Ammonia as a Carbon-Free Energy Carrier: NH₃ Cracking to H₂

Abstract

In the energy transition from fossil fuels to renewables, hydrogen is a realistic alternative to achieving the decarbonization target. However, its chemical and physical properties make its storage and transport expensive. To ensure the cost-effective H 2 usage as an energy vector, other chemicals are getting attention as H 2 carriers. Among them, ammonia is the most promising candidate. The value chain of NH 3 as a H 2 carrier, considering the long-distance ship transport, includes NH 3 synthesis and storage at the loading terminal, NH 3 storage at the unloading terminal, and its cracking to release H 2 . NH 3 synthesis and cracking are the cost drivers of the value chain. Also, the NH 3 cracking at large scale is not a mature technology, and a significant effort has to be made in intensifying the process as much as possible. In this respect, this work reviews the available technologies for NH 3 cracking, critically analyzing them in view of the scale up to the industrial level.

Nonmetal Atom Doping Induced Orbital Shifts and Charge Modulation at the Edge of Two-Dimensional Boron Carbonitride Leading to Enhanced Photocatalytic Nitrogen Reduction

“…2 Moreover, NH 3 is also regarded as a promising carrier for hydrogen storage which could promote the application of green hydrogen. 3 Nowadays, the large-scale production of ammonia primarily hinges upon the Haber− Bosch process, known for its enormous energy consumption and environmental strain. 4 Comparatively, photo/electrocatalytic NRR is capable of transforming nitrogen gas into ammonia under soft conditions, boasting low energy consumption and environmental friendliness.…”

“…Ammonia (NH 3 ) is a key nitrogen source material with crucial applications in diverse fields, including agriculture, chemical engineering, and energy among others . Moreover, NH 3 is also regarded as a promising carrier for hydrogen storage which could promote the application of green hydrogen . Nowadays, the large-scale production of ammonia primarily hinges upon the Haber–Bosch process, known for its enormous energy consumption and environmental strain .…”

Efficient Chemical Equilibria Calculation by Artificial Neural Networks for Ammonia Cracking and Synthesis

“…2. It is relevant: While ammonia is one of the most produced base chemicals worldwide [22], it lately also draws increasing interest as a potential hydrogen carrier [23][24][25]. Therefore, both the forward synthesis and the backward cracking reaction are important.…”

“…In the application as hydrogen carrier, ammonia needs to be cracked so that hydrogen is released. This reaction is endothermal and volume expanding and thus benefits from high temperatures of up to 1000 °C [25] and low or even atmospheric pressure [23,25]. This range of realistic operating parameters shall be the basis of this study, as we aim to provide a freely available and ready to use tool for a common and relevant application that the reader can intuitively and easily use to speed up equilibrium calculations with an average error of less than 5 %.…”

I&ECR: A Vision for Growth

“…Over the past century, the chemical engineering profession has evolved enormously and has had a massive global impact. Industrial & Engineering Chemistry Research , and its predecessor journals, have been at the forefront of our profession, closely reporting progress as our discipline revolutionized the production of transportation fuels, − boosted food production by growing fertilizer manufacturing, − and expanded the horizon of materials such as polymers and plastics. , Chemical engineering also pushed the boundaries of mathematical modeling and simulation, − optimization, − and process design, operations, and control. − Furthermore, chemical engineering played a key role in the development and scaleup of pharmaceuticals, including innovations in continuous production and vaccine deployment, and it is an essential part of the energy transition. − This list is by no means exhaustive. Now more than a century old, I&ECR is an institution with an impeccable reputation and journal name recognition as part of the ACS Publications portfolio.…”