Air-gap diffusion distillation (AGDD) is a thermal distillation technology that can convert low-grade heat sources into salinity gradient energy, offering broad application potential. Since the AGDD system operates under atmospheric pressure, it can be seamlessly integrated with reverse electrodialysis (RED) technology, facilitating the conversion of low-grade thermal energy into electricity, hydrogen, and chemical energy. This paper constructs, for the first time, an AGDD-RED mathematical model that simultaneously achieves hydrogen generation and wastewater purification. Accordingly, the influence behaviors of the concentration of AGDD feed solution (0.5 mol·L-1-5 mol·L-1) and low-grade heat source temperature (55–95 °C) on hydrogen generation performance and degradation efficiency are simulated and discussed. At a feed concentration of 3 M, hydrogen generation and COD degradation rates achieve their peak values of 0.19 kW and 46.4 %, respectively. At 55 °C, the degradation rate and hydrogen generation reach their highest values, at 47.1 % and 0.2 kW, with the total energy conversion efficiency reaching 1.65 %. Finally, the energy distribution of the entire system is analyzed, and the results show that the salinity gradient energy regeneration process in the AGDD subsystem is the key factor affecting the efficiency of the system. Reducing pump power consumption and non-ohmic resistance in the RED subsystem will effectively improve the energy conversion performance of the system.

中文翻译：

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同步制氢和废水净化：一种采用气隙扩散蒸馏的创新闭环反向电渗析系统


气隙扩散蒸馏 （AGDD） 是一种热蒸馏技术，可以将低品位热源转化为盐度梯度能，具有广泛的应用潜力。由于 AGDD 系统在大气压下运行，因此可以与反向电渗析 （RED） 技术无缝集成，促进将低品位热能转化为电能、氢能和化学能。本文首次构建了一个 AGDD-RED 数学模型，可同时实现制氢和废水净化。因此，AGDD 进料溶液浓度（0.5 mol·L-1-5 mol·L-1） 和低品位热源温度 （55–95 °C） 对制氢性能和降解效率的影响进行了模拟和讨论。当进料浓度为 3 M 时，产氢和 COD 降解率分别达到 0.19 kW 和 46.4% 的峰值。在 55 °C 时，降解率和氢气生成量达到最高值，分别为 47.1 % 和 0.2 kW，总能量转换效率达到 1.65 %。最后，分析了整个系统的能量分布，结果表明，AGDD 子系统中的盐度梯度能量再生过程是影响系统效率的关键因素。降低 RED 子系统中的泵功耗和非欧姆电阻将有效提高系统的能量转换性能。