Hydrogen production by steam-gasification of petroleum coke using concentrated solar power—III. Reactor experimentation with slurry feeding

We report on the experimental evaluation of a 5 kW solar chemical reactor for the steam-gasification of petcoke, carried out in a high-flux solar furnace. A petcoke–water slurry was continuously injected into a solar cavity-receiver to create a vortex flow directly exposed to concentrated solar radiation. For a nominal reactor temperature of 1500 K , a water–petcoke molar ratio of 4.8, and a residence time of 2.4 s , the maximum degree of petcoke conversion was 87%. Typical syngas composition produced was 62% H 2 , 25% CO, 12% CO 2 , and 1% CH 4 . The solar energy conversion efficiency—defined as the portion of solar energy absorbed as chemical energy and sensible heat—attained 17%. The effect of varying the particle size (range 8.5– 200 μ m ) and slurry stoichiometry (range 2.1–6.3) on the degree of chemical conversion and energy conversion efficiency was examined.