As a byproduct of desalination plants, brine is increasingly becoming a threat to the environment, and the design of zero-liquid discharge (ZLD) systems is gaining increasing attention. Existing ZLD systems are limited by a high energy intensity and high plant costs of their crystallizers. This study proposes a novel crystallization method based on the humidification-dehumidification (HDH) process, which exhibits the advantages of a low energy consumption, low component costs and a reduced scaling and fouling potential. A simple experimental setup is first designed to demonstrate the feasibility of the proposed system. Brine concentration and salt crystallization are successfully achieved with air heated to 40 °C as the heat source. Afterwards, a thermo-economic analysis is conducted for the whole system. The specific thermal energy and electricity consumption levels are found to range from 700-900 and 5-11 kJ, respectively, per kg of feed brine. The energy consumption is 56% lower than that of a conventional evaporative crystallizer, and the initial plant cost is reduced by 58%.

作为海水淡化厂的副产品，盐水日益成为对环境的威胁，零液体排放 (ZLD) 系统的设计越来越受到关注。现有的 ZLD 系统受限于其结晶器的高能量强度和高工厂成本。本研究提出了一种基于加湿-除湿 (HDH) 过程的新型结晶方法，该方法具有能耗低、组件成本低、结垢和结垢可能性降低等优点。首先设计了一个简单的实验装置来证明所提出系统的可行性。以加热到 40 °C 的空气作为热源，成功地实现了盐水浓缩和盐结晶。然后，对整个系统进行热经济分析。发现特定的热能和电力消耗水平分别为每公斤进料盐水 700-900 和 5-11 kJ。能耗比传统蒸发结晶器低56%，初始设备成本降低58%。