tEfficient energy production relies on complementary use of crop residues, to enhance the amount ofenergy obtained per unit biomass. In this frame, sugarcane bagasse (SB) was pretreated and the resultingslurry and liquid fraction served, respectively, for simultaneous saccharification and fermentation (SSF)at high solid concentration (15%), and anaerobic digestion (AD). More specifically, SB was subjected totwelve pretreatments to enhance fiber deconstruction and subsequent energy output: steam explosionalone (195◦C for 5, 10 and 15 min), after impregnation with 0.4% and 0.7% Ca(OH)2, and at 205◦C for thesame three times after 0.7% Ca(OH)2addition. After pretreatment, enzymatic hydrolysis was carried outon washed solid fraction; glucose and xylose were determined on this fraction as well as residual liquidfraction. On this latter, inhibitors (acetic and formic acid, furfural and 5-hydroxymethylfurfural) were alsodetermined. Based on high glucose yield in enzymatic hydrolysis, three pretreatments were selected forSSF of the slurry. The same pretreatments underwent AD of the liquid fraction. Inhibitors augmented atincreasing time and temperature, although never achieved critical levels. Lignin removal (range, 17–38%)was enhanced by lime addition, whereas increasing temperature and time did not contribute to delig-nification. Glucose yield in washed solid fraction varied accordingly. SSF exhibited the highest ethanolyield with mild lime addition (60% of theoretical) vs. steam alone (53%). However, modest yields weregenerally evidenced (average, 55%) as a result of high viscosity, especially in the case of high lime dose inSSF at high solid concentration. Combined energy yield (ethanol, methane and solid residue) proved limeeffectiveness as catalyst in steam explosion of SB, beside two intrinsic advantages: low water consump-tion in SSF at high solid concentration, and the possibility of lime removal from downstream effluentsthrough carbonation.
Lorenzo, C., Mats Galbe, Lorenzo Barbanti, Ola Wallberg (2015). Combined ethanol and methane production using steam pretreated sugarcane bagasse. INDUSTRIAL CROPS AND PRODUCTS, 74, 255-262 [http://dx.doi.org/10.1016/j.indcrop.2015.05.016].
Combined ethanol and methane production using steam pretreated sugarcane bagasse
CAPECCHI, LORENZO;BARBANTI, LORENZO;
2015
Abstract
tEfficient energy production relies on complementary use of crop residues, to enhance the amount ofenergy obtained per unit biomass. In this frame, sugarcane bagasse (SB) was pretreated and the resultingslurry and liquid fraction served, respectively, for simultaneous saccharification and fermentation (SSF)at high solid concentration (15%), and anaerobic digestion (AD). More specifically, SB was subjected totwelve pretreatments to enhance fiber deconstruction and subsequent energy output: steam explosionalone (195◦C for 5, 10 and 15 min), after impregnation with 0.4% and 0.7% Ca(OH)2, and at 205◦C for thesame three times after 0.7% Ca(OH)2addition. After pretreatment, enzymatic hydrolysis was carried outon washed solid fraction; glucose and xylose were determined on this fraction as well as residual liquidfraction. On this latter, inhibitors (acetic and formic acid, furfural and 5-hydroxymethylfurfural) were alsodetermined. Based on high glucose yield in enzymatic hydrolysis, three pretreatments were selected forSSF of the slurry. The same pretreatments underwent AD of the liquid fraction. Inhibitors augmented atincreasing time and temperature, although never achieved critical levels. Lignin removal (range, 17–38%)was enhanced by lime addition, whereas increasing temperature and time did not contribute to delig-nification. Glucose yield in washed solid fraction varied accordingly. SSF exhibited the highest ethanolyield with mild lime addition (60% of theoretical) vs. steam alone (53%). However, modest yields weregenerally evidenced (average, 55%) as a result of high viscosity, especially in the case of high lime dose inSSF at high solid concentration. Combined energy yield (ethanol, methane and solid residue) proved limeeffectiveness as catalyst in steam explosion of SB, beside two intrinsic advantages: low water consump-tion in SSF at high solid concentration, and the possibility of lime removal from downstream effluentsthrough carbonation.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
