Document KJEDRbKNZXYk5Z23j12ByGRk0

7 9.1.3 Company C These data are based on limited plant experience in Implementing Research and Development recommendations. The reduction in vinyl chloride has been achieved by increasing thermal input, vacuum, time, or combinations of these parameters during the monomer recovery step. Suspension Resins 1974 - Residual Vinyl Chloride Monomer Homopolymer Low M.W. Homopolymer High M.W. Into dryer Out of dryer 500 ppm 100 ppm 200-300 100 Dryer emission factor lb VCM/ 100 lb PVC 0.04 0.015 Dispersion-^ 1974 - Residual Vinyl Chloride Mpnomer Into dryer 8,000-22,000 ppm Out of dryer 15-50 ppm Dryer emission factor lb VCM/ 100 lb PVC 1.50 Copolymer All 100-150 50 0.0075 i^Wacher process 9.1.4 One company has reported residual monomer levels in their dispersion resins to 300 ppm dry basis on a laboratory basis. The stripping equipment and conditions to achieve this level have not been reported, as they are considered proprietary. On a commercial scale, the company has been able to reduce monomer levels to 2000 ppm with a 20* production loss.^ 9.2 CARBON ADSORPTION 9.2.1 Vendor Data4 One vendor of activated carbon has submitted data from laboratory studies 9-5 AP00029304 on i ' -.ontrol of vinyl chloride by carbon adsorption. The r.oncl ions o` the studies were: activated carbon readily absorbs vinyl chloride in concentrations ranging from 50 parts per million (ppm) to over 30 percent by volume (300,000 ppm); one hundred percent removal of vinyl chloride is techni; : ! feasible using dual beds of activated carbon; activated carbon saturated with vinyl chloride can be regenerated in-Dlace using either steam or hot nltroaen to desorb the vi /I chloride; and after 15 cycles of operation (saturation, desorption, and drying), no polymerization of vinyl chloride had occurred on the bed. The following data were developed by this vendor in their s' of the applicability of carbon adsorption to vinyl chloride recovery. Tr.. discussion and data are from the company's Bulletin 23-200. "Cyclic Test Results . .... ____ ^___ .. The data in table I represent the results of tests conducted t 'etermine the adsorption and desorption characteristics of activated carbon for a proposed VCM recovery system. A nitrogen stream containing 1 percent by volume VCM was passed through a 4.5-inch deep bed of Plttsb rgh Type PBL 6x16 mesh activated carbon at ambient temperature and pressure at a flow of 30 feet per minute (fpm) until VCM breakthrough occurred. At this point, the VCM was desorbed by passing either steam or nitrogen at 300 F through the carbon bed. The system was operated for fifteen cycles-uslng steam as the regenerant for the first ten cycles and hot nitrogen for the last five. As the data in table I indicate, no loss In adsorp tive capacity was observed over the entire 15 cycles of 9-6 AP00029305