Particle science advances agricultural practices

WEST LAFAYETTE, Ind. — Frequent explosions plagued the U.S. grain industry until the Occupational Safety and Health Administration introduced new grain-handling standards in 1988. The number of explosions soon dropped.

Still, grain handling and processing facilities in the U.S. have experienced a 10-year average of 8.4 incidents annually, said Kingsly Ambrose, professor of agricultural and biological engineering. During the last decade these incidents have led to dozens of injuries and fatalities, millions of dollars in damage, and operational downtime.

Ambrose specializes in the agricultural applications of particle science. His current work delves into grain dust explosion prevention, improved fertilizers and grain damage modeling. Funding for these projects comes from the U.S. Department of Agriculture, CNH Industrial and Bayer. 

“Particle science is helping to develop new controlled- and slow-release fertilizers that reduce the use of chemical coatings,” Ambrose said. “Through better characterization and by structural modifications, we are developing innovative solutions that optimize nutrient delivery in fertilizers, prevent dust explosions, minimize grain damage during harvesting and handling, and improve seed germination.”

In recent years, Ambrose and his associates have patented several processes, including one that

measures the amount of light passing through a dust cloud to quantify airborne dust in a grain facility. No previous method enabled grain operators to quickly, easily and continuously monitor dust accumulation in their facilities.  

Ambrose and his colleagues disclosed their discoveries to the Purdue Office of Technology and Commercialization, which applied for patents to protect the innovations. 

He also has patented an algorithm that uses artificial intelligence to automatically calibrate for the type and amount of dust being measured.

“Depending on the grains, the amount of dust will vary. Corn generates more dust than wheat, for example,” he said. “Properties will also differ, so you want separate calibration for each type of dust,” he said.

The economic stakes of damaged grains are significant. From 5% to 10% of all grains become damaged during combine harvesting or handling and storage.

“Damages could be both internal and external. We lose quality. We lose storability. The value goes down,” he said.

Ambrose blends model development with laboratory testing to identify where most grain damage occurs. His particle science approach reveals what forces act on the grains as they run through a threshing cylinder or a combine harvester. Companies can then apply his findings to improve their systems.

“The integration of particle modeling and design allows us to support modern agricultural practices with greater precision,” he notes.

Ambrose and his collaborators have also improved the efficiency of urea, a form of nitrogen fertilizer, with a patented process of layer-wise agglomeration of urea granulates—this refers to a process where urea granules are combined or compacted in layers to form larger clusters. This process improves the granules’ size, shape or handling properties.

“If you apply urea and there is rain, even if there’s high moisture, it dissolves immediately, so the plants may not have enough fertilizer during their growth period,” Ambrose said.  

“Our approach here is to make the urea dissolve slowly, without using any additional chemicals to make them release nutrients slowly,” he said. Instead, Ambrose modified the structural components of the urea and mixed it with environmentally friendly ingredients.

“We are also using other methods to control granule density and structural characteristics so that the fertilizer doesn’t dissolve quickly,” he said. “If we can reduce the leaching of urea from the soil, we can help prevent both land and water pollution.”

He hopes that a recent grant from USDA Agriculture and Food Research Initiative will lead to further improvement in developing innovative granular urea fertilizers. This work is in  collaboration with Carl Wassgren, professor of mechanical engineering, and Kurt Ristroph, assistant professor of agricultural and biological engineering, both at Purdue; and Chad Penn, soil scientist at the USDA Agricultural Research Service.

Ambrose began conducting particle research as a graduate student at Purdue, completing his PhD in agricultural and biological engineering in 2010. He lauded the influence of the interdisciplinary faculty and facilities of Purdue’s Center for Particulate Products and Processes (CP3) on his academic career path. Now he manages the center’s characterization lab, which spans faculty members from the colleges of agriculture, engineering and pharmacy.

“Leveraging the power of particle technology will drive agriculture toward a more sustainable and safer future, helping meet global food demands while minimizing the environmental footprint,” he said. Lowering the cost of production will also be a benefit.

Ambrose was recognized as a 2024 Fellow of the Indian Society of Agricultural Engineering in November. The society cited him “in recognition of his significant contribution in the field of agricultural engineering both in India and abroad.”

His research group draws undergraduates, graduate students and postdoctoral researchers from agricultural, chemical and mechanical engineering, along with food science. Past projects have involved pharmaceutical and beverage engineering, including the powders used to make energy drinks.

In previous work, for example, he developed a model to overcome the challenges presented by mixing more than a dozen different types of powders to yield a uniform taste for a popular energy drink.

Particle science and technology is a still a developing field in the U.S. “Not many people work in this area,” Ambrose said. Purdue offers several courses in agricultural particulates, taught by Ambrose and other faculty members in the colleges of agriculture and engineering. Alumni go on to work for pharmaceutical, food and agricultural companies.

“Industry wants this kind of expertise,” he said.

About Purdue Agriculture

Purdue University’s College of Agriculture is one of the world’s leading colleges of agricultural, food, life and natural resource sciences. The college is committed to preparing students to make a difference in whatever careers they pursue; stretching the frontiers of science to discover solutions to some of our most pressing global, regional and local challenges; and, through Purdue Extension and other engagement programs, educating the people of Indiana, the nation and the world to improve their lives and livelihoods. To learn more about Purdue Agriculture, visit this site.

About Purdue University  

Purdue University is a public research university leading with excellence at scale. Ranked among top 10 public universities in the United States, Purdue discovers, disseminates and deploys knowledge with a quality and at a scale second to none. More than 107,000 students study at Purdue across multiple campuses, locations and modalities, including more than 58,000 at our main campus in West Lafayette and Indianapolis. Committed to affordability and accessibility, Purdue’s main campus has frozen tuition 13 years in a row. See how Purdue never stops in the persistent pursuit of the next giant leap — including its comprehensive urban expansion, the Mitch Daniels School of Business, Purdue Computes and the One Health initiative — at https://www.purdue.edu/president/strategic-initiatives.

Writer: Steve Koppes