to scrub one or more components from a gas comprising at least a portion of the granulator scrubber vent gas, at least a portion of the dust cyclone offgas, at least a portion of the product cooler offgas, or a combination thereof, thus providing a recycle cooler-granulator primary scrubber spent scrubber liquor, and a recycle cooler-granulator primary scrubber tailgas; 
 dryer tailgas scrubbers configured to scrub one or more components from the dryer primary scrubber tailgas, thus providing a dryer tailgas scrubber spent scrubber liquor, and a dryer tailgas scrubber tailgas; and 
 recycle cooler-granulator tailgas scrubbers configured to scrub one or more components from the recycle cooler-granulator primary scrubber tailgas, thus providing a recycle cooler-granulator tailgas scrubber spent scrubber liquor, and a recycle cooler-granulator tailgas scrubber tailgas. 
 
     
     
       23. The system of  claim 22  further comprising one or more recycle paths whereby all or portions of one or more spent scrubber liquor liquors selected from the group consisting of granulator scrubber spent scrubber liquors liquor, dryer primary scrubber spent scrubber liquors liquor, recycle cooler-granulator primary scrubber spent scrubber liquors liquor, dryer tailgas scrubber spent scrubber liquors liquor, and recycle cooler-granulator tailgas scrubber spent scrubber liquors liquor, may be introduced into the PCR. 
     
     
       24. The system of  claim 1  further comprising an additive sparger configured to spray an additive into the granulator. 
     
     
       25. The system of claim  24  1 wherein the additive sparger is positioned above the ammonia sparger, above the elevation of introduction of the PCR product into the granulator, or both an additive is mixed with water prior to entering the PCR. 
     
     
       26. The system of claim  24  25, wherein the additive comprises aluminum sulfate. 
     
     
       27. A method of producing ammonium sulfate granules, the method comprising:
 introducing a pipe cross reactor (PCR) feed comprising water, ammonia, and an acid component comprising concentrated sulfuric acid and anhydrous ammonia into a PCR pipe cross reactor (PCR) configured to produce ammonium sulfate via ammoniation of the sulfuric acid, thus producing a PCR product comprising ammonium sulfate via ammoniation of the sulfuric acid, wherein the water is introduced into the reactor at a level that is above that of the acid component; and 
 separately introducing at least a portion of the PCR product, ammonium sulfate seed material, and liquid, anhydrous ammonia into a granulator configured to produce a granulator product comprising ammonium sulfate granules having size within a desired size range; 
 wherein at least a portion of the PCR product is introduced into the pipe cross reactor granulator via a discharge section thereof of the PCR located internal to the granulator. 
 
     
     
       28. The method of  claim 27  wherein the desired size range comprises size guide numbers (SGNs) from about 280 to about 350. 
     
     
       29. The method of  claim 27  wherein the concentrated sulfuric acid has a concentration in the range of from about 90 weight percent to about 99 weight percent. 
     
     
       30. The method of  claim 27  wherein the liquid anhydrous ammonia is introduced into the granulator via an ammonia sparger configured to distribute liquid anhydrous ammonia substantially uniformly across the granulator. 
     
     
       31. The method of  claim 27  wherein the at least a portion of the PCR product is introduced into the granulator at a level above the level at which the liquid anhydrous ammonia is introduced. 
     
     
       32. The method of  claim 27  further comprising introducing an additive into the granulator. 
     
     
       33. The method of  claim 32  wherein the additive is added via an additive sparger. 
     
     
       34. The method of claim  33  27 wherein the additive sparger distributes the additive substantially uniformly across the granulator, at a level above the level of introduction of the at least a portion of the PCR product, at a level above the level of introduction of the liquid, anhydrous ammonia, or both an additive is mixed with water prior to entering the PCR. 
     
     
       35. The method of  claim 34  wherein the additive is selected from the group consisting of alums. 
     
     
       36. The method of  claim 35  wherein the additive comprises aluminum sulfate. 
     
     
       37. The method of  claim 27  wherein the ammonium sulfate seed material is introduced into the granulator at or near a top thereof. 
     
     
       38. The method of  claim 27  further comprising drying the granulator product to produce a dried ammonium sulfate product having a moisture content of less than the moisture content of the granulator product. 
     
     
       39. The method of  claim 38  further comprising separating the dried ammonium sulfate product into an undersized ammonium sulfate product comprising ammonium sulfate granules having a largest dimension below the a desired size range, an oversized ammonium sulfate product comprising ammonium sulfate granules having a largest smallest dimension above the desired size range, and an on-size ammonium sulfate product comprising ammonium sulfate granules having a largest dimension within the desired size range. 
     
