Mechanical characteristics of standard fuel briquettes on biomass basis

Abstract

The measuring has proved that the energy herbs can be pressed into the form of compact briquettes. It regards 9 varieties of the energy crops, i.e. coriander, crambe, saphlor, sorrel, sorghum, reed canary grass, knotweed, barley straw and rapeseed straw. These energy crops are disintegrated by the grinding mill ŠV 15 (manufacturer Stoza, Ltd.) before the pressing. The fraction size is given by the mesh size of circular cross section of diameter 15 mm. All the crops have constant moisture content during the measuring and uniform diameter 65 mm of the resulting briquettes. The biomass moisture ranges from 9 to 11%. The pressing is conducted by the briquette press HLS 50 (manufacturer Briklis, Ltd.). The measuring results have shown the highest volume weight in following energy herbs: coriander, saphlor, rapeseed straw, sorghum, sorrel and knotweed. The lowest volume weight was found in these crops: reed canary grass, crambe and barley straw. The measuring proved that the highest force for the briquette disintegration is necessary for knotweed, saphlor, sorrel, sorghum and coriander. The lowest force for the briquette disintegration needs the reed canary grass, barley and rapeseed straw and crambe. Crambe contains a high level of oil in its seeds and this fact causes difficulties during their pressing as good mechanical parameters regards, thus they cannot be pressed into the briquette form.