Document 8EpayoNb05xmOadvR2rmmLKa

B.F.GOOORICH CHEMICAL COMPANY (ntcr-Organization Correipondcnce To J. D. Franklin Location Calvert City Laboratory Date From October 18, 1974 R. L. Parrish # Subjc* EFF 1C IFNCTf OF CARBON ADSORPTION - CAROON DISULFIDE DESORPTION IN AMDlENT VINYL CHLORIDE TEST PROCEDURE _ < >r> 11 v <' !)< t*nn i n' the carbon mlsorpt ion-cnrbnn disulfide desorption efficiency as they to ambient vinyl chloride toHtlri(|. Cone 1 usiomi With limitation* pointed out In the text of this report, conclusions are; 1. Efficiency of the adsorption of the ambient vinyl chloride onto the activated carbon in 99%. 2. Efficiency of the extraction of vinyl chloride off the activated carbon with carbon dlnulflde in 100%. Future Course of Action Carbon tube testing for ambient vinyl chloride, under the conditions noted herein, will assume 100% efficiency for adsorption and extraction of vinyl chloride in relation to the activated carbon. Discussion The vinyl chloride ambient perimeter survei1 lance program will employ two types o f sump Iing. Crab samples are to bo taken on the wind rectors. Charcoal tube samples are to be taken at stationary points ovor a 24 hour sampling period. Chris Orsborn is looking for a D.C. powered pump that will sample over a 2<* hour period. Until cne is found, an A.C. powered Kiliipore pump io available. The selected sampling rate is lOOC cc per minute of air. Over a 24 hour poriod, this rate will provide enough sampla volume (at the expected VC1 concentrations) to assuro good analytical accuracy. ^ It is ossontial to know the adsorption efficiency^ in respect to vinvl chloride, of the activated carbon at this sampling rato. A laboratory experiment was carriod out wherein tho carbon adsorption and the carbon disulfide extraction efficiencies wore determined. Summary of Lab Work A sampling train is prepared using throe 150 mm polyethylene tubes each containing 8.3 grams of Nuchar VY-H activated carbon. Teflon tubing 1* used to connect the tubes together. The sampling train is connected to a gas cylinder containing a 48 ppm vinyl chloride in air standard gas. A dry gas meter is used to measure tho total sample volume. The standard gas Is sampled for exactly 8 minutes at a rate of approximately 1000 cc per minute. After sampling, the tubes are extracted with carbon disulfide amt analyzed in the manner Used for personnel monitoring testing. Ca 1 cii I a t i oils A. Theorer t lea 1 Mi cropmms The theoroc t lea 1 total micrograraa vinyl chloride adsorbed is calculated from the total volume of standard sampled multiplied by the standard concentrations Total uga VC1 > volume x 1 mole air x atd. concentration x mole Vt. VC1 molar volume 79?4 'iters x 1 mole air x 48 x 10 ^ mole VC1 x 62.5 x 1Q*^ ug VC1 - 966 ug 24.6 liters 1 mole air mole VC1 Who re: Volume volume gas sampled as measured by dry gas motor ~ 0.280 eu. ft. x 28.3 litcr/cu. ft. 7.924 liters Molar volume 22.4 liter x ?60 mm x 296 * 24.6 litora 751.3 tarn 2?3 Standard concentration - 48 mole ppm or 48 x 10 ^ mole VC1 1 mole air MoK* Vt. vci - 62.5 X )06 uga VC 1/mole VC1 N. Srtfr.pl inq Unto Sampling rate Volume sampled 7.924 liters 0.990 1itera/minute or Time of sample 0 minutes 990 cc per minute C. Analytically Determined NicroQrams .The analytically determined total micrograma vinyl chloride adsorbed is calculated from the analysis of the extract of each tube. A blank (14 ugs) is subtracted from the analysis of each tubo. The bla.Jt is dorived from the instrument response for a CS^ oxtract of 6.3 grams of fresh activated carbon. BFGjI- 391 V. f -3- Calculation 1. Calibration of Can Chromatograph Method: A 48 mole ppm vinyl chloride in air .eivture ia the cali bration standard gas. With a Precision oas tight syringe, 2.5 ce of tho standard gas aro injected into the instrument* The area response is recorded and calculated. This response ia divided into the micrograma vinyl chloride in the standard Injection to obtain the GC calibration factor. Calculation of GC factor (C factor * Std. injection x 1 1 i ter x 1 mole air x mole cone. std. x mole Vt. VClj ---------- 1 COO cc mole volume Instrument response 2.5 cc x 1 liter x 1 mole air x 48 x IQ*** mole VC1 x 62.5 x 10^ up VC1 loco CC 24.6 liter 1.23 x 10 ^ ugs VCl/mra^ 21.837 1 mole air 1 mole VC1 Where: mole volume 22.4 liter x 760 mm x 296 24.6 liter 7?1.3 mm 273 Instrument renpemse * 138.6 mm x 1.4 mot x 128 2. Calculation of Dilution Factor The dilution factor ia the ratio of the microlltors extract injected into the instrument to tho total volume of the extract. There foro: D - __1____x IOOO ul x 50 ml 2 ul" 1 ml - 4 2.5 x iO 3. Micrograma VC 1 per Tube Calculation 1 Micrograas VCl per tubo - (GC factor x response x dilution factor) - blank Tube #1 (9-26-74) ugs VCl (1.23 x 10 o4 ugs/nuu x 166.4 ns x 0.6 nw x 32 X 2.5 x 10 ) - 14 UQJ 968 uga Tube if2 (9-26-74) 1. ugs VCl (1.23 x 10 5 ugs/nmt^ x 6l M 1 1.3 mm x 1 x 2.5 & 10 ) - 14 ugi 10 ugs ; BFG-I- 392 r !S -4- Tube #3 (9-26-74) _c 2 ^ ugs VC1 - (1.23 x 10 uos/nn x 48.6 mn x 0.9 02,1 x 1 x 2.5 x 10 ) - 14 U0s 0 ugs 4. Tutnl Hicroarajin on the 3 Tubes Total uga 3 tubes uga Tube #1 uga Tubes #2 uga Tube #3 <)6fl uga 10 ugs O uga - 978 uga, D. Adsorption Efficiency In routine soRipllr.g, a single carbon tube ia in the saapling train. There fore we are interested Jn the vinyl chloride adsorption .on the 1st tube (i>i the experiment). So the adsorption efficiency is here defined as the percent vinyl chloride adsorbed on the 1st tube. Below this efficiency ia calculated by two different methods. In the first mothod, the percent adsorption efficiency is the ratio cf the analytically determined VC1 on tube #1 versus total analytically determined VCl on the 3 tubes. In the second mothod, tho percent adsorption efficiency is the ratio of analytically determined VCl on tube #1 versus the theoretical VCl purged through the tubes. The two methods are in good agreement ascertaining that essentially 100% of the VCl in the air boing sampled ia adsorbed on the 1st tube. Calculat ions Method 1 % Adsorption efficiency tube #1 uqs VCl tube #1 ugs VCl on 3 tubes x 100% 968 uga 978 ugs x 100% 99% Method 2 % Adsorption efficiency tube #1 ugs VCl tube #1 X 100% theorectical uqs VCl 968 uqs 966 uga x 100% - 100% ^ E. Extraction Efficiency The extraction efficiency is a measurement of the ability of the CS^ solvent to ''wash" the VCl off the carbon into tho CS^. It is defined heroin by the following calculation] ;BFG-I- 393 t -5 % extraction efficiency - uga VCl tube 1t\ x 1< (Theoroctical ugs VC1) (% adsorption eff. Hethod l) - 968 uqs x 100% - 101% (966 ug*)(99%) Comments in Conclusion of Report This experiment la Intended to give a relatively precise estimate of the adaorption and extraction efficiencies. This is essential to analytical accuracy. It Is recognised that some parameters that could affect adaorption are not evaluated Ln thle work. A high concentration of contaminants (humidity, other hydrocarbons, etc.) can decrease the efficiency. The 1so work van done on September 26, 197^* R. L. Parrish RLP/lw C. L. WoodH, Jr. D. ti. Schrock E. E. Atkins R. V. Edwards CTF (Avon Lake Development) -Tr.! r