Hydrogen production by gasification of isooctane using supercritical water

The production of hydrogen by gasification of isooctane, a model compound of gasoline, was investigated in a continuously operated tubular reactor under supercritical water conditions without using any catalyst. Various experimental conditions, feed inlet temperature (80-412°C), residence time (8-16 s), reactor temperature (593-694°C), feed concentration (15-23 wt%), and oxidant concentration (0-2300 mmol/L) at a fixed pressure of 25 MPa, were examined in detail. Hydrogen peroxide was used as the oxidant. The major components of the produced gas were H₂, CH₄ and CO₂ and the minor components of the produced gas were CO and C₂H₆. As residence time, isooctane concentration, and reactor temperature increased, H₂, CH₄, and CO₂ gas yield increased while CO gas yield did not change much. Possible reaction pathways at each experimental condition are presented.