A thermochemical study of the W/WO_3 system: a solar to fuel converter for syngas production

摘要

Production of syngas is proposed utilizing the W/WO_3 redox system and employing a solar-powered two-step thermochemical cycle. Three chemical reactions occur in two chambers. Assisted by a solar concentrator, a high temperature reaction reduces WO_3 powder to metallic tungsten in both chambers. Subsequently, the temperature in one of the chambers is lowered and H_(2(g)) is produced via re-oxidation of the tungsten powder using steam. The temperature in the other chamber is simultaneously lowered to an intermediate temperature and CO_((g)) is produced via oxidation of the tungsten powder using CO_(2(g)). The gas streams coming out of the two chambers result in the syngas production. A complete thermodynamic analysis of the system is described. The W/WO_3 redox cycle offers greater gravimetric fuel productivity compared to previously proposed systems, and the entire cycle can be operated below 1273K.