Abstract:
The sources of renewable energy have acquired considerable interest in recent years, at global and national level. The
investigation of local as well as introduced herbaceous plant species for multiple energy purposes is an important objective.
We investigated some agro-biological peculiarities, the biochemical composition of the green mass and silage; energy
characteristics of dry biomass of the perennial herbaceous species: local cv. Energo of Virginia mallow, Sida
hermaphrodita, and an local ecotype of elecampane, Inula helenium, the most frequently used energy crops: maize – for
biogas production and wheat straw – for solid biofuel production were used as control variants. It has been established
that the gas-forming potential of the green mass of perennial species varied from 440 to 454 l/kg ODM and silage – 433
to 458 l/kg ODM, maize – 536 and 557 l/kg ODM, respectively. The best results of biomethane production were
achieved by cv. Energo of Sida hermaphrodita (4000-4050 m3
/ha) versus maize Zea mays (3127- 3296 m3
/ha). Inula
helenium substrate had higher content of methane (53.1-53.8 %). The briquettes of Sida hermaphrodita and Inula
helenium were distinguished by high bulk density (813-1162 kg/m3
), moderate gross calorific value (18.3-18.7 MJ/kg)
and ash content (1.5-3.0 %), but wheat straw– by low bulk density (704 kg/m3
) and calorific value (17.0 MJ/kg) and very
high content of ash (5.1 %). Potential of energy production – 240-380 GJ/ha. The best results were achieved
by cv. Energo of Virginia mallow, due to its high biomass productivity.