Bioethanol production using high density Eucalyptus crops in Uruguay

Experimental scale crops for Eucalyptus grandis, Eucalyptus benthamii, Eucalyptus dunnii and Eucalyptus tereticornis, at 2,220, 4,440 and 6,660 trees ha(-1) were established in two soil units, at Paysandu and Tacuarembo, Uruguay. Wood samples were taken from twenty-two-months-old trees, and were used to produce bioethanol by prehydrolysis simultaneous saccharyfication and fermentation process (PSSF). Cellulose and lignin content was analyzed. Species and planting density affected biomass production at both sites; the highest value was obtained with E. dunnii at 6,660 trees ha(-1) at Paysandu. Cellulose content of wood varied between species at both sites, but only between planting densities at Tacuarembo. The site effect showed that the highest amount of cellulose (14.7 Mg ha(-1)) was produced at Paysandu. E. benthamii and E. tereticornis wood showed higher lignin contents,conversely, the PSSF yields showed no differences, which led to a bioethanol average of 97 L Mg-1. Bioethanol productivity was associated to the biomass productivity. It was possible to obtain 2,650 L ha(-1) of bioethanol usingwood from E. benthamii, E. dunnii and E. grandis at 4,440 and 6,660 trees ha(-1) at Paysandu, and with E. benthamii at 4,440 and 6,660 trees ha(-1), and E. dunnii at 6,660 trees ha(-1 )at Tacuarembo.

Automated summary

The study planted different species of Eucalyptus trees in experimental fields in Uruguay, finding that species and planting density have an impact on biomass production and wood cellulose content. Different species showed varied performances at different sites, with the highest cellulose content and bioethanol productivity achieved in certain conditions.