Quantitative and qualitative characteristics of biomass derived from pruning Phoenix canariensis hort. ex Chabaud. and Phoenix dactilifera L

The lack of information about quantitative and qualitative characteristics of residual biomass from ornamental species means that these materials are often left out of biomass and bioenergy projects. Biomass derived from annual pruning operations of Phoenix canariensis hort. ex Chabaud. and Phoenix dactilifera L. was quantified and indirect biomass prediction equations for trees of both species were developed. Direct analysis of the gross calorific value (GCV), determination of elemental composition and moisture content were also performed. This allowed further development of indirect GCV prediction models, which are economically attractive and less time consuming in comparison to direct analysis. Mean quantity of dry biomass and mean moisture content per tree were 24.67 kg and 74.82% for Phoenix canariensis hort. ex Chabaud. and 36.13 kg and 71.03% for Phoenix dactilifera L., respectively. Best biomass and GCV prediction models were obtained when several explicative variables were taken into account (R2 = 53, R2 = 65) (R2 = 74, R2 = 93). The comparison of both species indicated that the Phoenix canariensis hort. ex Chabaud. fronds are longer (mean 3.86 m) and heavier (mean 3.35 kg) than those of Phoenix dactilifera L.. Oposite, the quantity of cut fronds per palm is higher in case of Phoenix dactilifera L. (mean 46.75 fronds).