Valorization of Eucalyptus, Giant Reed Arundo, Fiber Sorghum, and Sugarcane Bagasse via Fast Pyrolysis and Subsequent Bio-Oil Gasification

Abstract

Fast pyrolysis of giant reed Arundo ( Arundo donax ), fiber sorghum ( Sorghum bicolor L. Moench), eucalyptus ( Eucalyptus spp.), and sugarcane bagasse ( Saccharum officinarum ) was studied in bench-scale bubbling fluidized bed reactor. Product yields were determined, and detailed physicochemical characterization for produced fast pyrolysis bio-oils (FPBOs) was carried out. The highest organic liquid yield (dry basis) was observed with sugarcane bagasse (59–62 wt %), followed by eucalyptus (49–53 wt %), giant reed Arundo (39 wt %), and fiber sorghum (34–42 wt %). After the pyrolysis experiments, produced FPBOs were gasified in an oxygen-blown autothermal catalytic reforming system for the produced synthesis gas. The gasifier consists of a partial oxidation zone where the FPBO is gasified, and the raw syngas is then reformed over a fixed bed steam-reforming catalyst in the reforming zone. The gas production (∼1.7 Nm 3 /kg FPBO) and composition (H 2 ∼ 50 vol %, CO 20–25 vol %, and CO 2 25–30 vol %) were similar for all FPBOs tested. These results show that the combination of fast pyrolysis with subsequent gasification provides a technically feasible and feedstock flexible solution for the production of synthesis gas.

A Comparative Analysis of Bio-Oil Collected Using an Electrostatic Precipitator from the Pyrolysis of Douglas Fir, Eucalyptus, and Poplar Biomass

“…This signifies that these bio-oils could be used for bio-fuel applications after further chemical treatment. The ash content of the bio-oils was almost negligible (<0.03%), aligning with the results of Wu et al [34] and Pienihäkkinen et al [16]. A negligible ash content indicates bio-oils as the product of purely volatilizing organic matter present in the biomass [14].…”

“…Thus, the low water content in this study confirms a better final product. Also, the volatile content of the bio-oils was above 95%, which is higher than the values obtained in previous studies [16,34]. This signifies that these bio-oils could be used for bio-fuel applications after further chemical treatment.…”

“…The value of TAN can range from 25 to as high as 200 mg KOH g −1 for lignocellulosic biomass based on the pyrolysis operating conditions and the type and location of the biomass [35,36]. Bio-oils obtained from the pyrolysis of Douglas fir, eucalyptus, and poplar in previous studies had higher TAN values compared to the bio-oils obtained in this study [15,16,37]. The higher TAN values in those studies could be due to the regular condensation system applied in their experimental setup.…”

“…A negligible ash content indicates bio-oils as the product of purely volatilizing organic matter present in the biomass [14]. In addition, the values of fixed carbon on a dry basis were lower than those obtained by Wu et al [34] (7.92% for Douglas fir bio-oil) and Pienihäkkinen et al [16] (24.27% for eucalyptus bio-oil). As fixed carbon is calculated according to the subtraction method, higher volatile and ash content values reduced the fixed carbon content of the bio-oils.…”

“…Numerous studies have been conducted on the pyrolysis of woody biomass and have investigated the effects of varying operating conditions such as the feed rate, nitrogen flow rate, reaction temperature, and feed particle size on the yield and properties of bio-oil, such as its elemental composition, viscosity, high heating value (HHV), etc. [9,[12][13][14][15][16]. Characterization of the bio-oil obtained in such studies showed several phenolic compounds, in addition to carboxylic acids, sugars and dehydrosugars, hydroxy aldehydes, and hydroxy ketones, which are attributed to the thermal depolymerization of lignin, cellulose, and hemicellulose [14,17,18].…”