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PubMed2005

Olive bagasse (Olea europea L.) pyrolysis.

Olive bagasse (Olea europea L.) was pyrolysed in a fixed-bed reactor. The effects of pyrolysis temperature, heating rate, particle size and sweep gas flow rates on the yields of the products were investigated. Pyrolysis runs were performed using pyrolysis temperatures between 350 and 550 degrees C with heating rates of 10 and 50 degrees C min(-1). The particle size and sweep gas flow rate varied in the ranges 0.224-1.8mm and 50-200 cm3 min(-1), respectively. The bio-oil obtained at 500 degrees C was analysed and at this temperature the liquid product yield was the maximum. The various characteristics of bio-oil obtained under these conditions were identified on the basis of standard test methods. The empirical formula of the bio-oil with heating value of 31.8 MJ kg(-1) was established as CH(1.65)O(0.25)N(0.03). The chemical characterization showed that the bio-oil obtained from olive bagasse may be potentially valuable as a fuel and chemical feedstock.

Biomass↗
PubMed2005

Determination of the energy potential of gases produced in the pyrolysis processes of the vegetal carbon manufacture industry.

In this work, a pyrolysis plant located in Valverde de Leganes, Badajoz (SW Spain) was studied. At present, only the solid phase obtained by pyrolysis finds an application as domestic fuel. In order to analyze the feasibility of a further energetic exploitation of the plant under study, the gases flowing through the chimneys were collected at different times throughout the pyrolysis process. Next, they were characterized and quantified by gas chromatography, the energy potential of each of the gases being determined. According to the results obtained in this study, a total energy potential of 5.6 x 10(7) MJ (i.e., 1.78 MW(t)) might be generated yearly. Hence, considering an overall process yield equal to 20%, up to 358 KW(e) would be produced. This power would supply enough electric energy to the industry, the remaining being added to the common electric network.

Bioelectric Energy Sources↗
PubMed2006

Pyrolysis and combustion behaviour of coal-MBM blends.

In the present work, thermogravimetric analysis was employed in order to investigate the behaviour of MBM and their blends with Greek brown coal, under pyrolysis and combustion conditions. MBM presented enhanced pyrolysis rates reflecting its high volatile and low ash contents compared to Greek brown coal. Increased conversion rates were observed when MBM was added in the brown coal sample. Significant interactions were detected between the two fuel blend components leading to significant deviations from the expected behaviour. The catalytic effect of mineral matter on the pyrolysis of MBM resulted in reaction rate decrease and DTG curve shift to lower temperatures for the demineralised MBM. Alterations in the combustion process due to the mineral matter were minimal when testing the blends. Interactions maintained during combustion and lower reactivity of MBM was achieved due to the reduced oxygen content.

Biological Products↗
PubMed2006

Evolution of soil organic matter changes using pyrolysis and metabolic indices: a comparison between organic and mineral fertilization.

The aim of this study was to evaluate chemical and biochemical changes of organic matter in fertilized (ammonium nitrate) and amended (vermicompost and manure) soils using pyrolysis and metabolic indices. The metabolic potential [dehydrogenase (DH-ase)/water soluble organic carbon (WSOC)], the metabolic quotient (qCO2) and the microbial quotient (Cmic:Corg) were calculated as indices of soil organic matter evolution. Pyrolysis-gas chromatography (Py-GC) was used to study structural changes in the organic matter. Carbon forms and microbial biomass have been measured by dichromate oxidation and fumigation-extraction methods, respectively. Dehydrogenase activity has been tested using INT (p-Iodonitrotetrazolium violet) as substrate. The results showed that organic amendment increased soil microbial biomass and its activity which were strictly related to pyrolytic mineralization and humification indices (N/O, B/E3). Mineral fertilization caused a greater alteration of native soil organic matter than the organic amendments, in that a high release of WSOC and relatively large amounts of aliphatic pyrolytic products, were observed. Therefore, the pyrolysis and metabolic indices provided similar and complementary information on soil organic matter changes after mineral and organic fertilization.

Biomass↗
PubMed2005

Dimethyl carbonate as a novel methylating reagent for fatty acids in analytical pyrolysis.

