Compacting biomass waste materials for co-firing with coal

The purpose of this study is to develop a process that allows for the optimum compaction of various biomass waste materials to form fuels that can be co-fired with coal in conventional coal-fired power plants. Previous studies have shown that the use of biomass fuels in conjunction with coal in power plants is beneficial for several reasons. The use of biomass fuels reduces the amount of harmful gases that are emitted into the atmosphere by the firing of coal alone. In addition, the biomass used is primarily waste products that would be placed in a municipal landfill. By using this waste material as a fuel, the volume of waste being disposed of in landfills can be decreased significantly. However, in an uncompacted state these biomass wastes are bulky and costly to handle and transport. Compacting the biomass will increase its density and decrease the difficulty in handling and shipping costs. Four biomass products, wood chips, sawdust, low quality waste paper, and tree trimmings were compacted at various pressures into 1.91-inch diameter logs. After compaction, the logs were subjected to ASTM standard tests for unconfined compressive strength and splitting tensile strength. Tumbling tests and drop tests were also performed according tomore » ASTM standards. The logs were also subjected to a water absorption test. Finally, each log will be tested to determine its thermal characteristics, such as the heating value and the gases each log produces when burned.« less