(WALSIMBook)A NOVEL APPROACH TO MITIGATING SULPHUR DIOXIDE EMISSIONS AND PRODUCING A MERCURY SORBENT MATERIAL USING OIL-SANDS FLUID COKE

摘要

It has been shown that Alberta oil-sands fluid coke, a high-sulphur by-product of the upgrading ofbitumen, can be effectively used to reduce SO_2 to elemental sulphur. In the presence of O_2 and H2O, thereduction of SO_2 is enhanced due to the production of CO and H_2, which act as supplementary reducinggases. The reaction of SO_2 also creates a porous structure within the coke, generating a sulphurimpregnated activated carbon (SIAC). In the capture of mercury from industrial flue gases, SIAC has beenshown to be a highly effective adsorbent material. Thus, there lies great potential to apply this process tometallurgical operations, which are significant sources of both SO_2 and mercury worldwide. The currentresearch aims at developing an existing SIAC technology for this purpose, while making elemental sulphuras a co-product. The challenge behind this undertaking is that these flue gases generally contain highlevels of additional oxidising gases (O_2, CO_2, and H_2O). The effect of these species on the activation offluid coke, as well as their impact on mercury sorption, is still largely unresolved. It is hypothesised thatmercury capacity is strongly affected by the O_2 potential of the activation gas due to changes in surfacechemistry arising from different reduced sulphur species. To investigate this, gas chromatography is usedto analyse the activation reaction products, while mercury sorption capacity is determined using coldvapour atomic fluorescence spectroscopy.