Low-cost carbon-based briquettes for the reduction of no emissions from medium–small stationary sources

In this paper, a novel method for preparing low-cost carbon-based briquettes is described. This procedure includes the briquetting of the carbon material, subsequent activation and finally an equilibrium adsorption impregnation of the active phase. A local low-rank coal was used for the preparation of the carbon briquettes, while both a model vanadium compound (V2O5) and the ashes of a petroleum coke (PCA) were used as the precursors of the active phase. The catalytic briquettes have been tested for NO reduction. The effect of a HNO3-oxidation previous to the impregnation has been also evaluated. The reduction tests have been carried out in presence of oxygen and with the addition of ammonia as reducing agent. The briquettes have shown to be active for NO reduction at low temperature (100–300 °C). Surface chemistry as well as the porous structure of the support, affect the catalyst behaviour. In general terms, higher NO reduction efficiencies were measured for the catalysts prepared using the pre-oxidised briquettes.