In this study, activated carbon fibers (ACFs) were prepared from liquefied wood by chemical activation with ZnCl2, with a particular focus on the effects of temperature and ZnCl2: liquefied ...wood-based fiber (LWF) ratio on yield, porous texture, and surface chemistry. The characterization and properties of these ACFs were investigated by nitrogen adsorption/desorption, Fourier transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). When using a 6:1 impregnation ratio, the specific surface area (SBET) of the resultant ACFs was as high as 1423 m2/g. The effect of an increase in impregnation ratio on the porosity of ACFs was stronger than that of an increase in the activation temperature. However, the former had a weaker impact on the surface chemistry and structure. It was also found that the yields of ACFs obtained by ZnCl2 activation were higher than those obtained by physical activation. Besides, the prepared ACFs presented higher adsorption than other raw materials in the adsorption test, indicating that ACFs prepared from LWF by ZnCl2 activation could be used as an adsorbent for the adsorption of medium size organic compounds.
•Performance and emissions of Liquefied Wood in a MGT were investigated.•Liquefied wood with pure ethylene glycol as a solvent was produced.•The raw biocrude was upgraded by adding ethanol to further ...reduce viscosity.•Notably reduced extent of MGT adaptations was maintained.•Guidelines of MGTs requirements to allow viscous fuels combustion were presented.
This study investigates for the first time the combustion in a micro gas turbine (MGT) of a new bioliquid, a viscous biocrude, which is a liquefied wood (LW) produced via solvolysis of lignocellulosic biomass in acidified glycols. The test rig includes a modified fuel injection line, a re-designed combustion chamber and revised fuel injection positions. The main novelties of this work are: (1) producing of liquefied wood with pure ethylene glycol as a solvent, and methanesulfonic acid as a catalyst, to obtain a bio-crude with lower viscosity and higher lignocellulosics content than previous tested formulations; (2) upgrading raw liquefied wood by blending it with ethanol to further reduce the viscosity of the mixture; (3) utilizing a commercially available MGT Auxiliary Power Unit (APU) of 25 kW electrical power output, with notably reduced extent of adaptations to use the newly obtained fuel mixture. Fuel properties, and their impact on combustion performance using liquefied wood, are investigated by analyzing MGT performance and emissions response at different load and blend ratios. Emissions revealed that the presence of LW in the blends significantly affects CO and NOX concentrations compared to conventional fuels. CO roughly increased from 600 ppm (pure ethanol as fuel) to 1500 ppm (at 20 kW electrical power). The experimental study reveals that it is possible to achieve efficient MGT operation while utilizing high biocrude to ethanol ratios, but a number of adaptations are necessary. The achieved maximum share of liquefied wood in the fuel blend is 47.2% at 25 kW power output. Main barriers to the use of higher share of liquefied wood in these type of systems are also summarized.
Residues obtained after wood biomass liquefaction were used as precursors for the synthesis of two activated biochars. The source of biomass liquefaction constituted of industrial wood processing ...by‐products, including bark and wood sawdust. The liquefied residues were analyzed in terms of chemical components and structure. Carbonization under nitrogen atmosphere followed by physical CO2 activation allowed to obtain microporous activated carbons with specific surface areas of 741 and 522 m2 g−1, and micropore volumes of 0.38 and 0.27 cm3 g−1, respectively. The obtained activated carbons were used to remove toxic hexavalent chromium from the aquatic environment. The observed sorption capacities were 80.6 mg g−1 versus 36.7 mg g−1 for wood bark‐derived and wood sawdust‐derived carbon, respectively, indicating a key role of the wood residue source in the effectiveness of Cr(VI) removal by resulting carbons. Despite the dominant microporous structure, the adsorption kinetics was surprisingly fast, especially for the bark‐derived carbon, since the adsorption equilibrium was reached within 2 h. The sorption mechanism of chromium was based on the carbon surface‐mediated reduction of toxic hexavalent form to its non‐toxic trivalent form, as confirmed by the X‐ray photoelectron analysis. Therefore, the residues from wood liquefaction can be easily converted into porous activated biocarbons capable of adsorbing significant amounts of hazardous Cr(VI) while reducing them to non‐toxic Cr(III).
Wood biomass liquefaction residues were used to obtain two activated biochars. The obtained materials were used to remove toxic hexavalent chromium from the aquatic environment. The observed sorption capacities were high and sorption process was fast. Based on the presented data, it was demonstrated that the preparation of biochars is a promising strategy to find a sustainable way to manage the liquefaction process residues in line with the current worldwide bio‐economy approach.
