pf09-010 - Laserfiche WebLink

Home

` Mr. Kevin Kain �� Mr. Tarik Hanafy September 10, ZO10 Moss & Barnett Page 7 populate the available adsorption sites. This is critically fmportant because the capture rate of hydrogen sulfide may decrease markedly. Actual operatlng mnditlons also play an important role In carbon filter bed effectiveness. Obtaining hi9h removal effiGencies from carbon bed adsorbers requlres low basellne efftuent concentration (less than 10 ppm), wntatnment of breakthrough emissions by avoiding premature breakthrough or sending material emftted from a breakthrough to another on-line adsorber. It is undear from the materiai provided by BtCuminous Roadways if there Is more than one on-line adsorber in this system to address the breakthrough Issue. Efftdent operatlon also requires e�icient recovery of the desorbed organics whfch is usualty done by condensing the vapors and recycling the noncondensibles form the condenser back Into the on-line adsorber and thefe must be some method of containment of organia during tfie cooling and drying cycle which prepares the carbon bed for renewed service. Nelther tlie permit appllcation nor EAW documents for the proposed Bituminous Roadways faciliry address this aspec[ of carbon bed system operatlons. Heating asphalt produces sign'rficant condensable particulates in the exhaust stream. Many of these are long chain hydrocarbons whkh are either Ilquld or solid at ambient tempera[ures and which will rapidly condense in the carbon bed filter, This can wuse an excessively high pressure drop aaoss the filters and eventually biind them or render them ineffective. Hlgh toncentratlons of these aerosols can also produce an excessive temperature rise across the bed due to heat adsorptlon. Many applicatlons remove these droplets or aerosols upstre2m of the adsorbers. Beouse the permit appliption and the EAW do not address [he specific equipment, � k Is difflcult to determine how he proposed system wili address these issues. This operat(onal data deflclency needs to be addressed. To a large eMent it is difficult to saUsfadoNly and accuretely predict the pertormance of carbon bed adsorpGon systems from theory. Similarly, it is difficuit to extrapolate performance of a spedflc system based on very limited test data. Gladstone belfeves that the prediction of hydrogen sulfide emisslons and the control effiaency of the proposed equipment shouid be buttressed by a more thorough analysis of the North Carolina tests, including the speciflc operadng condidons and the composition of the material tested. A wmpariso� of the North Carolina test resul� with various operatlng parameters of the proposed Bitumfnous Roadways Roseville piant, inciuding materiai composiUon, would provide further basis for comparison. Bituminous Roadways could support this with either bench scale tests of thetr materials or tests of the proposed technology at one of thelr other facilities. The air pertnit should be revised to I�clude operaUng parameters for the proposed carbon bed adsorber(s) based on actual design data for the proposed system. The public can not evaluate the adequaty of these permit conditions without any manufacturer's data and wfthout a�y manufacturer's performance guarantee. Bituminous Roadways has proposed the carbon bed to treat emissions from the asphalt storege fadlity proposed for tl�is project. Bltuminous Roadways has not yet designed the asphalt storage tadlity and has not selected a vendor for the control equlpment because they do not e�cpect to build the asphalt storege faGlity for a muple of years. M incremental approach does �../