     
       40. The method of  claim 39  further comprising recycling at least a portion of the undersized ammonium sulfate product, at least a portion of the oversized ammonium sulfate product, a portion of the on-size ammonium sulfate product, or a combination thereof to the granulator as at least a portion of the seed material. 
     
     
       41. The method of  claim 39  further comprising dedusting at least a portion of the on-size ammonium sulfate product, thus producing a dedusted ammonium sulfate product, and a deduster offgas. 
     
     
       42. The method of  claim 41  wherein dedusting comprises contacting the at least a portion of the on-size ammonium sulfate product with a non-aqueous deduster. 
     
     
       43. The method of  claim 41  further comprising separating ammonium sulfate-containing dust from a dryer offgas comprising same, thus producing a reduced-solids dryer offgas, and a separated an ammonium sulfate-containing dust solids stream. 
     
     
       44. The method of  claim 43  further comprising recycling at least a portion of the separated ammonium sulfate-containing dust to the granulator as seed material. 
     
     
       45. The method of  claim 43  further comprising separating ammonium sulfate-containing dust from: a gas comprising same extracted from one or more elevators configured to transport ammonium sulfate granules; from one or more sizing screens utilized to separate the dried ammonium sulfate product into oversized, undersized, and on-size ammonium sulfate granules; or from a combination thereof, thus producing a reduced-solids offgas, and a second separated ammonium sulfate-containing dust solids stream. 
     
     
       46. The method of  claim 45  further comprising:
 scrubbing unreacted ammonia from a granulator vent gas, thus producing a granulator scrubbing spent scrubber liquor comprising ammonia, and a granulator scrubbing vent gas; 
 scrubbing one or more components from a gas comprising at least a portion of the reduced-solids dryer offgas, thus providing a dryer primary scrubbing spent scrubber liquor, and a dryer primary scrubbing tailgas; 
 scrubbing one or more components from a gas comprising at least a portion of the granulator scrubbing vent gas, at least a portion of the reduced-solids offgas, at least a portion of the deduster offgas, or a combination thereof, thus providing a recycle cooler-granulator primary scrubbing spent scrubber liquor, and a recycle cooler-granulator primary scrubbing tailgas; 
 scrubbing one or more components from the dryer primary scrubbing tailgas, thus providing a dryer tailgas scrubbing spent scrubber liquor, and a dryer tailgas scrubbing tailgas; 
 scrubbing one or more components from the recycle cooler-granulator primary scrubbing tailgas, thus providing a recycle cooler-granulator tailgas scrubbing spent scrubber liquor, and a recycle cooler-granulator tailgas scrubbing tailgas; or a combination thereof. 
 
     
     
       47. The method of  claim 46  further comprising recycling all or portions of one or more spent scrubber liquor liquors selected from the group consisting of granulator scrubbing spent scrubber liquors liquor, dryer primary scrubbing spent scrubber liquors liquor, recycle cooler-granulator primary scrubbing spent scrubber liquors liquor, dryer tailgas scrubbing spent scrubber liquors liquor, and recycle cooler-granulator tailgas scrubbing spent scrubber liquors liquor to the PCR. 
     
     
       48. The method of  claim 27  wherein not less than about 10 weight percent and not more than about 40 weight percent of the stoichiometrically required amount of anhydrous ammonia is introduced directly into the granulator. 
     
     
       49. The method of claim 27, wherein the ammonia component comprises water and ammonia, wherein water and anhydrous ammonia are combined in an ammonia feed conduit prior to being introduced into the PCR. 
     
     
       50. The method of claim 27, wherein the ammonia component introduced into the PCR has a pressure of about 40 to about 90 psig in an ammonia feed conduit. 
     
     
       51. The method of claim 27, wherein the acid component introduced into the PCR has a pressure of about 40 to about 90 psig in an acid feed conduit. 
     
     
       52. The method of claim 27, wherein an amount of water introduced to the PCR from the ammonia component, the water component, and the acid component is about 25% to about 75% by weight. 
     
     
       53. The method of claim 27, further comprising feeding granulator product to a dryer, wherein the dryer operates with less than about 0.08 MMBTU of fuel gas per ton of granulator product introduced thereto. 
     
     
       54. The system of claim 1, comprising an ammonia feed conduit having a first branch comprising ammonia and a second branch comprising water that converge into a single conduit prior to being fed into the PCR via the second opening. 
     
     
       55. The system of claim 1, wherein the ammonia feed conduit is configured such that ammonia flows at about 40 to about 90 psig in the ammonia feed conduit. 
     
     
       56. The system of claim 1, comprising an acid feed conduit in communication with the first opening and configured such that acid flows at pressure of about 40 to about 90 psig in the acid feed conduit. 
     