Dimethyl carbonate (DMC) was investigated as a mild, harmless and odorless reagent for pyrolytic methylation of fatty acids. Soybean oil was selected as test material for its high content of (poly)unsaturated fatty acids. Pyrolyses were performed at 500, 700 and 900 degrees C by means of a heated platinum filament pyrolyser on-line and off-line to the GC-MS apparatus. Methyl esters of palmitic, linoleic, oleic and stearic acid were formed as prominent products from off-line pyrolysis of soybean oil in the presence of DMC and zeolite 13X. Fatty acid methyl esters (FAMEs) were not observed at important levels in the absence of zeolite, while on-line Py-GC-MS experiments resulted principally in the formation of free fatty acids and hydrocarbons. The FAME profiles obtained from the DMC/zeolite off-line pyrolysis were compared to those resulting from tetramethylammonium hydroxide (TMAH) thermochemolysis and BF3-methanol procedure. The observed differences between pyrolysis and methanolysis methods were principally attributed to the thermal degradation of unsaturated fatty acids. The effectiveness of the DMC/zeolite pyrolytic methylation was further demonstrated by the analysis of tripalmitine and soybean seeds.

Fatty Acids↗
PubMed2005

Profiling fatty acids in vegetable oils by reactive pyrolysis-gas chromatography with dimethyl carbonate and titanium silicate.

A novel methodology in on-line pyrolysis-gas chromatography (Py-GC) for the fast analysis of fatty acids in vegetable oils with minimal sample treatment and the use of non-toxic reagents is described. Pyrolysis at 500 degrees C for 10 s of sub-microgram quantity of vegetable oil dissolved in dimethyl carbonate (DMC) and in the presence of nanopowder titanium silicon oxide resulted in the production of fatty acid methyl esters (FAMEs) as unique products. Pyrolysis performed by means of a resistively heated filament pyrolyser interfaced to a GC-MS apparatus enabled the direct analysis of evolved FAMEs. The DMC/Py-GC-MS analysis was tested on soybean, coconut, linseed, walnut and olive oil and the results compared to the classical BF(3)-methanol as reference methodology. The DMC method exhibited a lower precision and was biased towards lower levels of polyunsaturated fatty acids (PUFA) in comparison to the BF(3)-methanol method, but was more advantageous in terms of reduced sample treatment, waste generation and risk factors of employed chemicals.

Fatty Acids↗
PubMed2006

Determination of ergosterol as an indicator of fungal biomass in various samples using non-discriminating flash pyrolysis.

Ergosterol is the major sterol constituent of most fungi. Since it is present in negligible amounts in higher plants, it can be used as a chemical marker for the presence of fungal contamination. A number of different ergosterol assays have been developed for the quantification of fungi in various samples. The paper presents the development of a new method for ergosterol detection based on the combination of non-discriminating flash pyrolysis with gas chromatography/mass spectrometry (Py-GC/MS). The design of the non-discriminating Py-GC/MS systems assures efficient transfer of high-molecular-weight pyrolysis products to the GC column for separation, followed by analyte detection by MS. The method was tested on different types of samples, including baker's yeast (Saccharomyces cerevisiae), moldy bread, indoor dust, and a leaf infected with powdery mildew. Ergosterol was detected in all these samples at levels ranging from approximately 4 mg/g for the baker's yeast to approximately 6 microg/g for household dust. The main benefits of non-discriminating pyrolysis over other techniques include elimination of the need for sample preparation, small sample size required and short analysis time.

Biomass↗
PubMed2006

Identification of a new C28H14 polycyclic aromatic hydrocarbon as a product of supercritical fuel pyrolysis: Tribenzo[cd,ghi,lm]perylene.

