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  • 1.
    Evangelopoulos, Panagiotis
    KTH, School of Industrial Engineering and Management (ITM).
    Pyrolysis and Detoxification of Waste Electrical and Electronic Equipment (WEEE) for Feedstock Recycling2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The trends in waste electrical and electronic equipment (WEEE) generation shows that their volume constantly increases, while the current waste management technologies have proven to be insufficient in order to meet the strict criteria and the new legislations of the European Union. Pyrolysis and thermal treatment in general could be a valuable solution for closing the loop of materials and could contribute to the energy demands of modern society.

    Pyrolysis as a process and combination of other pre-treatment techniques was investigated with a focus on energy production, metal separation and feedstock recycling. In this work, several fractions of real WEEE have been tested based on the process requirements and the focus of each individual study.

    Firstly, the investigation was focused on the primary products of the process, revealing most of the environmental pollutants as well as the valuable monomers that can enhance feedstock recycling. A correlation of the process’ final temperature with the evolution of the major products was performed. Moreover, a conceptual reaction mechanism of Bisphenol A decomposition was suggested based on the process products.

    Then, a reduction of the bromine content of the initial WEEE fraction was achieved by solvent extraction pre-treatment. Isopropanol and toluene were tested as solvents capable of removing one of the main flame retardants at WEEE fractions, Tetrabromobisphenol A. The results indicate that the reduction of bromine was successfully performed even at ~37%. This result was further confirmed by the reduction or total removal of brominated species in the pyrolysis products. The toluene seems to be a valuable option for the pre-treatment, since it can be provided by the pyrolysis process itself, making the entire treatment more sustainable and in accordance with the concept of circular economy.

    Density separators used in the sorting of WEEE materials usually produced high moisture content fractions. As soon as those fractions follow thermal treatment, the moisture will eventually become steam, which influences the process. Therefore, WEEE materials were pyrolysed in nitrogen and steam atmospheres and their decomposition was evaluated. Steam had a negative impact on the products, since several high molecular weight products were detected, revealing that steam limits secondary cracking reactions. Additionally, the results show that the presence of steam complicates the separation of oils and favours the migration of antimony to the gas phase. Therefore, a drying step before using pyrolysis for this fraction is necessary.

    Low temperature pyrolysis was also investigated for making the WEEE more fragile to enhance metal separation from the carbonised solid residue while the fate of bromine was also monitored. The results indicate that the separation is possible at low temperatures for minimising the energy consumption of the process but it should be at least 40 ° higher than the onset temperature of the selected material. The separation was also evaluated with fractionation of the solid residue, revealing that the produced bromine-free solid carbonised material can be further utilised for energy production.

    Finally, the entire process was tested in a continuous screw reactor for overall process evaluation. The results indicate that the liquid products of pyrolysis can be used for feedstock recycling, producing necessary organic compounds that can be used for manufacturing new plastics or can be used as liquid fuel. The brominated compounds tend to migrate to the gas phase, as the temperature of the process increases, making the recycling of metals from the solid residue easier. The process in general can be self-sustained since the energy needed for the system to heat up can be covered from its gas production.

  • 2.
    Evangelopoulos, Panagiotis
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Arato, Samantha
    Persson, Henry
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Kantarelis, Efthymios
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Yang, Weihong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Reduction of brominated flame retardants (BFRs) in plastics from waste electrical and electronic equipment (WEEE) by solvent extraction and the influence on their thermal decompositionIn: Waste Management, ISSN 0956-053X, E-ISSN 1879-2456Article in journal (Refereed)
    Abstract [en]

    Consumption of electronics increases due to modern society’s growing needs, which leads to increasing generation of waste electrical and electronic equipment (WEEE). Recycling of WEEE has been a global concern during the last few decades because of the toxic compounds that are produced during recycling. Different recycling techniques have been adapted on a commercial scale in order to overcome this issue, but the recycling of WEEE still lacks the technology to treat different kinds of feedstocks and to maximise the recycling rates. Pyrolysis is an alternative that has not been commercialised yet. One of the challenges for the implementation of this technology is the toxic brominated organic compounds that can be found in the pyrolysis oils.