     
       57. The system of claim 1, wherein an amount of water introduced to the PCR from the first opening, the second opening, and the third opening is about 25% to about 75% by weight. 
     
     
       58. A system for producing ammonium sulfate comprising a pipe cross reactor (PCR) comprising
 an inlet flange and   a discharge section opposite the inlet flange,   wherein the inlet flange defines an interior surface of the PCR, wherein the interior surface comprises a first opening, a second opening, and a third opening,   wherein the first opening is configured such that a concentrated acid comprising sulfuric acid is emitted therefrom into the PCR,   wherein the second opening is coupled to a nozzle configured to emit ammonia from a plurality of openings, and   wherein the third opening is configured such that water is emitted therefrom into the PCR to produce a PCR product comprising ammonium sulfate.   
     
     
       59. The system of claim 58, wherein the first opening is disposed below the second opening and third opening. 
     
     
       60. The system of claim 58, wherein the interior surface consists of a first opening, a second opening, and a third opening. 
     
     
       61. The system of claim 58, wherein a center of the second opening is within 2 inches of a center of the inlet flange. 
     
     
       62. The system of claim 61, wherein a center of the first opening is below a central horizontal axis of the inlet flange. 
     
     
       63. The system of claim 62, wherein the center of the first opening is within 4 inches of the central horizontal axis of the inlet flange. 
     
     
       64. The system of claim 63, wherein a center of the third opening is within 3 to 5 inches of a central vertical axis of the inlet flange. 
     
     
       65. The system of claim 64, wherein the center of the third opening is within 2 inches of the central horizontal axis of the inlet flange. 
     
     
       66. The system of claim 65, wherein the inlet flange has a maximum width in the range from 10 to 20 inches. 
     
     
       67. The system of claim 66, wherein each of the first opening, second opening, and third opening have a maximum width in the range from 1 to 5 inches. 
     
     
       68. The system of claim 67, comprising a reaction section located between the inlet flange and the discharge section and having a length in the range from 10 to 20 feet. 
     
     
       69. The system of claim 68, wherein the discharge section has a length in the range from 6 to 12 feet. 
     
     
       70. The system of claim 69, wherein the discharge section is disposed within a granulator. 
     
     
       71. The system of claim 58, comprising an ammonia feed conduit in fluid communication with the second opening and having a first branch configured to contain ammonia and a second branch configured to contain water that converge into a single conduit at a location upstream of the second opening. 
     
     
       72. The system of claim 71, wherein the ammonia feed conduit is configured such that ammonia flows at about 40 to about 90 psig in the ammonia feed conduit. 
     
     
       73. The system of claim 71, comprising an acid feed conduit in communication with the first opening and configured such that acid flows at pressure of about 40 to about 90 psig in the acid feed conduit. 
     
     
       74. A method for producing ammonium sulfate granules, the method comprising using a system that comprises:
 a pipe cross reactor (PCR) having an inlet flange and a discharge section opposite the inlet flange, wherein the inlet flange defines an interior surface of the PCR, wherein the interior surface comprises a first opening, a second opening, and a third opening,   wherein the first opening is feeding concentrated sulfuric acid into the PCR, the second opening is feeding ammonia into the PCR, and the third opening is feeding water into the PCR to produce a PCR product comprising ammonium sulfate; and   a granulator fluidly connected to the PCR, whereby PCR product from the PCR is introduced into the granulator via the discharge section.   
     
     
       75. The method of claim 74, wherein the second opening is in fluid communication with an injector configured to emit ammonia into the PCR. 
     
     
       76. The method of claim 74, further comprising an ammonia feed conduit in fluid communication with the second opening and having a first branch comprising ammonia and a second branch comprising water that converge into a single conduit at a location upstream of the second opening. 
     
     
       77. The method of claim 76, wherein the ammonia feed conduit comprises ammonia and water flowing at about 40 to about 90 psig in the ammonia feed conduit. 
     
     
       78. The method of claim 74, comprising an acid feed conduit in communication with the first opening and comprising acid flowing at pressure of about 40 to about 90 psig in the acid feed conduit. 
     
     
       79. The system of claim 12, further comprising cooler configured to reduce the temperature of the on-size ammonium sulfate granules and a polishing screen configured to polish the on-size ammonium sulfate granules after the cooler. 
     
     
       80. The system of claim 12 further comprising a deduster configured to dedust at least a portion of the on-size ammonium sulfate granules, thus producing a dedusted ammonium sulfate product, and a deduster offgas. 
     
     
       81. The system of claim 79, wherein the deduster is configured to contact the at least a portion of the on-size ammonium sulfate granules with a non-aqueous deduster.