Urea recovery from stabilized urine using a novel ethanol evaporation and recrystallization process
Urea is a raw material in the production of various chemicals and is a key nitrogen-based fertilizer. The conventional process to manufacture synthetic urea operates at high temperatures and pressures and is therefore energy intensive. The aim of this work was to investigate the feasibility of recov...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2021-11-01
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| Series: | Chemical Engineering Journal Advances |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2666821121000909 |
| _version_ | 1818834203961196544 |
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| author | H. Marepula C.E. Courtney D.G. Randall |
| author_facet | H. Marepula C.E. Courtney D.G. Randall |
| author_sort | H. Marepula |
| collection | DOAJ |
| description | Urea is a raw material in the production of various chemicals and is a key nitrogen-based fertilizer. The conventional process to manufacture synthetic urea operates at high temperatures and pressures and is therefore energy intensive. The aim of this work was to investigate the feasibility of recovering and purifying urea crystals from human urine using a novel ethanol evaporation and recrystallization process that exploits the solubility differences of urea and impurities in water and ethanol. This approach could provide an alternative method to produce urea that operates at atmospheric pressure and low temperatures (< 30°C).Synthetic and real human urine was treated with Ca(OH)2 to prevent urea hydrolysis and then dried to recover the solids. These solids were dissolved in a predetermined amount of ethanol and the urea present was recrystallized. A complex synthetic urine solution (with various organics and inorganics) had a urea solubility of 56.7 g L−1 at 22°C. It was determined that the solubility of urea in ethanol increased when more organics were present in the solution. Urea was recovered from inorganic synthetic urine (SI), organic synthetic urine (SO) and real human urine (RU) with yields of 88%, 77% and 67%, respectively. The purity of urea increased from 41%, 41% and 43% to 91%, 76% and 76% for SI, SO and RU using the ethanol evaporation and recrystallization process. |
| first_indexed | 2024-12-19T02:31:06Z |
| format | Article |
| id | doaj.art-bf6cf98cc1184251bb3983a1feb9c5e5 |
| institution | Directory Open Access Journal |
| issn | 2666-8211 |
| language | English |
| last_indexed | 2024-12-19T02:31:06Z |
| publishDate | 2021-11-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Chemical Engineering Journal Advances |
| spelling | doaj.art-bf6cf98cc1184251bb3983a1feb9c5e52022-12-21T20:39:38ZengElsevierChemical Engineering Journal Advances2666-82112021-11-018100174Urea recovery from stabilized urine using a novel ethanol evaporation and recrystallization processH. Marepula0C.E. Courtney1D.G. Randall2Civil Engineering Department and Future Water Institute, University of Cape Town, Cape Town 7700, South AfricaCivil Engineering Department and Future Water Institute, University of Cape Town, Cape Town 7700, South AfricaCorresponding author.; Civil Engineering Department and Future Water Institute, University of Cape Town, Cape Town 7700, South AfricaUrea is a raw material in the production of various chemicals and is a key nitrogen-based fertilizer. The conventional process to manufacture synthetic urea operates at high temperatures and pressures and is therefore energy intensive. The aim of this work was to investigate the feasibility of recovering and purifying urea crystals from human urine using a novel ethanol evaporation and recrystallization process that exploits the solubility differences of urea and impurities in water and ethanol. This approach could provide an alternative method to produce urea that operates at atmospheric pressure and low temperatures (< 30°C).Synthetic and real human urine was treated with Ca(OH)2 to prevent urea hydrolysis and then dried to recover the solids. These solids were dissolved in a predetermined amount of ethanol and the urea present was recrystallized. A complex synthetic urine solution (with various organics and inorganics) had a urea solubility of 56.7 g L−1 at 22°C. It was determined that the solubility of urea in ethanol increased when more organics were present in the solution. Urea was recovered from inorganic synthetic urine (SI), organic synthetic urine (SO) and real human urine (RU) with yields of 88%, 77% and 67%, respectively. The purity of urea increased from 41%, 41% and 43% to 91%, 76% and 76% for SI, SO and RU using the ethanol evaporation and recrystallization process.http://www.sciencedirect.com/science/article/pii/S2666821121000909FertilizerHaber-BoschNitrogenPhosphorusSanitation |
| spellingShingle | H. Marepula C.E. Courtney D.G. Randall Urea recovery from stabilized urine using a novel ethanol evaporation and recrystallization process Chemical Engineering Journal Advances Fertilizer Haber-Bosch Nitrogen Phosphorus Sanitation |
| title | Urea recovery from stabilized urine using a novel ethanol evaporation and recrystallization process |
| title_full | Urea recovery from stabilized urine using a novel ethanol evaporation and recrystallization process |
| title_fullStr | Urea recovery from stabilized urine using a novel ethanol evaporation and recrystallization process |
| title_full_unstemmed | Urea recovery from stabilized urine using a novel ethanol evaporation and recrystallization process |
| title_short | Urea recovery from stabilized urine using a novel ethanol evaporation and recrystallization process |
| title_sort | urea recovery from stabilized urine using a novel ethanol evaporation and recrystallization process |
| topic | Fertilizer Haber-Bosch Nitrogen Phosphorus Sanitation |
| url | http://www.sciencedirect.com/science/article/pii/S2666821121000909 |
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