MOULDED FUEL, VARIANTS, AND METHODS FOR PRODUCING THE SAME

摘要

The present invention pertains to the production of moulded solid fuel obtained from waste. The moulded fuel comprises a dried mixture of ground solid fuels and of a binder containing waste from the crude-oil processing industry such as oil sludge and/or recycled engine oil. This fuel also includes components selected from the following group (in % relative to the weight of the mixture): from 2 to 7 % of lignosulphonate or molasses and/or from 3 to 8 % of dehydrated activated sludge and/or from 3 to 10 % of clay and/or from 1 to 6 % of raw paraffin. The components are fed in the mould in a proportion of between 10 and 32 wt.% for the binder, the balance consisting of ground solid fuels selected from the following group: wood sawdust, peat, dehydrated manure, dehydrated bird litter, coke or coal fines, coal sludge, lignin or mixtures thereof. The method for producing moulded fuel involves mixing the ground solid fuels with the binder, moulding the mixture in the shape of bricks under a pressure of between 1 and 30 MPa and drying the mouldings (bricks) at a temperature lower than 300 °C. In a second embodiment, the moulded fuel comprises a dried mixture of ground solid fuel and of concentrated sludge from wastewater processing plants. The concentrated sludge has a water content of between 5 and 14 % and represents from 13 to 18 wt.% of the moulded fuel, the balance consisting of a ground solid fuel selected from the following group: wood or vegetal waste, lignin, peat, coke or coal fines, textile waste or mixtures thereof. The method for producing the moulded fuel according to the second embodiment involves dosing and mixing the concentrated activated sludge with the ground solid fuel, moulding said mixture and drying the mouldings. The concentrated activated sludge used in the mixture has a water content of between 70 and 80 wt.% and the mixture is moulded under a pressure of between 0.1 and 25 MPa. The mouldings are further dried at a temperature of between 50 and 180 °C for a duration of 1.5 to 0.4 hours or said mouldings are dried at room temperature for a duration of 5 to 30 hours.