Shock Tube Studies of Formaldehyde Pyrolysis.
Abstract
Formaldehyde decay was followed by IR emission at 3.5 micrometers behind relfected shocks at total concentrations near 2.4 and 4.5 x 10 to the 18th power molecule/cc. Data were obtained at 0.5 microsec intervals over a temperature range of 1700-2710 K for mixtures containing 0.1%, 0.5%, and 1.0% CH2O in Ar. Exponential decay was observed in all cases; at lower temperatures there was evidence of an induction time prior to the onset of the decay. An apparent rate was defined as k(a) = -(d(ln signal)/dt)/(M); k(a) was observed to be first order in argon and to decrease with increasing dilution. These data were analyzed in terms of the mechanism: (1) CH2O + M = HCO + H + M; (2) CH2O + H = HCO + H2; (3) HCO + M = H + CO + M; (4) HCO + H = H2 + CO. Using literature values for k2, k3, and k4, a reasonable fit to all the data, both in terms of temperature and concentration dependence, was obtained with k(1) = 6.0 x 10 to the -7th power exp(-364 kJ/RT) cc/molecule s. Evidence is also presented to suggest that the reaction, CH2O + M = CO + H2 + M, does not play a significant role in the high temperature pyrolysis of formaldehyde. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1978
- Accession Number
- ADA053695
Entities
People
- Anthony M. Dean
- Brian L. Craig
- Edward E. Wang
- M. Claire Schultz
- Ron L. Johnson
Organizations
- Purdue University