Ammonia traces

Fig. 26 Fourier transform spectrum of v2 of ammonia. Trace (a) is a section of the infrared absorption spectrum of ammonia recorded on a Digilab Fourier transform spectrometer at a nominal resolution of 0.125 cm-1. In this section of the spectrum near 848 cm-1 the sidelobes of the sine response function partially cancel, but the spectrum exhibits negative absorption and some sidelobes. Trace (b) is the same section of the ammonia spectrum using triangular apodiza-tion to produce a sine-squared transfer function. Trace (c) is the deconvolution of the sine-squared data using a Jansson-type weight constraint.

Ammonia,. trace trace trees trace. . . trees... 

Ammonia, produced due to the coexistence of H2 and N2 at high temperatures in the presence of catalyst, was estimated to be in the concentration range of 30 to 90 ppm [37, 38], Uribe et al. [39] examined the effects of ammonia trace on PEM fuel cell anode performance and reported that a trace in the order of tens of parts per million could lead to considerable performance loss. They also used EIS in their work. By measuring the high-frequency resistance (HFR, mainly contributed by membrane resistance) with an operation mode of H2 + NH3/air (feeding the anode with hydrogen and ammonia), they obtained some information related to membrane conductivity, and found that conductivity reduction due to ammonia contamination is the major cause of fuel cell degradation. 

The use of an alkaline fuel cell also involves an ammonia cracker, but since the electrolyte of the AEC is not sensitive to ammonia traces, the system is slightly simpler because of the elimination of the purification step. In addition, alkaline cells can run at slightly elevated temperatures (like the high-temperature PEM or higher), and they do not contain expensive platinum. AFCs could be operated with the same choice of metal ammine complex as the PEM. 

Hazardous Decomp. Prods. Thermal decomp, prods. nitrogen, CO ammonia, traces of cyanic acid combustion prods. CO<, NO<, smoke, ash... 

Precaution May form explosive dust-air mixts. will continue to burn once ignited incompat. with strong oxidizers, adds, bases, metallic compds. (will reduce decomp, temp.) evolves large vols. of gas during decomp. Hazardous Decomp. Prods. TTiermal decomp, prods. nitrogen, CO ammonia, traces of cyanic add combustion prods. CO NO, smoke, ash... 

Hazardous Decomp. Prods. Heated to decomp, emits CO, CO2, NOx, ammonia, traces of organic compds. inc. hydrogen cyanide, nitriles, isocyanates, nitrosamines, amines NFPA Health 3, Flammability 4, Reactivity 0 Uses Intermediate in organic synthesis intermediate for water-gel explosives, accelerators, pharmaceuticals, insecticides, N-methylpyrrolidine, methylalkanolamines, surface active agents, fungicides in tanning component of photographic developers and paint removers fuel additive prod, of dyes polymerization inhibitor rocket propellant See also Methylamine... 

As with other processes involvir reactions between hydrochloric acid (or chlorides) and ammonia, traces of free chlorine in the acid feed can lead to disastrous explosions caused by the formation of nitrogen trichloride in the saturator. Hence, adequate safety precautions must be installed whereby the HCI gas feed is monitored and the flow discontinued when chlorine is detected. This can be accomplished by such means as bypassing a small stream of gas through a photocell-calorimeter unit containing potassium iodide or using a modern continuous gas analyzer of the absorption or chromatographic type. 

A. Ninhydrin spray. Developed plates dried at 100°C and sprayed with pyridine reheat to aid removal of ammonia traces... 

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