Impact and feasibility of a membrane pre-concentration step in kraft recovery
| Autor: | Stephen H. Frayne, Diego F. Rivera, Brent D. Keller, Max Kleiman-Lynch |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
0106 biological sciences
Chemistry Mechanical Engineering General Chemical Engineering food and beverages 02 engineering and technology General Chemistry 021001 nanoscience & nanotechnology Pulp and paper industry complex mixtures 01 natural sciences Membrane 010608 biotechnology Media Technology General Materials Science 0210 nano-technology Pre concentration Kraft paper |
| Zdroj: | May 2021. 20:331-340 |
| ISSN: | 0734-1415 |
| DOI: | 10.32964/tj20.5.331 |
| Popis: | Emerging robust membrane systems can perform the first section of black liquor (BL) concentration by separating clean water from the black liquor stream using only mechanical pressure. By doing so, they can reduce the steam and energy required for BL concentration. Because of the high osmotic pressure of strong BL, a membrane system would not replace evaporators but would operate in series, performing the first section of BL concentration. In this work, we use a multi-effect evaporator (MEE) model to quantify the steam and energy savings associated with installing membrane systems of different sizes. When maintaining a constant BL solids throughput, we find that a pulp mill could reduce steam usage in its evaporators by up to 65%. Alternatively, a membrane system could also serve to increase BL throughput of the recovery train. We find that a membrane system capable of concentrating BL to 25% could double the BL solids throughput of a mill’s evaporators at the same steam usage. We also demonstrate that installing a membrane system before an MEE would minimally affect key operating parameters such as steam pressures and BL solids concentrations in each effect. This indicates that installing a membrane pre-concentration system would be nonintrusive to a mill’s operations. |
| Databáze: | OpenAIRE |
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