Abstract The hydrothermal/soft templating method is an effective way to synthesize ordered mesoporous carbon (OMC), yet the mechanism of this strategy is not well illustrated. Herein, a hydrothermal ...temperature‐controlled approach is developed to precisely synthesize OMCs with well‐defined morphologies from liquefied wood (LW). As the hydrothermal temperature increases from 130 to 210°C, the hydrophilicity of the hydrophilic blocks decreases accompanied by the increase of the relative volume of the hydrophobic block, resulting in the packing parameter p of micelles changing from p ≤ 1/3 to 1/3 < p < 1/2, which transforms the micelle's structure from spherical to cylindrical. Additionally, accelerated nucleation occurred with the increased hydrothermal temperature. When the rate of nucleation is matched to the self‐assembly of the composite micelles, the composite micelles grow into worm‐like morphology and an ordered p 6m mesostructure. This hydrothermal temperature‐controlled strategy provides a straightforward and effective approach for synthesizing OMCs with various morphologies from LW, addressing the previously insufficiently elucidated micelle formation mechanism in the hydrothermal/soft templating method.
The utilization of forestry waste resources in the production of polyurethane resins is a promising green alternative to the use of unsustainable resources. Liquefaction of wood-based biomass gives ...polyols with properties depending on the reagents used. In this article, the liquefaction of forestry wastes, including sawdust, in solvents such as glycerol and polyethylene glycol was investigated. The liquefaction process was carried out at temperatures of 120, 150, and 170 °C. The resulting bio-polyols were analyzed for process efficiency, hydroxyl number, water content, viscosity, and structural features using the Fourier transform infrared spectroscopy (FTIR). The optimum liquefaction temperature was 150 °C and the time of 6 h. Comprehensive analysis of polyol properties shows high biomass conversion and hydroxyl number in the range of 238–815 mg KOH/g. This may indicate that bio-polyols may be used as a potential substitute for petrochemical polyols. During polyurethane synthesis, materials with more than 80 wt% of bio-polyol were obtained. The materials were obtained by a one-step method by hot-pressing for 15 min at 100 °C and a pressure of 5 MPa with an NCO:OH ratio of 1:1 and 1.2:1. Dynamical-mechanical analysis (DMA) showed a high modulus of elasticity in the range of 62–839 MPa which depends on the reaction conditions.
Activated carbon fibers (ACFs) have been prepared from liquefied wood (W
) by chemical activation with KOH, with a particular focus on the effect of KOH/fiber ratio in term of porous texture and ...surface chemistry. ACFs based on steam activation served as a blank for comparison. The properties of the ACFs were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), nitrogen adsorption/desorption, Fourier transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). The results show that the KOH-activated ACFs have rougher surfaces and more amorphous structure compared with the blank. The pore development was significant when the KOH/fiber ratio reached 3, and achieved a maximum Brunauer-Emmett-Teller (BET) surface area of 1371 m
g
and total pore volume (V
) of 0.777 cm
g
, of which 45.3% belong to mesopores with diameters of 2–4 nm, while the blank activated at the same temperature had a BET surface of 1250 m
g
and V
of 0.644 cm
g
, which are mainly micropores. The surface functional groups are closely associated with the KOH/fiber ratios. KOH-activated ACFs with KOH/fiber ratio of 3 have more oxygenated surface functional groups (C-O, C=O, -COOH) than the blank.
Activated carbon fiber was prepared from liquefied wood by chemical activation with ZnCl2 (Z-LWACF) at different impregnation ratios, with a particular focus on its adsorption property, kinetic and ...isotherm. The characterization and properties of Z-LWACFs were investigated by nitrogen adsorption/desorption, X-ray photoelectron spectroscopy (XPS), methylene blue (MB) and iodine adsorption. Two activation process methods were employed to prepare Z-LWACF and contrasted with others fibers. The results showed that the Z-LWACF obtained by one-step ZnCl2 activation present higher yields and specific surface area than others fibers. Besides, the change of MB adsorption value at different impregnation ratios was consistent with pore structure distribution above 1.5 nm pore size, indicating that larger micropores (1.5 to 2 nm) and mesopores played a major role in the MB adsorption by Z-LWACF. The kinetics of MB adsorption process was found to follow the pseudo-second-order kinetic model and the adsorption rate was controlled by chemisorption. It was also found that MB adsroption by Z-LWACF belonged to monolayer adsorption and Z-LWACF was easy to adsorb MB.
To acquire activated carbon fiber from phenol-liquefied wood (PLWACF) with better developed pore structure and a high proportion of mesoporosity, the porosity evolution of PLWACF activated at ...temperatures from 850 to 950 °C by water steam was detected by the physical adsorption of N2 at -196 °C. Results showed that the pore structure was well developed by prolonging the activation time at 850 to 910 °C, and it was easy to obtain PLWACF having exceptionally high surface area (larger than 2560 m2 g-1). However, PLWACF with a specific surface area larger than 3000 m2 g-1 could only be obtained in the late activation stages from 850 to 880 °C. Using this activation process, the mesoporosity was remarkably developed. The mesopore proportion drastically increased with an increase in activation temperature or time, reaching a maximum of 49.5%. The pore size distribution widened as the activation time increased and appeared to accelerate with the use of a higher activation temperature. The mesopore size distribution was enlarged from 2.8 to 5.8 nm.
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