Hydride chemical compressor. Phase I, final report

Technical Report · Thu Jan 01 04:00:00 EST 1981

DOI:https://doi.org/10.2172/6318164· OSTI ID:6318164

Lynch, F. E.; Nye, R. A.; Turillon, P. P.

A proof-of-concept, bench-size hydride chemical compressor has been successfully designed, constructed, and tested. It consists of two electrically heated tube bundles each containing 15 kg of hydriding alloys. The tube bundles are alternately heated and cooled in order to provide continuous output of high pressure hydrogen. Electrical resistance heating was selected for ease of demonstration and testing. In continuous operation, this hydride compressor delivered 20.3 liters/min (43 SCFH) of hydrogen at a pressure of 42.2 atmospheres (650 psia). In one experiment, a peak pressure of 75 atm (1100 psia) was obtained with the power supply available. The efficiency of operation was lower than anticipated (4.5% instead of 12%). The reduced efficiency of the bench-scale unit was caused by mechanical design details (such as the excessive amount of copper due to the electrical heating system) as well as problems with the hydriding alloy (reduced capacity at elevated temperature and low plateau pressure at room temperature). After 700 cycles of operation, an increase in heating time and corresponding reduction in efficiency were observed. A sample of the hydriding alloy was removed from the unit and analyzed. Evaluation of this sample revealed a decrease in plateau pressure for a given temperature compared to a sample of the same alloy before compressor cycling. The increase in alloy stability resulted in longer cycling time. A step-by-step analysis of the parameters affecting overall efficiency showed that the major factors were the thermal mass of the system, the fraction of hydride decomposed at high temperature and the losses by radiation and thermal convection. The results of these tests will be used in the design of improved hydride chemical compressor for industrial applications.

• Research Organization: Brookhaven National Lab., Upton, NY (USA); Hydrogen Consultants, Inc., Denver, CO (USA); Denver Research Inst., CO (USA); ERGENICS, Wyckoff, NJ (USA)
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 6318164
• Report Number(s): BNL-51369; ON: DE81030199
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420200* -- Engineering-- Facilities
Equipment
& Techniques
ALLOYS
ALUMINIUM ADDITIONS
ALUMINIUM ALLOYS
CHEMICAL REACTIONS
COMPRESSORS
ELEMENTS
FEASIBILITY STUDIES
GAS COMPRESSORS
HYDRIDATION
HYDROGEN
INTERMETALLIC COMPOUNDS
LANTHANUM ALLOYS
NICKEL ALLOYS
NICKEL BASE ALLOYS
NONMETALS
PERFORMANCE
RARE EARTH ALLOYS
TUBES