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1.
  • Blomquist, G., et al. (författare)
  • Data-analysis of pyrolysis-chromatograms by means of simca pattern-recognition
  • 1979
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 1873-250X .- 0165-2370. ; 1:1, s. 53-65
  • Tidskriftsartikel (refereegranskat)abstract
    • The variability between repetitive pyrolysis—chromatograms of the same type of samples is not totally random, but can in part be modelled by a principal components (PC) model. This makes it possible to use efficiently repetitive pyrolysis-chromatograms of samples of known types to obtain separate PC models for each type. Samples of unknown origin can then be classified according to which of the PC models their pyrolysis-chromatograms are most similar. The methodology is illustrated using pyrolysis—gas chromatograms of two species of the fungal genus Penicillium.
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2.
  • Agar, David (författare)
  • Energy recovery through co-pyrolysis of wastewater sludge and forest residues -The transition from laboratory to pilot scale
  • 2021
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 158
  • Tidskriftsartikel (refereegranskat)abstract
    • Anaerobically digested sewage sludge mixed with forest residues was pyrolysed at 800 °C, at laboratory and pilot scale. The study quantified differences in char and gas yields for tests carried out in a simple fixed bed laboratory reactor and rotating retort pyrolyser at pilot scale, when the residence time of feedstock was 10 min in both cases. The yield of char from pilot scale was 4 % lower than from laboratory scale while the yield of gas was 15.7 % higher. During the pilot scale pyrolysis of anaerobically digested sewage sludge blended with forest residues the gas quality for energy recovery applications was assessed and the fate of impurities (tar, NH3 and H2S) was investigated. The raw pyrolysis gas contained 14.6 g/Nm3 of tar, 36.9 g/Nm3 of NH3 and 793 ppm of H2S. Sixteen N-containing tar species were identified of which pyridine, propenenitrile, 2-methyl-, benzonitrile, and indole are found to be the most abundant. The yield of N-containing tar compounds accounted for approx. 12 % of total tar content. Conditioned pyrolysis gas contained 7.1 g/Nm3 of tar, 0.036 g/Nm3 of NH3 and 119 ppm of H2S. Benzene was by far the most abundant tar compound followed by toluene and styrene. The specifications of the used internal combustion engine were exceeded due to the sum of tar compounds such as fluorantrene and pyrene with 4+ aromatic rings (at 0.0015 g/Nm3) and NH3 content The effectiveness and sustainability of energy recovery in wastewater treatment can be improved using forest industry by-products.
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3.
  • Brodin, Ida, et al. (författare)
  • The behavior of kraft lignin during thermal treatment
  • 2010
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 87:1, s. 70-77
  • Tidskriftsartikel (refereegranskat)abstract
    • Purified kraft lignin fractions from technical pulping liquors of softwood and hardwood have been subjected to step-wise analytical pyrolysis in the temperature interval 200-900 degrees C. The heterogenic structure of kraft lignin was revealed by the formation of pyrolysis products throughout the entire temperature interval although the majority of products were formed at 500-600 degrees C. Beyond 700 degrees C, no further pyrolysis products could be detected but a substantial portion of the lignin was shown to be converted into thermally stable products (char) not accessible by analytical pyrolysis. With pre-oxidation of the lignin with air at 250 degrees C prior to pyrolysis, a shift towards higher pyrolysis temperature was observed with a concomitant change in product composition. Thermal gravimetric analysis on such lignins also showed an improved stability against degradation. Methylation of the lignin prior to pyrolysis did not induce any significant changes in behavior, except for much lower T-g values.
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4.
  • Brostrom, Markus, et al. (författare)
  • Influence of torrefaction on the devolatilization and oxidation kinetics of wood
  • 2012
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 96, s. 100-109
  • Tidskriftsartikel (refereegranskat)abstract
    • Devolatilization and oxidation kinetics of torrefied wood have been studied by evaluating thermogravimetric curves measured in nitrogen and air at various heating rates. Samples consist of Norway spruce wood chips torrefied at several process temperatures and residence times. Data about untreated wood have also been obtained for comparison. Measured curves are well predicted by means of a five-reaction mechanism, consisting of three devolatilization reactions for the pseudo-components hemicellulose. cellulose and lignin and, in air, of two additional reactions for char devolatilization and combustion. The torrefaction pre-treatment only requires model modifications in the amounts of volatiles generated from the decomposition of pseudo-components, indicating that only their relative percentages and not their reactivities are modified. On the other hand, a slightly different thermal stability is found for the char generated from torrefied wood, which results in higher activation energy and lower reaction order for the oxidation step. Hence torrefaction conditions can affect the subsequent conversion characteristics of the char product. (C) 2012 Elsevier B.V. All rights reserved.
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5.
  • Carlsson, Per, et al. (författare)
  • High-speed imaging of biomass particles heated with a laser
  • 2013
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 103, s. 278-286
  • Tidskriftsartikel (refereegranskat)abstract
    • In this work two types of lignocellulosic biomass particles, European spruce and American hardwood (particle sizes from 100 μm to 500 μm) were pyrolysed with a continuous wave 2 W Nd:YAG laser. Simultaneously a high-speed camera was used to capture the behavior of the biomass particle as it was heated for about 0.1 s. Cover glasses were used as a sample holder which allowed for light microscope studies after the heating. Since the cover glasses are not initially heated by the laser, vapors from the biomass particle are quenched on the glass within about 1 particle diameter from the initial particle. Image processing was used to track the contour of the biomass particle and the enclosed area of the contour was calculated for each frame.The main observations are: There is a significant difference between how much surface energy is needed to pyrolyses the spruce (about 75% more) compared to the hardwood. The oil-like substance which appeared on the glass during the experiment is solid at room temperature and shows different levels of transparency. A fraction of this substance is water soluble. A brownish coat is seen on the unreacted biomass. The biomass showed insignificant swelling as it was heated. The biomass particle appears to melt and boil at the front that is formed between the laser beam and the biomass particle. The part of the particle that is not subjected to the laser beam seems to be unaffected.
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6.
  • Chen, Xu, et al. (författare)
  • Catalytic fast pyrolysis of biomass to produce furfural using heterogeneous catalysts
  • 2017
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 127, s. 292-298
  • Tidskriftsartikel (refereegranskat)abstract
    • Furfural is a valuable chemical, the production of furfural from renewable biomass resources becomes more attractive in recent years. In this study, biomass fast pyrolysis with heterogeneous catalysts (titanium compounds (TiN, TiO2 and TiOSO4) and metal nitrides (MoN, GaN and VN)) for furfural production was investigated experimentally by means of pyrolysis-gas chromatography/mass-spectrometry (Py-GC/MS). The measurement results indicated that TiN and GaN promoted the furfural compounds production notably mainly through direct decomposition of oligosaccharides. The formation of furfural was promoted when the amount of TiN was increased, and the yield of furfural formed was about 5.5 times the size of that from non-catalytic pyrolysis when TiN/cellulose mass ratio was 4. The furfural yield decreased when the pyrolysis residence time increased from 10 to 30 s, which suggests competitive reactions (formation of 1, 6-anhydro-beta.-D-glucopyranose) against the formation of furfural. TiN, as a catalyst for fast pyrolysis towards furfural production, can be well applied to agriculture biomass residues. Comparing three biomass residues: corncob, wheat straw and cotton stalk, corncob showed higher furfural yield due to the higher holocellulose content, while wheat straw showed higher furfural selectivity. 
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7.
  • Cui, Yuxiao, et al. (författare)
  • Achieving carbonized minitablet-shaped structures from lignin : The importance of heating rate on shape
  • 2023
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 176, s. 106260-
  • Tidskriftsartikel (refereegranskat)abstract
    • Shape-anisotropic building blocks are vital in the creation of hierarchical materials in nature, as it enables directional alignment, property anisotropy and overall functionality improvement in biological materials. Likewise, the performance of carbonized superstructures could potentially be more precisely designed by using anisotropic building blocks. Lignin represents an important and sustainable alternative in the production of carbonized materials, which is due to its abundance and high carbon content (∼60%). However, to expand its utility, for producing carbonized shape-anisotropic materials, adequate synthesis and pyrolysis-protocols are essential. Here, a fractionated and acetylated Kraft lignin was used to successfully self-assemble shape-anisotropic microcapsules. Then a carbonization procedure (slow heating at 0.6 °C min−1), that retained the original shape-anisotropy after carbonization, was developed. The formation mechanism was discussed as a function of the heating rate. The overall strategy was template-free and the attained shape-anisotropies were well-defined and narrow in size distribution. This is a scalable route for achieving shape-anisotropic carbonized building blocks from lignin.
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8.
  • Evangelopoulos, Panagiotis, et al. (författare)
  • Investigation of the thermal decomposition of printed circuit boards (PCBs) via thermogravimetric analysis (TGA) and analytical pyrolysis (Py-GC/MS)
  • 2015
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier. - 0165-2370 .- 1873-250X. ; 115, s. 337-343
  • Tidskriftsartikel (refereegranskat)abstract
    • 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.
