POTENTIAL OF CARDOON LIGNOCELLULOSIC BIOMASS TO GENERATE THERMAL ENERGY

MANCINI, M.; BOVER, J.; POLVERINI, E.; RUA F.; CORTI, J.; BALABAN, D.; BRESÓ, A.; GARELLI, A.; CRAVERO, V.

Mendoza

Congreso; IV Joint Meeting of The Biology Societies of Argentina; 2020

In last year, the use of biomass as fuel has been increasing worldwide. Replacing fossil energy input with renewable energy within the energy consumption matrix is not only an environmental responsibility, but also a benefit in production costs. Cardoon (Cynara cardunculus var. altilis) is a perennial species belonging to the Asteraceas family, it has an annual crop cycle, low maintenance requirements and produces between 15 to 20 tons/ha/year of lignocellulosic biomass. The aim of this work was to evaluate the potential of cardoon lignocellulosic biomass for thermal energy production. A triturate sample of lignocellulosic biomass (5 kg) was used to determine: apparent density (DA) and percentage of moisture (on wet basis) and ash content (% Cz), volatile matter (% MV), fixed carbon content (% CF) and heating value (on dry basis). Analyses were performed according to standardized protocols reported in UNE 164001: 2005 EX. The energetic potential was calculated considering that the main demand of the energy generated by combustion is for thermal energy production (hot air, hot water, or steam). The biomass presented a DA = 139.88 kg/m3, slightly lower than recommended value (150 kg/m3). The moisture percentage was 16.08% m/m, the % Cz was 7.60% m/m, MV = 74.98%, and CF = 7.41% m/m. The higher heating value was 4123.56 kcal/kg while the lower heating value was 3117.42 kcal/kg. This last value indicates that the heat energy yield after combustion is similar to other solid fuels, such as firewood (3000?3700 kcal/kg). The energy density presented a value of 442.81 Mcal/m3. These results were used to determine the energy potential by direct combustion of cardoon biomass. It was found that to heat a 100 m2 room, a thermal energy power of 11000 kcal/h is required, which is reached with 4.9 kg of biomass/h; while to obtaining hot water in a horizontal humotubular boiler (required thermal energy power 3000 kcal/h), 1.5 kg/h are needed and for stream production (thermal energy power 480000 kcal/h) the requirement amounts to 275 kg/h. According to these results, it is concluded that the crushed cardoon is suitable as an energy source, mainly in short logistics schemes and also it can be used for multiple thermal energy applications. In future studies, the residue generated by combustion will be characterized to determine whether an additional benefit is obtained from its use as a by-product.