Search results for "pyrolysis"

Thermal kinetics for the energy valorisation of polylactide/sisal biocomposites

2018

[EN] The thermal stability and decomposition kinetics of PLA/sisal biocomposites was discussed to evaluate the suitability of their use in energy recovery processes such as pyrolysis and combustion. The influence of the addition of sisal up to 30%wt, the presence of coupling agent, and the atmosphere of operation, i.e. inert or oxidative was discussed by means of multi-rate linear non-isothermal thermogravimetric experiments. All biocomposites showed a mean high heating value of 15 MJ/kg indicating their suitability for energy recovery processes. The thermal requirements of PLA/sisal decomposition were assessed in terms of onset decomposition temperature and apparent activation energy. A mi…

Study on the effects of chemical cleaning on pinaceae resin-based varnishes from panel and canvas paintings using pyrolysis-gas chromatography/mass s…

2006

Abstract Cleaning of varnish coatings is one of the most critical steps in the restoration treatment of paintings and characterization of physical and chemical processes involved in this practical procedure has attracted interest of scientists in the field of conservation. Evaluation of chemical cleaning methods based on the application of organic solvents and detergents on Pinaceae resin-based varnishes from panel and canvas paintings has been successfully carried out using pyrolysis-gas chromatograpy/mass spectrometry (Py-GC/MS). The proposed method includes the on-line derivatization of the diterpenoid resin using hexamethyldisilazane (HMDS). Analyses performed on a series of model varni…

DIRECT PYROLYSIS OF AROMATIC AND ALIPHATIC POLYESTERS IN THE MASS SPECTROMETER

1977

Arynic species; effect of substituents on the reactivity of monosubstituted dehydrobenzenes

1986

Abstract Evidence is presented demonstrating the existence of free dehydrobenzenes in the thermal decomposition of diaryliodonium-2-carboxylates, and that o-benzyne itself and its 4-methyl-, 4-chloro-,4-bromo- and 4-nitro-derivatives are generated from insoluble polymer-bound precursors and trapped by a second solid phase in Diels-Alder reactions. Lifetimes for these elusive species are determined.

Block copolymers from ionic liquids for the preparation of thin carbonaceous shells

2017

This paper describes the controlled radical polymerization of an ionic-liquid monomer by RAFT polymerization. This allows the control over the molecular weight of ionic liquid blocks in the range of 8000 and 22000 and of the block-copolymer synthesis. In this work we focus on block copolymers with an anchor block. They can be used to control the formation of TiO2 nanoparticles, which are functionalized thereafter with a block of ionic-liquid polymer. Pyrolysis of these polymer functionalized inorganic nanoparticles leads to TiO2 nanoparticles coated with a thin carbonaceous shell. Such materials may, e.g., be interesting as battery materials.

Influence of Elevated Pressure on the Torrefaction of Wood

2016

The use of pressurized reactors in industrial processes can improve efficiency and economics. Torrefaction is a partial pyrolysis of lignocellulosic biomass designed to result in a solid product with improved fuel properties for utilization in combustion and gasification. In this work, the influence of elevated pressure on the torrefaction of wood has been investigated. Wood samples were torrefied using a pressurized thermogravimetric reactor (PTGR) with pressures of 0.1 to 2.1 MPa. The results indicate that reactor pressure, particle size of feedstock, and wood species are all factors in torrefaction yield improvements. Torrefaction at 2.1 MPa pressure improved the higher heating value (ca…

Gas-phase detection of HSOH: synthesis by flash vacuum pyrolysis of di-tert-butyl sulfoxide and rotational-torsional spectrum.

2003

Gas-phase oxadisulfane (HSOH), the missing link between the well-known molecules hydrogen peroxide (HOOH) and disulfane (HSSH), was synthesized by flash vacuum pyrolysis of di-tert-butyl sulfoxide. Using mass spectrometry, the pyrolysis conditions have been optimized towards formation of HSOH. Microwave spectroscopic investigation of the pyrolysis products allowed-assisted by high-level quantum-chemical calculations--the first measurement of the rotational-torsional spectrum of HSOH. In total, we have measured approximately 600 lines of the rotational-torsional spectrum in the frequency range from 64 GHz to 1.9 THz and assigned some 470 of these to the rotational-torsional spectrum of HSOH …

Upgrade of citrus waste as a biofuel via slow pyrolysis

2015

Abstract Slow pyrolysis (200–650 °C) experiments on citrus residues (orange peel waste “OP” and lemon peel waste “LP”) were carried out in lab scale fixed bed batch reactor. Bio-oil and bio-char obtained by thermal degradation are more stable, more homogeneous and higher energy content fuels when compared to the parent feedstock. Thermogravimetric analysis (TGA) showed higher stability of LP waste, which appears related to the higher lignin content . Mass and energy yields of solid and liquid products (i.e., char and oil) were measured to determine the effects of peak temperature on feedstock. A linear correlation between Gross Calorific Value (GCV), peak temperatures and mass loss (ML) all…

Sewage Sludge Derived Materials for CO2 Adsorption

2021

The study tried to contribute to solving two serious environmental issues: CO2 reducing and sewage sludge disposal. Thus, sewage-sludge-derived materials were obtained in order to be evaluated for CO2 adsorption capacity. Therefore, the char resulted after the sewage sludge pyrolysis was subjected to oxidation and chemical activation processes by using different quantities of alkaline hydroxide. One of the obtained materials, activated with a lower quantity of alkaline hydroxide, was also treated with acid chloride. Further, the materials were structural and texturally characterized, and material treated with acid chloride was used for CO2 adsorption tests, due to high surface area and pore…

Pyrolysis-gas chromatography : mass spectrometry analysis of di- and triterpenoids

2017

The objective of this work was to study a specific class of extractives existing in lignocellulosic biomass and more precisely in wood materials, and their thermochemical behavior during pyrolysis. The focus was centered on the class of terpenes and terpenoids; specifically two model compounds, abietic acid and betulinol, were chosen to represent the subclasses of di- and triterpenoids, respectively. The model compounds were investigated via pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and the main objective was to study their product profiles and characteristic fragmentations, as well as the influence of specific variables (pyrolysis temperature and time) on pyrolysis products…