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9.
  • Gao, Qiuju, et al. (författare)
  • Formation of PCDDs and PCDFs in the torrefaction of biomass with different chemical composition
  • 2017
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : ELSEVIER SCIENCE BV. - 0165-2370 .- 1873-250X. ; 123, s. 126-133
  • Tidskriftsartikel (refereegranskat)abstract
    • Torrefaction is a thermal pre-treatment technology used to refine biomass, mainly for energy production purposes. However, there is currently a lack of information on the potential formation of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) in the torrefaction process. In this study, torrefaction was conducted using five different types of feedstock: stemwood, bark, wood from a discarded telephone pole, cassava stems and particle board. The feedstock as well as the torrefied biomass (chars) and the volatiles (non-condensable and condensable) generated during torrefaction were analyzed for PCDDs and PCDFs. PCDD concentrations in the torrefaction products were about 2-5 fold of those in the feedstocks. Torrefaction of particle board resulted in extensive formation of PCDDs (7200 ng kg(-1)) compared to the other four feedstocks (13-27 ng kg(-1)). Examination of the homologue profiles suggested that the observed PCDDs in the torrefaction products partly originated from new formation and partly physical transformation from volatilization and re-condensation of PCDDs present in the feedstock. Dechlorination of highly chlorinated compounds (HpCDD and OCDD) in the feedstock to form less chlorinated PCDDs was also observed. Compared to PCDDs, the net formation of PCDFs in the torrefaction process was low, except for the telephone pole sample, for which a dramatic increase (44-fold) of PCDFs was observed. PCDDs and PCDFs were mainly retained in the chars, accounting for 76-96% and 39-74% of the total concentration, respectively. It was also found that the highly chlorinated congeners tended to be retained in the chars, whereas the less chlorinated ones were predominantly volatilized into the gas phase.
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10.
  • Gerber, Lorenz, et al. (författare)
  • Multivariate curve resolution provides a high-throughput data processing pipeline for pyrolysis-gas chromatography/mass spectrometry
  • 2012
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 95, s. 95-100
  • Tidskriftsartikel (refereegranskat)abstract
    • We present a data processing pipeline for Pyrolysis-Gas Chromatography/Mass Spectrometry (Py-GC/MS) data that is suitable for high-throughput analysis of lignocellulosic samples. The aproach applies multivariate curve resolution by alternate regression (MCR-AR) and automated peak assignment. MCR-AR employs parallel processing of multiple chromatograms, as opposed to sequential processing used in prevailing applications. Parallel processing provides a global peak list that is consistent for all chromatograms, and therefore does not require tedious manual curation. We evaluated this approach on wood samples from aspen and Norway spruce, and found that parallel processing results in an overall higher precision of peak area from integrated peaks. To further increase the speed of data processing we evaluated automated peak assignment solely based on basepeak mass. This approach gave estimates of the proportion of lignin (as syringyl-, guaiacyl and p-hydroxyphenyl-type lignin) and carbohydrate polymers in the wood samples that were in high agreement with those where peak assignments were based on full spectra. This method establishes Py-GC/MS as a sensitive, robust and versatile high-throughput screening platform well suited to a non-specialist operator.
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11.
  • Girardin, Bertrand, et al. (författare)
  • Measurement of kinetics and thermodynamics of the thermal degradation for flame retarded materials : Application to EVA/ATH/NC
  • 2017
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 124, s. 130-148
  • Tidskriftsartikel (refereegranskat)abstract
    • The modelling of the behavior of a material exposed to fire is very complex and needs the coupling of fluid dynamics, combustion, heat and mass transfer, kinetics and so forth. A growing amount of studies and numerical models are reported in this field since the last decade. The aim of these models is to predict the fire behavior of wood, charring or non-charring polymers and even intumescent materials. However, these studies are seldom applied to formulated materials and especially flame retarded materials. In this study, an ethylene-vinyl acetate copolymer was formulated with a flame retardant (aluminum tri-hydroxide) and a synergist (nanoclays). A systematic approach for the characterization of the thermo-physical properties of the material as well as of its optical properties and the heat capacity of the decomposition gases is proposed and applied in this study. It is shown that it is possible to evaluate the input data required for pyrolysis modelling, even for multi decomposition steps materials. It is also shown that the diffusion of the gases inside the material had to be considered on the opposite of the classical assumption found in other studies. Indeed, using low mass diffusivity was the sole way to predict in the same time the temperature distribution and the mass loss rate of the material in a gasification experiments.
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12.
  • Gulshan, Samina, et al. (författare)
  • Performance analysis and production of aromatics for ex situ catalytic pyrolysis of engineered WEEE
  • 2024
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 179
  • Tidskriftsartikel (refereegranskat)abstract
    • Ex situ catalytic pyrolysis of engineered waste electrical and electronic equipment (WEEE) was conducted in a two-stage reactor using HZSM-5 catalyst. The effect of the catalysis temperature and the catalyst-to-feedstock (C/F) ratio on products yield, gas and oil composition, and products characterization were investigated in this study. Results indicated that lower reforming temperature and C/F ratio favored organic fractions production. The highest yield of organic fraction was obtained at a catalysis temperature of 450 °C and at a C/F ratio of 0.15, corresponding to 28.5 and 27.4 wt %, respectively. The highest selectivity toward aromatic hydrocarbons and the lowest TAN value of the organic fraction were obtained at a catalysis temperature of 450 °C and a C/F ratio of 0.2, respectively. Most of the alkali and transition metals and 23 % of Br remained in the solid residue after the catalytic pyrolysis of low-grade electronic waste (LGEW).
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13.
  • Han, Tong, et al. (författare)
  • Evolution of sulfur during fast pyrolysis of sulfonated Kraft lignin
  • 2018
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 33, s. 162-168
  • Tidskriftsartikel (refereegranskat)abstract
    • 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 ( SO−3) 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.
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14.
  • Hou, Yi, et al. (författare)
  • Feasibility of monomer aromatic substances as calibration standards for lignin quantitative analyses in Pyrolysis-GCMS
  • 2013
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 101, s. 232-237
  • Tidskriftsartikel (refereegranskat)abstract
    • In this article, the feasibilities of five different monomer aromatic substances as calibration standards by analytical pyrolysis with gas chromatographic separation and mass selective detection (Py-GC/MS) were applied for the quantification of lignin in paper and pulp. The stabilities of these substances in the pyrolysis process were evaluated and the curves of peak response area to mass also were obtained. The results showed that the substances with exact same substitutions on the benzene ring as lignin units had good stabilities in the pyrolysis process with good lineabilities of peak response area to the mass curves, which implicated these substances can be applied as calibration standards in the liginin quick quantitative analyse without tedious pretreatments and structure changes.
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15.
  • Iisa, Kristiina, et al. (författare)
  • Chemical and physical characterization of aerosols from fast pyrolysis of biomass
  • 2019
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier B.V.. - 0165-2370 .- 1873-250X. ; 142
  • Tidskriftsartikel (refereegranskat)abstract
    • Biomass fast pyrolysis vapors contain a significant quantity of persistent aerosols, which can impact downstream processing by e.g. fouling of surfaces and deposition on downstream catalysts. In this study, aerosol concentrations and size distributions were measured by an impactor in two pyrolysis systems, a bench-scale fluidized-bed pyrolyzer and a pilot-scale cyclone pyrolyzer. In both units, the mass-based mode aerosol diameter was approximately 1 μm before aerosol collection devices in cooled vapors of 300–370 K but the number-based median was < 0.1 μm. Aerosols < 1 μm were formed and aerosols > 1 μm deposited during cooling of pyrolysis vapors from 620 to 370 K in the fluidized-bed pyrolysis system. The oil fraction collected from the aerosols constituted approximately 40 wt% of the total oils collected in both systems. Compared to the total collected oil, the oil fraction from the aerosols was enriched in lignin-derived components and anhydrosugars and had lower concentrations of low molecular weight cellulose derived oxygenates, such as hydroxyketones. 
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16.
  • Islam, Md. Kamrul, et al. (författare)
  • Catalytic fractionation of Palm Kernel shell with Co and Cu over zeolite HY catalysts
  • 2024
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier. - 0165-2370 .- 1873-250X. ; 178
  • Tidskriftsartikel (refereegranskat)abstract
    • Lignocellulosic biomass has the potential to be transformed valuable chemicals. This study extracted lignin from palm kernel shell with liquid phased oxidative fractionation in the presence of Co and Cu loaded over Zeolite HY catalysts. The oxidative fractionation was conducted at temperatures ranging from 140 °C to 180 °C, with various reaction times of 2–4 h. The GCMS analysis identified various products from the oxidative conversion including phenol derivatives (Butylated hydroxytoluene, 1,2-Benzenediol, etc.), phenolic aldehydes (Vanillin, Syringaldehyde, p-hydroxybenzaldehyde, etc.), and carboxylic acids (p-hydroxybenzoic acid, vanillic acid etc.). At a reaction temperature of 180 °C with a 2 h reaction time, Co/Zeolite HY catalyst yielded 9.81% and Cu/Zeolite HY catalyst yielded 13.53% for phenol derivatives. The optimal yield of lignin-derived compounds was achieved with a 5 wt% catalyst loading in the context of biomass weight, particularly with a 10% metal loading of Co and Cu over Zeolite HY support. Additionally, the total yield of lignin-derived compounds obtained was 32.85% for 10%Co/Zeolite HY and 23.89% for 10%Cu/Zeolite HY, catalysts respectively. This research displays incorporating metals into zeolite support subsequently boosts their catalytic efficiency in lignin oxidation. 
