Biofuel particles comprising sewage sludge, cellulosic material and binder, prepared by coating a granular mixture of these components with a mixture of binder and sludge

摘要

Sludge, cellulosic material and binder are mixed in a specific weight ratio depending on their moisture contents, forming dry granules which are coated with a layer of a mixture of binder and sludge. A method for burning sewage sludge comprises mixing the sludge with particulate combustible cellulosic material (e.g. sawdust) and a binder comprising biofuel ash and/or unslaked lime, and using the mixture as a fuel for a biofuel-burning oven. The sludge, which contains 65-85 wt.% water, cellulosic material and binder are mixed using a screw in an approximate weight ratio of 30:60:10 when the moisture contents are 75, 50 and 0 % respectively. The resulting dry, granular material predominantly comprising individual cellulosic particles is coated with a layer of a mixture of binder and sludge. The resulting biofuel can be added directly to the oven or it can be stored prior to burning. An Independent claim is also included for the biofuel obtained by this method.