Cost and Performance of Woody Biomass Size Reduction for Energy Production
Size reduction is often a first step in primary processing of biomass for its handling and downstream processing applications. Selecting appropriate equipment for size reduction has a very important role in the biomass preparation. One of the main reasons is that size reduction equipment consumes large quantities of power. In this paper, we reviewed commercial equipment used for size reduction of woody biomass. The review also included the capital cost, operating costs and performance of equipment. The performance of equipment is evaluated based on its power consumption and the quality of chip production, which includes average particle size and particle size distribution. The type of equipment used depends upon the end use of biomass. For pulping applications, woody biomass is chipped to a uniform size of 2.5cm x 5cm (1in x 2in) with a thickness of 6mm (1/4in). For energy production, the size of biomass depends upon the type of burners used and it ranges from 6mm (¼in) to 5cm (2in). To distinguish between wood chips for pulping and ground material for energy production the word "hog fuels" is used. The quality requirements for wood chips are much more stringent than the quality requirement for hog fuel. Both wood chips and hog fuels need to be clean and as much as possible free from impurities (dirt). Cost of producing wood chip ranges from $161 to $91/h, where as cost of producing hog fuels range from 252 to $229/h.
2. Transportation, Logistics and Pre-Conversion