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17.
  • Johansson, Ann-Christine, et al. (författare)
  • Chemical recycling of complex reject streams from the paper industry via thermal and catalytic pyrolysis
  • 2024
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier B.V.. - 0165-2370 .- 1873-250X. ; 181
  • Tidskriftsartikel (refereegranskat)abstract
    • Paper-based packaging is a complex multi-material composed of paper (fibers), plastics, and metals, making efficient material recycling complicated. Currently, most of the fibers are recycled into new paper products while the residual material is commonly incinerated. Therefore, to improve the circularity and reduce the fossil dependency chemical recycling is needed. In this study, recycling of the residual materials was evaluated by thermal and catalytic pyrolysis. First, screening tests were performed using five reject materials and four catalysts in an analytical scale and then, a selection of catalyst and reject materials were evaluated in lab-scale followed by a techno-economic assessment. Experimental results indicated that the conversion was more efficient if the reject had high content of plastics compared to fibers, leading to products with increased heating value, higher hydrocarbon yield and less reactive oxygenates compared to the rejects with low plastic ratio. In the thermal pyrolysis 54 % of the weight of the feedstock and 70 wt% of the carbon in the feedstock ended up in a solid organic product (wax) which contained hydrocarbons and alcohols. In the analytical catalytic pyrolysis, HZSM-5 gave the best result in terms of cracking, deoxygenation, and aromatization. Ex-situ catalytic pyrolysis using HZSM-5 resulted in an improved quality of organic liquid with reduced hydrocarbon length as well as deoxygenated and aromatic compounds. The yield of the organic liquid was up to 19 wt% and contained mainly monoaromatics. The techno-economic evaluation showed, for processing 100,000 tons year−1 residual material, the total plant investment and the annual profit are about 29 and 12 million Euros, respectively, if no incentive for treating the residual material.
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18.
  • Johansson, Ann-Christine, et al. (författare)
  • Co-pyrolysis of woody biomass and plastic waste in both analytical and pilot scale
  • 2018
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 134, s. 102-1113
  • Tidskriftsartikel (refereegranskat)abstract
    • Earlier studies show that co-pyrolysis of biomass and plastics can improve the quantity and quality of the produced pyrolysis oil compared to pyrolysis of the separate feedstocks. In this work three relevant plastic wastes; paper reject, shredder light fraction and cable plastics; were evaluated together with woody biomass (stem wood from spruce and pine) using analytical pyrolysis, Py-GC–MS/FID. One verification experiment was also conducted in a cyclone pyrolyser pilot plant at industrially relevant conditions. The addition of plastic waste to woody biomass pyrolysis was found to significantly affect the composition and properties of the produced pyrolysis products. In analytical pyrolysis experiments, positive synergetic effects were observed in the co-pyrolysis of paper reject and cable plastics together with the stem wood. The yield of reactive oxygenated compounds (ketones, aldehydes and acids) was suppressed while more stable alcohols and esters were promoted. The formation of hydrocarbons was also promoted in the co-pyrolysis of plastics from paper reject and stem wood. The results from the analytical pyrolysis were partly verified in the pilot scale experiment by co-pyrolysing stem wood and paper reject. However, the co-pyrolysis also affected other parameters that cannot be detected in analytical pyrolysis such as higher acidity and viscosity of the oil which highlights the need for undertaking experiments at different scales. The product yields in pilot scale were about the same for the co-pyrolysis case as for pure stem wood. However, a high volatile content of the solid product indicated that the process conditions can be further optimized for co-pyrolysing cases.
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19.
  • Johansson, Ann-Christine, et al. (författare)
  • Fractional condensation of pyrolysis vapors produced from Nordic feedstocks in cyclone pyrolysis
  • 2017
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 123, s. 244-254
  • Tidskriftsartikel (refereegranskat)abstract
    • Pyrolysis oil is a complex mixture of different chemical compounds with a wide range of molecular weights and boiling points. Due to its complexity, an efficient fractionation of the oil may be a more promising approach of producing liquid fuels and chemicals than treating the whole oil. In this work a sampling system based on fractional condensation was attached to a cyclone pyrolysis pilot plant to enable separation of the produced pyrolysis vapors into five oil fractions. The sampling system was composed of cyclonic condensers and coalescing filters arranged in series. The objective was to characterize the oil fractions produced from three different Nordic feedstocks and suggest possible applications. The oil fractions were thoroughly characterized using several analytical techniques including water content; elemental composition; heating value, and chemical compound group analysis using solvent fractionation, quantitative 13C NMR and 1H NMR and GC x GC − TOFMS. The results show that the oil fractions significantly differ from each other both in chemical and physical properties. The first fractions and the fraction composed of aerosols were highly viscous and contained larger energy-rich compounds of mainly lignin-derived material. The middle fraction contained medium-size compounds with relatively high concentration of water, sugars, alcohols, hydrocarbonyls and acids and finally the last fraction contained smaller molecules such as water, aldehydes, ketones and acids. However, the properties of the respective fractions seem independent on the studied feedstock types, i.e. the respective fractions produced from different feedstock are rather similar. This promotes the possibility to vary the feedstock depending on availability while retaining the oil properties. Possible applications of the five fractions vary from oil for combustion and extraction of the pyrolytic lignin in the early fractions to extraction of sugars from the early and middle fractions, and extraction of acids and aldehydes in the later fractions.
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20.
  • Kalogiannis, Konstantinos G., et al. (författare)
  • Pyrolysis of lignin with 2DGC quantification of lignin oil : Effect of lignin type, process temperature and ZSM-5 in situ upgrading
  • 2015
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 115, s. 410-418
  • Tidskriftsartikel (refereegranskat)abstract
    • Thermal and catalytic pyrolysis of various types of lignin and their influence on the yield and the quality of the produced lignin oil were studied. Lignins originated from a mixture of pine and spruce wood (softwood), a mixture of birch and aspen wood (hardwood) and Eucalyptus Urograndis. High degree of deoxygenation of the bio-oil and maximum yield of value-added chemicals were the main targets of this work. 2DGC-ToFMS analysis was used for the qualitative and quantitative characterization of the lignin oils. Softwood lignin was found to be the most attractive feedstock and high yields of a mixture of phenolic compounds were detected in all cases. High char production was also evident for all types of lignins accounting for almost 50% of the original feedstock. The use of a commercial ZSM-5 catalyst was extremely beneficial for the process, enhancing deoxygenation at higher oil yields compared to thermal pyrolysis. Depending on the nature of the lignin, guaiacyl or syringyl groups were dominant in the oils and it was found that process optimization, involving lignin, catalyst selection and temperature could significantly improve the process efficiency.
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21.
  • Kätterer, Thomas (författare)
  • Coupling pyrolysis with mid-infrared spectroscopy (Py-MIRS) to fingerprint soil organic matter bulk chemistry
  • 2018
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 133, s. 176-184
  • Tidskriftsartikel (refereegranskat)abstract
    • A novel method coupling pyrolysis with mid-infrared spectroscopy (Py-MIRS) was developed to characterize soil organic matter (SOM) chemistry in soils. The pyrolyzer was interfaced to the MIR spectrometer by means of a Brill cell (TM) (CDS Analytica). The set-up generates pyrolysis fingerprint spectra from which individual pyrolysis products can be related to SOM bulk chemistry. Py-MIRS development involved the testing of experimental conditions like pyrolysis temperature (550, 700, 1000 degrees C), heating rate (20 degrees C s(-1) and 20 degrees C ms(-1)) and time (15, 30 and 60 s) using reference standard compounds ranging from carbohydrates to phenols varying in chemical and structural composition like levoglusogan, gluten, tannin, syringol, pectin and leucine falling within different compound categories (carbohydrates, amino acids, proteins, phenols, etc.) as well as soil samples. Pyrolysis yields of prominent specific functional groups, like aliphatics (C-H stretching at 2930 cm(-1)) and C=C aromatics (1510 cm(-1)), varied with pyrolysis temperature, heating rate and time. The preferred settings for high pyrolysis yield and minimized secondary reactions were obtained at a pyrolysis temperature of 700 degrees C, heating rate of 20 degrees C ms(-1) and heating time of 30 s. The suitability of Py-MIRS to detect changes in SOM composition was evaluated by comparing Py-MIRS results to Diffuse Reflectance Fourier Transform mid-Infrared Spectroscopy (DRIFTS) results. Soil samples taken from the Static Fertilization Experiment, Bad Lauchstadt, Germany (Chernozem) revealed a major SOM contribution of the peak at 1750 cm(-1) (C=O), followed by peaks at 950 (C-H), 1510 (C=C), 1176 (C-H, O-H) cm(-1), with smaller contributions from the 2930 (C-H) and 3015 (CH4) cm(-1) peaks, apart from a dominant CO2 peak. Using the preferred pyrolysis settings, Py-MIRS as well as DRIFTS results further indicated that soils receiving organic (e.g. farmyard manure) inputs were highly enriched in aliphatic groups, while their absence favored the accumulation of carboxyl and aromatic groups as well as polysaccharides. Py-MIRS allowed via semi-quantification of pyrolysis products a rapid monitoring of SOM bulk chemistry with a high degree of reproducibility. It was concluded that Py-MIRS represents a fast, effective and reproducible technique to characterize changes in the SOM bulk chemistry as a result of management practices. It also allows to minimize acknowledged constraints of other analytical techniques used to characterize SOM bulk chemistry such as mineral interferences and associated secondary reactions.
