Electrolyzer Testing

FIGURE 8.9 Current density for MEA 38 in the SPE electrolyzer test module set up at various temperatures. 

The Hydrogen Research Institute in Canada has developed and tested a stand-alone renewable energy system composed of a 10 kW wind turbine, a 1 kWpeak photovoltaic array, a 5 kW alkaline electrolyzer, and a 5 kW PEM fuel cell. The components of the system are electrically integrated on a 48 V DC bus [50]. 

Murray J.N., Yaffe M.R., Testing aqueous caustic electrolyzers at high temperatures, Int. ]. Hydrogen Energ., 4,193-204,1979. 

Standards Development Electrolyzers UL, CSA Reformers UL, CSA, API Performance Test Procedures ASME, CSA Chemical Hydrides UL, CSA.NFPA... 

The tests are run in two parallel streams the first stream is electrolyzed in... 

Test Electrolyzer Version 2 - Pocket Type A- 55 FrM — —Test Electrolyzer Version 2 -Pocket Type B- 80 USM... 

Moissan reasoned that if he were trying to liberate chlorine he would not choose a stable solid like sodium chloride, but a volatile compound like hydrochloric acid or phosphorus pentachloride. His preliminary experiments with silicon fluoride convinced him that this was a very stable compound, and that, if he should ever succeed in isolating fluorine, it would unite with silicon with incandescence, and that therefore he might use silicon in testing for the new halogen. After many unsuccessful attempts to electrolyze phosphorus trifluoride and arsenic trifluoride, and after four interruptions caused by serious poisoning, he finally obtained powdered arsenic at the cathode and some gas bubbles at the anode. However, before these fluorine bubbles could reach the surface, they were absorbed by the arsenic trifluoride to form pentafluoride (18, 23). 

The Northern States Power facility experienced significant operational problems with their electrolyzed pebble bed scrubber during tests burning from 7 to 9 percent TDF (mixed with woodwaste) in a retrofitted fluidized combustion bed boiler. The electrostatic voltage dropped to near zero on several occasions on others, the collection efficiency declined continually. Several reasons for this are suggested. First, the ash during the test was more cohesive... 

Table II indicates the four major areas to be treated in the overall development program. These are the Electrolyzer, Sulfur Trioxide Reduction, Integrated Testing, and Process Studies. The sections below describe the current status and the effort to be accomplished in each area for the duration of the program.

Electrode Materials and Fabrication Separator Materials Pressurized Cell Performance Electrolyzer Design Optimization Scale-Up Tests... 

The experimental work done to date in the reaction kinetics of SO2 depolarized electrolyzers, electrocatalyst evaluation, and tests on small experimental cells has led to projections of cell voltage for a mature technology. Table III presents these projections, as a function of electrolyte concentration and operating temperature. These projections will be refined, as the development work progresses, to expand the matrix of variables, increase the confidence level in the figures, and define an optimum set of operating parameters. 

Following the gas pocket solution, test electrolyzers of industrial size (e.g. 2.5 m2 cross section) were equipped with ODC s and run successfully over a longer period. Current densities up to 6 kA m-2 are accessible, going along with cell voltages of only 2.0-2.2 V. 

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