Disposal and upgrading of the oil shale wastes by fluid- and gas-phase extraction in chemically active media
Extensive utilization of the oil shale as the main natural resource of Estonia for oil and electricity production has been engendered millions of tons organomineral wastes and to those millions of tons are added every year. Semicoke, fusses and shale ash are oil shale wastes of different degree of technological transformation and contain different content of organic matter. In this fashion the oil shale wastes are unfit for use and hazardous ones and there is no technology for those re-utilization. Just the re-utilization of oil shale wastes is the clue question for continuation of the pre-existing technology of oil shale processing. The main goals of the present project are to work out novel and effective methods basing on sub- and supercritical extraction in chemically active media for separation the organic matter from fusses and semicoke as the liquid product in order to upgrade simultaneously both the organic (into a product similar to shale oil or its fractions) and mineral part (purified as much as possible from organics by the yield of liquid and gaseous products) with the aim for further utilization of the products obtained as well as to determine the character and stability of carbon and sulphur modifications present in shale ash. The project results in utilization of oil shale wastes as an alternative raw material for production of the products needed, estimation and diminishing the environmental hazard of oil shale wastes deposits and that all leads to the significant increase in oil shale processing and to the liquidation of more and more enlarging semicoke and ash deposits - the main source of pollution in Estonia.
Oil-shale mining causes numerous negative changes in the environmental conditions, some of which are unavoidable due to technological, some for economic reasons.
Fortunately environmental achievements also matter for our oil shale companys and they keep up with the regulations and future principes.
Urmas Metsmaa, Henek Tomson, Madis Salumaa 12A