    In this study, tetrabromobisphenol A (TBBPA), one of the major flame retardants, is reduced in three different WEEE fractions through solvent extraction as a treatment prior to pyrolysis. Two solvents have been experimentally investigated: isopropanol and toluene, the latter of which can be derived from pyrolysis oil. The results indicate that TBBPA was extracted during pre-treatment. Moreover, the total bromine content of WEEE material was reduced after the treatment with a maximum reduction of 36.5%. The pyrolysis experiments indicate that reduction of several brominated organic compounds was achieved in almost all the tested cases, and two brominated compounds (2,4,6-tribromophenol and 2,5-Dibromobenzo(b)thiophene) reached complete removal. Also, the thermal decomposition behaviour of the raw samples and the treated was investigated, showing that the reduction of TBBPA influences the decomposition by shifting the starting decomposition temperature.

  • 3.
    Evangelopoulos, Panagiotis
    et al.
    KTH, School of Industrial Engineering and Management (ITM).
    Arvelakis, Stylianos
    National Technical University of Athens.
    Kantarelis, Efthymios
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering, Process Technology.
    Yang, Weihong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Experimental investigation of low temperature pyrolysis of printed circuit boards (PCBs) and printed circuit board components (PCB sockets)Manuscript (preprint) (Other academic)
    Abstract [en]

    Printed circuit boards (PCBs) are the heart of all electronics due to their compact size and the broad spectrum of applications but very challenging when their life ends. Recycling of these components is problematic since they consist of different metallic parts packed on plastic compressed cover. The present study focuses on low temperature pyrolysis of PCBs since this process can separate the organic fraction from the inorganics. The latter, enables further separation and purification of the metals which are not oxidized during mild treatment. The low Br content of the resultant char after treatment at 320 oC for 30 min indicates that it could be used as solid fuel if efficient separation from the inorganic part would be performed. Moreover, the liquids obtained by this process can be used for feedstock recycling since the results indicates that toxic bromine containing on the organic compounds has been decreased both by increasing the residence time of pyrolysis process or by increasing the temperature conditions.

  • 4.
    Evangelopoulos, Panagiotis
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Kantarelis, Efthymios
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Yang, Weihong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Experimental Investigation of Pyrolysis of Printed Circuit Boards for Energy and Materials Recovery under Nitrogen and Steam Atmosphere2017In: 8th International Conference on Applied Energy, ICAE 2016; Beijing; China; 8 October 2016 through 11 October 2016, Elsevier, 2017, Vol. 105, p. 986-991Conference paper (Refereed)
    Abstract [en]

    Printed circuit boards (PCB) are one of the most challenging fractions of e-waste in terms of material recycling and energy recovery. In this study, pyrolysis of PCBs in inert and steam atmosphere has been investigated as a valuable alternative for energy recovery of the organic fraction with simultaneous recycling of metals. The decomposition of two different PCB fractions has been investigated by means of thermogravimetric analysis (TGA) and lab scale pyrolysis experiments in steam and nitrogen atmospheres. The composition of the gas obtained from the pyrolysis experiments was strongly influenced by the reactive atmosphere. The characterization of the solid residue by X-ray Powder Diffraction (XRD) and scanning electron microscopy (SEM) showed high influence of steam to the migration of the antimony in the produced vapors.

  • 5.
    Evangelopoulos, Panagiotis
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Kantarelis, Efthymios
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Yang, Weihong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Experimental investigation of the influence of reaction atmosphere on the pyrolysis of printed circuit boards2017In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 204, p. 1065-1073Article in journal (Refereed)
    Abstract [en]

    Printed circuit boards (PCB) are one of the most challenging fractions of waste electrical and electronic equipment (WEEE) in terms of recycling due to their complexity and diversity. Pyrolysis seems to be a promising alternative for production of energy carriers from its organic fraction with simultaneous recovery of metals. Reaction atmosphere is among the process parameters that affects the thermal decomposition as well as the products’ formation and distribution. In this study, the decomposition of two different PCB fractions in inert and steam atmospheres has been investigated by means of thermogravimetric analysis (TGA) and lab scale fixed bed reactor experiments. It was found that the decomposition of the tested materials in steam atmosphere starts at lower temperatures and proceeds slower compared to the N2 atmosphere. Moreover, a two-step decomposition has been observed on the PCB sockets fraction due to the fact that high amount of antimony oxide was present, a common additive for improving the flame retardancy, which have been also observed on previous studies (Wu et al., 2014). The presence of steam influence the pyrolysis gas composition and promotes additional vaporisation of antimony as verified by powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). Finally, the liquid fraction has been qualitatively analysed using a GC/MS in order to determine the brominated compounds as well as other compounds that are produced from this process.