Tribenzo[cd,ghi,lm]perylene has been identified as a product of the supercritical pyrolysis of both toluene and Fischer-Tropsch synthetic jet fuel. This identification is based on HPLC/UV/MS data, which show that compound I, eluting immediately after five other C28H14 isomers, is also a C28H14 PAH. The UV spectrum of compound I has features of a benzenoid PAH, of which there are only eight C28H14 isomers. Four of these isomers--benzo[a]coronene, phenanthro[5,4,3,2-efghi]perylene, benzo[cd]naphtho[3,2,1,8-pqra]perylene, and benzo[pqr]naphtho[8,1,2-bcd]perylene--have already been identified as supercritical pyrolysis products by matching their UV spectra with those of respective reference standards. A fifth C28H14 PAH--benzo[ghi]naphtho[8,1,2-bcd]perylene, which does not have a reference standard--has also been recently identified through MS and UV data, use of annellation theory to predict UV spectral characteristics, and length-to-breadth ratio/retention time data. Of the remaining three isomers, bisanthene (IUPAC name phenanthro[1,10,9,8-opqra]perylene) has been determined not to be present in our product mixture, as its UV spectrum does not match that of any of our product PAH. Using annellation theory, we predict the UV spectral characteristics of the two remaining C28H14 benzenoid isomers, for which there are no reference standards (tribenzo[cd,ghi,lm]perylene and naphthaceno[3,4,5,6,7-defghij]naphthacene). Results from this analysis show that the predicted UV spectral features of tribenzo[cd,ghi,lm]perylene match those of compound I--and that those of naphthaceno[3,4,5,6,7-defghij]naphthacene are inconsistent with those of compound I. The length-to-breadth ratio of tribenzo[cd,ghi,lm]perylene also agrees with compound I's HPLC elution behavior. This is the first time that tribenzo[cd,ghi,lm]perylene (IUPAC name phenanthro[2,1,10,9,8,7-pqrstuv]pentaphene) has been identified as a product of fuel pyrolysis or combustion.

Chromatography, High Pressure Liquid↗
PubMed2006

Identification of components in fast pyrolysis oil and upgraded products by comprehensive two-dimensional gas chromatography and flame ionisation detection.

Pyrolysis oil and upgraded products are promising energy carriers. Characterisation of the oils is hampered due to the presence of a large number of components (>400) belonging to a broad variety of chemical compound classes (i.e., acids, aldehydes, ketones). In this study, a comparison of the capabilities of 2D-GC-FID and GC-MS to determine the molecular composition of these oils is made. As such, it represents a chromatographic study for a real application in green catalytic technology. Split-injection of the oil samples, diluted in tetrahydrofuran (THF), was applied without any sample pre-treatment. GC-MS application resulted in coelution, while 2D-GC showed significantly higher chromatographic resolution. Model compound mixtures were used for compound identification in the 2D-GC analysis while GC-MS was used to confirm the molecular structures. The combination of both 2D-GC-FID and GC-MS proved to be a useful method, without the requirement of a 2D-GC/TOF instrument. The technique was applied successfully to identify and quantify the main components in pyrolysis oil and upgraded pyrolysis oil made by hydrodeoxygenation (HDO) technology. Compared to GC-MS, 2D-GC-FID provides a fast overview of the various chemical compound classes present in the oils.

Chromatography, Gas↗
PubMed2006

On-line size exclusion chromatography-pyrolysis-gas chromatography-mass spectrometry for copolymer characterization and additive analysis.

On-line coupled size exclusion chromatography-pyrolysis gas chromatography mass spectrometry (SEC-Py-GC-MS) is studied as a novel tool for the characterization of complex polymer samples. An automated system for on-line SEC-Py-GC-MS allowing transfer of multiple fractions was developed based on stop-flow operation of the SEC dimension, syringe-based transfer of the SEC fraction to the GC instrument and solvent elimination with subsequent pyrolysis in a programmed temperature vaporization (PTV) injector. After optimization the system was applied to the characterization of a complex terpolymer composed of very similar monomers. The use of the system for combined pyrolysis and additive analyses in polycarbonate was also demonstrated. Results obtained with the new method indicate the interesting potentials of the method for detailed characterization of polymeric materials.

Chromatography, Gel↗
PubMed2004

Effects of temperature, atmosphere and pH on the generation of smoke compounds during tobacco pyrolysis.

The pyrolysis of tobacco under a variety of conditions was performed to examine the generation profiles of 29 known toxic compounds in tobacco smoke (hydrogen cyanide, benzo[a]pyrene, aldehydes, volatile organic compounds, phenolics, aromatic amines, etc.). The generation profiles of smoke compounds varied according to three conditions: the pyrolysis temperature (300-1000 degrees C), the pyrolysis atmosphere (in nitrogen and air) and pH of the tobacco leaf (2.89-7.07). Most of the smoke compounds (28 compounds) were generated primarily at temperatures less than 800 degrees C. More than half of the smoke compounds (17 compounds) were unaffected by the type of atmosphere, and seven compounds were significantly affected by pH. These results can provide basic and useful information to further study on the formation mechanisms and the technology involved in the control of smoke generation.

