Pyrolysis of asphalt in the presence and absence of water

Schlepp, Laurence; Montchowui, Élie; Landais, P.; Romero, Miguel A.

doi:10.1016/s0378-3820(01)00207-7

Cited by 33 publications

(14 citation statements)

References 22 publications

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“…The modus location and slope of the Schulz‐Flory distribution depends on the experimental conditions such as temperature, humidity, oxygen fugacity, type of alloy of catalyst, and gas feed composition. In contrast to such Fischer‐Tropsch synthesized, linearly falling n ‐alkane patterns, pyrolysis (both confined and hydrous) of biogenic material produces gently exponentially falling n ‐alkane patterns at the temperatures currently typical for the Vulcano fumaroles, ∼400°C [e.g., Schlepp et al , 2001]. We therefore consider that this fumarolic gas sample (site 14) may be the result of abiogenic formation of hydrocarbons in the gas phase.…”

Section: Resultsmentioning

confidence: 99%

Diffuse emission of organic trace gases from the flank and crater of a quiescent active volcano (Vulcano, Aeolian Islands, Italy)

et al. 2004

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[1] Volcanoes discharge a range of inorganic major gas species (e.g., H 2 O, CO 2 , SO 2 , and CO) not only during eruptions but also during quiescent phases through fumarolic and diffuse degassing in their craters and on their flanks. The emission of organic trace gases from volcanoes is similarly not expected to be restricted to discrete fumarolic gas discharges alone. To test this hypothesis, we have sampled soil gas emissions for organic compounds and determined CO 2 fluxes along a profile extending from the vegetated base of the active La Fossa cone (Vulcano Island, Italy) over the unvegetated volcanic flank and up into the crater rim and base and then continuing over fumarolic areas. The results indicate that the majority of volatile organic compounds in the soil gas show significant increases in concentration toward the crater and fumaroles and that diffuse emissions contribute significantly to the volcanic halocarbon source strength. Emissions of the halocarbon CFC-11 (CCl 3 F) correlate well with soil CO 2 fluxes measured on site (R 2 = 0.89, slope = 1.42 ± 0.1) and both increase toward the crater and fumaroles. Other ozone-depleting substances were found in concentrations significantly above those found in field and system blanks, including CH 3 Br, CH 3 Cl, CH 3 I, C 2 H 5 Br, and chlorinated benzenes. Abundances ranged from upper pptv to ppmv; for example, the maximum observed CFC-11 concentrations were 1200 pptv in diffuse emissions and 3700 pptv in dry fumarolic gas (average dry air is 268 pptv). On the basis of these results the natural volcanic source strength of halocarbon emissions to the atmosphere requires reevaluation, and in some cases, correction to higher values. Global average fumarolic and diffuse halocarbon source strengths were estimated and scaled to known global volcanic fumarolic and diffuse CO 2 flux data. Among these were CFC-11 (8.56 ± 4.7 Â 10 À6 Tg y À1 ), CH 3 Br (0.98 ± 0.47 Â 10 À6 Tg y À1 ), CHCl 3 (94.9 ± 27.6 Â 10 À6 Tg y À1 ), and CCl 4 (3.41 ± 1.0 Â 10 À6 Tg y À1 ).

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Section: Resultsmentioning

confidence: 99%

Diffuse emission of organic trace gases from the flank and crater of a quiescent active volcano (Vulcano, Aeolian Islands, Italy)

et al. 2004

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“…Finally, when the temperature is over 470 °C, the composite sample is in the carbonization stage. Only a small number of volatiles are released due to the further fracture of carbon‐hydrogen (CH) and carbon‐oxygen (CO) bonds and aromatization reaction . The condensation reactions of thermal decomposition products and free radical interaction also result in the formation of residues .…”

Section: Resultsmentioning

confidence: 99%

“…Only a small number of volatiles are released due to the further fracture of carbonhydrogen (CAH) and carbon-oxygen (CAO) bonds and aromatization reaction. 26 The condensation reactions of thermal decomposition products and free radical interaction also result in the formation of residues. 27 It is noted that 3D FTIR spectra are consistent with the test results of TG as shown in Figure 5.…”

