Ammonia

About: Ammonia is a research topic. Over the lifetime, 16217 publications have been published within this topic receiving 271940 citations. The topic is also known as: NH3 & azane.

Electrochemical Ammonia Recovery from Source-Separated Urine for Microbial Protein Production

Abstract: Conventional plant and meat protein production have low nitrogen usage efficiencies and high energy needs. Microbial protein (MP) is an alternative that offers higher nitrogen conversion efficiencies with low energy needs if nitrogen is recovered from a concentrated waste source such as source-separated urine. An electrochemical cell (EC) was optimized for ammonia recovery as NH3/H2 gas mixtures usable for MP production. Undiluted hydrolyzed urine was fed to the caustic-generating cathode compartment for ammonia stripping with redirection to the anode compartment for additional ammonium extraction. Using synthetic urine at 48 A m–2 the nitrogen removal efficiency reached 91.6 ± 2.1%. Tests with real urine at 20 A m–2, achieved 87.1 ± 6.0% and 68.4 ± 14.6% requiring 5.8 and 13.9 kWh kg N–1 recovered, via absorption in acid or MP medium, respectively. Energy savings through accompanying electrolytic H2 and O2 production were accounted for. Subsequently, MP was grown in fed-batch on MP medium with convention...

Combination of V2O5/WO3−TiO2, Fe−ZSM5, and Cu−ZSM5 Catalysts for the Selective Catalytic Reduction of Nitric Oxide with Ammonia

Abstract: Cordierite monoliths coated with V2O5/WO3−TiO2, Fe−ZSM5, and Cu−ZSM5 catalysts were combined to investigate the possibility of combining the advantages of the different single catalysts for the selective catalytic reduction of nitric oxide with ammonia (NO SCR) while minimizing their drawbacks. Selected combinations of two of the three above-mentioned catalysts were connected in series such that the volume of each catalyst was halved in order to maintain the total space velocity constant. The combinations V2O5/WO3−TiO2 followed by Fe−ZSM5 and the reversed catalyst order achieved markedly lower NOx reduction efficiencies (DeNOx) than the pure vanadia-based catalyst. Fe−ZSM5 applied downstream of V2O5/WO3−TiO2 did not reduce the N2O formed over the V-based catalyst at temperatures above 450 °C, as expected from the known N2O decomposition and N2O SCR activities of Fe−ZSM5. When V2O5/WO3−TiO2 was mounted downstream of Fe−ZSM5, ammonia slip was observed even at small NOx reduction efficiencies. The combinatio...