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Proceedings Paper

Design of a formaldehyde photodissociation process for carbon and oxygen isotope separation
Author(s): Richard C. Stern; Karl F. Scheibner
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Paper Abstract

The current shortage of 18O has revived interest in using one step UV photodissociation of formaldehyde to enrich 13C, 17O and 18O. The frequency doubled output of the copper laser pumped dye laser system currently in operation at LLNL can be used to drive this dissociation. We use a simple kinetics model and our experience with Atomic Vapor Laser Isotope Separation (AVLIS) process design to examine the relative merits of different designs for a formaldehyde photodissociation process. Given values for the molecular photoabsorption cross section, partition function, spectroscopic selectivity, collisional exchange and quenching cross sections (all as parameters), we perform a partial optimization in the space of illuminated area, formaldehyde pressure in each stage, and formaldehyde residence time in each stage. We examine the effect of cascade design (heads and tails staging) on molecule and photon utilization for each of the three isotope separation missions, and look in one case at the system's response to different ratios of laser to formaldehyde costs. Finally, we examine the relative cost of enrichment as a function of isotope and product assay. Emphasis will be as much on the process design methodology, which is general, as on the specific application to formaldehyde.

Paper Details

Date Published: 28 May 1993
PDF: 9 pages
Proc. SPIE 1859, Laser Isotope Separation, (28 May 1993); doi: 10.1117/12.145498
Show Author Affiliations
Richard C. Stern, Lawrence Livermore National Lab. (United States)
Karl F. Scheibner, Lawrence Livermore National Lab. (United States)

Published in SPIE Proceedings Vol. 1859:
Laser Isotope Separation
Jeffrey A. Paisner, Editor(s)

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