【HaiChuan Discussion】New approaches for ammonia synthesis plants: New processes convert liquid ammonia directly into hydrogen

One more road is always good; you can choose the route that suits you based on the actual circumstances.

I wonder if anyone has noticed that in the past 10 years, so-called experts have been increasingly advocating this idea. Back in 2015, a foreign scientist claimed that the CO2 produced by wood burning is neutral and does not cause a greenhouse effect; at first, this idea seemed astonishing. But in the past couple of years, more and more people have started to accept it – it’s really amazing

Interpret it as temporarily neutral for now; this pathway is designed primarily to facilitate better hydrogen storage. If the hydrogen produced in the conversion furnace is difficult to separate and store, liquid ammonia is used as an intermediate medium for storing hydrogen. When hydrogen is needed, it can be released after simple processing, thereby avoiding the various high-pressure issues associated with hydrogen storage

For now, everyone is exploring multiple paths

You may not be very familiar with the process of ammonia synthesis; high purity of hydrogen is required for this process. At present, the only industrial method for producing ammonia is high-pressure synthesis, and the conversion efficiency in a single pass is only around 30%. A lot of effort is needed to convert hydrogen into ammonia, and then energy is required to break ammonia back down into hydrogen. When compared to water electrolysis, it’s clear that water electrolysis is more energy-efficient. Since ammonia is used as an intermediate storage medium, electrolysis is still necessary. So where does the electricity come from?

This post was last edited by Huang Xinhui on 2021-8-17 at 11:04. Agree with this view. Hydrogen production by liquid ammonia electrolysis is merely an indirect method for storing and transporting hydrogen. But what needs to be determined is where the ammonia comes from. While ammonia electrolysis may be more energy-efficient compared to water electrolysis for hydrogen production, water is a naturally occurring substance whereas ammonia is not. It is only meaningful to compare the cost of producing ammonia synthetically along with the cost of electrolyzing it to produce hydrogen, with the cost of producing hydrogen through water electrolysis. In my opinion, as a major basic material, the path forward for synthetic ammonia, or rather its path toward sustainable development, should involve using renewable electricity for water electrolysis to produce hydrogen, with nitrogen being obtained from the air. If urea or ammonium bicarbonate is to be produced as a by-product, then other carbon dioxide sources with high emission levels can be utilized, subject to carbon capture and storage. It is an efficient, low-carbon, and green path for development. Hydrogen energy is highly favored, but only green hydrogen is truly low-carbon. Another obstacle to the development of hydrogen energy is hydrogen storage. Hydrogen is too light; it is necessary to find solutions for its safe, efficient, and cost-effective storage and transportation, as well as to address the issue of energy storage density. This should rely on technological advancements and innovative developments in new materials; adjusting the manufacturing processes, in my opinion, represents a roundabout approach. Although it is one possible strategy, it is not certain that an appropriate method can be found, and I believe the chances of success are uncertain.

It seems that this process avoids one problem, namely the large amount of carbon dioxide generated in ammonia synthesis

Good question; green hydrogen is the truly clean hydrogen