Ammonia as a Fuel

Ammonia-air mixtures are flammable in a narrow zone of concentrations between 16% and 25%. The products of combustion from burning ammonia are predominately nitrogen and water. No CO2 or CO are produced as ammonia does not contain any carbon. Ammonia is a carrier of hydrogen however it is far easier to store, distribute and use than hydrogen.

Ammonia can be used as a fuel in most applications where hydrocarbons are currently used. These applications include internal combustion engines, gas turbines and boilers. Most piston engines will run very well on ammonia-air mixtures with some modifications to the fuel and ignition systems. Engines running on ammonia may produce NOx however in quantities , certainly no greater than those produced by an equivalent hydrocarbon fuelled engine. An engine running on ammonia can therefore be classified as producing zero carbon emissions.

Ammonia has been successfully used as a ground transport fuel dating as far back as the 1940’s where it was used to fuel public motor buses in Belgium. One of the more recent applications has been the conversion of a 2013 model popular sports car, to a dual fuel vehicle which runs on ammonia at low speeds.

The technology and means are rapidly being established to store, distribute and use ammonia as a zero emissions fuel for transport and energy systems. The challenge now is to develop processes to cost effectively manufacture ammonia using renewable energy. That is, to discontinue using hydrocarbons to obtain hydrogen for the ammonia manufacturing process, and develop other zero carbon emission systems to efficiently produce ammonia. When this is achieved, it will “close the loop” on the ammonia carbon free fuel cycle and pave the way for a clean energy future.

A concerted global research effort is required to develop ways of “closing the loop” on the ammonia carbon free fuel cycle.

Ammonia has been least exploited as a fuel however this is where it has the most potential in attaining humanity’s dream of a carbon free energy future.

The next instalment will discuss ammonia manufacture.

Until then

Kind Regards


Ammonia as a Fertilizer

Ammonia is one of the most commonly produced industrial chemicals worldwide, second only to sulphuric acid. Around 200 million tonnes of ammonia is produced each year and the bulk of this is used in the agricultural fertilizer industry. Anhydrous ammonia liquid is direct drilled into the soil in many areas around the world. This method provides a very efficient and cost effective delivery of nitrogen to the subsoil which encourages excellent crop growth. In other situations the fertilizer is delivered to the plants as an aqueous-ammonia solution typically 25% ammonia in water. Ammonia is also widely used in the manufacture of a range of granular fertilizers.

In the US Midwest there is a network of more than 40 ammonia storage terminals interconnected with over 5000 km of piping to facilitate the distribution of anhydrous ammonia for use as a fertilizer. This network spans from Louisiana in the south to Minnesota in the north and from Indiana to Texas. Large quantities of ammonia are also transported by sea, rail and road. The US uses around 15 to 20 Million tonnes of ammonia per year in the fertilizer industry.

China is currently the largest producer of ammonia. Most ammonia is at present produced using natural gas or coal to provide the hydrogen with the nitrogen coming from air. It is possible to manufacture ammonia using renewable energy like solar, wind, hydroelectricity etc. rather than using hydrocarbons; however this is usually more expensive and therefore less popular than making ammonia with cheap natural gas or coal.

Ammonia is a massive contributor and essential to efficient world food production. Its use can only grow in future as the global appetite for food grows.

In the next session we will discuss the potential for ammonia as a carbon free, zero emission fuel. This is where ammonia has the most to offer in preserving the future of our planet.

Until then,

Kind Regards