SUNFLOWER STALKS AS A POSSIBLE FUEL SOURCE

Sunflower (Helianthus annus) is a deciduous plant whose yearly production has grown dramatically in Spain over the last few decades. From sunflower wastes, consisting chiefly of stalks, it is possible (by acid hydrolysis and subsequent fermentation of the hydrolysate) to obtain ethanol for use as fuel. The kinetics of the acid hydrolysis of sunflower stalks has been studied in the temperature range 110-140 °C, using hydrochloric acid at concentrations between 0.5 and 6.0 wt %. The experimental results obtained conform to a sequence of two consecutive first-order reactions: cellulose residue → k1 sugar → k2 decomposition products. The rate constants k1 and k2 are proportional to the acid concentration and exponentially related to the temperature. © 1990.