Ammonia - the root cause of the problem or the solution?
It's argued that the rapid rate of population growth was down to one key chemical engineering breakthrough: the Haber-Bosch process. When Fritz Haber invented the process and Carl Bosch scaled it up, one doubts
that they could have imagined the impact that the ammonia production technology could have had on our planet. By developing a high pressure, catalysed process, they were able to curate an environment for nitrogen fixation (nitrogen to ammonia). Haber's process remains the accepted best practice and has been engineered around due to its unparalleled efficiencies for since 1908 .
Few alive today could imagine a world without ammonia. Ammonia is the base ingredient for synthetic fertilisers and synthetic fertilisers are the reason why the human race has been able to produce crops at the rates capable of almost quadrupling the worlds population in 100 years .
In contrast, there is also an argument that the world would not be subject to the environmental crisis that it is today if the population hadn't exploded as it did. Perhaps it isn't natural for the world to sustain this many people. The situation is certainly not made any better when you consider that this mass of people are no longer hunters and gatherers living off the land, but gas guzzlers hell bent on industrialisation and doing things faster and bigger than ever before.
Human-kind is an incredible force driven by desire, creativity and innovation. As a population, we are one that somehow manages to survive regardless of the troubles that we create for ourselves. Or at least it feels that way. Human beings can happily say that we rule the earth, due to our ingenuity, our intellect and of course our wonderful dexterity. It feels as though this has been the case forever. And it has, in the timeframe that we can truly perceive: our lifetime. Outside of this, we have stories, historical literature, studies and fossils to guide us on what went before. Human-kind as we know it only came about approximately 1.9 million years ago but it's predicted that the world has been spinning on its axis and orbiting the sun for 2.4 million times longer!  
We are insignificant in time, but hugely significant in the moment.
Where innovation has got us to where we are today, it is innovation that will get us out. I truly believe that there is a majority out there, a force that is going to enable this change. If not for selfless, caring, environmentally conscious reasons, then for selfish reasons. Our inherent desire to survive will drive this change. We are beginning to see natural disasters evermore frequently that are genuinely scaring us. Environmental changes that are bringing horrible discomfort into our otherwise lovely lifestyles.
Where ammonia may have landed us, it may well also get us out. With an ability to be stored as a liquid at -33.4°C at 1 bar or 20°C at 10bar , it is one of few zero carbon fuels with the potential to rival our much relied upon oil and natural gas in distribution. What's more, due to its critical role in our agricultural supply chain, means of transport and storage of ammonia are well established. There are vessels the size of 15 olympic sized swimming pools floating on the oceans today capable of delivering 38,000m³ of ammonia in any one journey . Ammonia represents a true opportunity for energy carrying and delivery. Ammonia can be burnt like the fuels we know and love, it can be broken down again in to hydrogen and nitrogen so that the hydrogen can be used in a fuel cell and companies are even looking at using ammonia directly in fuel cells.
Today however, ammonia is produced with the help of natural gas, via a process called steam methane reforming. Some call natural gas a cleaner fossil fuel, but it is one that emits around 10 tonnes of carbon dioxide for every tonne of hydrogen it produces! Stoichiometrically, you need approximately 1.8 tonnes of hydrogen for every 10 tonnes of ammonia. That gives an estimate of approximately 18 tonnes of CO2 produced for every 10 tonnes of ammonia produced using natural gas via steam reforming.
Until recently, not many have taken much notice of this fact. Until recently, to be fair to everyone involved, there has not been another feasible way. Today, due to years of effort and investment, we are finally seeing costs of renewable power not just meet but go far beneath the costs of power generated from fossil fuels. It is the turning of the tide! With technology development and legislative policy finally aligning to facilitate innovation that will enable a greener world.
Ammonia can be produced from any form of hydrogen. If the hydrogen comes from water through electrolysis powered by renewables, it will be without any emissions and ammonia can go on feeding the earth, as well as fuelling the earth with zero emissions to its name.
A great example of progress is in Neom, Saudi Arabia. The Kingdom has taken on the mammoth task of building a zero emission city. Part of this development will see world leading industrial gas producer Air Products, alkaline electrolyser technnology developer ThyssenKrupp and ammonia technology developer Haldor Topsoe joining forces to build the world's first industrial green ammonia facility . The facility will be capable of producing 1.2 million tonnes of ammonia per year! This is an impressive undertaking, but will equate to approximately 0.5% of the worlds production . With all the best intentions in the world, the change will not be swift or without immense financial support.
235 million tonnes of ammonia was produced in 2019 . For the last 100 years, companies like KBR, Linde, Ammonia Casale have progressed the plant efficiency and capital costs with incremental innovations that make a massive difference at such scale. The world scale facilities operating today are hugely complex and heavily integrated. The AIChE wrote a brilliant article about the progression of the ammonia synthesis flowsheet over the years. See here.
Heat produced from the burning of methane to get the steam methane reformer to its operating temperature of ~1000°C also raises steam to supply heat and power for the rest of the system. The exothermic nature of the Haber Bosch process is exploited, capturing that heat to deliver higher efficiencies across the plant.
To continue feeding our planet, one cannot turn these plants off over night. To enable farmers and families to survive, you cannot suddenly and dramatically increase the price of this precious commodity. Technical innovation and economical support are needed to drive us out of this hole that we have dug ourselves.
Existing electrolyser technologies, like PEM, Alkaline and Solid Oxide electrolysers operate at low temperatures or low pressures, or both! Unfortunately for the ammonia producers of the world, this is bad news. This challenges the well established plant wide efficiencies demonstrated above. This will require additional equipment, dramatic plant changes, potentially even plant decommissioning.
Novel approaches will need to be invented and we once again open the door for step-change innovation.
Supercritical has developed an electrolyser with industry leading efficiency which works at just in excess Haber-Bosch pressure and just below Haber-Bosch temperatures. Operating in excess of 375°C and 221bar (the critical point of water), we fit like the proverbial electrolyser hydrogen glove on the Haber-Bosch ammonia hand.
Could this be the beginning of a new age of cost competitive zero emission ammonia? The next step in the history of the Haber-Bosch process?
If you would like to find out more about Supercritical's integration opportunities, please contact us at firstname.lastname@example.org.