Pyrolysis

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

Pyrolysis of Polyethylene in a Fluidized Bed Reactor

Abstract: A fluidized sand bed reactor was used to study the production of gases from polyethylene (HDPE) at five nominal temperatures (ranging from 500 to 900°C). Both HDPE primary decomposition and wax cracking reactions take place inside the reactor. Yields of 13 pyrolysis products (methane, ethane, ethylene, propane, propylene, acetylene, butane, butylene, pentane, benzene, toluene, xylenes, and styrene) were analyzed as a function of the operating conditions. The results are compared with the data obtained by pyrolysis of HDPE in a Pyroprobe 1000, where secondary wax and tar cracking is small. Correlations between the products analyzed with those of methane are discussed.

Noncatalytic Conversion of Cellulose in Supercritical and Subcritical Water

Abstract: This paper describes the noncatalytic conversion of cellulose in supercritical and subcritical water. First, it was demonstrated that even without any acid catalyst, cellulose was rapidly converted to water soluble species with a relatively high glucose yield in near critical water and glucose yield increased with elevating temperature. Then the rate constants for cellulose decomposition and glucose decomposition were evaluated at a pressure of 25 MPa over a temperature ranging from 473 K to 673 K by using semi-batch reactor and a flow reactor, respectively. From the reported cellulose pyrolysis rate constant and the evaluated cellulose decomposition rate constant, cellulose hydrolysis rate constant was evaluated. By using the cellulose hydrolysis rate, cellulose pyrolysis rate and the glucose decomposition rate, glucose yield obtained in the semi-batch experiment was reasonably explained.

Electronic Conduction in Polymers. I. The Chemical Structure of Polypyrrole

Abstract: The pyrolysis of tetraiodopyrrole in an inert atmosphere at temperatures from 120-700° yields black, infusible, amorphous polymers insoluble in solvents. Depending on the pyrolysis temperature, iodine may be present in the polymers as iodine of substitution and as chemisorbed molecular iodine, which is very tenaciously held. As a first approximation, the structure may be regarded as a three-dimensional network of pyrrole rings cross-linked in a nonplanar fashion by direct carbon to carbon linkages. The secondary nitrogen atoms form a hydroquine type system which may be oxidized by iodine or molecular oxygen under alkaline conditions. The extent of oxidation depends on the hydroxyl ion concentration. The nonplanarity of the oxidized quinonoid system renders it unstable but stability is enhanced, as in the triphenylmethane dyestuffs, by the formation of a carbinol. Despite their nonplanarity polypyrroles are relatively good conductors of electricity. The resistivity ranges from 1-200 ohm cm depending on the temperature of pyrolysis.