United States Environmental Protection Agency Air and Energy Engineering Research Laboratory Research Triangle Park NC 27711 Research and Development EPA/600/S9-85/009 May 1985 v>EPA Project Summary Proceedings: EPA's Industry Briefing on the Organic-Acid-Enhanced Limestone FGD Process (July 1984) J. David Mobley The proceedings document presenta- tions made during an EPA-sponsored industry briefing, July 19,1984, in San Antonio. "TX. The brief ing dealt with the status of EPA's research activities on the organic-acid-enhanced limestone flue gas desulfurization (FGD) process. Subjects covered included: (1) a tech- nical and economic evaluation of organ- ic acid addition to the San Miguel FGD system—results of parametric tests and the utility's perspective, (2) results of the first 2 years of commercial operation of an organic-acid-enhanced FGD sys- tem, (3) economics of retrofitting Big Rivers Electric Corporation's lime- based FGD system to organic-acid-en- hanced limestone operations, and (4) an economic evaluation of limestone and lime FGD processes for new systems. The briefing provided users, architects, engineers, vendors, consultants, and government personnel with a compre- hensive assessment of this innovative technology for controlling SO2 emis- sions. This Project Summary was developed by EPA's Air and Energy Engineering Research Laboratory, Research Triangle Park, NC, to announce key findings of the research project that is fully docu- mented in a separate report of the same title (see Project Report ordering infor- mation at back). Introduction EPA's Air and Energy Engineering Research Laboratory (AEERL)* periodical- ly sponsors symposia and industry brief- ings for the transfer of information re- garding research, development, and ap- plication activities with the objective of further accelerating the development and commercialization of technology. One of the major AEERL efforts for the past several years has been advancement of thetechnology for flue gas desulfurization (FGD). A key element of the FGD program has been the advancement of lime/lime- stone wet scrubbing technology, which has led to the development of the organic- acid-enhanced limestone FGD process. The July 19, 1984, Industry Briefing" was designed to provide interested people with EPA's latest findings on the use of organic acid in lime/limestone scrubbers. The presentations covered testing work performed at the laboratory, bench, pilot, prototype, industrial, and utility scales. In addition, an economic assessment of the use of the technology on new and retrofit systems was included. The presentations were complemented by a tour of the FGD system at San Miguel Electric Cooper- ative's Jourdanton Station in Jourdanton, TX; a summary of the tour is provided as an appendix to the proceedings. •Formerly EPA's Industrial Environmental Research Laboratory, Research Triangle Park, NC. ------- More than 220 people representing electric utilities, industrial sources, arch- itect and engineering firms, vendors, consultants, and governmental personnel attended the briefing in San Antonio, TX. Abstracts of the presentations follow. Asterisks by authors' names denote pre- senters. Technical and Economic Evaluation of Organic Acid Addition to the San Miguel FGD System—Part 1 —Results of Parametric Tests Jack M. Burke* Radian Corporation Robert P. Metcalfe and Robert Cmiei San Miguel Electric Cooperative J. David Mobley U.S. Environmental Protection Agency This paper summarizes the results of organic acid addition tests at a commer- cial FGD system. The tests were con- ducted at San Miguel Electric Cooper- ative's 410 MW lignite-fired Unit 1, outside Jourdanton, TX. During the pro- gram, several organic acid mixtures were tested over a range of operating condi- tions. The objective of these tests was to determine if the use of organic acids would allow San Miguel to reduce FGD system operating costs. Based on the test results, a cost analysis indicated that the use of organic acid addition at San Miguel will result in a first-year cost savings of over $600,000. In terms of cumulative net present worth, the estimated savings over a 15-year period will be $7.2 million 1984 dollars. Technical and Economic Evaluation of Organic Acid Addition to the San Miguel FGD System—Part 2—The Utility's Perspective Robert Cmiel* Robert P. Metcalfe*, and Wade Sebby San Miguel Electric Cooperative San Miguel Electric Cooperative's FGD system started up in 1981 and immed- iately became an area of operating prob- lems for the utility. After fighting major problems for over a year, San Miguel participated in an EPA-sponsored study to explore the costs and benefits of an organic acid conversion to improve the performance of their limestone based FGD unit. Based on the results of the initial study, San Miguel agreed to partic- ipate with the EPA in a test program to gather actual data on the conversion of a large commercial unit to organic-acid- enhanced operations. Benefits include: • Improved process operation and sub- stantial cost savings were estimated to be $7.2 million over a 15-year period. Current operating experiences indicate that this figure is low. To ensure that these savings are real, San Miguel will continue to develop and refine its operating skills. • Reduced limestone stoichiometry, ac- complished by reducing the operating pH, has resulted in better limestone utilization and slurry oxidation. • Reduced scaling and pluggage in scrubber modules has increased ef- ficiency