No abstract

No abstract

No abstract

The kinetics of the pyrolysis of pyridine was studied in the temperature range of 875-1O5O0C, at 1 atm total pressure, in a Vycor stirred-flow reactor. Initial concentrations ranged from 0.25 to 2 mol % in helium and reaction times from 0.25 to 4 sec. It was found at the lower temperatures that the reaction was mixed first and second order. At the higher temperatures an autocatalytic term, zero order in the substrate and first order in the concentration of pyridine decomposed, was necessary in addition to the other two terms to describe the kinetic data. Most of the product was in the form of a primarily aromatic, nonvolatile tar; the major volatile products were HCN and CzH2. An increase in the surface-to-volume ratio of the reactor decreased the rate, indicating a radical chain or sequential reaction with radical consumption on the surface. Experiments with additives showed that C2H2 increased the rate. Using the kinetic and product data, some mechanistic considerations are discussed, and a mechanism is proposed to account for the first-order term.

No abstract