ON-LINE MEASUREMENTS OF OXIDATION OF CARBON USING VISIBLE SPECTROSCOPY

We have identified four different band heads belonging to the B1 Σ-A1 Π bands of the Angstrom system of the CO spectrum in the visible region at λ = 561.0, 519.8, 451.1 and 439.3 nm, for on-line monitoring of conversion of carbon to carbon monoxide in the ‘de-coking’ process of a ‘coked’ catalyst. A low-power glow discharge in oxygen gas was used as a source for oxidizing carbon from a ‘coked’ zeolite catalyst. Evolution of CO as a function of time was systematically monitored using the 451.1 nm band head since there is no overlap with any possible impurities including oxygen, nitrogen or water vapor. An interesting observation is an exponential increase in the evolution of CO typically after about 10 minutes from the initiation of the discharge. The results may be of particular interest in monitoring catalyst regeneration on-line as well as environmental monitoring of CO