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22.
  • Latham, Kenneth G., et al. (författare)
  • Examination of how variations in lignin properties from Kraft and organosolv extraction influence the physicochemical characteristics of hydrothermal carbon
  • 2021
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier. - 0165-2370 .- 1873-250X. ; 155
  • Tidskriftsartikel (refereegranskat)abstract
    • Seven different lignin samples, three from Kraft extraction and four from organosolv extraction, were subjected to hydrothermal treatment at 260℃ for four hours to assess the impact of lignin type on the physicochemical properties of the hydrothermal material. The 13C Solid state NMR, XPS, FTIR and SEM analysis revealed that the different sources of lignin and the extraction conditions created variations in the degree of syringyl and guaiacyl subunits, inter-unit bonding arrangements, morphology and surface composition. Hydrothermal carbonization appeared to “normalize” the differences between each of the lignin samples, via breaking β-O-4 or α-O-4 linkages, removal of methoxy and syringyl subunits, and creation of C C and 4-O-5 linkages to polymerization into large 100−200 μm amorphous carbon particles. Overall, this study indicates that the source and extraction type have minimal influence on the physicochemical structure and morphology of the final hydrothermal product.
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23.
  • Latham, Kenneth G., et al. (författare)
  • Impact of Temperature and Residence Time on the Hydrothermal Carbonization of Organosolv Lignin
  • 2022
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier. - 0165-2370 .- 1873-250X. ; 166
  • Tidskriftsartikel (refereegranskat)abstract
    • Herein, we have investigated how pure lignin extracted from birch and spruce via a hybrid organosolv/steam explosion method reacts under hydrothermal carbonization (HTC) to produce hydrochar, a product that has found applications in environmental remediation, energy storage and catalysis. We subjected thirteen lignin samples obtained from birch and spruce under different extraction conditions to HTC at 260 ℃ for four hours. The yield of hydrochar varied between the different extraction conditions and source, although no clear correlation between extraction conditions and yield could be observed. For instance, lignin from birch pretreated in 60%v/v ethanol for 15 minutes resulted in a hydrochar yield of 39 wt%. Increasing the time to 30 and 60 resulted in a hydrochar yield of 27 wt% and 23 wt%, respectively. This suggested that small changes in the organosolv reaction conditions might produce highly structurally different lignin, resulting in the difference in HTC yield. Thus, we chose a subset of four lignin samples to investigate in-depth, subjecting these samples to a range of hydrothermal reaction temperatures and residence times. Solid State NMR and FTIR analysis indicated that the most significant structural changes occurred below 230 ℃ resulting in the breaking of C-O- linkages. Increasing the temperature or time had minimal impact, with no further C-O- linkages broken and no changes to the ring structure of C-C groups. Size exclusion chromatography indicated that the degree of micro and macromolecules in the liquid product varied significantly with lignin source and HTC reaction conditions. Overall, this study demonstrated that lignin has a large reaction range where it produces a very chemically similar solid product, with the only major difference being the yield of material. This is important for industry, as it indicates that a similar solid product can be easily achieved independently of extraction conditions allowing the HTC reaction to be tuned towards extracting the maximum benefit from products contained in the liquid.
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24.
  • Lestander, Torbjörn, et al. (författare)
  • Characterization of fast pyrolysis bio-oil properties by near-infrared spectroscopic data
  • 2018
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 133, s. 9-15
  • Tidskriftsartikel (refereegranskat)abstract
    • Pyrolysis transforms bulky and heterogeneous lignocellulosic biomass into more easily-handled oils that can be upgraded into bio-based transportation fuels. Existing systems for monitoring pyrolysis processes and characterizing their products rely on slow and time-consuming wet chemical analyses. On-line near-infrared (NIR) spectroscopy could potentially replace such analyses, providing real-time data and reducing costs. To test the usefulness of NIR methods in characterizing pyrolysis oils and processes, biomass from conifers, Salix, and reed canary grass was milled and pyrolyzed at 675, 750, and 775 °C. Two separate pyrolytic fractions (aerosol and condensed) were produced in each experiment, and NIR spectra were collected for each fraction. Multivariate modelling of the resulting data clearly showed that the samples’ NIR spectra could be used to accurately predict important properties of the pyrolysis oils such as their energy values, main organic element (C, H and O) contents, and water content. The spectra also contained predictive information on the samples’ origins, fraction, and temperature treatment, demonstrating the potential of on-line NIR techniques for monitoring pyrolytic production processes and characterizing important properties of pyrolytic oils from lignocellulosic biomass.
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25.
  • Lu, Xincheng, et al. (författare)
  • Comprehensive insights into the influences of acid-base properties of chemical pretreatment reagents on biomass pyrolysis behavior and wood vinegar properties
  • 2020
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 151
  • Tidskriftsartikel (refereegranskat)abstract
    • Pyrolysis of biomass is an effective approach to produce high-value added solid, liquid and gaseous products. Wood vinegar (WV) is obtained as one of the main liquid products of biomass pyrolysis and has been used as the sustainable chemicals in agriculture. In this study, the effects of acid-base properties of chemical reagents on the biomass pyrolysis behavior and WV properties were investigated, and the mechanism was further discussed. The results indicated that acid-base properties of chemical reagents exhibited the significant effects on pyrolysis behavior and WV properties. Alkaline compounds showed the more obviously effects on changes in biomass chemical structure rather than acids, while acids removed the metallic species more efficiently than alkaline compounds. All chemical pretreatments increased the cellulose crystallinity, and the alkaline compounds were more favorable than the acidic compounds for increasing the crystallinity. Meanwhile, chemical pretreatments changed the chemical structure of biomass and promoted the pyrolysis process. All chemical pretreatments increased the organic content of WV. The relative content of phenols increased after all pretreatments, which increased more obviously by the acids pretreatments. Whereas, the relative content of acids decreased after pretreated by inorganic acids, and increased after pretreated by organic acids and alkaline compounds.
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26.
  • Lu, Xincheng, et al. (författare)
  • Enhanced antioxidant activity of aqueous phase bio-oil by hydrothermal pretreatment and its structure-activity relationship
  • 2021
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 153
  • Tidskriftsartikel (refereegranskat)abstract
    • The antioxidant activity and the structure-activity relationship of aqueous phase bio-oil (APBO), obtained from hydrothermal treatment (HTT) combined with pyrolysis of biomass, have been investigated in this study. HTT increased the relative content of phenolic compounds and reduced the relative content of acids. Phenolic compounds possessed as the dominant chemical components in APBO, representing up to 61.68 %. 2-methoxyphenol (guaiacol) and its derivatives were the major components of phenolic compounds. HTT promoted the antioxidant activity of APBOs and APBO-180 showed higher antioxidant activity than that of commercial chemical antioxidant (butylated hydroxyl toluene) with IC50 values of 0.402 mg/mL of reducing power, 0.132 mg/mL of DPPH free radical scavenging capacity and 0.405 mg/mL of hydroxyl free radical scavenging capability. The antioxidant activity of APBO was affected by its chemical composition. Phenols exhibited a promotion effect on antioxidant activity, while acids showed an inhibition effect. In addition, the substituent structure of phenols played a key role in antioxidant activity. Phenols with the shorter carbon side chain showed higher antioxidant activity (e.g. 2-methylphenol>2-methoxyphenol, 4-methyl-2-methoxyphenol>4-ethyl-2methoxyphenol). This study suggested that APBO could be developed as the natural feed additives or alternative antioxidant, providing a new strategy for efficient utilization of APBO.
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27.
