Karthish Manthiram, Warren K. Lewis Career Development Professor in the Department of Chemical Engineering at MIT, is leading one of seven research projects recently awarded J-WAFS funding. Karthish aims to develop a solar-powered electrochemical device that can convert nitrogen from air, water and sunlight into ammonia that can be added to soil to promote plant growth.
Opening Doors spoke to Professor Manthiram about the project and its aims.
What’s the title of your research project?
It’s called ‘Electrochemical Nitrogen Fixation for Distributed Fertilizer Production’.
What is the project about?
Low crop yields are a key contributor to malnourishment and poverty in Africa. At the same time, the use of fertilizers is much lower in Africa compared to other regions of the world, limiting the agricultural productivity of the soil. This is partly because there are no robust local markets for fertilizers in Africa. Farming remains largely small-scale and scattered, and the costs of fertilizer distribution are very high due to poor infrastructure. This situation is not compatible with the highly centralized production of ammonia for fertilizers, which uses the Haber-Bosch process. This process needs to be conducted at large scales due to the high temperatures and pressures used, which are cost-prohibitive at smaller scales.
Our research aims to demonstrate a new way to produce ammonia locally, using commonly available feedstocks, and avoid the problems of cost and distribution that have hindered the use of fertilizer in Africa to date.
We propose an electrochemical device, which can be driven using solar panels, to convert nitrogen from air and water to produce ammonia. Because the device requires only air, water and sunlight, it can be deployed at remote locations. The ammonia produced can then be directly injected into soil or reacted with carbon dioxide to create urea, which can be easily handled by farmers for local use.
Altogether, the research will help to illuminate whether local, electrochemical generation of fertilizers is a viable method for small communities of farmers to take control of their own soil health.
Why is ammonia so important in the production of fertilizer?
Ammonia is an important source of nitrogen, which is one of the key nutrients that plants need to grow. When we use fertilizer, we are putting nitrogen back into the soil that has been depleted by previous agricultural use. Increasing the nutrients in the content of the soil in this way helps to increase the agricultural productivity of the land.
Why is there a relatively low level of fertilizer use in Africa?
It’s a combination of infrastructure and resources. There’s a big need for fertilizer in Africa to improve soil health, but the infrastructure to import, store and distribute fertilizer to areas where it’s most needed just isn’t developed enough. There is also a lack of resources at an individual level. Fertilizer can be too costly for individual farmers, even though it can increase their productivity, which helps them to lift themselves out of poverty. So it becomes a ‘chicken and egg’ problem, with limited local demand meaning that regional governments and the private sector are reluctant to invest in developing the infrastructure.
Are fertilizers widely used in the Middle East?
The use of fertilizers in the Middle East is more common, and the region has considerable natural potential for fertilizer production. To produce ammonia, you require hydrogen, and a great source of hydrogen is natural gas, which of course is a mainstay of the Middle East’s economy. But producing ammonia in this way results in a very large carbon footprint. Our technology would potentially enable the Middle East to capitalize on the global market for fertilizer, while reducing carbon emissions.
“there is no need for centralized infrastructure and it is easier to break the poverty cycle”
Can you briefly describe how your proposed device works?
What we’re proposing is a new process to harness clean electricity from domestic solar panels or wind turbines, for example, and combine it with nitrogen and water to create ammonia. This could be done at an individual level, or even at a village or community level, so there is no need for centralized infrastructure and it is easier to break the poverty cycle.
What would the technology actually produce?
The technology could produce ammonia or urea, both of which are effective fertilizers. There are two practical ways of doing this. One method is to make ammonia and then find a way to inject it directly into the soil. This is what our research will partly be focusing on. The other is to react the ammonia with CO2 to make urea, which can then be sold as a solid fertilizer that is easy to handle and distribute.
Given that the technology could be driven by solar or wind energy, it would seem to be ideally suited to the Middle East and North Africa. Is this the case?
Yes absolutely. There is a strong commitment from many governments in the region to make the most of their sustainable natural resources like solar and wind, to help improve their societies, and the lives of their citizens
If we can provide a new process to take clean energy and use it to produce fertilizer in a more sustainable way, expanding current markets and pioneering new ones, it could be a very exciting development.
What about the wider environmental impact?
Current methods of ammonia production derive from processes that were invented 100 years ago, which have a big carbon footprint. Our technology could significantly reduce the carbon footprint of fertilizer production. A second environmental benefit involves fertilizer run-off. Traditionally, adding fertilizer to the soil in large amounts means that when it rains, a certain amount of ammonia and other ingredients is lost through run-off discharged into streams and rivers. Our hope is that by producing fertilizers locally and injecting them into the soil in a much more controlled way, we reduce the run-off problem by delivering only the amount of fertilizer that the crop actually requires.
This latest round of J-WAFS funding will run until August 2019. Do you expect your research to be complete by then?
We are still only at the early stage of this research. Although we are very positive about the project, there is still some fundamental science to figure out first in order to enable this technological innovation. There are likely to be further phases of research where we fine tune the technology and find the best way to implement it, so that it has the maximum impact on people’s lives.