Hot Temperature↗
PubMed2004

Effects of vacuum pyrolysis conditions on the characteristics of activated carbons derived from pistachio-nut shells.

Preparation of effective adsorbents from pistachio-nut shells was carried out. Optimization of the vacuum pyrolysis parameters prior to activation was carried out to study the effects of vacuum pyrolysis temperature, hold time, and heating rate on the properties of chars and activated carbons, while CO2 activation conditions were fixed at a temperature of 900 degrees C, an activation time of 30 min, a heating rate of 10 degrees C/min, a CO2 flow rate of 100 cm3/min, and a nitrogen flow rate of 150 cm3/min. The optimum vacuum pyrolysis conditions for preparing activated carbons with high surface area and pore volume were identified. The microstructure and microcrystallinity of the activated carbons prepared were examined by scanning electron microscopy and powder X-ray diffraction techniques respectively while the Fourier transform infrared spectra determined any changes in the surface functional groups produced during different preparation stages. Experimental results show that it is feasible to prepare activated carbons with high BET surface area from pistachio-nut shells.

Absorption↗
PubMed2005

Rapid phenotypic characterization of Salmonella enterica strains by pyrolysis metastable atom bombardment mass spectrometry with multivariate statistical and artificial neural network pattern recognition.

Pyrolysis mass spectrometry was investigated for rapid characterization of bacteria. Spectra of Salmonella were compared to their serovars, pulsed-field gel electrophoresis (PFGE) patterns, antibiotic resistance profiles, and MIC values. Pyrolysis mass spectra generated via metastable atom bombardment were analyzed by multivariate principal component-discriminant analysis and artificial neural networks (ANNs). Spectral patterns developed by discriminant analysis and tested with Leave-One-Out (LOO) cross-validation distinguished Salmonella strains by serovar (97% correct) and by PFGE groups (49%). An ANN model of the same PFGE groups was cross-validated, using the LOO rule, with 92% agreement. Using an ANN, thirty previously unseen spectra were correctly classified by serotype (97%) and at the PFGE level (67%). Attempts by ANN to model spectra grouped by resistance profile-but ignoring PFGE or serotype-failed (10% correct), but ANNs differentiating ten samples of the same serotype/PFGE class were more successful. To assess the information content of PyMS data serendipitously associated with or directly related to resistance character, the ten isolates were grouped into four, three, or two categories. The four categories corresponded to four resistance profiles. The four class and three class ANNs showed much improved but insufficient modeling power. The two-class ANN and a corresponding multivariate model maximized inferential power for a coarse antibiotic-resistance-related distinction. They each cross-validated by LOO at 90%. This is the first direct correlation of pyrolysis metastable atom bombardment mass spectrometry with immunological (e.g. serology) or molecular biology (e.g. PFGE) based techniques.

Bacterial Typing Techniques↗
PubMed2004

Pyrolysis of tyres. Influence of the final temperature of the process on emissions and the calorific value of the products recovered.

A study was made of the pyrolysis of tyre particles, with the aim of determining the possibilities of using the products resulting from the process as fuel. Three final temperatures were used, determined from thermogravimetric data. The design of the experiment was a horizontal oven containing a reactor into which particles of the original tyre were placed. After the process, a solid fraction (char) remained in the reactor, while the gases generated went through a set of scrubbers where most of the condensable fraction (oils) was retained. Finally, once free of this fraction, the gases were collected in glass ampoules. Solid and liquids fractions were subjected to thermogravimetric analyses in order to study their combustibility. The gas fraction was analysed by means of gas chromatography to establish the content of CO, CO2, H2 and hydrocarbons present in the samples (mainly components of gases produced in the pyrolysis process). A special study was made of the sulphur and chlorine content of all the fractions, as the presence of these elements could be problematic if the products are used as fuel. Tyre pyrolysis engenders a solid carbon residue that concentrates sulphur and chorine, with a relatively high calorific value, although not so high as that of the original tyre. The liquid fraction produced by the process has a high calorific value, which rises with the final temperature, up to 40 MJ/kg. The chlorine content of this fraction is negligible. Over 95% of the gas fraction, regardless of the final temperature, is composed of hydrocarbons of a low molecular weight and hydrogen, this fraction also appearing to be free of chlorine.

Air Pollution↗
PubMed2006

Characteristics of liquid product from the pyrolysis of waste plastic mixture at low and high temperatures: influence of lapse time of reaction.