  • 6.
    Evangelopoulos, Panagiotis
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Kantarelis, Efthymios
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Yang, Weihong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Investigation of the thermal decomposition of printed circuit boards (PCBs) via thermogravimetric analysis (TGA) and analytical pyrolysis (Py-GC/MS)2015In: Journal of Analytical and Applied Pyrolysis, ISSN 0165-2370, E-ISSN 1873-250X, Vol. 115, p. 337-343Article in journal (Refereed)
    Abstract [en]

    The purpose of this study is to experimentally investigate the pyrolytic behavior of printed circuit boards (PCBs) waste fraction at a temperature range of 400 °C to 900 °C by means of thermogravimetric analysis (TGA) and analytical pyrolysis (Py-GC/MS) was carried out. The experimental results reveal that the chemical composition of the PCBs and the relatively high ash content (=79% w/w) are strongly connected with the high quantity of metals and ceramic materials. The main decomposition of PCBs occurs between 250 °C and 370 °C. The pyrolysis of PCBs showed a varying production of aromatic compounds such as phenol, bromophenol, styrene, methylstyrene, and bisphenol A as well as non-aromatic compounds such as acetone and bromomethane, which are strongly related with the initial chemical composition of PCBs. Moreover, Py-GC/MS revealed that temperature increase favours the production of aromatic hydrocarbons, while the phenol which is the most abundant compound produced, shows an opposite trend, as a result of its further decomposition to simpler products. Furthermore, brominated compounds produced, such as bromomethane and bromophenol, are derived from the flame retardant used during the manufacturing process and in that case the Py-GC/MS showed a slight decrease of brominated compounds with increase in temperature.

  • 7. Evangelopoulos, Panagiotis
    et al.
    Persson, Henry
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Kantarelis, Efthymios
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering, Process Technology. KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Yang, Weihong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Pyrolysis of waste electrical and electronic equipment (WEEE) on a single screw reactor for bromine free oil productionManuscript (preprint) (Other academic)
    Abstract [en]

    This study focuses on pyrolysis on waste electrical and electronic equipment or WEEE as it is usually referred in the literature. A new auger reactor has been designed and tested with WEEE material. The performance of the reactor as well as the fate of the bromine has been investigated and evaluated in order to be used for designing of industrial process. The mass balance calculations performed for the tested cases of 400, 500 and 600 °C, showed a high gas yield (44%) at the temperature of 600 °C, which can be used to fulfil the process energy needs. At the low temperature of 400 °C the oil production reach its maximum yield, while the bromine content of the oil has also a maximum percentage of 0.5% wt. Several valuable compounds have been detected in the oil composition, which can be used either as fuels or for feedstock recycling.

  • 8.
    Evangelopoulos, Panagiotis
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Sophonrat, Nanta
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Jilvero, Henrik
    Stena Recycling Int AB, Dept Res & Dev, POB 4088, S-40040 Gothenburg, Sweden..
    Weihong, Yang
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Investigation on the low-temperature pyrolysis of automotive shredder residue (ASR) for energy recovery and metal recycling2018In: Waste Management, ISSN 0956-053X, E-ISSN 1879-2456, Vol. 76, p. 507-515Article in journal (Refereed)
    Abstract [en]

    The automotive shredder residue (ASR) or shredder light fraction (SLF) is the remaining fraction from the metal recovery of end-of-life vehicles (ELVs). While processes for metal recovery from ELVs are well developed, the similar process for ASR remains a challenge. In this work, low-temperature pyrolysis of the ASR fraction was investigated under the assumption that a low temperature and inert environment would enhance the metal recovery, i.e. the metals would not be further oxidised from their original state and the organic material could be separated from the metals in the form of volatiles and char. Pyrolysis experiments were performed in a tube reactor operating at 300, 400 and 500 degrees C. The gas and oil obtained by pyrolysis were analysed by micro-GC (micro-Gas Chromatography) and GC/MS (Gas Chromatography/Mass Spectrometry), respectively. It was found that the gas produced contained a high amount of CO2, limiting the energy recovery from this fraction. The oil consisted of a high concentration of phenolic and aromatic compounds. The solid residue was crushed and fractionated into different particle sizes for further characterization. The pyrolysis temperature of 300 degrees C was found to be insufficient for metal liberation, while the char was easier to crush at tested temperature of 400 and 500 degrees C. The intermediate temperature of 400 degrees C is then suggested for the process to keep the energy consumption low.

