Be sure that the chemicals you make or use meet the latest ACS reagent specifications!
Reagent Chemicals, Eighth Edition
Completely revised and updated
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eagent Chemicals is the only resource of its kind that provides specifications and analytical procedures to assure the quality of your chemicals. ACS specified reagent chemicals are the choice of most organizations such as APHA, ASTM, FCC, SEMI, USP, etc., and many regulatory agencies, such as the EPA. Improved and expanded, the eighth edition of this authoritative reference now comes in a user-friendly format that makes look-up quick and easy. In it you'll find all the necessary information on
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atomic absorption spectrophotometry chromatography colorimetry and t u r b i d i m e t r y direct electrometric methods gravimetric methods measurement of physical properties reagent solutions solid reagent mixtures solvents for special purposes specifications and tests standard volumetric solutions titrimetry
New in this edition are a section on determining detection limits, the general elimination of boiling point and density specifications, the use of LC in assay determinations, and a section on preparation of volumetric solutions. Twenty-four new reagents have been added. Updated methods include gas chromatography where capillary columns are now used, water determinations where coulometric methods have been added, and the replacement of flame emission techniques by atomic absorption for metal determinations. In addition, the general methods for chromatography and atomic absorption have been extensively revised to reflect their practical use in today's typical analytical laboratory. 815 pages (1993) Clothbound ISBN 0-8412-2502-8 $149.95
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Environ. Sci. Technol., Vol. 28, No. 2, 1994
completely. At the same time, practically all t h e remaining dust in t h e gas is retained in t h e catalyst bed, w h i c h must be cleaned at intervals. Cleaning is done by sifting t h e catalyst. This procedure may be necessary once or several times a year, dep e n d i n g o n t h e efficiency of t h e dust removal equipment (e.g., a fabric filter or an electrostatic precipitator upstream of t h e process). T h e o x i d i z e d flue gas is t h e n cooled in its second pass through the gas—gas heat exchanger, a n d the sulfur trioxide in t h e gas is hydrated into sulfuric acid (gas): S 0 3 + H 2 0 = H 2 S0 4 (g) + 100 kj/mol The gas that is still above t h e sulfuric acid d e w p o i n t t e m p e r a t u r e enters t h e WSA condenser, w h e r e it is further cooled in vertical glass t u b e s by air to a t e m p e r a t u r e of about 210 °F. T h e sulfuric acid vapor is condensed a n d concentrated to m o r e t h a n 9 3 % p u r i t y i n t h e WSA condenser, a n d heat is transferred to t h e cooling air as follows: H 2 S0 4 (g) = H 2 S0 4 (1) + 69 kj/mol Plans for the future The SNOX process is fully automated and can be operated and m a i n t a i n e d w i t h m i n i m a l personnel. Unlike conventional scrubbers, the SNOX process does not require substantial r a w material a n d waste handling systems. At this time w e have n o experience w i t h t h e N O x and S 0 2 catalyst replacement cycle a n d cost. Although our experience to date is limited, w e have found t h e SNOX process easy to operate a n d maintain. Demonstration of t h e system h a s been highly successful. ABB Environmental Systems a n d Ohio Edison are making certain mechanical modifications to t h e Niles SNOX system to enhance its usefulness for t h e r e m a i n i n g life of t h e Niles plant a n d to reduce operating costs. O h i o E d i s o n p l a n s to take over t h e system in January 1995. Sher M. Durrani, a general project engineer with Ohio Edison Company, has in-depth experience in the management of large generating-plant projects. He has a bachelor's degree in electrical and mechanical engineering from the University of Karachi, Pakistan, and is a registered professional engineer in Ohio.
