Kinetic studies of phosgene reduction via in situ Fourier transform infrared analysis

Stuart Farquharson; J. Paul Chauvel Jr.

doi:10.1117/12.48468

1 April 1991 Kinetic studies of phosgene reduction via in-situ Fourier transform infrared analysis

Stuart Farquharson, J. Paul Chauvel Jr.

Proceedings Volume 1434, Environmental Sensing and Combustion Diagnostics; (1991) https://doi.org/10.1117/12.48468
Event: Optics, Electro-Optics, and Laser Applications in Science and Engineering, 1991, Los Angeles, CA, United States

Abstract

Phosgene, a common reactant in the production of polyurethanes and polycarbonates, is unfortunately hazardous (threshold limit value equals 0.1 ppm). Consequently, the detection and elimination of atmospheric releases are paramount safety and environmental concerns. Proper design of systems to mitigate phosgene requires knowledge of the reaction kinetics for the chemistry involved. This paper presents our investigation of the reactions for phosgene with steam and ammonia. A Fourier transform infrared spectrometer (FTIR) equipped with a large volume (15 L), temperature controlled (+0.5 degree(s)C), 24.5 cm path length cell was used to measure the reaction kinetics. The reaction of phosgene with steam at 110 degree(s)C followed first order kinetics (t1/2 equals 10.2 min.) producing carbon dioxide and hydrogen chloride. The reaction of phosgene with ammonia at 80 degree(s)C followed second order kinetics (t1/2 equals 1.2 min.) producing ammonium chloride and urea. It was found, however, that at 25 degree(s)C this reaction follows a previously unreported pathway producing ammonium chloride and ammonium isocyanate at a faster rate (t1/2 equals 15 sec.). Based on this reaction, a pilot scale scrubbing tower was built with a manifold to mix ammonia with ppm levels of phosgene. A complete description of the experimental conditions, the reaction pathways as a function of temperature, and the performance of the ammonia scrubbing tower are given.

Citation Download Citation

Stuart Farquharson and J. Paul Chauvel Jr. "Kinetic studies of phosgene reduction via in-situ Fourier transform infrared analysis", Proc. SPIE 1434, Environmental Sensing and Combustion Diagnostics, (1 April 1991); https://doi.org/10.1117/12.48468

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available