  • 9. Gadek, W.
    et al.
    Mlonka-Medrala, A.
    Prestipino, M.
    Evangelopoulos, Panagiotis
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Kalisz, S.
    Weihong, Yang
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Gasification and pyrolysis of different biomasses in lab scale system: A comparative study2016In: 1ST INTERNATIONAL CONFERENCE ON THE SUSTAINABLE ENERGY AND ENVIRONMENT DEVELOPMENT (SEED 2016), EDP Sciences, 2016, article id UNSP 00024Conference paper (Refereed)
    Abstract [en]

    Gasification and pyrolysis are very promising technologies for clean energy production especially from low rank fuels. Biomass and wastes with high chlorine, alkali and even heavy metals content are fuels preferential for thermal utilization. However, several problems during combustion in conventional steam boilers occurs e.g. slagging, fouling, chlorine corrosion, boiler efficiency deterioration. New efficient and cost effective technologies are needed, even in small-scale applications. The main objective of this work was to compare the thermochemical behaviour and process parameters effects of different biomass under air gasification and pyrolysis conditions. Three important fuels for European power industry were selected: woody biomass and two residual biomass, such as oat straw and dried citrus wastes. In order to evaluate the possibility to use different feedstocks or to combine and/or integrate them in thermochemical processes, a comparison among typical and untypical feedstocks is needed. Tests performed on small scale fixed bed reactor show the gas yield, its composition and LHV parameter. The results were performed in Royal Institute of Technology (KTH) in Sweden during BRISK program (Biofuels Research Infrastructure for Sharing Knowledge).

  • 10.
    Han, Tong
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Sophonrat, Nanta
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Evangelopoulos, Panagiotis
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Persson, Henry
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Weihong, Yang
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Jönsson, Pär
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Evolution of sulfur during fast pyrolysis of sulfonated Kraft lignin2018In: Journal of Analytical and Applied Pyrolysis, ISSN 0165-2370, E-ISSN 1873-250X, Vol. 33, p. 162-168Article in journal (Refereed)
    Abstract [en]

    Sulfonated Kraft lignin, the most available commercial lignin of today, has high sulfur content due to the extraction and the subsequent sulfonation processes. In this work, the evolution of sulfur during fast pyrolysis of sulfonated Kraft lignin has been studied. Fast Pyrolysis experiments have been done using Py-GC/MS. It is found that main sulfur-containing products in the pyrolytic vapors are present as the following small molecular compounds: H2S, SO2, CH3SH, CH3SCH3, and CH3SSCH3. This indicates that sulfur-containing radicals preferentially combine with the other small radicals such as H and CH3 during fast pyrolysis process. Sulfur is suggested to be mainly present as sulfite (SO3) and sulfide (S) in the sulfonated Kraft lignin. Sulfite that is incorporated into lignin during the sulfonation process mainly result in the formation of SO2. The nature of the sulfur links created during the Kraft pulping process is difficult to determine, but they are supposed to mainly exist in form of sulfide (S) bonds, which lead to the formation of H2S, CH3SH, CH3SCH3 and CH3SSCH3.

  • 11.
    Persson, Henry
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Evangelopoulos, Panagiotis
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Svanberg, Rikard
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Weihong, Yang
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Two-step pyrolysis of biomass to enhance the chemical stability of pyrolytic liquids2017In: European Biomass Conference and Exhibition Proceedings 2017, ETA-Florence Renewable Energies , 2017, Vol. 7, no 25thEUBCE, p. 1186-1189Conference paper (Refereed)
    Abstract [en]

