Hydrogen production using solid-polymer-electrolyte technology for water electrolysis and hybrid sulfur cycle

Technical Report · Sat Sep 01 04:00:00 EDT 1979

DOI:https://doi.org/10.2172/5496962· OSTI ID:5496962

Sedlak, J. M.; Russell, J. H.; LaConti, A. B.; Gupta, D. K.; Austin, J. F.; Nugent, J. S.

An evaluation was made of the comparative technoeconomics of hydrogen production using the General Electric Company's solid polymer electrolyte technology in two advanced processes: Water Electrolysis and Hybrid Sulfur Cycle Water Decomposition. In water electrolysis, based on the solid polymer electrolyte, only purified water is fed to the cell. The cell voltage is typically 1.65V at 1000 amp/ft/sup 2/ (ASF), 300 psia and 300/sup 0/F. The sulfur cycle electrolyzer requires a feed stream of water and sulfur dioxide in concentrated sulfuric acid (50-80%). The cell reaction in this case is: 2H/sub 2/O + SO/sub 2/ ..-->.. H/sub 2/SO/sub 4/ + H/sub 2/. Stoichiometrically formed sulfuric acid must be subsequently decomposed at very high temperature to recover the sulfur dioxide for recycling. An experimental solid polymer electrolyte sulfur cycle electrolyzer projected a voltage of 0.69 volts at 186 ASF in 50% H/sub 2/SO/sup 4/ at 300 psia and 183/sup 0/F. Undesirable sulfur and sulfide by-products were detected at the cathode. Comparative costs of producing hydrogen by solid polymer electrolyte water electrolysis, and by solid polymer electrolyte sulfur cycle electrolysis, were determined on the basis of performance and economic analysis of plants running at a level of 380 million SCFD. The optimum solid polymer electrolyte water electrolysis plant operates with an overall efficiency of 40.2% at 1000 ASF and a hydrogen gate price of $2.25 per thousand SCF (at 1976 cost levels). A highly optimistic assessment of solid polymer electrolyte sulfur cycle plant indicated an overall efficiency of 42.5% at 400 ASF. The hydrogen gate price (at 1976 cost levels) was 9.8% higher than for solid polymer electrolyte water electrolysis. The principal conclusion of this study is that the solid polymer electrolyte-based hybrid sulfur cycle process shows no technological or economic advantage over existing (solid polymer electrolyte-based) water electrolysis systems for the production of hydrogen.

• Research Organization: General Electric Co., Wilmington, MA (USA)
• OSTI ID: 5496962
• Report Number(s): EPRI-EM-1185
• Country of Publication: United States
• Language: English

Related Subjects

08 HYDROGEN
080101* -- Hydrogen-- Production-- Electrolysis
080102 -- Hydrogen-- Production-- Thermochemical Processes
080400 -- Hydrogen-- Economic
Industrial
& Business Aspects
COST
ECONOMICS
EFFICIENCY
ELECTROLYSIS
ELECTROLYTES
HYDROGEN COMPOUNDS
HYDROGEN PRODUCTION
INORGANIC ACIDS
LYSIS
POLYMERS
SULFURIC ACID
TECHNOLOGY ASSESSMENT
THERMOCHEMICAL PROCESSES