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Particle size distributions of soot from needles and branches after scCO 2 extraction and non-treated branches.
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This work demonstrated that supercritical carbon dioxide extraction is effective as a pre-treatment technology to generate soot particles with the fullerene-like structure and increase syngas yield from extracted residues during coupled microwave activation with gasification. Supercritical carbon dioxide extraction removes over half of the fatty an...
Citations
... 9 Recent studies highlight its versatility for heat conversion, focusing on value recovery in the form of biochar, 10 pozzolanic ash, 11 and soot. 12 The thermal valorization of tree bark through biomass conversion methods such as gasification and pyrolysis has been documented in the literature recently. [13][14][15] Depending on the target material and energy derivatives, recent studies have explored slow, 16 fast, 17 and co-pyrolysis methods. ...
The inefficient disposal of biomass waste poses environmental and economic challenges, highlighting the need for sustainable valorization strategies. This study investigates the simultaneous production of biochar, soot, and ash from Daniella oliveri bark using a Top‐Lit Updraft (TLUD) reactor, with the aim of maximizing resource recovery while minimizing waste. The thermochemical conversion process was optimized to yield three distinct carbonaceous materials. The thermal process was conducted at a peak temperature of 347.34 °C with a total carbonization/combustion time of 150 min. The results demonstrated that the biochar exhibited a porous morphology with high carbon retention, the ash was rich in mineral oxides suitable for soil amendment, and the soot possessed a high surface area, making it a promising candidate for adsorption and catalytic applications. The study introduces an integrated approach to biomass conversion, reducing dependency on external energy sources by utilizing the bark as both feedstock and fuel. This process presents a scalable alternative for biomass utilization, particularly in regions with abundant agricultural waste and limited industrial infrastructure. Its adoption could contribute to circular economy initiatives, enhancing sustainable material recovery while mitigating environmental pollution.
... Figure 7 displays the SEM photos of the formulated soot products under different S/C ratios. The SEM observation process showed that the soot obtained from 3-ply sample (Fig. 7A, B) was very small debris with irregular shape and contained very fine particles in a spherical shape (fullerene-like soot particles) with free-stream particles [52]. These fullerene particles were formulated because of higher gasification temperature (900 °C) that acted as calcination process leading to elimination of impurities and conversion of amorphous carbon phase into a turbostratic structure [53]. ...
... However, C = O bonding (ideal position for carbon dioxide) was the major peak in all samples and its absorption was changed significantly as S/C and composition of feedstock changed, especially in case of FFP2 sample, where the intensity of this peak was increased significantly at S/C = 2. This chemical structure is a typical structure of fullerene soot and these results matched with the results received from SEM analysis [52,54]. ...
Surgical mask waste (SMW) is one of the challenges left by Corona pandemic and other possible epidemics in the future. Gasification treatment is one of the most eco-friendly solutions that are usually used to convert biomass into flammable-rich gas with high economic outcome. This paper aims to study the potential applications of using steam‑oxygen gasification in treating SMW and environmental impact. The experiments were carried out in an updraft fixed bed gasifier system with operation capacity 1 kg/h using two different types of SMW (3-ply face and FFP2/N95) at 900 °C, air–fuel equivalence ratio of 0.19, and at a different steam-to-carbon molar ratio (S/C: 1 and 2). Under these circumstances, the SMW decomposed into saturated vapour in gasification chamber followed by condensed tar fraction in the sampling unit, then the soot was separated from syngas product using a ceramic filtration. The properties of the formulated syngas, tar, and soot products were analysed using GC-FID, FTIR, and SEM. Finally, the environmental performance of treating both types of SMW using gasification technology was investigated using a life-cycle analysis (LCA) tool based on the S/C ratio that can achieve the maximum abundance of hydrogen (H2) in syngas. The results showed that syngas was the major component of the gasification products with a high content of H2, especially at S/C = 1 with abundance estimated at 40.6% (3-ply, 17.44 MJ/kg) and 38.3% (FFP2, 15.97 MJ/kg). Also, some benzene-rich tar (82–118 g/m³) and fullerene-like soot particles (53–75 g/h) were received. LCA results indicated that SMW composition did not have a significant effect on the assessment. While, the total scores of the gasification scenario (0.0029 for FFP2 masks and 0.0031 for 3-ply masks) were very small compared to the scores of the pyrolysis (0.0355) and incineration scenario (0.0128). Also, the gasification scenario proved a higher performance compared with incineration practice, especially in terms of the Global Warming, with 76% reduction. Based on that, gasification process has a higher potential in treatment of SMW.
