A shortage of sulphuric acid could stop the advancement of green technology and threaten food security, according to a study published in the Royal Geographical Society journal The Geographical Journal.
Global demand for sulphuric acid is projected to rise from 246 to 400 million tonnes by 2040, primarily to be used in intensive farming and green technologies. A team of researchers from the University College London (UCL), UK, estimate that this will result in a yearly shortage between 100 and 320 million tonnes. This represents 40-130% of the current supply. These results come from three different scenarios from 2021 to 2040 based on forecast and historical demand, with annual growth rates between 1.8 and 2.4%.
Sulphuric acid is essential for modern manufacturing. This compound is used to produce phosphorus fertilizers and to extract rare metals, including cobalt and nickel.
Currently, 80% of the global supply comes from waste from the desulphurisation of crude oil and natural gas to reduce sulfur content in gas emissions. However, the process of decarbonisation of the global economy to fight climate change is going to reduce the production of fossil fuels and, subsequently, the production of sulphur.
The team of UCL researchers is the first to identify this issue. For the authors, the solution is to reduce the need for this chemical, or a massive increase in mining — which will damage the environment — will be needed to find an alternative source.
“Sulfur shortages have occurred before, but what makes this different is that the source of the element is shifting away from being a waste product of the fossil fuel industry. What we’re predicting is that as supplies of this cheap, plentiful, and easily accessible form of sulfur dry up, demand may be met by a massive increase in direct mining of elemental sulfur. This, by contrast, will be dirty, toxic, destructive, and expensive,” said lead author, Professor Mark Maslin (UCL Geography). “Research is urgently needed to develop low-cost, low environmental impact methods of extracting large quantities of elemental sulfur from the abundant deposits of sulfate minerals in the Earth’s crust. The international community should consider supporting and regulating sulfur mining to minimise the impacts of the transition and also to avoid cheap unethical production from distorting the market.
“Our concern is that the dwindling supply could lead to a transition period when green tech outbids the fertiliser industry for the limited, more expensive sulfur supply, creating an issue with food production, particularly in developing countries,” added co-author Dr. Simon Day (UCL Institute for Risk & Disaster Reduction).
The team suggests various ways to reduce dependence on sulphuric acid, including increasing the recycling of lithium batteries and using lower energy capacity batteries, both of which require less sulphur. They also speculate that it may make more sense to develop alternative production methods, given that the current process will decrease as we use less fossil fuels. Finally, if governments recognise the sulphur crisis now, they can develop new policies to manage future demand, including stimulating recycling and finding new alternative sources.
Maslin M, Heerde L and Day S (2022) Sulfur: A potential resource crisis that could stifle green technology and threaten food security as the world decarbonises. The Geographical Journal, https://doi.org/10.1111/geoj.12475