  • Moser, Konstantin, et al. (författare)
  • Screw reactors and rotary kilns in biochar production – A comparative review
  • 2023
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier. - 0165-2370 .- 1873-250X. ; 174:September 2023
  • Tidskriftsartikel (refereegranskat)abstract
    • One promising technology in the field of residue valorization is the pyrolytic conversion of biomass to biochar. There are a lot of proven technologies for this task, with many of them being quite distinctive. Biochar has a lot of valuable properties and it shows potential to be applicated in many different fields of industry as a green carbon resource. Thus, as the demand for its production rises, more and more people from different fields share interest in the same technologies and the demand for guidance in form of readily available information increases. Two prominent technologies rather similar in appearance are rotary kilns and screw reactors. Both technologies consist of a long, hollow cylinder and both technologies use some form of longitudinal rotation as a means to transport feedstock. In this review, both technologies are described and their biggest differences and similarities are discussed, all under the aspect of biochar production. In total, 21 unique rotary kilns and 58 unique auger reactors were identified. The paper addresses process specific aspects, like heat supply or residence time, but it also gives an overview on current research and general aspects like scale-up considerations. Differences between both technologies were found in all of these aspects, with some of the most pronounced being the bigger maximum capacities and the greater residence time distributions in rotary kiln pyrolysis. Both technologies are viable candidates for producing biochar on a commercial level, however, literature comparing the influence of the reactor type on biochar properties was very scarce. As a future outlook it is recommended to produce data that can be compared on a quantitative level, so a more accurate assessment of each technologies up- and downsides can be made.
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28.
  • Naqvi, Salman Raza, et al. (författare)
  • Impact of layered and delaminated zeolites on catalytic fast pyrolysis of microalgae using fixed-bed reactor and Py-GC/MS
  • 2021
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier. - 0165-2370 .- 1873-250X. ; 155
  • Tidskriftsartikel (refereegranskat)abstract
    • The aim of this work is to exploit the pyrolysis characteristics of microalgae Botryococcus braunii (BB) with a medium pore framework zeolite (MCM-22) and its delaminated counterpart with a higher external surface area zeolite (ITQ-2) using pyrolysis-gas-chromatography-mass-spectrometry (Py-GC/MS) and a fixed-bed reactor. The study evaluates the effect of synthesized zeolites that possess different pore size, shape and acidity on promoting deoxygenation reactions and producing aromatic compounds during the pyrolysis of microalgae. Further, the role of the shape of zeolites (layered & delaminated) for carbohydrate, protein and lipid-derived compounds formation is discussed. The Py-GC/MS results showed that the aromatic compounds (area%) was significantly higher (35.17 %) for delaminated & (28.76 %) for layered zeolites than non-catalytic pyrolysis (17.85 %) at the catalyst/biomass ratio of 10.1. The increase in catalyst/biomass ratio from 3 to 10 at 550 °C has increased the aromatics (90.66 % for ITQ-2 & 75.25 %) for MCM-22 zeolites. In addition, ITQ-2 zeolite produced 20.47 % higher aromatics than MCM-22 zeolites which is attributed to the thinner delaminated structure of ITQ-2 that makes reactants more accessible to the catalytic site and accelerate the deoxygenation reactions.
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29.
  • Persson, Henry, et al. (författare)
  • Catalytic pyrolysis over transition metal-modified zeolites: a comparative study between catalyst activity and deactivation
  • 2019
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier. - 0165-2370 .- 1873-250X. ; 138, s. 54-61
  • Tidskriftsartikel (refereegranskat)abstract
    • The utilization of metal-doped zeolites in catalytic pyrolysis of biomass is a well-known approach to promote the formation of certain compounds. One major technical issue of using zeolites in biomass pyrolysis processes is their rapid deactivation due to coke formation. However, little is known about how metal-doping influences the characteristics of coking, such as coking rate and its composition.In this study, four different materials were experimentally evaluated based on their catalytic activity and coking characteristics: HZSM-5, Fe/ZSM-5, Ni/ZSM-5 and FeNi/ZSM-5. The materials were prepared and characterized followed by screening in a bench-scale setup for in-situ catalytic pyrolysis. The mass balance and composition of pyrolysis products including catalyst coke were analyzed.It was found that metal-doping increases the concentration of aromatic hydrocarbons in the liquid product from 59.0 to 82.8 % of GC/MS peak area, especially monoaromatic hydrocarbons (MAHs) and naphthalenes. Fe mainly promotes MAHs whereas Ni additionally promotes naphthalenes. FeNi/ZSM-5 enhances the production of both compound groups as well as further reducing the total acid number (TAN). Regarding the catalyst coke, metal-doped catalysts present an increased concentration of aromatic hydrocarbons in terms of MAHs, naphthalenes and polyaromatic hydrocarbons. For each catalyst, the chemical composition of catalyst coke reflects the catalyst’s activity seen in vapor upgrading. A reaction pathway based on the observed catalyst activities of metal-doped ZSM-5 and HZSM-5 is proposed.The results also show that metal-doping of catalysts increases the formation of catalyst coke, mainly due to a higher concentration of strong acid sites. Also, the rate of coking is dependent on the strength of acid sites, where the strength correlates with the severity of coking. The coke yield was seen to increase from 3.5 wt% in the case of HZSM-5 to maximum 7.2 wt% over Fe/ZSM-5. However, the metal-doping of catalysts reduces the temperature of catalyst regeneration and catalyzes the oxidation of coke. Overall, this work presents a comparative study between catalyst activity and deactivation during thermochemical conversion of biomass.
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30.
  • Persson, Henry, 1991-, et al. (författare)
  • Wood-derived acid leaching of biomass for enhanced production of sugars and sugar derivatives during pyrolysis : Influence of acidity and treatment time
  • 2017
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier. - 0165-2370 .- 1873-250X. ; 127, s. 329-334
  • Tidskriftsartikel (refereegranskat)abstract
    • 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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31.
  • Prins, M. J., et al. (författare)
  • Biomass pyrolysis in a heated-grid reactor: Visualization of carbon monoxide and formaldehyde using Laser-Induced Fluorescence
  • 2011
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 1873-250X .- 0165-2370. ; 92:2, s. 280-286
  • Tidskriftsartikel (refereegranskat)abstract
    • The development of improved biomass pyrolysis models is vital for more accurate modelling and design of biomass conversion equipment. Such improved models must be based on reliable experimental data: biomass should be pyrolyzed at high heating rates and the reaction products should be measured using an on-line, non-intrusive method. Therefore, a heated grid reactor with heating rate of 300-600 K/s was used to study pyrolysis of biomass at temperatures in the range of 500-700 degrees C. The formation of formaldehyde and carbon monoxide from wood at high heating rates was successfully visualized using Laser-Induced Fluorescence (LIF). A thin vertical laser line or sheet was present directly above the biomass lying on the heated grid. Two-photon excitation at 230 nm was applied to induce fluorescence of carbon monoxide present in the volatiles, whereas excitation of formaldehyde was done at 355 nm. Visualization of these compounds shows that the release rises strongly with temperature; this typically happens on a timescale in the order of seconds. In principle, the method described allows for the determination of truly primary products. Future research is recommended, aimed at quantifying the concentrations measured by LIE. Care must be taken to calibrate for quenching of the fluorescence signal. Avoiding secondary reactions taking place in the gas phase is another experimental challenge. (C) 2011 Elsevier B.V. All rights reserved.
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32.
  • Ratnasari, Devy Kartika, 1990-, et al. (författare)
  • Two-stage ex-situ catalytic pyrolysis of lignocellulose for the production of gasoline-range chemicals
  • 2018
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 134, s. 454-464
  • Tidskriftsartikel (refereegranskat)abstract
    • The appropriate system is needed to produce a scalable and economically viable renewable energy from biomass. The objective of this study is to improve the quality of bio-oil, in terms of Organic Liquid Product (OLP), water content, acidity, favourable fractions, as well as gasoline-range chemicals. The influence of a staged layered catalyst system consists of a mesoporous catalyst, Al-MCM-41, and a microporous catalyst, HZSM-5, on the bio-oil quality was investigated. Additionally, the effect of reaction temperatures in the range of 400–600 °C with the optimum staged catalyst system on the catalytic pyrolysis product was analysed. The experiments of lignocellulosic biomass pyrolysis and catalytic pyrolysis were performed using a fixed bed reactor equipped with oil condensers and a gas collection sample bag. The quality of bio-oil produced from the thermal pyrolysis of lignocellulosic biomass, catalytic pyrolysis with single catalysts, catalytic pyrolysis with the staged catalyst system, as well as catalytic pyrolysis with mixed catalyst system was studied. The results show that Al-MCM-41 with HZSM-5 in the staged catalyst system enhanced the production of favourable compounds: hydrocarbons, phenols, furans, and alcohols. The favourable compounds yield that boosted 5.25–6.43% of that with single HZSM-5 catalyst was produced with HZSM-5:Al-MCM-41 mass ratio of 3:1 and 7:1. The pyrolysis and catalysis temperature of 500 °C with HZSM-5:Al-MCM-41 ratio of 3:1 obtained the optimum quality of bio-oil with 11.08 wt.% of OLP, 76.20% of favourable fractions, 41.97 wt.% of water content, low TAN of 43.01 mg-KOH/g, high deoxygenation, as well as high gasoline-range production of 97.89%.
