Aadco Hydrogen Generators
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History
In the past, all hydrogen generators relied upon a strongly alkaline
electrolyte mixed and replenished by the operator as it was
expended. In 1959 the solid polymer electrolyte (SPE) was
introduced for such electrochemical devices as fuel cells,
electrolysis units and oxygen concentrators, all utilizing the same
basic SPE and electrode components. In 1974 a hydrogen
generator was developed by applying the solid polymer electrolyte
technology from the aerospace applications. The SPE is a cation
exchange membrane that has the stability and performance
requirements for a long-lived electrolysis system and replaces the
caustic electrolyte. It is a solid plastic sheet of perfluorinated
sulfonic acid polymer producing hydrogen and oxygen by the
electrolysis of water. This same polymer is incorporated in all
AADCO hydrogen generators.
Installation
Once connection to the proper electrical outlet has been made, the
water storage tank filled with deionized water and the deionizer and
indicating desiccator installed, the generator is ready for operation.
The output can be connected to a single using instrument or "tee'd"
to several instruments, provided the total hydrogen consumption
does not exceed 225 cc/min at operating pressure. Where higher
flows are required, several hydrogen generators can be
manifolded.
Models
AADCO hydrogen generators are available in both bench and rack
mounted instruments designed to meet the needs of laboratory
operations or other small hydrogen requirements. Performance,
operation and components are identical for both units.
Operation
Within ten to eleven minutes upon completion of the installation and
applying power to the generator, full internal pressure, as shown on
the Internal Pressure gauge,will be reached. The operator then sets
the output pressure at any pressure from 2 to 60 psig with the
output pressure regulator, monitoring this pressure on the Output
Pressure gauge. The flow is then regulated at the using equipment
from 1 – 225 cc/min. The performance of the generator during
operation is indicated automatically by various diagnostic lamps
and pressure gauges. Water consumption is 11 cc/hr at maximum
output, allowing 14 days uninterrupted operation. Water can be
added at any time without ceasing operation.
Safety
Of major significance are the OSHA regulations governing the
siting and usage of high pressure cylinders. The AADCO
1225-series hydrogen generators, with their low interval volume and
low pressure, satisfy OSHA requirements and eliminate most
problems associated with hydrogen use. Also eliminated are the
hazard of stored hydrogen in the laboratory, the tedious and
dangerous changeout of cylinders and regulators, and also
personnel injuries. The SPE membrane allows use by untrained
technicians without the worrisome handling of concentrated caustic
solutions.
Purity
The Ultra High Purity (Gold Label) grade of hydrogen supplied by
compressed gas manufacturers is equivalent to the hydrogen purity
(99.995+%) generated by the AADCO 1225-series of hydrogen
generators. This purity exceeds the requirements for most
laboratory applications. For those applications that demand
extremely pure hydrogen: nickel or ruthenium catalyst systems used
in the conversion of CO and CO2, to CH4 and subsequent FID
detection, TOC analyzers used in micro level water analysis,
electrolytic conductivity detectors operated in the
reductive mode and microcoulometric systems, it is
recommended that an AADCO 560 series hydrogen purifier be
incorporated to eliminate the low level gases dissolved in the water
supply. These purifiers will deliver hydrogen, under pressure, of
such purity as to defy detection of any contaminant by any known
analytical technique. |
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