Selected topics on hydrogen fuel

Abstract

The feasibility of using hydrogen as a fuel will be determined by the availability and cost of hydrogen.This chapter considers techniques and costs of producing gaseous hydrogen along with costs of producing liquid, slush and solid hydrogen. It also examines the potential by-products that could lower the overall cost of using hydrogen.Fossil fuels and water are the two sources of hydrogen. Today most industrial hydrogen is derived from hydrocarbons (mainly natural gas) and costs 10 to 15c/kg to produce. When natural gas costs more than approximately 80c/MBTU, coal becomes a competitive source Vith production costs of 20 to 25c/kg. MBTU = BTU x 10 throughout this chapter.As the fossil fuels are depleted, water will become the principal source of hydrogen.The two most promising means of producing hydrogen from water are electrolysis and thermochemical decomposition. Although electrolysis is an existing technology, it is not cost competitive with other existing processes unless electrical power costs less than 5 mills/ kW-h-exceptions occur in those cases where ultra-high purity and/or small quantities of hydrogen are required. Thermochemical decomposition uses a combination of heat and chemicals to decompose water; the process requires several intermediate steps involving chemical reactions and separations.1.3 COST TO MAKE LIQUID, SLUSH, AND SOLID HYDROGEN FROM GASEOUS HYDROGEN Producing liquid, slush, and solid hydrogen from gaseous hydrogen requires capital investment, energy expense, and operating expense for the liquefier and/or refrigerator.An estimate of these costs can be obtained using information from a survey and correlation of current refrigerator/liquef ier capital costs and energy requirements by Strobridge [15].Liquefaction costs presented herein include the cost of gas purification; however, we are unable to supply a breakdown of purifying costs, as these are proprietary industrial data.

Is hygrogen safe?

“…Hydrogen is being considered as a replacement fuel [95] in all of the major fuel markets and will continue to penetrate these markets as time passes.…”

“…Hydrogen is a feedstock in the process industries [95,97] and has been successfully handled for decades.…”