United States

A Lagrangian-based one-dimensional approach has been developed using Cantera to study the dynamics of spherically expanding flames. The detailed reaction model USC-Mech II has been employed to examine flame propagating in hydrogen-air mixtures. In the first part our approach has been validated against laminar flame speed and Markstein number data from the literature. It was shown that the laminar flame speed was predicted within 5% Read More

Synthetic ammonia manufactured by the Haber–Bosch process and its variants is the key to securing global food security. Hydrogen is the most important feedstock for all synthetic ammonia processes. Renewable ammonia production relies on hydrogen generated by water electrolysis using electricity generated from hydropower. This was used commercially as early as 1921. In the present work we discuss how renewable ammonia production s Read More

Non-energy use of natural gas is gaining importance. Gas used for 183 million tons annual ammonia production represents 4% of total global gas supply. 1.5-degree pathways estimate an ammonia demand growth of 3–4-fold until 2050 as new markets in hydrogen transport shipping and power generation emerge. Ammonia production from hydrogen produced via water electrolysis with renewable power (green ammonia) and from natural gas with CO2 stora Read More

In  a  liquid  hydrogen  storage  tank  hydrogen  vapor  exists  above  the  cryogenic  liquid.  A  common modeling  assumption  of  a  liquid  hydrogen  tank  is  thermodynamic  equilibrium. However  this assumption may not hold in all conditions. A non-equilibrium storage tank with a pressure relief valve and a burst disc in parallel was modeled in this work. The model includes different boiling regimes to handle scenarios with high heat transfer. The model was Read More

The minimum distances between exposures and bulk liquid hydrogen listed in the National Fire Protection Agency’s Hydrogen Technology Code NFPA 2 are based on historical consensus without a documented scientific analysis. This work follows a similar analysis as the scientific justification provided in NFPA 2 for exposure distances from bulk gaseous hydrogen storage systems but for liquid hydrogen. Validated physical models from Sandia’s HyRAM softwar Read More

In this paper we review our recent results in developing gas sensors for hydrogen using various device structures including ZnO nanowires and GaN High Electron Mobility Transistors (HEMTs). ZnO nanowires are particularly interesting because they have a large surface area to volume ratio which will improve sensitivity and because they operate at low current levels will have low power requirements in a sensor module. GaN-based devices offer the adva Read More

Replacing fossil fuels with non-carbon fuels is an important step towards reaching the ultimate goal of carbon neutrality. Instead of moving directly from the current natural gas energy systems to pure hydrogen an incremental blending of hydrogen with natural gas could provide a seamless transition and minimize disruptions in power and heating source distribution to the public. Academic institutions industry and governments globally are supporting researc Read More

Anion exchange membrane water electrolysis (AEMWE) is considered the next generation of green hydrogen production method because it uses low-cost non-noble metal oxide electrocatalyst electrodes and can store highpurity hydrogen under high pressure. However the commercialization of AEMWE with non-precious metal oxide electrocatalysts is challenging due to low electrocatalytic activity and durability. Overcoming the low kinetics caused by f Read More

Strength hardness and ductility characteristics were determined for a series of palladium-copper alloys that compositionally vary from 5 to 25 weight percent copper. Alloy specimens subjected to vacuum annealing showed clear evidence of solid solution strengthening. These specimens showed as a function of increasing copper content increased yield strength ultimate strength and Vickers microhardness while their ductility was little affected by composit Read More

The paper explores options for a 2050 carbon free energy future for India. Onshore wind and solar sources are projected as the dominant primary contributions to this objective. The analysis envisages an important role for so-called green hydrogen produced by electrolysis fueled by these carbon free energy sources. This hydrogen source can be used to accommodate for the intrinsic variability of wind and solar complementing opportunities for Read More