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33.
  • Sobiesiak, Magdalena, et al. (författare)
  • Thermal degradation behavior of lignin-modified porous styrene-divinylbenzene and styrene-bisphenol A glycerolate diacrylate copolymer microspheres
  • 2017
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : ELSEVIER SCIENCE BV. - 0165-2370 .- 1873-250X. ; 123, s. 364-375
  • Tidskriftsartikel (refereegranskat)abstract
    • This paper describes the thermal properties of polymeric porous microspheres that contain a natural wood-derived polymer, lignin, as one of the components. Polymeric microspheres were obtained by the reaction of divinylbenzene (DVB) or bisphenol A glycerolate diacrylate (BPA.DA) with styrene (St) and a lignin component. The lignin components were unmodified lignin (L), lignin esterified with acrylic acid (LA) or lignin initially reacted with epichlorohydrin and then with acrylic acid (LEA). The copolymers were obtained by emulsion-suspension polymerization at a constant mole ratio of the tetrafunctional monomer DVB or BPA.DA to styrene St (1:1 w/w) and different types of lignin components. The thermal stabilities and degradation behavior of the obtained microspheres were studied by a thermogravimetric (TG/DTG/DSC) analysis. The evolved gases were analyzed by FTIR spectrometry. The influence of the lignin component on thermal properties of the obtained polymeric microspheres is evaluated and discussed. Due to the presence of the specific functional groups and well-developed porous structure, the obtained lignin-containing microspheres have a potential application as specific sorbents. Based on the high char content during the pyrolysis, the copolymers containing the lignin additives can be also considered as potential precursors for preparation of carbon materials.
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34.
  • Supriyanto, Supriyanto, et al. (författare)
  • Gaseous products from primary reactions of fast plastic pyrolysis
  • 2021
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 158
  • Tidskriftsartikel (refereegranskat)abstract
    • This study aimed to establish primary reactions and identify gaseous products during fast pyrolysis of low-density polyethylene (LDPE), polypropylene (PP) and polystyrene (PS). Fast pyrolysis was performed by using Py-GC/MS/FID at 574 ± 22 °C for 5 s. Gaseous fractions formed during pyrolysis of LDPE, PP and PS were 14 ± 1 wt%, 31 ± 3 wt% and 103 ± 12 wt%, respectively. The main gaseous compounds from LDPE were butane, 1-pentane and 1-hexene. PP pyrolysis gave propene, pentane and 2,4-dimethyl-1-heptene as the main gaseous compounds. Styrene monomer was the dominant gas from PS. The results showed that polyolefin (PP and PE) produced aliphatic hydrocarbons, while PS formed aromatic hydrocarbons. Furthermore, the proposed mechanism suggests that both inter- and intra-molecular hydrogen transfer occur during PP and PE pyrolysis. PS pyrolysis involves a C-C cleavage at the aliphatic side chain. This work is important to understand the mechanism of gas formation of primary reactions from pyrolysis of common plastics.
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35.
  • Supriyanto, Supriyanto, et al. (författare)
  • Identifying the primary reactions and products of fast pyrolysis of alkali lignin
  • 2020
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 151
  • Tidskriftsartikel (refereegranskat)abstract
    • This study focused on the effect of temperature and residence time on the primary thermal decomposition reactions during a fast pyrolysis of softwood alkali lignin. The use of Py-GC/MS/FID (Micropyrolyser-Gas Chromatography/Mass Spectrometry/Flame Ionization Detector) allowed for rapid heating of the sample and detailed identification and quantification of the pyrolysis products at a temperature range of 400–600 °C, with residence times from 0.5–5 s. The identified primary pyrolysis products were mainly volatile guaiacyl-type compounds. There was a general increase in yield for the majority of the volatile compounds with increased temperature and time. The cleavage of the lignin polymer to linear carbonyl (acetaldehyde) and guaiacyl-type aromatic compounds increased with temperature, while that of catechol and cresol type was mainly favoured at 500 and 600 °C. Based on these results, a mechanistic pathway for the pyrolytic process was proposed, drawing a linkage from structural units of lignin to the formed primary products. In summary, our findings suggest that the primary decomposition reactions that occur under the fast pyrolysis conditions can be controlled by varying the process temperature and residence time, and deliver mechanistic insight into the product distribution from structurally complex lignin material.
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36.
  • Teece, Bronwyn L., et al. (författare)
  • Using laser micropyrolysis to assess potential relationships between Cambrian tommotiids and organophosphatic brachiopods
  • 2021
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 158, s. 105277-105277
  • Tidskriftsartikel (refereegranskat)abstract
    • Laser micropyrolysis gas chromatography-mass spectrometry enables researchers to selectively obtain chemical information about the organic matter in specific parts of a variety of specimens, such as coals and fossils, in order to elucidate chemical composition. This paper briefly reviews the history of this type of pyrolysis and examines whether the technique can be used to isolate and recover biogeochemical signatures directly from the mineralised organophosphatic sclerites of Cambrian tommotiids—a group of enigmatic lophotrochozoans—and potentially related organophosphatic brachiopods. We analysed specimens of two tommotiids (Micrina etheridgei and Dailyatia sp.) and the paterinate brachiopod Askepasma toddense from the lower Cambrian of South Australia. Pyrolysate hydrocarbons from the sclerites of these species were detected and compared. Results indicate that A. toddense is more chemically complex than either of the two tommotiid taxa, but that M. etheridgei is compositionally more similar to A. toddense. Importantly, this study has demonstrated that laser micropyrolysis gas chromatography-mass spectrometry of Cambrian organophosphatic small shelly fossils yields detectable pyrolysates that have geochemical significance. It will be analytically possible and useful in the future to apply this technique to a larger sample set to elucidate deep time biogeochemical homologies, and to test intra-shell heterogeneity.
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37.
  • Usino, David, et al. (författare)
  • Influence of temperature and time on initial pyrolysis of cellulose and xylan
  • 2020
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; Volume 147:104782
  • Tidskriftsartikel (refereegranskat)abstract
    • The aim of this study was to investigate the effects of temperature and reaction time on the primary pyrolysis of cellulose and xylan. Fast pyrolysis of cellulose and xylan was carried out with a micropyrolyser connected to a gas chromatograph-mass spectrometer/flame ionisation detector (GC–MS/FID) to separate and identify volatile components, both qualitatively and quantitatively. This set-up meant a minimum amount of secondary reactions, low impact of the heating period and at the same time provided rapid and accurate analyses. The two biomass components investigated were: cellulose and hemicellulose (represented by xylan). They were pyrolysed during 0.5, 1, 2 and 5 s (s) and within a temperature range of 400–600 °C. The results showed that levoglucosan (1, 6-anhydro β-D-glucopyranose) is the main chemical compound released during cellulose pyrolysis. It increased with increasing temperature and time. The main volatile compounds produced from pyrolysis of xylan are: 1-hydroxy-2-butanone, 4-hydroxy-5, 6-dihydro-(2 H)-pyran-2-one, 1-hydroxy-2-propanone (acetol), acetaldehyde and hydroxyacetaldehyde (HAA). HAA was the most abundant chemical compound released during xylan pyrolysis, increasing with higher temperatures and time. Acetol and acetaldehyde also showed similar behaviour. The chemical compounds released from cellulose and xylan fast pyrolysis are primary products and assumed to be produced directly from both cellulose and xylan molecules and not from secondary degradation. In this study, possible reaction routes during biomass primary pyrolysis are also suggested based on the product distribution from the thermal decomposition of cellulose and xylan.
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38.
  • Usino, David, et al. (författare)
  • Primary interactions of biomass components during fast pyrolysis
  • 2021
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 159
  • Tidskriftsartikel (refereegranskat)abstract
    • Fast pyrolysis is an industrially attractive method to produce fuels and chemicals from biomass; however, to gain better control over the process, the reactions and interactions between the components and decomposition products need elucidation. This study investigated primary reactions during fast pyrolysis of biomass. Pyrolysis of the three main biomass components (cellulose, hemicellulose and lignin) and their blends was carried out with a micro-pyrolyser connected to a Gas Chromatograph-Mass Spectrometer/Flame Ionisation Detector (GC–MS/FID). The blends of the individual components were prepared in similar proportions to that of native biomass (birchwood) and were pyrolysed at 600 °C for 2 s. The results showed that the two-component blends decrease the production of saccharides to a large extent. This was especially noticeable for levoglucosan when cellulose was mixed with either hemicellulose or lignin. Similarly, in the presence of cellulose, the formation of phenolic compounds from lignin was inhibited by 62 %. However, no differences were found in yields of the main products for the xylan-lignin blend compared to those from the individual components. The yields of volatile products from the cellulose-xylan blend were promoted for a majority of the product categories and were most pronounced for the aldehydes. Furthermore, while the formation of the phenols and saccharides was slightly inhibited for the three-component blend, the aldehydes, ketones and furans showed an increased production compared to the weighed sum of products expected, based on the pyrolysis of the individual components. The native biomass showed a similar trend as the three-component blend in all product categories except for the saccharides, which were inhibited to a large extent. This study provides a better understanding of the interactions occurring between different components during fast pyrolysis of biomass.
