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.