Combined steam/dry reforming of bio-oil for H2/CO syngas production with blast furnace slag as heat carrier

Abstract

Combined steam/dry reforming of bio-oil with blast furnace slag as heat carrier for the syngas production with the H2/CO ratio of 3:1 for further methanation, was investigated. The increase of H2O addition can increase the total yield of H2 and CO, but also increase the critical temperature at which 3:1-H2/CO syngas was obtained, while the increase of CO2 addition can decrease the critical temperature, but the syngas yield was also decreased. When the steam/carbon (S/C) ratio was 3.0 and the CO2/carbon (CO2/C) ratio was 0.5, the critical temperature decreased to 804 °C, with the potential H2 yield of over 90%. Although the addition of slag and how much slag to be added had almost no any thermodynamic effect on the combined reforming of bio-oil under the condition where higher potential H2 yield can be obtained, the slag as heat carrier could supply all heat for the combined reforming process. When the added slag mass was 3.99 times bio-oil mass, the combined reforming at the S/C ratio of 3.0 and the CO2/C ratio of 0.5 can occur spontaneously for the production of 3:1-H2/CO syngas. The present study could offer important guidance toward utilization of this novel process for further methanation.