Controlled-release solid nitride fertilizer from coal fly ash--continuation
EMSL Project ID
50128
Abstract
Production of coal fly ash in the USA currently totals about 53 million tons (48 Mt), 15% of the worldtotal. 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 as much as 40-50% of the GHG footprint of N fertilizer would be eliminated. A
patent application claiming compositions and the controlled-release aspects of the fertilizer was
submitted in July 2016.
The overall project involves developing a new synthetic process for the N fertilizer, and testing of the
fertilizer in the presence of plants to demonstrate its efficacy as a fertilizer and its ability to achieve lower
N2O emissions per unit of plant growth. 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. We are also
requesting access to a large drying oven located in EMSL for drying the final biomass generated during
the testing. 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
2017-12-12
End Date
2018-09-30
Status
Closed
Released Data Link
Team
Principal Investigator