  •  
39.
  • Wagner, David R., et al. (författare)
  • Time-dependent variations of activation energy during rapid devolatilization of biomass
  • 2016
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 118, s. 98-104
  • Tidskriftsartikel (refereegranskat)abstract
    • Industrial gasifiers and combustors are assumed to reach particle heating rates of 10(5)-10(6) degrees C/s and understanding how particles behave in these extreme conditions can improve the utilization of solid fuels in these reactors and in downstream applications. By studying intermediate devolatilization processes during solid fuel pyrolysis, detailed models for solid fuel conversion can be formulated. Key objectives of this study included (1) investigate possible mechanisms that promote the formation of synthesis gas components and char, (2) compare the devolatilization behavior of pyrolysis by varying particle size, hold time, and temperature and (3) correlate char deactivation with hold time. The objectives of the study were accomplished using a wire-mesh reactor with a uniform heating rate of 500 degrees C/s in nitrogen under atmospheric pressure. A design of experiments approach was used to quantify the effects that hold time, temperature, and particle size had on char yield, evolved gas composition, and apparent activation energy of pine stem wood and wheat straw. Key results indicate that with increased temperature and hold time more volatiles evolve from the fuels and favor carbon monoxide and methane production at higher temperatures. Apparent activation energy of the volatile matter decreases with hold time. An abbreviated model for apparent activation energy correlates well with experimental data and assumes that along a devolatilization pathway, that not all volatiles are driven from the fuel.
  •  
40.
  • Werner, Kajsa, et al. (författare)
  • Thermal decomposition of hemicelluloses
  • 2014
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 110, s. 130-137
  • Tidskriftsartikel (refereegranskat)abstract
    • Decomposition modeling of biomass often uses commercially available xylan as model compound representing hemicelluloses, not taking in account the heterogeneous nature of that group of carbohydrates. In this study, the thermal decomposition behavior of seven different hemicelluloses (beta-glucan, arabinogalactan, arabinoxylan, galactomannan, glucomannan, xyloglucan, and xylan) were investigated in inert atmosphere using (i) thermogravimetric analysis coupled to Fourier transform infrared spectroscopy, (ii) differential scanning calorimetry, and (iii) pyrolysis-gas chromatography/mass spectroscopy. Results on decomposition characteristics (mass loss rate, reaction heat and evolving gas composition) were compared and summarized for the different hemicelluloses and for comparison also crystalline cellulose was included in the study. The mass loss rate characteristics differed between the polysaccharides, with cellulose and glucan-based hemicelluloses as the thermally most stable and xylan as the least stable sample. The heat flow during slow heating in nitrogen flow showed a much more exothermal decomposition of xylan compared with the other hemicelluloses. The composition of off-gases during heating showed large differences between the samples. During decomposition of xylan high levels of CO2 and lower levels of other components were formed, whereas also CO, methanol, methane, furfural, 5-hydroxymethylfurfural and anhydrosugars were formed in substantial amounts from the other polysaccharides. The formation of anhydrosugar was correlated to the monosaccharide composition of the polysaccharide chain. The results from the current study contribute to new knowledge concerning thermochemical behavior of different hemicelluloses.
  •  
41.
  • Xie, Y., et al. (författare)
  • A critical review on production, modification and utilization of biochar
  • 2022
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier B.V.. - 0165-2370 .- 1873-250X. ; 161
  • Tidskriftsartikel (refereegranskat)abstract
    • There has been an increased interest in the production of sustainable biochar in the past years, as biochar shows versatile physicochemical properties and, can have a wide applicability in diverse fields. Comprehensive studies have been made to characterize biochar produced from various biomass materials, using different production technologies and under different process conditions. However, research is still lacking in correlating biochar properties needed for certain applications with (i) feedstock, (ii) biochar production processes and conditions and (iii) biochar upgrading and modification strategies. To produce biochar with desired properties, there is a great need to establish and clarify such correlations, which can guide the selection of feedstock, tuning and optimization of the production process and more efficient utilization of biochar. On the other hand, further elucidation of these correlations is also important for biochar-stakeholder and end-users for predicting physiochemical properties of biochar from certain feedstock and production conditions, assessing potential effects of biochar utilization and clearly address needs towards biochar critical properties. This review summarizes a wide range of literature on the impact of feedstocks and production processes and reactions conditions on the biochar properties and the most important biochar properties required for the different potential applications. Based on collected data, recommendations are provided for mapping out biochar production for different biochar applications. Knowledge gaps and perspectives for future research have also been identified regarding the characterization and production of biochar. 
  •  
42.
  • Yang, Hanmin, et al. (författare)
  • Influence of the porosity and acidic properties of aluminosilicate catalysts on coke formation during the catalytic pyrolysis of lignin
  • 2022
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier B.V.. - 0165-2370 .- 1873-250X. ; 165
  • Tidskriftsartikel (refereegranskat)abstract
    • Five aluminosilicate catalysts with different textural and acidic properties are used to study the influence of their acidic and porous properties on the coke formation during the fast catalytic pyrolysis of lignin. The competition between coke formation and target product (hydrocarbons) formation in regard to different pore sizes and Si/Al ratios is classified via performing X-Ray Diffraction (XRD), nitrogen adsorption-desorption, pyrolysis–gas chromatography–mass spectrometry (Py-GCMS), kinetic calculations, and thermogravimetric (TG)/temperature programmed oxidation (TPO) measurements. The results indicated that a pore size consistent with the critical diameters of the pyrolysis products of lignin is a prerequisite for a catalyst to reach a high selectivity for the desired products with less coke formation. A relatively large pore size can cause severe coke formation; however, large pores are favorable for increasing the reaction rate by increasing the diffusion efficiency. A catalyst with sufficient acidity is also essential for high selectivity towards target products. © 2022 The Authors
  •  
43.
  • Zhang, Xiaolei, et al. (författare)
  • Levoglucosan formation mechanisms during cellulose pyrolysis
  • 2013
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 104, s. 19-27
  • Tidskriftsartikel (refereegranskat)abstract
    • Levoglucosan is one important primary product during cellulose pyrolysis either as an intermediate or as a product. Three available mechanisms for levoglucosan formation have been studied theoretically in this paper, which are free-radical mechanism; glucose intermediate mechanism; and levoglucosan chain-end mechanism. All the elementary reactions included in the pathway of every mechanism were investigated; thermal properties including activation energy. Gibbs free energy, and enthalpy for every pathway were also calculated. It was concluded that free-radical mechanism has the highest energy barrier during the three levoglucosan formation mechanisms, glucose intermediate mechanism has lower energy barrier than free-radical mechanism, and levoglucosan chain-end mechanism is the most reasonable pathway because of the lowest energy barrier. By comparing with the activation energy obtained from the experimental results, it was also concluded that levoglucosan chain-end mechanism fits better with the experimental data for the formation of levoglucosan.
  •  
44.
  • Zhang, Xiaolei, et al. (författare)
  • Thermal decomposition mechanism of levoglucosan during cellulose pyrolysis
  • 2012
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 96, s. 110-119
  • Tidskriftsartikel (refereegranskat)abstract
    • Levoglucosan (1,6-anhydro-beta-D-glucopyranose) decomposition is an important step during cellulose pyrolysis and for secondary tar reactions. The mechanism of levoglucosan thermal decomposition was studied in this paper using density functional theory methods. The decomposition included direct C-O bond breaking, direct C-C bond breaking, and dehydration. In total, 9 different pathways, including 16 elementary reactions, were studied, in which levoglucosan serves as a reactant. The properties of the reactants, transition states, intermediates, and products for every elementary reaction were obtained. It was found that 1-pentene-3,4-dione, acetaldehyde, 2,3-dihydroxypropanal, and propanedialdehyde can be formed from the C-O bond breaking decomposition reactions. 1,2-Dihydroxyethene and hydroxyacetic acid vinyl ester can be formed from the C C bond breaking decomposition reactions. It was concluded that C-O bond breaking is easier than C-C bond breaking due to a lower activation energy and a higher released energy. During the 6 levoglucosan dehydration pathways, one water molecule which composed of a hydrogen atom from C3 and a hydroxyl group from C2 is the preferred pathway due to a lower activation energy and higher product stability.
  •  
45.
