Document kpLrMKpKw38ME4yqY1L9k4oJ

conoco Interoffice Communication To Prom Date SutjK! J. c. Ledvina - Houston J. 0. Gibson - Baltimore June 17, 1980 NESHAPS STANDARD FOR BENZENE STORAGE TANKS RECEIVED JUN 2 41980 Attached Is a letter from George Hopkins outlining the potential costs if we are forced to replace the benzene storage tanks at Baltimore with internal floating roof tanks designed per the draft NESHAPS regulation. The estimated cost is based on quotations obtained for the new LAB storage tanks. The letter also outlines some of the problems encountered in the design of the LAB tanks. The vent collection system we are installing to control benzene emissions from the benzene storage tanks, crude storage tanks, and process sources is still three to four weeks from start-up. Thus we still do not have actual data on benzene absorption from vent streams. The design efficiency is 99-9t plus, however, and all critical rotating equipment is spared. Thus it would seem that equivalency could be shown if some reasonable pro visions are included in the final regulation. Please review the enclosed information and let me know if anything else is required to develop your comment strategy for the draft regulation. J. 0. Gibson Chief Process Engineer mtw attachment cc: RTF THH GEH SAL 000019958 conoco Interoffice Communication To J. 0. Gibson From G. E. Hopkins Date June 10, 1980 Subject REPLACEMENT OF T-244/T-250 WITH INTERNAL FLOATING ROOF TANKS Per your request, an approximate cost estimate to replace the two benzene storage tanks (T-244/250) with tanks containing internal floating roofs has been prepared. This estimate was made to give Joe Ledvina an idea of the expense we would incur should EPA benzene standards require these modifica tions at our plant. The total cost, not including removal of T-244 and T-250 and piping changes, is estimated at $559,600 for both tanks and breaks down as follows: I tern No. Reg 1d Cost per Tank Total Cost 1. Tank Replacement: a) New 73 1 -6" |6x 40' Hgt. Cone Roof Tank (30 M bbl) 2 $173,900 b) Pad for New Tank c) Painting for New Tank 2 2 3, 'too 9,000 Total Tank Replacement Cost (Installed) $186,300 2. Internal Floating Roof: a) Floating Roof with Dbl Seal, Btm Seal, Viton, Top Seal Neoprene 2 b) Revisions for Double Deck Assembly to make roof unsinkable 2 c) Revisions to make Top Seal Viton (instead of Neoprene) 2 Total Internal Floating Roof Cost (Installed) $ 53,800 28,500 11 ,200 $93,500 $347,800 6,800 18,000 $372,600 $107,600 57,000 22,400 $187,000 Total Project Cost: $279,800 $559,600 The costs for replacing the ellipsoidal T-244/250 with cone-roof tanks were estimated using the CEO Estimating Manual. The internal floating roof costs were obtained by revising quotes transmitted to Fred Linstead from Chicago Bridge and Iron Company for installing internal floating roofs in the benzene storage tanks to be used in the new LAB plant. .These quotes were obtained for 30 foot and 40 foot diameter tanks. SAL 000019959 J.O. Gibson June 10. 1980 Page 2 Therefore, the costs for our 73*5 foot diameter tanks were estimated by scaling these quotes up based on: roof surface area for the internal floating roof; c1rcumference for the viton top seal; and cost to diameter ratios for the double deck assembly. The internal floating roof system basically consists of a 3/16" double deck floating roof with about 12" to 1-4" between decks. The assembly would have two seals (both viton) wi th pol yurethane foam between them. The primary (or lower) seal is an envelope seal and the secondary (or upper) seal is a slick-faced non-reversing wiper seal. The double-deck assembly, as opposed to the standard single-pan arrangement, was* included at R. W. Seymour's re quest to ensure that the floating roof assembly does not sink (as has happened previously at Baltimore and other location^. The Ultrafloat aluminum roofs that Conoco have used in the past were deemed unsatisfactory because they do not meet the EPA requirement that the floating roof rest on the liquid benzene surface. As a result, the proposed roof turns upward instead of downward. The deck rims have about 6" clearance from the tank wall. In evaluating the cost estimate, the following additional items should be considered: 1) Of the major tank vendors contacted by the new LAB plant project group, Chicago Bridge and Iron Company was the only one that would quote an internal floating roof tank. 2) The estimate does not include the cost of either removing T-244 and T-250 or of preparing new dikes and installing the new tanks at a different location. Another possibility is to use T-251 and T-252 as benzene tanks and T-244/250 as crude tanks. However, the costs of these items cannot be effectively estimated without more project definition. 3) The piping and instrument tie-ins to the new benzene tanks are not in cluded in the estimate. Some piping would be required due to the new tanks being cyl in.drical instead of ellipsoidal but the costs of these revisions are assumed to be small in comparison to the total project cost (unless the new tanks are installed in another location). G. E. Hopkins Senior Process Engineer mtw SAL 000019960