Violet Perkins Phillippo (BSc Chemistry) was awarded the Second Highly Commended prize for her dissertation exploring small-scale electrochemical ammonia production, with a focus on Kenya.
Read on for more information about Violet's intriguing entry.
Small-scale electrochemical ammonia production: a quantitative literature review of promising catalysts for future development
Rural farming communities in Kenya produce ≈70% of Kenya’s marketed agricultural produce (Muriuki, 2016) but the lack of access to affordable fertiliser limits the agricultural output from the land. The motivation behind my research is to improve the food and financial securities of farming communities across Africa, by increasing their independence from international supply chains and centralised distribution networks, for fertiliser.
Atmonia have shown that it is possible to produce ammonia, the principle ingredient in ammonium nitrate fertilisers, on a small-scale, using self-contained electrochemical units that farmers can operate safely. In this process, molecular nitrogen from the air and hydrogen ions from the electrolysis of water, react electrochemically to produce ammonia. A catalyst is used to sufficiently increase the rate of ammonia production, by lowering the minimum energy that is required for the reaction to occur. Metal based compounds have proven to be efficient catalysts for ammonia production, but they are relatively scarce and therefore, costly and extraction is environmentally damaging. The aim of my quantitative literature review was to identify new materials for the fabrication of catalysts for electrochemical ammonia production, which are more affordable than established technology. Carbon based catalysts have shown promise, as carbon is an abundant and cost-effective material, however they are not yet viable, due to a lack of refinement and stringent testing. In the last decade, this has been an exciting area of research, due to the prospect of far-reaching social impacts, therefore, the literature was critically evaluated, to ensure that the findings would be informative for future stakeholders, such as funding bodies.
Kenyan agriculture is predominantly carried out on a small-scale, in areas of the highest agricultural potential. The literature identifies micro-dosing, the targeted application of small amounts of ammonium nitrate fertiliser, as the method that has the most profound impact on crop yields. Currently, most Kenyan farmers depend on international supply chains and international Government led distribution programmes, for fertiliser. The fertiliser is shipped into ports, such as Mombasa, and the centralised distribution network across the country means that the many farmers, who are in geographically isolated locations, have no access to inorganic fertilisers, such as ammonium nitrate. Although, farming communities need little fertiliser for micro-dosing applications, they cannot afford to buy the fertiliser in the bulk quantities that it is commonly sold in nor benefit from economies of scale.
Atmonia’s patented small-scale, electrochemical ammonia production units are currently the most viable solution, to improve the accessibility and affordability of fertiliser, for isolated farmers. The manufactured units are safe, adaptable and demonstrate sustainable ammonia production. The metal nitride catalyst used, leads to the production of sufficient ammonia, for the micro-dosing application of fertiliser. However, with the farmers’ needs at the forefront, it was important to evaluate metal-free catalysts, as a more affordable alternative. One of the catalytic materials identified, was alfalfa derived nitrogen doped carbon, which highlights the possibility of using biomass derived catalysts, made from abundant materials. With more stringent testing and further refinement, the catalyst could be made locally, which would reduce the cost and carbon footprint of manufacturing the unit and could provide employment opportunities for local people.
For the far-reaching social impact of affordable in-situ ammonia production units to be realised, there must be good collaboration between scientists who are able to develop affordable yet durable catalytic materials and engineers who can address the practical issues associated with the design of the overall unit. The literature shows that a project led by the UK’s Department for International Development (DFID), distributed small amounts of fertiliser to over 570,000 Nigerian farmers. There have also been local projects in Zimbabwe, that have provided education programmes, for the safe and cost-effective use of fertiliser. Therefore, there are both local and international organisations that would be able to support and advise on the short and long-term funding, distribution and education objectives, to ensure that the social impact of the technology is maximised.
The well-established psychological theory of Maslow’s Hierarchy of Needs, illustrates that before a human’s psychological needs can be addressed, their physiological needs must be fulfilled. My research shows that if a community has access to sufficient fertiliser, for micro-dosing applications, then not only does it help them to fulfil their physiological needs through increased food security, but it would lead to greater financial security. If the project is successful, then the social benefits of long-term financial security would be felt by the community, such as improved mental wellbeing and improved access to education and healthcare.