Graphical Abstract
... 32,34,35 A recent study demonstrated that scCO 2 extraction coupled with microwave activated gasication of spruce forestry residues led to enhanced production of fullerene-like soot nanoparticles and increased syngas yield. 36 Low temperature microwave activation of scCO 2 extracted spruce produced biooils and the resulting biochar was an excellent feedstock for gasication. Lipid content and composition of biomass can have a signicant effect on microwave pyrolysis. ...
... scCO 2 was able to successfully extract the resin acids, aromatics, and steroids from the woody biomass. 36 Such compounds are typically less reactive than the many volatile components, leading to enhanced syngas production during gasication with limited effect on the yields of solid product. Importantly, woody biomass such as spruce has a signicantly higher fatty and resin acid content to cereal crops such as rice straw. ...
A combination of supercritical carbon dioxide (scCO2) extraction and microwave-assisted pyrolysis (MAP) have been investigated for the valorisation of waste rice straw. ScCO2 extraction of rice straw led to a 0.7% dry weight yield of lipophilic molecules, at elevated temperatures of 65 °C and pressures of 400 bar. Lipid compositions (fatty acids, fatty alcohol, fatty aldehydes, steroid ketones, phytosterols, n-alkanes and wax esters) of the waxes obtained by scCO2 were comparable to those obtained Soxhlet extraction using the potentially toxic solvent n-hexane. ScCO2 extraction positively influenced the pyrolysis heating rate, with a rate of 420 K min⁻¹ for particles of 500–2000 μm, compared to 240 K min⁻¹ for the same particle size of untreated straw. Particle size significantly affected cellulose decomposition and the distribution of pyrolysis products (gaseous, liquid and char), highlighting the importance of selecting an adequate physical pre-treatment. TG and DTG of the original rice straw and resulting biochar produced indicated that cellulose was completely decomposed during the MAP. While a rapid pressure change occurred at ∼120 °C (size > 2000 μm) and ∼130 °C (size 500–2000 μm) during MAP and was associated with the production of incondensable gas during cellulose decomposition, this takes place at significantly lower temperatures than those observed with conventional pyrolysis, 320 °C. Wax removal by scCO2 influences the dielectric properties of the straw, enhancing microwave absorption with rapid heating rates and elevated final pyrolysis temperatures, illustrating the benefits of combining these sustainable technologies within a holistic rice straw biorefinery.
... The absence of levoglucosan suggests that this intermediate first underwent a depolymerisation step. Then, from dehydration, fragmentation, and condensation reactions, it forms acids, furans, and aldehydes such as acetic acid, furfural, and methyl glyoxal [87]. Acetol is another product found during cellulose-fast pyrolysis, formed by the relocation of C-4 from the pyran ring cleft owing to levoglucosan degradation. ...
Pinus radiata (PR) and Eucalyptus globulus (EG) are the most planted species in Chile. This research aims to evaluate the pyrolysis behaviour of PR and EG from the Bío Bío region in Chile. Biomass samples were subjected to microwave pretreatment considering power (259, 462, 595, and 700 W) and time (1, 2, 3, and 5 min). The maximum temperature reached was 147.69 °C for PR and 130.71 °C for EG in the 700 W-5 min condition, which caused the rearrangement of the cellulose crystalline chains through vibration and an increase in the internal energy of the biomass and the decomposition of lignin due to reaching its glass transition temperature. Thermogravimetric analysis revealed an activation energy (Ea) reduction from 201.71 to 174.91 kJ·mol⁻¹ in PR and from 174.80 to 158.51 kJ·mol⁻¹ in EG, compared to the untreated condition (WOT) for the 700 W-5 min condition, which indicates that microwave pretreatment improves the activity of the components and the decomposition of structural compounds for subsequent pyrolysis. Functional groups were identified by Fourier transform infrared spectroscopy (FTIR). A decrease in oxygenated compounds such as acids (from 21.97 to 17.34% w·w⁻¹ and from 27.72 to 24.13% w·w⁻¹) and phenols (from 34.41 to 31.95% w·w⁻¹ and from 21.73 to 20.24% w·w⁻¹) in PR and EG, respectively, was observed in comparison to the WOT for the 700 W-5 min condition, after analytical pyrolysis. Such results demonstrate the positive influence of the pretreatment on the reduction in oxygenated compounds obtained from biomass pyrolysis.
