Pyrolysis

About: Pyrolysis is a research topic. Over the lifetime, 34918 publications have been published within this topic receiving 833524 citations.

Gas Permeation through Micropores of Carbon Molecular Sieve Membranes Derived from Kapton Polyimide

Abstract: The evolution of micropores and the gas permeation properties have been investigated on carbon molecular sieve dense membranes prepared by pyrolysis of Kapton polyimide films under several conditions. With decreasing the pore sizes upon pyrolization under vacuum, the gas permeability decreased, whereas the permselectivity increased. The change in the heating rate was found to affect the permeation properties to a lesser extent; however, the pyrolysis atmosphere (vacuum or inert purge pyrolysis) did not appreciably influence the properties within the experimental conditions studied. The highest permselectivities attained by a membrane were H2/N2 4700, He/N2 2800, CO2/N2 122, and O2/N2 36, respectively, at 308 K. The permeabilities of the selected gases were shown to be in the order H2 > He > CO2 > O2 > N2 for almost all the membranes, whose order was not exactly in accordance with the order of kinetic gas diameters. From the temperature dependencies of permeability, diffusivity, and sorptivity of the membr...

Production of carbon nanotubes

Abstract: Carbon nanostructures such as single-walled and multi-walled nanotubes (SWNTs and MWNTs) or graphitic polyhedral nanoparticles can be produced using various methods. Most of them are based on the sublimation of carbon under an inert atmosphere, such as the electric arc discharge process, the laser ablation method, or the solar tech- nique. But chemical methods can also be used to synthesize these kinds of carbon materials: the catalytic decomposi- tion of hydrocarbons, the production by electrolysis, the heat treatment of a polymer, the low temperature solid pyrolysis, or the in situ catalysis.

Fast Pyrolysis of Forestry Residue. 3. Storage Stability of Liquid Fuel

Abstract: The storage properties of fuels are critical in regard to the introduction of a new fuel into markets. The fuel must be homogeneous, and the properties of the fuel should not change significantly during the storage at the customer's facility. In this research, the storage stability of wood-based pyrolysis liquids was followed by analysis of the changes in the physical properties and chemical composition during storage. The main physicochemical changes took place during the first six months. The high-molecular-mass (HMM) fraction of water-insolubles, which were originally lignin-derived material, increased, because of polymerization and condensation reactions of carbohydrate constituents, aldehydes, and ketones. Therefore, the average molecular mass of pyrolysis liquids increased, which was also observed as an increase in viscosity. There was a clear correlation of the average molecular mass with the viscosity, water-insolubles, and the HMM fraction of water-insolubles. The chemical changes in the aging we...

Potential of pyrolysis processes in the waste management sector

Abstract: The fundamentals of pyrolysis, its latest developments, the different conditions of the process and its residues are of great importance in evaluating the applicability of the pyrolysis process within the waste management sector and in waste treatment. In particular the types of residue and their further use or treatment is of extreme interest as they could become the source of secondary raw materials or be used for energy generation in waste treatments. The main area of focus of this paper is the investigation of the link between the pyrolysis conditions, the chemical and mineralogical composition of their products and the benefits of pyrolysis in the waste management sector. More specifically the paper covers the fast, intermediate and slow pyrolysis of organic waste and mixtures of inorganic and organic waste from households. The influence of catalysts during fast pyrolysis on the product yield and composition is not being considered in this review.