Production of COx-free hydrogen from biomass and NaOH mixture:: Effect of catalysts

Hydrogen without CO and CO2 was produced through the reactions of cellulose with NaOH and water at 473-773 K according to the following overall stoichiometric reaction: (C6H10O5) + 12NaOH + H2O = 6Na(2)CO(3) + 12H(2). Cellulose reacted with NaOH and water to produce hydrogen, Na2CO3, and a small amount of methane as the byproduct. The total yield of hydrogen obtained through the reaction at a temperature range 473-773 K was estimated to be 62% on the basis of the stoichiometric equation. The formation of hydrogen was specifically enhanced by the addition of Ni, Co, Rh, or Ru catalyst supported on Al2O3 to the mixture of cellulose and NaOH, and the total yields of hydrogen were dramatically improved to almost 100%. Among the many catalysts tested, Ni/TiO2 and Ni/Cr2O3 were promising catalysts which maintained catalytic activity during repeated reactions, keeping the hydrogen yield almost 100%.