Processes and systems for producing ammonia products and/or calcium carbonate products
Systems and processes for producing ammonia products and calcium carbonate products, the latter containing sequestered carbon dioxide, from an effluent derived from one or more organic feedstocks. Solids are removed from an organic feedstock that contains a nitrogen compound to produce an organic liquid effluent that contains ammonium and/or ammonia. Ammonia is stripped and concentrated from the organic liquid effluent to produce a gaseous mixture that contains ammonia and carbon dioxide, and the gaseous mixture is cooled to produce a condensed aqueous ammoniacal nitrogen solution of aqueous ammonia, ammonium bicarbonate, and/or ammonium carbonate. The condensed aqueous ammoniacal nitrogen solution is then contacted with a stabilizing agent to cause a reaction therebetween to produce at least a stabilized ammoniacal nitrogen product and calcium carbonate in which carbon dioxide captured in the ammonium bicarbonate and/or the ammonium carbonate is sequestered.
1 . A process comprising:
providing an organic feedstock that contains at least one nitrogen compound;
removing solids from the organic feedstock to produce an organic liquid effluent that contains at least one of ammonium and ammonia;
stripping and concentrating ammonia from the organic liquid effluent to produce a gaseous mixture that contains water vapor, carbon dioxide, and entrained gaseous ammonia, the stripping and concentrating step being a distillation process performed in a distillation tower comprising a stripping section and a concentration section, the stripping section containing media through which the organic liquid effluent flows downward and steam is caused to flow upward, the organic liquid effluent and the steam contacting the media to remove the ammonium and/or ammonia from the organic liquid effluent and yield the gaseous mixture that contains the water vapor, the carbon dioxide, and the entrained gaseous ammonia, after which the gaseous mixture flows through the concentration section above the stripping section and the entrained gaseous ammonia is concentrated in the concentration section;
cooling the gaseous mixture to produce a condensed aqueous ammoniacal nitrogen solution comprising one or more of aqueous ammonia, ammonium bicarbonate, and ammonium carbonate, whereby the carbon dioxide in the gaseous mixture is captured in the condensed aqueous ammoniacal nitrogen solution;
recycling a portion of the condensed aqueous ammoniacal nitrogen solution through the concentration section of the distillation tower, the portion of the condensed aqueous ammoniacal nitrogen solution raising the concentration of ammonia within the concentration section and increasing the efficiency of removal of the ammonium and/or ammonia from the effluent; and
contacting the condensed aqueous ammoniacal nitrogen solution with a stabilizing agent to cause a reaction therebetween to produce at least a stabilized ammoniacal nitrogen product and calcium carbonate, whereby the carbon dioxide captured in the condensed aqueous ammoniacal nitrogen solution is sequestered in the calcium carbonate.
2 . The process of claim 1 , wherein the condensed aqueous ammoniacal nitrogen solution contains ammonium carbonate, the stabilizing agent contains gypsum, and the stabilized ammoniacal nitrogen product contains sulfur.
3 . The process of claim 2 , wherein at least some of the sulfur contained in the stabilized ammoniacal nitrogen product is in the form of ammonium sulfate.
4 . The process of claim 2 , wherein the reaction between the condensed aqueous ammoniacal nitrogen solution and the stabilizing agent further produces calcium carbonate.
5 . The process of claim 1 , wherein the organic feedstock is derived from organic animal manure or organic food waste.
6 . The process of claim 5 , further comprising preparing the organic feedstock in an anaerobic digester, an anaerobic solid mass, or an anaerobic lagoon.
7 . The process of claim 1 , further comprising drying the stabilized ammoniacal nitrogen product to produce a dried ammonium product that contains sulfur.
8 . The process of claim 7 , wherein the dried ammonium product is ammonium sulfate.
9 . The process of claim 1 , further comprising preparing the organic feedstock by causing organic animal manure and/or organic food waste to undergo anaerobic digestion, wherein the carbon dioxide is a byproduct of the anaerobic digestion of the organic feedstock.
10 . The process of claim 1 , further comprising applying the stabilized ammoniacal nitrogen product and the calcium carbonate as a fertilizer.
11 . The process of claim 1 , wherein the at least one nitrogen compound comprises ammonia.
12 . The process of claim 1 , wherein the organic liquid effluent contains ammonium and ammonia.
13 . The process of claim 1 , wherein the removing of the solids from the organic feedstock comprises a centrifuge process and/or a filtering process.
14 . The process of claim 1 , wherein the recycling of the portion of the condensed aqueous ammoniacal nitrogen solution comprises obtaining the portion from an external reflux loop system that is external of the distillation tower or from an internal reflux loop system that is within the distillation tower.
15 . The process of claim 1 , further comprising increasing the temperature of the organic liquid effluent to an operating temperature prior to the stripping and concentrating step.
16 . The process of claim 1 , wherein the media is packed media or trays.
17 . The process of claim 1 , wherein the cooling of the gaseous mixture is performed with a reflux loop system that also performs the recycling of the portion of the condensed aqueous ammoniacal nitrogen solution back to the distillation tower to increase the concentration of ammonia in the distillation tower.