with less maintenance. • Reduced scrubber waste production requires less operation time for the system and less truck hauling time back to the mine. Results of the First 2 Years of Commercial Operation of an Organic-Acid-Enhanced FGD System R. L. Glover, G. E. Brown, J. C. Dickerman, and 0. W. Hargrove Radian Corporation N. Dale Hicks* and D. M. Fraley Springfield City Utilities J. David Mobley U.S. Environmental Protection Agency The U.S. EPA has sponsored research to develop organic-acid-enhanced flue gas desulfurization (FGD) technology for existing and new coal burning facilities. A 1981 EPA-sponsored demonstration pro- gram at Springfield City Utilities' South- west Power Plant (SWPP), near Spring- field, MO, showed that adipic acid and dibasic acid (DBA) greatly enhanced FGD performance. SWPP has continuedto use DBA to comply with the 1971 SO2 emis- sions standard under which they are regulated. Thus, SWPP became the first commercial-scale system to use an or- ganic additive to enhance S02 removal. This paper documents the first 2 years (1982 and 1983) of commercial operation of the DBA system at SWPP. During 1982 and 1983, SWPP averaged an SO2 emis- sion rate of less than I.O Ib S02/106 Btu (430 ng/J). Conversely, in 1980 (prior to DBA addition), SWPP averaged about 5 Ib SO2/106 Btu (2,170 ng/J). FGD system reliability has also greatly improved, averaging 97.9 percent in 1982 and 98.7 percent in 1983, compared to 45 percent in 1980. Overall, DBA has increased the flexibility of the SWPP system and, most importantly, allowed SWPP to operate in compliance. Economics of Retrofitting Big Rivers Electric Corporation's Lime Based FGD System to Organic-Acid-Enhanced Limestone Operations Dennis Laslo*, Norman Ostroff, Richard Foley, and Donald G. Schreyer Peabody Process Systems J. David Mobley U.S. Environmental Protection Agency In 1982-83, Peabody Process Systems, Inc. (PPSI) conducted pilot plant tests at the R. D. Green Station of Big Rivers Electric Corporation (BREC). PPSI's final report of the pilot testing included com- parisons of the operating costs of a lime based, full-sized absorber, to a retrofit limestone system enhanced with dibasic acid (DBA) or adipic acid. The site specific changes required for BREC to convert their existing lime FGD system to a limestone system enhanced by DBA or adipic acid, and the costs of making such a change, are described in this paper. Results of this analysis indicated that an annual cost savings of $2.6 million could be achieved by converting the existing lime system to an adipic-acid-enhanced limestone system, and an annual savings of $3.1 million could be achieved by converting to a DBA-enhanced system. ------- Economic Evaluation of Limestone and Lime Flue Gas Desulfurization Processes for New Systems T. A. Burnett, C. D. Stephenson, F. A. Sudhoff, J. D. Veitch, and R. L Torstrick* Tennessee Valley Authority J. David Mobley U.S. Environmental Protection Agency The preliminary-grade economics (ac- curacy: -15 percent, +30 percent) of various alternative limestone and lime flue gas desulfurization (FGD) processes are examined using the current design and economic premises established for the continuing series of economic evalua- tions performed by TVA for EPA. The economics are projected using the Shaw- nee lime/limestone computer model, which is based on long-term operating data from EPA's alkali scrubbing test facility at TVA's Shawnee Steam Plant near Paducah, KY. The capital investment for the base-case limestone scrubbing process (500 MW, 3.5 percent sulfur coal, 1979 NSPS, spray tower, forced oxida- tion, landfill) is $206/kW. The first-year and levelized annual revenue require- ments are 10.59 and 15.09 mills/kWh, respectively. Costs for the equivalent limestone scrubbing process using a Turbulent Contact Absorber (TCA) are lower, while those for the venturi/spray tower absorber are higher. Forced-oxida- tion/landfill disposal has a lower capital investment than unoxidized/pond dis- posal for all options studied; however, the first-year and levelized annual revenue requirements are slightly higher for the forced-oxidation/landfill process for most coal applications. For the spray tower limestone process to achieve a specified SO2 removal efficiency, it is more eco- nomical to increase the limestone stoich- iometry and minimize the absorber liquid/ gas ratio (L/G). The use of adipic acid or possibly dibasic acid (DBA) as an additive to enhance S02 removal in the limestone scrubbing process is an economically attractive option. ------- The EPA author. J. DavidMob/ay (also the EPA Project Officer, see below), is with Air and Energy Engineering Research Laboratory, Research Triangle Park, NC 27711. The complete report, entitled "Proceedings: EPA's Industry Briefing on the Organic-A cid-Enhanced Limestone FGD Process—July 1984," (Order No. PB 85-181 105/AS; Cost: $16.00, subject to change) will be available only from: National Technical Information Service 5285 Port Royal Road Springfield, VA 22161 Telephone: 703-487-4650 The EPA Project Officer can be contacted at: Air and Energy Engineering Reearch Laboratory U.S. Environmental Protection Agency Research Triangle Park. NC 27711 it U.S. GOVERNMENT PRINTING OFFICE: 1985-559-016/27046 >7 United States Environmental Protection Agency Center for Environmental Research Information Cincinnati OH 45268 Official Business Penalty for Private Use $300 OOOC329 PS U S ENVIR PROTSCTIOK AGENCY RfSlON 5 LIBRARY 230 S OfARBCtN STREi CHICAGO IL ------- |