| 1. |
- Blomquist, G., et al.
(författare)
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Data-analysis of pyrolysis-chromatograms by means of simca pattern-recognition
- 1979
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Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 1873-250X .- 0165-2370. ; 1:1, s. 53-65
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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)
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Energy recovery through co-pyrolysis of wastewater sludge and forest residues -The transition from laboratory to pilot scale
- 2021
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Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 158
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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)
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The behavior of kraft lignin during thermal treatment
- 2010
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Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 87:1, s. 70-77
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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)
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Influence of torrefaction on the devolatilization and oxidation kinetics of wood
- 2012
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Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 96, s. 100-109
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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)
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High-speed imaging of biomass particles heated with a laser
- 2013
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Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 103, s. 278-286
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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)
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Catalytic fast pyrolysis of biomass to produce furfural using heterogeneous catalysts
- 2017
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Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 127, s. 292-298
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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)
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Achieving carbonized minitablet-shaped structures from lignin : The importance of heating rate on shape
- 2023
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Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 176, s. 106260-
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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)
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Investigation of the thermal decomposition of printed circuit boards (PCBs) via thermogravimetric analysis (TGA) and analytical pyrolysis (Py-GC/MS)
- 2015
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Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier. - 0165-2370 .- 1873-250X. ; 115, s. 337-343
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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)
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Formation of PCDDs and PCDFs in the torrefaction of biomass with different chemical composition
- 2017
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Ingår i: Journal of Analytical and Applied Pyrolysis. - : ELSEVIER SCIENCE BV. - 0165-2370 .- 1873-250X. ; 123, s. 126-133
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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)
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Multivariate curve resolution provides a high-throughput data processing pipeline for pyrolysis-gas chromatography/mass spectrometry
- 2012
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Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 95, s. 95-100
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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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