    Aging of pyrolytic liquid during storage changes its chemical and physical properties. The reason for aging is the chemical instability of the liquid, which is not at thermodynamic equilibrium when quenched after pyrolysis. Compounds active in these reactions mainly derivatives from hemicellulose (e.g. acids and carbonyls). In this work, a two-step pyrolysis concept was investigated to separate these compounds in a lower temperature treatment step upstream a conventional pyrolyzer. Different temperatures of the lower temperature treatment was investigated with constant conditions of the conventional treatment. The total liquid yield derived did not vary from pyrolysis in one step. Results show that the two-step pyrolysis process significantly reduces the concentration of organic acids and carbonyls in the liquid product from the second pyrolyzer, which instead are found in the liquid from the lower temperature treatment. Also, the concentration of sugar derivatives from the second step treatment is increased with the temperature of the first step. However, a complete separation of aging active compounds is not possible without sacrificing partial fractions of others (lignin derivatives were found in the low-temperature treatment). By varying the temperature of the first step one can control the concentrations and the liquid yield from each step.

  • 12.
    Persson, Henry
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Han, Tong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Xia, Wei
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Evangelopoulos, Panagiotis
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Weihong, Yang
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Fractionation of liquid products from pyrolysis of lignocellulosic biomass by stepwise thermal treatment2018In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 154, p. 346-351Article in journal (Refereed)
    Abstract [en]

    The thermal properties of cellulose, hemicellulose and lignin can be utilized to improve the characteristics of pyrolysis liquids. In this study, a concept of stepwise pyrolysis to fractionate the liquid based on the thermal properties of the biomass constituents was investigated. Lignocellulosic biomass was thermally treated in two steps: 200–300 °C followed by 550 °C. Derived liquids were studied for GC/MS analysis, water content, acid concentration and a solvent extraction method. Pyrolytic liquid derived from 550 °C after treatment at lower temperatures have a higher relative composition of phenolic compounds compared to one-step pyrolysis (increased from 58 to 90% of GC/MS peak area). Also, compounds known to promote aging, such as acids and carbonyl compounds, are derived at lower temperatures which may suppress aging in the liquid derived downstream at 550 °C. For liquids derived at 550 °C, the total acid number was reduced from 125 in one-step treatment to 14 in two-step treatment. Overall, no significant difference in the total liquid yield (sum of the liquids derived in separated treatments) nor any variations in their collective composition compared to one-step treatment at 550 °C was observed, i.e. stepwise pyrolysis can be utilized for direct fractionation of pyrolytic vapors.

  • 13.
    Persson, Henry
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Kantarelis, Efthymios
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Evangelopoulos, Panagiotis
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Yang, Weihong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Wood-derived acid leaching of biomass for enhanced production of sugars and sugar derivatives during pyrolysis: Influence of acidity and treatment time2017In: Journal of Analytical and Applied Pyrolysis, ISSN 0165-2370, E-ISSN 1873-250X, Vol. 127, p. 329-334Article in journal (Refereed)
    Abstract [en]

    Inorganic matter in biomass (especially alkali and alkaline earth metals) acts like intrinsic catalysts during pyrolysis and influences the composition of derived liquids. In this work, the influence of acidity and time on leaching of inorganics with wood pyrolysis-derived acids was investigated in order to understand their effect on the biomass characteristics and the composition of pyrolysis products, as well as to study the mechanism of leaching of different inorganic elements. Aqueous solutions of 5 and 10. wt% acetic acid (main acid in pyrolysis products and in similar concentrations) were used for demineralizing softwood at 85. °C for 30-90. min. Biomass characteristics, composition of intrinsic inorganics and primary pyrolytic vapors from different pretreatment cases are presented. Results show that removal of inorganics was in all cases enhanced by higher acidity; time of treatment was only seen to have a positive effect at lower acidity. The volatile matter of biomass was not affected by the pretreatment, confirming the conditions investigated being relatively mild. Results from Py-GC/MS of leached biomass show an increased selectivity towards sugars and sugar derivatives and simultaneous suppression of the relative composition of carbonyls and phenolic compounds in derived vapors. Sugars and sugar derivatives was enhanced by increasing the leaching time at higher acidity, without seeing a clear correlation to removal of alkali and alkaline earth metals. It is therefore suggested that other factors might influence the pathway of formation of primary pyrolysis products than what has previously been suggested by others. Because of the enhanced production of sugars and sugar derivatives from pyrolysis of leached biomass, this procedure might serve as a pathway to be enable the utilization of pyrolytic liquids as feedstock for existing fermentation-based biorefineries.

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