  • Zhu, Y., et al. (författare)
  • Catalytic pyrolysis of duckweed with phosphoric acid : Pyrolysis behavior and kinetics analysis
  • 2024
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 177
  • Tidskriftsartikel (refereegranskat)abstract
    • Duckweed (DW) has a promising potential for wastewater treatment due to its outstanding performance in the fixation of nutrient elements and heavy metals. The conversion of harvested duckweed into value-added products through pyrolysis is an attractive method for duckweed utilization as fuels or chemicals. In this work, the duckweed was prepared by deashing treatment and subsequent impregnation with different phosphoric acid concentrations (ADW-P). The pyrolysis behavior and kinetics of raw and impregnated duckweeds were studied with respect to the ash contained in the duckweed and the phosphoric acid catalytic effect by thermogravimetric analysis-fourier transform infrared spectrometer (TG-FTIR) and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The results show that the pyrolysis reaction zone is extended for the impregnated duckweed by reducing the initial pyrolysis temperature and increasing the final temperature. Specifically, a shoulder peak situated at the right side of the main peak is present in the DTG curves of ADW-P, suggesting the formation of relatively stable substance after phosphoric acid impregnation. Phosphoric acid promotes the release of H2O, CH4, CO2 and NH3 as well as light volatiles with C[dbnd]C and C[dbnd]O groups during pyrolysis. Meanwhile, decarboxylation and aromatization as well as deamination of organic compounds are strengthened, resulting in an increase of aromatic hydrocarbons and furans and a decrease of N-heterocyclic compounds. The activation energy of ADW-P is lower than that of DW and ADW at conversion rate less than 75% but increases remarkably at high conversion rate. This implies that phosphoric acid facilitates the thermal decomposition of DW at low temperatures but hinders its decomposition at high temperatures probably due to the formation of stable cross-linked structures such as phosphate and polyphosphate esters. 
  •  
46.
  • Andersson, Mattias, 1982, et al. (författare)
  • Dielectric loss determination of fine residual waste electrical and electronic equipment for understanding of heat development during microwave pyrolysis
  • 2013
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370. ; 103, s. 142-148
  • Tidskriftsartikel (refereegranskat)abstract
    • Waste electrical and electronic equipment (WEEE) contains rare and valuable metals which are important to recycle, but it also has high organic content. The conventional methods used today for treatment of WEEE cannot recycle 100%; they generate valuable fine residual fractions. For further processing of these residues, microwave pyrolysis has shown to be promising since it reduces the organic content and liberate enclosed metal pieces. However, to fully control the process, the dielectric properties of the materials need to be known but are difficult to determine due to the complex composition and structure of WEEE. This paper aims to describe a suitable procedure for determination of dielectric loss in six WEEE residual fine fractions and to correlate the results to heating behaviour during microwave pyrolysis. Three fractions are "dusts" (light, medium and heavy dust) and three fractions are called "particulate materials" and contain smaller particles (0-7 mm, 0-20 mm and 7-12 mm). The method chosen was Vector Network Analyzer (VNA) using waveguide WR430 equipped with polymer foam to contain the samples which consisted of 1 dl of WEEE fine fraction. The scattering parameters were measured and dielectric loss in the materials was calculated. The measurements were performed in frequency region 1.3-2.7 GHz to include the industrial frequency 2.45 GHz. Differences between dielectric losses for the materials were determined by ANOVA. It was shown that the scattering parameter measurements were rather stable for the dust materials and the losses could be determined. For the larger sized particulate materials a lot of reflection was observed during the measurements, due to fine metal wires in the material. The losses could be determined after removing these wires. The previously observed higher heating rate and shorter time for mass reduction of dusts could not be explained by differences in dielectric loss. However, since VNA measurements indicate that metal wires in the material disturb the field; presence of wires in the particulate materials might be one cause for slower heating rate and observed temperature drops during pyrolysis.
  •  
47.
  • Bowden, Stephen, et al. (författare)
  • The thermal alteration by pyrolysis of the organic component of small projectiles of mudrock during capture at hypervelocity
  • 2008
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370. ; 82, s. 312-314
  • Tidskriftsartikel (refereegranskat)abstract
    • In a series of experiments the pyrolytic effects of the heating induced during the hypervelocity impact(HVI) of small projectiles of high TOC mudrock were observed. Impacts at these high speeds (km s-1)release sufficient energy to vaporise metal projectiles, and the temperatures created greatly exceed thepyrolysis temperatures typically employed during laboratory studies of the thermal alteration ofsedimentary organic matter. Despite this the organic geochemical analyses of projectiles of OrcadianLaminite impacted into targets of sand and water at hypervelocities provides evidence that the structuralbackbone of biomarkers has remained intact and that only a comparatively low degree of thermalalteration (pre-oil window) has occurred. While further studies are necessary, it appears that the organiccomponent of a projectile captured at hypervelocity will be a slightly thermally altered sample of itsprecursor.
  •  
48.
  • Ebin, Burcak, 1983, et al. (författare)
  • Effects of gas flow rate on zinc recovery rate and particle properties by pyrolysis of alkaline and zinc-carbon battery waste
  • 2016
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370. ; 121, s. 333-341
  • Tidskriftsartikel (refereegranskat)abstract
    • Zinc (Zn) recovery rate and the properties of Zn particles obtained by pyrolysis of alkaline and Zn-C battery waste were studied at a reaction temperature of 950 degrees C for 60 min residence time using various N-2(g) flow rate (0.5-3.014min) without using any additive. The battery black mass was characterized with respect to the properties of waste battery particles, and chemical content. The thermodynamics of the pyrolysis process was studied using the HSC Chemistry 5.11 software. A carbothermic reduction reaction of the washed battery black mass by Milli-Q water takes place at choosen temperature and makes it possible to produce fine Zn particles by a rapid condensation following the evaporation of zinc from the pyrolysis batch. The amount of Zn that can be separated from the black mass slightly increases at higher N-2(g) flow rates than 0.5 L/min and stabilizes by controlling the gas flow. Zn recovery of 80% was achieved at 950 degrees C and 60 min residence time using 1.0 L/min and higher flow rates by pyrolysis of the washed battery black mass. The pyrolysis residue was shown to be mainly composes of MnO and Mn2O3 with traces of impurities. The particle size of the produced Zn particle decreased from 874nm to 534 nm with increasing flow rate and those particles are formed by the aggregation of primary condensed particles with nano-range sizes. The morphology of the zinc particles also changes from hexagonal shape to spherical morphology by increasing gas flow rate.
  •  
49.
  • Mandviwala, Chahat, 1995, et al. (författare)
  • Comparing bed materials for fluidized bed steam cracking of high-density polyethylene: Olivine, bauxite, silica-sand, and feldspar
  • 2023
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - 0165-2370. ; 173
  • Tidskriftsartikel (refereegranskat)abstract
    • Steam cracking in fluidized beds is an alternative method for producing valuable petrochemicals from plastic waste. Previous studies on the conversion of plastics in fluidized beds have revolved around non-catalytic cracking using silica sand as the bed material. On the other hand, studies on catalytic cracking have focused on the use of active materials such as olivine, bauxite, feldspar, and zeolites. The potential influence of the above-mentioned materials, in their natural or inactive state, on fluidized bed hydrocarbon cracking, is not well-documented in the literature. In this paper, steam cracking of polyethylene in a bubbling fluidized bed at 750 °C is investigated in the presence of four different natural ores: olivine, bauxite, silica sand, and feldspar. The paper compares the performance of the steam cracking process in terms of cracking severity, conversion, and product distribution among different hydrocarbon groups. The results show that there is only a marginal difference in cracking severity among the different bed materials, while the conversion remain relatively consistent, ranging from 93% to 95% (carbon.%). The yields of paraffins and carbon oxides are narrow, ranging from 15% to 16% and 3–4%, respectively, while the yields of light olefins and aromatics show a slightly wider range. The yield of olefins is in the range of 52–57%, and for aromatics, it ranges from 16% to 21%. The paper also discusses the potential impact of these bed materials on the cracking reactions, including their thermal and reactive interactions.
  •  
50.
  • Mandviwala, Chahat, 1995, et al. (författare)
  • Thermochemical conversion of polyethylene in a fluidized bed: Impact of transition metal-induced oxygen transport on product distribution
  • 2022
  • Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370. ; 163
  • Tidskriftsartikel (refereegranskat)abstract
    • Thermochemical conversion in dual fluidized bed (DFB) systems is a potential alternative to the recycling of abundantly available plastic waste. The development of oxygen transport in DFB systems is in most cases unavoidable due to the transition metal content of the bed material as well as the metal fraction in the waste stream. This work investigates the influence of transition metal oxide-induced oxygen transport on the thermochemical conversion of high-density polyethylene, a model plastic feedstock, in a bubbling fluidized bed reactor. Conversion in the reactor at 700 °C was investigated using four different bed materials that had different concentrations of iron oxide. The share of carbon oxides among the gaseous products increased with an increase in the iron oxide content of the bed material. The yield of light olefinic and paraffinic compounds decreased with increased iron oxide content of the bed. The presence of iron oxide in the bed material significantly increased the formation rates of aromatic compounds and solid carbon deposits on the bed material. The observed shift in the product distribution due to oxygen transport follows a dehydrogenation-type reaction mechanism.
  •  
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