... Finally, the functional groups of the obtained soot product from each WMs gasification batch were examined using FTIR and the spectra, as shown in Figure (9). The analysis showed a strong functional group at 2360 cm −1 corresponding to C=O bonding, thus being an ideal position for carbon dioxide (Trubetskaya et al. 2021). This means that carbon was the predominant element of these conditions. ...
The COVID-19 pandemic has created a new type of waste (surgical mask waste “WMs”) that presents a major challenge now and in the future, given the strong possibilities of similar epidemics to reoccur. In order to find an effective industrial solution to the millions of WMs produced daily, this research aims to develop a new eco-friendly strategy to convert WMs into H2-CH4-rich syngas, carbon nanoparticles (CNPs), and benzene-rich tar using an updraft gasifier system. The experiments started with the preparation of WM granules using shredding followed by granulation processes. Subsequently, the granules were processed in a lab-scale reactor with a capacity of 0.9–1 kg/h and consisted of a continuous WM feed system, a gasifier, a sampling system for syngas and tar, a ceramic filtration unit for separating the CNPs against the synthesis gas, and a burner. The gasification experiments were performed in ambient air with different air−fuel equivalence ratios (ER: 0.21, 0.25, and 0.29) and temperatures (700°C, 800°C, and 900°C) to determine the optimal conditions that yield the maximum amount of H2-CH4-rich syngas and CNPs with less impurities. The chemical composition and morphology of the obtained gasification products (syngas, tar, and CNPs) were observed using GC-FID, FTIR, and SEM. The results showed that the maximum production of syngas (4.29 ± 0.16 kg/h with HHV of 3804 kJ/kg) and CNPs (0.14 ± 0.011 kg/h) accompanied by a moderate tar rate (0.123 ± 0.009 kg/h with HHV of 41,139.88 kJ/kg) could be obtained at 900°C and ER = 0.29, while the highest H2 (16.93 ± 1.7 vol.%) and CH4 (10.44 ± 0.85 vol.%) contents in syngas product were synthesized at 900°C and ER = 0.19. Benzene and toluene were the major GC-FID compounds in the formulated tar product with abundance up to 25.6% and 11%, respectively. Meanwhile, gasification conditions of 900°C and ER = 0.24 allowed the best morphology to be formulated for spherical-shaped CNPs with a diameter of less than 200 nm.
... The effects of wood composition (i. e., the relative contents of bark, branches, and needles) and supercritical CO 2 extraction on charcoal production have also been investigated (Surup et al., 2020), and it was shown that the microstructure of soot formed during high temperature (1100 • C) pyrolysis depends on which tree parts (i.e., needles or branches) are used as the feedstock (Trubetskaya et al., 2021). Other examples of co-gasifying are wood and algae (Zhu et al., 2016), wood and coconut (Sulaiman et al., 2018) and coconut and oil palm (Inayat et al., 2019). ...
The aim of this work was to investigate whether the use of individual tree components (i.e., stem wood, bark, branches, and needles of spruces) as feedstocks during oxygen blow gasification is more efficient than using mixtures of these components. Experiments were performed at three oxygen levels in an 18-kW oxygen blown fixed bed gasifier with both single and mixed component feedstocks. The composition of the resulting syngas and the cold gas efficiency based on CO and H2 (CGEfuel) were used as response variables to evaluate the influence of different feedstocks on gasification performance. Based on the experimental results and data on the composition of ∼26000 trees drawn from a national Swedish spruce database, multivariate models were developed to simulate gasifier performance under different operating conditions and with different feedstock compositions. The experimental results revealed that the optimal CGEfuel with respect to the oxygen supply differed markedly between the different spruce tree components. Additionally, the models showed that co-gasification of mixed components yielded a lower CGEfuel than separate gasification of pure components. Optimizing the oxygen supply for the average tree composition reduced the GCEfuel by 1.3–6.2% when compared to optimal gasification of single component feedstocks. Therefore, if single-component feedstocks are available, it may be preferable to gasify them separately because doing so provides a higher gasification efficiency than co-gasification of mixed components.
... 27 Typical extraction conditions are 180 g of biomass in a 500 mL vessel at 300 bar, 50°C, and 40 g min −1 CO 2 . 28 Pyrolysis Gas Chromatography−Mass Spectrometery. Py-GC/MS analysis and quantification were carried out according to previously published methods by Trubetskaya et al. 28 ToF-SIMS Analysis. ...