Section: Dynamic Evolution Of Released Volatilesmentioning

confidence: 99%

Effects of two‐dimensional programming on microstructures and thermal properties of shape memory polymer‐based composites

Shen

Shi

2017

J of Applied Polymer Sci

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To evaluate the effects of two‐dimensional (2D) programming on thermal properties of shape memory polymer (SMP)‐based composites when exposed to high temperature, the specimens of composites were prepared and programmed. Then the morphology, thermal properties, dynamic evolution, and constituents of released gaseous products were characterized. Results indicate that the programmed composite is more compacted, but the proportion of interconnected voids is larger than that in the nonprogrammed sample. 2D programming causes molecular or segmental orientations in SMP, and leads to the decrease in the char yield from 16.1 to 8.1%. The programmed sample shows a lower thermal stability. Further, the melting enthalpy of nonprogrammed composite is 1012 J/g which is lower than 1100 J/g of the programmed sample. The prestored stress in oriented molecules or segments of SMP is more prone to cause the chain scissions. The dynamic evolution and constituents of released volatiles from nonprogrammed and programmed samples are similar, but the release amount of volatiles from the latter is larger. Finally, the more compacted charring layer of nonprogrammed composite is more efficient to prevent volatiles from releasing out. The 2D programming has a slight influence on the elemental contents of O, Si, and C in the charring layer. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45480.

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“…5, the mass loss of asphalt binder starts at about 330°C, and over 85 % of the mass loss occurs in the temperature range from 330°C to 500°C. When asphalt binder was heated from room temperature to 330°C, a small mass was first lost due to the evaporation of moisture or volatilization of some light components with low molecular weights [28]. It indicates that there are a few chemical or physical reactions below 330°C, showing no noticeable changes on TG-DTG curves.…”

Section: Tg Analysis Of Sara and Asphaltmentioning

confidence: 99%

Physicochemical and pyrolysis properties of SARA fractions separated from asphalt binder

Zhang

Shi

et al. 2015

J Therm Anal Calorim

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To further understand thermal properties of asphalt binder, four fractions, namely saturates, aromatics, resins and asphaltenes (SARA), were first separated from asphalt binder. Then, physicochemical and pyrolysis properties of SARA fractions were characterized. The results indicate that the contents of aromatics and resins in asphalt binder are higher than that of saturates and asphaltenes. The number-average molecular weights show a successive increase trend from saturates to asphaltenes. Saturates and aromatics contain similar bonds or functional groups, and aromatics contain a smaller number of saturated hydrocarbons than saturates. Also, resins and asphaltenes show several similar transmittance peaks in Fourier transform infrared spectroscopy (FTIR) spectra. Saturates, aromatics and asphaltenes contain more saturated hydrocarbons than that of resins. Further, FTIR spectra of saturates and aromatics are more similar to that of asphalt binder. Some chemical compositions, bonds and functional groups are only shown in FTIR spectra of SARA fractions through which asphalt components can be further understood. Furthermore, differential thermogravimetry curves of asphalt binder and its SARA fractions exhibit obvious unimodal characteristics, indicating that their pyrolysis processes are one-step reaction. The residue yield ratios, the temperatures corresponding to initial decomposition temperature, the main decomposition range and the maximum mass loss rate successively increase from saturates to asphaltenes. It is concluded that the thermal stability of each SARA fraction is successively increased from saturates to asphaltenes.

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Pyrolysis of asphalt in the presence and absence of water

Cited by 33 publications

References 22 publications

Diffuse emission of organic trace gases from the flank and crater of a quiescent active volcano (Vulcano, Aeolian Islands, Italy)

Diffuse emission of organic trace gases from the flank and crater of a quiescent active volcano (Vulcano, Aeolian Islands, Italy)

Effects of two‐dimensional programming on microstructures and thermal properties of shape memory polymer‐based composites

Physicochemical and pyrolysis properties of SARA fractions separated from asphalt binder

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