Hydrogen production from heavy oil in the presence of calcium hydroxide☆

A new hydrogen production method, the HyPr-RING process was applied to a vacuum residue of Arabian light crude oil to clarify the effects of added water, calcium hydroxide, which absorbs carbon dioxide, and the reaction temperature. It was determined that when a sufficient amount of calcium hydroxide was present, it provided enough water to produce hydrogen and additional water was not necessary. To consume all of the carbon dioxide in 1 mol of carbon from the feedstock, 25 mol% of calcium hydroxide was needed and hydrogen production was saturated at 50 mol%. Carbon conversion was dependent mainly on the temperature and was slightly dependent on water and pressure. The reaction pressure was as low as 4.2 MPa. Thermal decomposition of the feedstock was the dominant reaction below 600 °C, which produced methane.