DICP's 250-kW system co-produces hydrogen and fresh water from seawater

A team at the Dalian Institute of Chemical Physics, part of the Chinese Academy of Sciences, reports a 250-kW system that produces hydrogen and fresh water from seawater in one process, in a paper published in Nature Energy on September 15, 2026. Rather than electrolysing seawater directly, the team led by Dehui Deng and Yanting Liu pairs an alkaline electrolyser with low-temperature distillation; per the abstract, "low-grade waste heat from the electrolyser drives seawater distillation to generate fresh water for both electrolysis and external use." At 250 kW the abstract reports 48 Nm³/h of hydrogen and 31.6 kg/h of fresh water, with "a 14.4% improvement in system electrical efficiency relative to alkaline electrolysis of fresh water alone."

The abstract calls direct seawater electrolysis "challenging due to the poor stability and low energy efficiency"; the distinction here is the heat loop, in which the electrolyser's waste heat drives the distillation that supplies its own feed water and a surplus. The institute's release, dated September 16, says commercial alkaline electrolysers turn about 30% of their electricity into waste heat at 80 to 90 °C that industrial operators usually remove with a cooling-water system, a warmer grade than the approximately 40 °C waste heat KIMM demonstrated cooling from on August 5, 2026; the release says the distillation runs at reduced pressure. The abstract says a 20-kW industrial pilot ran stably for 100 days at 3.8 Nm³/h of hydrogen and 1.2 kg/h of fresh water. The release adds that the 250-kW unit was completed and started up in August 2024, has run stably for more than 40 days, and makes hydrogen at 99.9999% purity; it gives the fresh-water output as 32 kg/h against the abstract's 31.6. The release also says the concentrated brine could feed the recovery of salt, uranium, bromine and other marine resources.

The paper's techno-economic analysis, per the abstract, "indicates higher profitability than the traditional tandem process of desalination followed by electrolysis." The full paper is behind Nature Energy's paywall; every figure about the Dalian system in this article comes from its published abstract and the institute's release. The 20-kW pilot passed a technology evaluation organised by the China Petroleum and Chemical Industry Federation in 2023, the release says, and the work is funded in part by China's National Key R&D Program and the National Natural Science Foundation.