Pyrolysis of a waste plastic mixture (high-density polyethylene: low-density polyethylene: polypropylene: polystyrene = 3:2:3:1) into a liquid product was carried out in a stirred semi-batch reactor at low (350 degrees C) and high (400 degrees C) temperatures. The effect of lapse time of reaction in the reactor and also degradation temperature on the characteristics of the liquid product from pyrolysis of the mixture was investigated. Liquid products were described by cumulative amount distribution, paraffin, olefin, naphthene and aromatic (PONA) distribution and molecular weight distribution. Their characteristic was quite differed with a lapse time of reaction and also at a low and high degradation temperatures, because of the different physicochemical properties of the plastic types in the mixture. With increase of lapse time of reaction, the order for the main products in PONA components obtained at 350 degrees C was firstly aromatic products and then olefin products, while at 400 degrees C the order was firstly aromatic products, then olefin products and finally paraffin products. The experiments also showed from the molecular weight distribution of liquid PONA components that the paraffin and olefin products had a wide distribution by mainly random scission of polymer, but in the case of olefin products were produced by an end-chain scission mechanism as well as random scission mechanism, as evidenced by much more light olefin products. This phenomenon was evident at a higher degradation temperature. Also, both the light olefin and naphthene products with a molecular weight of around 120, as a main product, showed a similar trend as a function of lapse time, which had a maximum fraction at 343 min (at 350 degrees C) and 83 min (at 400 degrees C). Among PONA components, the highest concentrations of aromatic products were obtained with a molecular weight of around 100 at the fastest lapse time of reaction, regardless of degradation temperature. It was concluded that the characteristics of liquid product on the pyrolysis of plastic mixtures were strongly influenced by lapse time of reaction and degradation temperature.

Hot Temperature↗
PubMed2001

Pyrolysis of oil sludge in a fluidised bed reactor.

The oil sludge of tanker cleaning was pyrolysed in fluidised bed reactors. Three experiments were conducted in a laboratory plant and two on a technical plant. Separation of oil from the solids and distribution of the oil products were investigated at temperatures from 460 degrees C to 650 degrees C. Between 70% and 84% of the oil could be separated from the solids. Distribution of the oil products depended on the feed material and the pyrolysis conditions. The higher the temperature the more the oil was cracked into low boiling compounds. Under the conditions of pyrolysis carbon reduced gridiron to iron. Thus some solid fractions were pyrophoric and oxidised with high heat generation. Therefore the solid products have to be turned into inert substances. The fluidised bed pyrolysis is an adequate process to recycle oil sludge with high yields.

Carbon↗
PubMed2000

Fate of bromine in pyrolysis of printed circuit board wastes.

Behavior of Br in pyrolysis of the printed circuit board waste with valuable copper and oil recycling has been studied in the present work. Experimentally, pyrolysis of the printed circuit board waste generated approximately 40.6% of oils, 24.9% of noncondensible gases and 34.5% of solid residues that enriched in copper (90-95%). The cuts of the oils produced from pyrolysis of the printed circuit board waste into weighted boiling fraction were primarily light naphtha and heavy gas oil. Approximately 72.3% of total Br in the printed circuit board waste were found in product gas mainly as HBr and bromobenzene. However, by extended X-ray absorption fine structural (EXAFS) spectroscopy, Cu-O and Cu-(O)-Cu species with bond distance of 1.87 and 2.95 A, respectively, were observed in the solid residues. Essentially, no Cu-Br species was found.

Bromine↗
PubMed1995

Analytical pyrolysis experiments of Titan aerosol analogues in preparation for the Cassini Huygens mission.

Comparative pyrolysis mass spectrometric data of Titan aerosol analogues, called "tholins", are presented. The Titan tholins were produced in the laboratory at Cornell by irradiation of simulated Titan atmospheres with high energy electrons in plasma discharge. Mass-spectrometry measurements were performed at FOM of the solid phase of various tholins by Curie-point pyrolysis Gas-Chromatography/Mass-Spectrometry (GCMS) and by temperature resolved in source Pyrolysis Mass-Spectrometry to reveal the composition and evolution temperature of the dissociation products. The results presented here are used to further define the ACP (Aerosol Collector Pyrolyser)-GCMS experiment and provide a basis for modelling of aerosol composition on Titan and for the interpretation of Titan atmosphere data from the Huygens probe in the future.

Aerosols↗