Controlled-release solid nitride fertilizer from coal fly ash--characterization
EMSL Project ID
50599
Abstract
Production of coal fly ash in the USA currently totals about 53 million tons (48 Mt), 15% of the world total. Roughly half of this ash finds beneficial use in products such as concrete. Given the increasing difficulty in stockpiling coal ash due to environmental concerns, the development of new value-added product streams is a critical need. The overall goal of this project is to further develop a new slow release fertilizer product that addresses key environmental issues associated with the coal and nitrogen (N) fertilizer industries. The key concept behind this product is the fixation of N in the form of one or more solid nitride compounds that, when contacted with water, release N at an acceptable rate for plant uptake. By releasing N at a slow rate tuned to the plant needs, the creation of large pools of reactive nitrogen in the soil is avoided and the overall efficiency of N use by plants can be improved. For example, in the US roughly half of all the N applied as fertilizer is never taken up by the plants, and in other parts of the world the value is closer to two-thirds. Because, these pools of excess N give rise to emissions of nitrous oxide (N2O), either while in the soil or in waterways after the excess N is leached from the soil profile, their elimination can significantly decrease the greenhouse-gas (GHG) footprint of the N fertilizer, 90% of which is due to N2O. With successful development and commercial adoption of the solid-nitride fertilizer, we estimate that 29-58% of the GHG footprint of N fertilizer would be eliminated. A patent claiming compositions and the controlled-release aspects of the fertilizer was issued in June 2018. The specific goals of this PNNL(PDM)-funded project, which build on prior work funded by USDOE and PNNL's Technology Investment Council, are to prepare and characterize a sufficient quantity of solid-nitride fertilizer derived from fly-ash and aluminum-nitride (AlN) feedstocks to allow confirmatory testing of the fertilizer for efficacy (plant growth and N2O emissions) by an industrial collaborator. Most of this work will be performed outside of the EMSL facility. However, as part of the environmental performance work we need to determine the N content of the fertilizer product as well as how much N is released over time. We are requesting access to the total-N analyzer located in EMSL, as well as to available bench space and non-EMSL equipment located in EMSL laboratories in order to prepare for experiments and to conduct the N analyses. Our project will bear the costs of staff time required to operate the total-N analyzer. We anticipate the need for molecular-scale mechanistic analysis of the N-fertilizer release process in future iterations of this work, and so the current project, if successful, will lay the groundwork for further use of the EMSL facility.
Project Details
Start Date
2018-10-19
End Date
2019-09-30
Status
Closed
Released Data Link
Team
Principal Investigator