AUTHOR=Dingra Nin , Witty Michael , Celis Marie , Boppana Narendra , Ayudhya Theppawut 

TITLE=Transformation of struvite from wastewater to a hydrogen fuel storage compound ammonia borane

JOURNAL=Frontiers in Chemistry

VOLUME=11

YEAR=2023

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2023.1269845

DOI=10.3389/fchem.2023.1269845

ISSN=2296-2646

ABSTRACT=<p>Ammonia borane (NH<sub>3</sub>BH<sub>3</sub>) is a carrier of hydrogen gas that is known as a carbon-free renewable energy source. A high hydrogen content of ammonia borane and its stability in air at ambient temperatures make it a valuable molecule for its potential use as a hydrogen storage compound. In this study, we investigate a new approach for synthesizing ammonia borane using wastewater-derived ammonia source. Wastewater recycling has always been a global interest towards sustainability. In addition to reclaiming the water, recycling nutrients in wastewater is a topic of interest. Nutrients such as nitrogen, magnesium, and phosphorous are readily recovered from wastewater as struvite (NH<sub>4</sub>MgPO<sub>4</sub>·6H<sub>2</sub>O). This new process involves converting urine into struvite, and then reacting struvite with alkali borohydrides to produce a high-purity ammonia borane. The use of mild reaction conditions without extensive purification process, together with high purity ammonia borane product make this process a desirable course of action for recycling the nitrogen waste. In the course of moving towards a sustainable environment, the energy and wastewater industries will benefit from this combined process of nitrogen removal from wastewater to generate a renewable carbon-free energy molecule.</p>