Anton Paar USA,
Keywords: hydrogen storage, reduced carbon footprint, absorbent materials
Summary:Optimizing Hydrogen Storage for Carbon Footprint Reduction Abstract With the “Net Zero” initiative, researchers are seeking alternative fuel systems to reduce the carbon footprint of traditional fossil fuels. One alternative is to use hydrogen, the most abundant fuel on the planet. The key to using hydrogen as a fuel source for fuel cells within the transportation industry is storing the gas safely - at a pressure as low as 50 bar. Currently, hydrogen fuel tanks are pressurized as high as 10,000 psi (700 bar) which hold about 5kg of hydrogen, sufficient to travel 300 miles. Several techniques, such as the use of metal hydrides, adsorbent materials, and gas liquification, are considered to accomplish this range at the lowest possible pressure. Metal hydrides and adsorbent materials show particular promise towards increasing the implementation of safe hydrogen storage. However, these techniques still require analytical methods to assess and control the quality of selected synthesized novel materials. Gas liquefaction, on the other hand, requires complex infrastructure and is still susceptible to hydrogen loss through bleed off. The main focus will be the implementation of lab methods to characterize novel materials as they transition from research and development to full commercialization. In the past, surface property measurements of these materials relied on nitrogen isotherms at 77K and for microporous materials, argon isotherms at 87K. However, when studying gas-solid interactions, it is preferable to utilize the actual gas that will be stored. With advancements in cryogenic instrumentation, reaching the boiling point of hydrogen is now achievable and affordable. Utilizing a digital 1 bar transducer, one can accurately measure pressures as low as 5E-04 bar which is in the range of BET surface area calculations. From hydrogen isotherms at 20K, the calculated surface area is approximate 40% higher than that reported on the same material with nitrogen at 77K or argon at 87K. The measured pore volume is also increased due to the smaller hydrogen molecule accessibility. Using the latest improvements in technology, the performance of metal hydrides has been studied through the use of solid-gas interaction kinetics where the evolved gas is held close to constant pressure. This method reduces the degrees of freedom so the true kinetics can be studied through cycle testing. Such cycle testing also reveals the material’s performance; stability and degradation, though the desired functioning period. Also, utilizing single dose kinetic adsorption/regeneration process cycles for a sorbent material is used to study its life cycle at various pressures. Fully automated, bench top, cryogenic, high pressure adsorption analyzer (Sieverts) helps researchers reduce the time providing solutions to the most difficult challenges our planet faces. From research to commercialization, the above techniques in hydrogen gas storage are made possible with this latest technology.