Production of zinc from the reduction of ZnO in the presence of cellulose in a solar simulator

The present paper reports first experimental results showing that it is possible to produce zinc from the thermal reduction of zinc oxide in the presence of cellulose. The experiments are performed in a solar simulator where small pellets of ZnO+cellulose mixtures are submitted to a brief controlled concentrated radiation. The reaction is very fast and occurs at temperatures that are more than 1000 K lower than those corresponding to the direct ZnO splitting. Several possible reaction mechanisms are discussed and it is concluded that the ZnO reduction seems to involve interactions with the liquid species formed during cellulose thermal depolymerization. Side experiments performed in less severe conditions with an electric furnace confirm the low temperatures of reaction. In order to errand the results to the more practical case of biomass, it is suggested to continue similar experiments with other components such as lignin.