Laserfiche WebLink
�w <br /> B:\CYCLOPUR.DOC <br /> By calculating the dew points for benzene and gasoline at the 43-F <br /> the lower temperature limit caused by the freezing poi..J of <br /> benzene, and at the concentrations of the compounds present, <br /> estimates of the pressures need to condense out benzene and <br /> gasoline can be made. <br /> The amount of vapor that can be in air is found by the following <br /> formula <br /> ` C -VPc/P <br /> C m Concentration vapor <br /> NPc a vapor pressure compound <br /> P m Pressure <br /> The dew point of a substance is that point at which the <br /> concentration in air exceeds the Concentration Vapor; therefore, <br /> the compound will condense out. <br /> The concentration of the vapor can be found by the following <br /> formula <br /> C ® mg/l * 22.4 1/mole / MW mg <br /> Mid - the molecular weight <br /> 22.4 volume of one mole of gas at standard temperature and <br /> pressure. <br /> Solving for P <br /> P-VP/(mg/1*22.4)*MW <br /> COMPOUND VP MW mg CONCENTRATION Pressure <br /> j at 43-F mg/1 STP mm/Hg atmospheres <br /> mm/Hg <br /> - Benzene 35 78110 .72 174353 229.4 - - <br /> Gasoline 211.9 90900 23.00 37386 49.2 <br /> Gasoline 211.9 90900 1131.44 760 1.0 <br /> Gasoline 82 B O-F 90900 23.00 14467 1.9.0 <br /> At the above ratios condensation would begin . <br /> 1131.4 mg/l - 27.9 % by volume Gasoline Vapor. <br /> The above indicates that at normal concentrations found during <br /> 4 vapor extraction of gasoline soil contamination the Cyclo Purge <br /> should be ineffective at removing gasoline vapors. <br /> i this discussion of the problem assumes that the vapors will <br /> respond as ideal gasses and should only be used as an indication <br /> of the probable responses of the system. <br /> 4 <br /> f v <br />