Document ZxpK8X8Ogdo1nRmv32BzJ358

To: M. L. Nathan, Manufacturing, Aberdeen A Inltrofflcs Communication From: Data: Subject: R. J. Lahiere, W. C. Turk, R. R. Hammons August 31, 1987 SILO AND FLUID BED AERATION DOES NOT REDUCE REACTOR CULLS RVCM SIGNIFICANTLY VKI\ Stricter RVCM requirements for resin and a tighter PVC market have resulted in a need for more vinyl chloride removal from reactor culls. The objective of this study was to determine if silo or fluid bed aeration can reduce the concentration of RVCM in reactor culls to acceptable levels. Equipment used in the investigation included an 8-inch diameter laboratory silo and the fluid bed dryer for the PVC pilot plant in Ponca City. V The RVCM removal rate from reactor culls with silo and fluid bed aeration was inadequate with regard to current environmental regulations. Results from the study were: Silo aeration with air at 150F and 1.90 scfrn (corresponds to 500 scfin in plant silos) did not reduce the RVCM level in culls below 400 ppm. Although this represented a 75% reduction in RVCM, most of the reduction occurred during the initial stages of aeration and the RVCM level remained relatively unchanged from 6 to 48 hours. This effect is demonstrated in Figure 1. Bench-scale aeration with 77F-air at 0.95 scfm reduced RVCM levels from about 2000 ppm to 1540 ppm, as shown in Figure 1. This represented only a 22% reduction over a 37-hour period. Aeration in the fhnd bed dryer with 180F-air did not significantly reduce the concentration of RVCM in the culls. Less than 25% RVCM was removed during 29 hours of aeration time. The fluid bed data, exhibited in Figure 2, show that RVCM reduction did not occur after 3-4 hours of aeration. RVCM Re The poor removal of RVCM from reactor culls during aeration can be attributed to the high number of glassies and the low porosity of the resin particles. An examination of photographs of the culls (magnified by 40x) in Figure 3 reveals the large amount of glassies in the resin. VAB.0001172730 r M. L. Nathan Page 2 August 31, 1987 To obtain better RVCM removal, the reactor culls should be ground to a smaller diameter. The culls aerated in these experiments were rather course (average particle diameter of 294 microns). Finer cull particles will contain less RVCM because of two factors: (1) the additional heating required to process fine reactor culls will remove more VCM and (2) the smaller diameter of the particles will increase VCM transfer from the resin. A William C. Turk RJL/ck attachments cc/attachments: Ponca City: SEM RBQ CJMc AWW MEO Aberdeen: VEM SF VAB.0001172731 Figure 3. Reactor Culls (40x) - 40 Mesh Reactor Culls (40x) - 60 Mesh * i I L iIl i l t l tl l i i i t i i i i i4 VAB.0001172732 Fig. 1: Silo Aeration of Reactor Culls ntrotlon ( i a 77 F Air. 0.95 Kfm Time (hour*) 150 F AlT'UOO r VAB.O^ftl172733 Fig.2: Reoctor Culls Fluid Bed Aeration ISO F Air V Tim# (hours) VAB.0001172734