Have you ever wondered about the carbon impact of growing your dinner? Scientists have just found a new way to calculate part of it.

A major ingredient in the production of fertilizers for global food production, ammonia, also contributes significantly to global greenhouse gas emissions and the use of fossil fuels. Recently, scientists from the Argonne National Laboratory of the United States Department of Energy (DOE) have modeled how much it would cost to use more environmentally friendly methods that emit less carbon to produce ammonia.

Ammonia is primarily made by reforming natural gas, a process that contributes to atmospheric emissions of carbon dioxide and methane. “The ultimate goal is to use renewable or nuclear energy and clean hydrogen to produce it instead,” said Argonne lead scientist Amgad Elgowainy.

Elgowainy and his colleagues used Argonne’s Greenhouse gas, Regulated Emissions, and Energy use in Technologies (GREET®) model to estimate the environmental impact of ammonia production from various energy sources. Next, they used a techno-economic model to examine the cost of two different ways to produce ammonia more sustainably.

The first way avoids part of the carbon release by capturing a certain percentage of the carbon produced and then storing it in geological formations. This technological path can be implemented at a relatively low cost, since the total cost of ammonia production only increases by about 20%.

In the other nearly carbon-free pathway, water is electrolyzed to produce hydrogen, which is then combined with nitrogen to produce ammonia. “Using renewable or nuclear energy to separate water through electrolysis gives us a way to produce ammonia with almost no carbon impact,” Elgowainy said. “That said, the cost of doing it is currently higher than the carbon capture route.”

According to Elgowainy, there is significant scope for reducing the cost of electrolysis technology that could eventually make the water electrolysis route more competitive. “Research in this area could end up changing the market significantly, but it will take investment in developing and scaling up production of electrolysis technologies,” he said. “With cost reductions and efficiency improvements to meet the DOE’s goal of $1/kg of clean hydrogen, the path to electrolysis could enable a nearly carbon-free and affordable way to produce hydrogen. ammonia.”

– This press release was originally published on the Argonne National Laboratory website