@article{KemppainenBagackiScharyetal., author = {Kemppainen, Erno and Bagacki, Rory and Schary, Christian and Bao, Fuxi and Dorbandt, Iris and Janke, Stefan and Emery, Quiterie and Stannowski, Bernd and Schlatmann, Rutger and Calnan, Sonya}, title = {Dynamic Operation of a Heat Exchanger in a Thermally Integrated Photovoltaic Electrolyzer}, series = {Energy Technology}, volume = {11}, journal = {Energy Technology}, number = {2}, doi = {10.1002/ente.202201081}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:523-16903}, abstract = {The outdoor operation of an up-scaled thermally photovoltaic electrolyzer (PV EC), constructed using a heat exchanger (HE) made of low-cost materials, compared to its nonintegrated counterpart to quantify heat transfer and its effects, is studied. Thermal coupling of the PV and EC can reduce the difference between their temperatures, benefitting device performance. Such devices can produce hydrogen at rooftop installations of small-to-medium-sized nonindustrial buildings. The devices are tested outdoors using automated real-time monitoring. Under ≈880 W m-2 peak irradiance, they produced hydrogen at ≈120 and ≈110 mL min-1 rate with and without HE, respectively, corresponding to about 8.5\% and 7.8\% solar-to-hydrogen efficiencies. During about 700 h of testing, the HE is beneficial at over ≈500 W m-2 due to cyclic device operation. Under lower irradiance levels, pumping previously heated electrolyte through the HE increases the PV and reduces the electrolyte temperature, reducing the device performance. The HE increases the cumulative hydrogen production (≈800 L from both devices), so even relatively modest heat transfer rates can improve the PV EC operation. Improving the HE should further increase the benefits, but additional measures may be needed to maximize the hydrogen production.}, subject = {W{\"a}rmeaustauscher}, language = {en} } @article{BagackiReinhardtSchlatmannetal., author = {Bagacki, Rory and Reinhardt, Maximilian and Schlatmann, Rutger and Calnan, Sonya and van de Krol, Roel and Browne, Michelle P.}, title = {Electrochemical hydrogen pumps: a researcher's guide and review}, series = {Chemical Communications}, volume = {61}, journal = {Chemical Communications}, number = {56}, publisher = {The Royal Society of Chemistry}, issn = {1359-7345}, doi = {10.1039/d5cc01815c}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:523-21017}, pages = {10210 -- 10227}, abstract = {Hydrogen is considered an attractive energy vector and an indispensable base chemical for a wide variety of chemical products. As more hydrogen is produced via electrolysis, finding ways to store the H2 will become increasingly important due to the low volumetric energy density at ambient pressure. While high pressure storage is favoured for many applications, compressing hydrogen poses distinct challenges due to its low density and high diffusivity. Electrochemical hydrogen pumps (EHP) present a solution to this challenge by efficiently compressing hydrogen. Hydrogen compression is more efficient using electrochemical hydrogen pumps than conventional mechanical compressors because they operate through isothermal rather than adiabatic compression. Additionally, they can be used to separate hydrogen from gas mixtures, for example from natural gas pipelines supplemented with hydrogen, creating the possibility of integrating them with existing energy transport infrastructure. This paper summarizes recent progress in electrochemical hydrogen pump research and presents a case study on an EHP test cell, test rig and a measurement guide to advance research in this field. Although electrochemical hydrogen pumps offer many advantages, shortcomings remain, including the lack of standardized measurement conditions and procedures, as well as a limited understanding of degradation mechanisms. This review aims to provide insights into these issues and discuss future directions for electrochemical hydrogen pump research.}, language = {en} }