HYDROGEN PRODUCTION METHODS - A CRITICAL ASSESSMENT.

OLD, PRESENT AND NEW PROCESSES FOR PRODUCING HYDROGEN ARE ASSESSED CRITICALLY. THE EMPHASIS THROUGHOUT IS PLACED ON THOSE PROCESSES WHICH COULD BE COMMERCIALLY VIABLE BEFORE THE TURN OF THE CENTURY FOR LARGE-SCALE HYDROGEN MANUFACTURE. ELECTROLYSIS OF WATER IS THE ONLY INDUSTRIAL PROCESS NOT DEPENDENT ON FOSSIL RESOURCES FOR LARGE-SCALE HYDROGEN PRODUCTION AND IS LIKELY TO REMAIN SO FOR THE NEXT TWO OR THREE DECADES. WHILE MANY NEW PROCESSES, INCLUDING THOSE UTILIZING SUNLIGHT DIRECTLY OR INDIRECTLY, ARE PRESENTLY NOT CONSIDERED TO BE COMMERCIALLY VIABLE FOR LARGE-SCALE HYDROGEN PRODUCTION, RESEARCH AND DEVELOPMENT EFFORT IS NEEDED TO ENHANCE THE UNDERSTANDING OF THE NATURE OF THESE PROCESSES. WATER VAPOR ELECTROLYSIS IS COMPARED WITH THERMOCHEMICAL PROCESSES: THE FORMER HAS THE POTENTIAL FOR DISPLACING ALL OTHER PROCESSES FOR PRODUCING HYDROGEN AND OXYGEN FROM WATER.