Air-Gap Membrane Distillation of Industrial Brine: Effect of Brine Concentration and Temperature

Ugarte, Patricia ; Renda, Simona ; Cano, Miguel ; Pérez, Jorge ; Peña, José Ángel (Universidad de Zaragoza) ; Menéndez, Miguel (Universidad de Zaragoza)

Resumen: Precipitated silica is a highly required and employed product on the worldwide market; its production involves the reaction of sulfuric acid and sodium silicate in aqueous solutions, leading to the undesired generation of a significant volume of brine containing Na2SO4. The treatment of this brine is crucial within the framework of a circular economy, as it enables the dual objective of preventing pollution and extracting value from waste. This study focused, at first, on evaluating the performances of the air-gap membrane distillation (AGMD) technology using a synthetic Na2SO4 brine. Then, the feasibility of applying this technology to the concentration of an industrial Na2SO4 brine was evaluated. To achieve these goals, an AGMD pilot plant with a flat sheet membrane module with an effective area of 0.025 m2 was employed. The effects of the brine concentration and feed temperature on flux were analyzed. It was observed that the flow rate and the temperature of the brine were significant parameters influencing the magnitude of the permeate flux, while flow rate and temperature of the cooling water were not particularly influential. The industrial brine concentration ranged from 120 to 270 g/L, and continuous 2-month operation was successfully achieved. Very low values for permeate conductivity were observed (1–12 μS/cm), and values close to 100% for salt rejection were measured, resulting in perfectly depurated water. A 1-D model for flat sheet-type AGMD was also developed, and it was observed to strongly correlate with the experimental data. Since no adjustable parameters were included in the model, this result validates the experimental tests and suggests that the model could be further employed to predict with accuracy many different operating conditions.

Idioma: Inglés

DOI: 10.1021/acs.iecr.3c03415

Año: 2024

Publicado en: Industrial and Engineering Chemistry Research 63, 3 (2024), 1546-1553
ISSN: 0888-5885

Financiación: info:eu-repo/grantAgreement/ES/DGA/EC-208-2022

Tipo y forma: Artículo (Versión definitiva)

Área (Departamento): Área Ingeniería Química (Dpto. Ing.Quím.Tecnol.Med.Amb.)