Residue pelleted agricultural

In this analysis, only air-dried wood chips or billets, and pelletized agricultural residues will be considered. The moisture content of these fuels is assumed to be - 20 weight percent. Charcoal briquets are also a highly desirable fuel, but their production requires significant capital investment. The use of charcoal, however, warrants consideration in future studies. (See references 3 and 15 for detailed discussions of biomass fuel use in vehicle engines.)... 

Fabrication. Processes for fabricating solid fuel pellets from a variety of feedstocks, particulady RDF, wood, and wood and agricultural residues, have been developed. The pellets are manufactured by extrusion and other techniques and, in some cases, a binding agent such as a thermoplastic resin is incorporated during fabrication. The fabricated products are reported to be more uniform in combustion characteristics than the raw biomass. Depending on the composition of the additives in the pelletized fuel, the heat of combustion can be higher or lower than that of the unpelletized material. 

Although not listed in Table 6.4, the combustible fraction of municipal solid waste, RDF, is commercially available as pellets that are similar to those produced from agricultural and woody residues (c/. Davis and Koep, 1990). The pellets have heating values of about 16.3 to 18.6 MJ/kg, moisture contents of 8 to 10 wt %, less than 10 wt % ash, and densities of 600 to 700 kg/m. ... 

The types of fuel that will be considered for use in vehicle mounted gasifiers include wood chips ( 30 weight percent H2O) and densified fuel pellets ( 10 weight percent H2O) produced from agricultural residues. 

If five plants were required for the production of densified fuel pellets from agricultural residues, the investment costs for a total capacity of 580 metric tons/day would probably exceed 10 million. Therefore, the investment costs associated with the option of using vehicle-mounted gasifiers may be about 15 million. 

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