Effects of potassium salts loading on calcium oxide on the hydrogen production from pyrolysis-gasification of biomass

Abstract

The effects of potassium (K) salts loading on CaO on the H₂ production from pyrolysis-gasification of wheat straw were investigated. The loading of 0.25 wt% KCl could significantly enhance the CO₂ absorption capability of CaO. The CO₂ concentration in the product gas decreased sharply from 20.83 to 11.70 vol%, and the H₂ concentration increased from 48.2 to 55.5 vol%. While the loading of 0.25 wt% K₂CO₃/K₂SO₄ inhibited the enhancing effect of CaO. Further increasing the loading of KCl on CaO, the CO₂ absorption of CaO declined, but the catalytic effect of KCl on the gasification process was promoted. The loading of 0.25 wt% KCl on CaO significantly improved the cyclic performance of CaO during the pyrolysis-gasification process. Higher H₂ concentration and more CO₂ absorbed by CaO were obtained with the loading of 0.25 wt% KCl even after 5 cycles compared with those of pure CaO in the first cycle.

Keywords: Biomass pyrolysis-gasification; CO(2) absorption; Calcium oxide; Hydrogen production; Potassium salts.