... 28 Pyrolysis Gas Chromatography−Mass Spectrometery. Py-GC/MS analysis and quantification were carried out according to previously published methods by Trubetskaya et al. 28 ToF-SIMS Analysis. ToF-SIMS pelletized samples were analyzed with an ION-TOF secondary-ion mass spectrometer with a 25 kV pulsed Bi 3 + primary-ion gun in the static mode. ...
This research demonstrates that supercritical extraction of the biomass has a remarkable and complex influence on Scots pine tree fractions changing the surface concentration of water, lipids, and metals simultaneously. Surprisingly, this surface composition modification makes a considerable impact on the pyrolysis of the bulk biomass mechanism, leading to the alternation of the volatile and inorganic matter composition. The unique combination of time-of-flight secondary-ion mass spectrometry analysis and utilization of pyrolysis gas chromatography−mass spectrometry data on the thermal behavior of woody biomass demonstrates, for the first time, the extraordinary influence of surface adsorbed metals on the composition of pyrolysis products. ScCO2 could extract the surface metals in the form of fatty acid salts, demonstrating a sustainable and environmentally friendly pretreatment method for controlling the pyrolysis products.
... Supercritical carbon dioxide extraction (SFE) significantly reduces the risks associated with off-gassing and oxygen depletion during fuel storage [7], while the extracted fatty acids can be utilized as primary feedstocks for chemicals and biorefinery applications [8]. Supercritical carbon dioxide extraction can remove over half of the fatty and resin acids from wood [9]. Like other supercritical carbon dioxide processes, extraction of forest residues is carried out at low temperatures and pressures [10,11]. ...
... A recent study on the slow pyrolysis of lignin demonstrates that the remaining extractives in the organosolv lignin do not affect the thermal stability of lignin; to a limited extend, however, they influence the formation of released products during HSGC-MS heating [22]. Another study shows that the extraction of needles can lead to greater yields of steroids and terpenes, while the pyrolysis of scCO 2 pretreated branches formed porous soot particles with a less ordered nanostructure in fast pyrolysis [9]. ScCO 2 extraction of branches followed by pyrolysis leads to the formation of soot particles with a ring graphitic structure. ...
This work demonstrates that the coupling of supercritical carbon dioxide extraction with pyrolysis is an effective method for the removal of extractives from forestry residues and generation of solid char with different properties from the remaining solid wood fractions. Extraction of the needles and stumps shows greater yields of resin acids, terpenes, steroids and other derivatives than that of pinewood bark, cones and branches. The char yields of both non-treated and scCO2 extracted wood fractions varied from approximately 17.5 to 38.5 wt. % on dry basis at fast heating rates. The catalytic effect of extractives is significant on the yields and morphology of solid chars in fast pyrolysis and less pronounced at slow heating rates. These results are promising as they show that both the composition and location of extractives inclusions in the interior of wood particle can affect the morphology of char samples. Moreover, the impact of alkali metals on the wood devolatilization appears to be less compared to the lignocellulosic composition in slow pyrolysis. These results demonstrate that supercritical carbon dioxide extraction can be integrated in biorefinery as a pretreatment step to control the properties of pyrolysis products by varying the heating rate.
The surge in population growth, urbanization, and shifts in food consumption patterns have resulted in a rise in the global production of organic waste. This waste material must be repurposed and effectively managed to minimize environmental footprints. The generation of abundant biowaste, especially from marine sources, may have detrimental impacts on the environment and human health if left untreated. In recent years, substantial efforts have been made to valorize seafood waste, contributing significantly to the sustainability of the blue economy through the repurposing of marine discards. Seafood waste can be transformed into different by-products which can be applied as soil amendment to enhance soil quality and health, demonstrating a holistic approach to repurposing and waste utilization. The extraction of bioactive metabolites from these waste materials has opened avenues for developing nanofertilizers. This intersection of waste valorization and nanotechnology is pertinent in the context of sustainable agriculture. While conventional fertilizers improve soil fertility with significant leaching and gaseous losses, the advent of nanofertilizers introduces a paradigm shift with their targeted and controlled delivery mechanisms, rendering them significantly more efficient in resource utilization and mitigation of environmental crises. This review delves into the global issue of seafood waste accumulation, offering an overview of various methods for repurposing. The primary aim of this review is to bring into limelight the recent efforts in developing a portfolio of carbon-based nanofertilizers derived from organic waste, replacing previous valorization methods due to their sustainability, efficiency, and eco-friendliness. There are immense opportunities for future work in this direction by exploring innovative nanoengineering approach owing to the potential of carbon nanofertilizers in enhancing the production of value-added products and reduction of environmental pollution.
