United States Environmental Protection Agency Air and Energy Engineering Research Laboratory Research Triangle Park 27711 Research and Development EPA/600/S9-917015 July 1991 Project Summary Proceedings: 1990 SO2 Control Symposium Charles B. Sedman This report compiles 110 presented papers from the 1990 SO2 Control Sym- posium held in New Orleans, LA, May 8-11,1990. Topics include: SO2 control economics, furnace sorbent injection, byproduct utilization, spray dryer tech- nology, wet flue gas desulfurization (FGD) and combined SOx/NOx control technologies, and post-combustion dry sorbent injection. Many papers present results from full-scale operational stud- ies, while laboratory and pilot-scale re- search on new technologies is also em- phasized. This Project Summary was developed by EPA's Air and Energy Engineering Research Laboratory, Research Tri- angle Park, NC, to highlight key topics of Interest on SO2 control that are fully documented In a separate report of the same title (see Project Report ordering Information at back). Introduction The Symposium, jointly sponsored by the Electric Power Research Institute (EPRI) and the Air and Energy Engineer- ing Research Laboratory, U.S. Environ- mental Protection Agency (AEERL/ USEPA) is held periodically to transfer technical information and advance tech- nology development and application for control of SO2 emissions from fuel com- bustion. The 1990 SO2 Control Sympo- sium was held in New Orleans, LA, May 8-11, 1990. The proceedings from this Symposium consist of four volumes, con- taining 110 presented papers covering 14 technical sessions: Session Subject Area 1 2 3A 3B 4A 4B 4C 5 6A 6B 6C 7A 7B International Overview Economics Furnace Sorbent Injection (FSI) Byproduct Utilization FSI Recycle Wet FGD Reliability Spray Dryers Wet Full Scale Operation Emerging Technologies Combined SO|(/NOX Technologies Wet FGD Vendor Designs Post-Combustion Dry Technologies Wet FGD Research Poster Session Misc. FGD Topics International Developments Four papers on international SO2 con- trol at electric generating stations were presented covering Japan, Canada, the United Kingdom, and Europe. Flue gas desulfurization (FGD) technology in Japan dated to 1973. Currently wet FGD has evolved with a fourth generation system using limestone, a single oxidation and absorption tower, and generating a gyp- sum byproduct. A combined SO/NOx sys- tem using activated coal char as the sor- bent is scheduled for demonstration in 1990-91. Fluidized bed combustion is also used in Japan but is not widespread. The author concludes that future systems of choice will be the dry bed, combined SOx/ NO removal system using char sorbent. Printed on Recycled Paper ------- United States Environmental Protection Agency Air and Energy Engineering Research Laboratory Research Triangle Park 27711 Research and Development EPA/600/S9-91/015 July 1991 v/EPA Project Summary Proceedings: 1990 SO2 Control Symposium Charles B. Sedman This report compiles 110 presented papers from the 1990 SO2 Control Sym- posium held in New Orleans, LA, May 8-11,1990. Topics include: SO2 control economics, furnace sorbent injection, byproduct utilization, spray dryer tech- nology, wet flue gas desulfurization (FGD) and combined SOx/NOx control technologies, and post-combustion dry sorbent injection. Many papers present results from full-scale operational stud- ies, while laboratory and pilot-scale re- search on new technologies Is also em- phasized. This Project Summary was developed by EPA's Air and Energy Engineering Research Laboratory, Research Tri- angle Park, NC, to highlight key topics of Interest on SOa control that are fully documented In a separate report of the same title (see Project Report ordering Information at back). Introduction The Symposium, jointly sponsored by the Electric Power Research Institute (EPRI) and the Air and Energy Engineer- ing Research Laboratory, U.S. Environ- mental Protection Agency (AEERL/ USEPA) is held periodically to transfer technical information and advance tech- nology development and application for control of SO2 emissions from fuel com- bustion. The 1990 SO2 Control Sympo- sium was held in New Orleans, LA, May 8-11, 1990. The proceedings from this Symposium consist of four volumes, con- taining 110 presented papers covering 14 technical sessions: Session Subject Area 1 2 3A 3B 4A 4B 4C 5 6A 6B 6C 7A 7B International Overview Economics Furnace Sorbent Injection (FSI) Byproduct Utilization FSI Recycle Wet FGD Reliability Spray Dryers Wet Full Scale Operation Emerging Technologies Combined SO/NOx Technologies Wet FGD Vendor Designs Post-Combustion Dry Technologies Wet FGD Research Poster Session Misc. FGD Topics International Developments Four papers on international SO2 con- trol at electric generating stations were presented covering Japan, Canada, the United Kingdom, and Europe. Flue gas desulfurization (FGD) technology in Japan dated to 1973. Currently wet FGD has evolved with a fourth generation system using limestone, a single oxidation and absorption tower, and generating a gyp- sum byproduct. A combined SOx/NOx sys- tem using activated coal char a*s the sor- bent is scheduled for demonstration in 1990-91. Fluidized bed combustion is also used in Japan but is not widespread. The author concludes that future systems of choice will be the dry bed, combined SO/ NO removal system using char sorbent." Printed on Recycled Paper ------- Canada currently has no commercial add-on SO2 control technologies in place, but has considerable developmental ac- tivities ongoing. Individual utility compa- nies have initiated research programs to comply with provincial SO reduction goals by the mid 1990s. The individual research programs for Nova Scotia Power, New Brunswick Electric Power Commission, Ontario Hydro (Saskatchewan) Power Cor- poration, and Alberta Power Limited were discussed. A full array of technologies, many of which are detailed later in this Symposium, were cited as candidates for research and/or evaluation. The United Kingdom has 70,000 MWe of electrical generating capacity, the ma- jority being coal-fired. Recent legisla- tion targets 40% SO reduction by 1998 and 60% reduction by 2003, which will result in considerable retrofit of existing facilities. The West German retrofit program (GFAVO) was enacted in 1983 and has resulted in 150 units, over 30,000 MWe capacity, retrofitted with FGD, along with* 7400 MW of new capacity. Wet limestone, forced-oxidation scrubbers have accounted for 90% of FGD installations. FGD Economics The Economics Session emphasized the anticipated costs of FGD retrofit for acid rain legislation. One paper compares spray dryer and wet FGD system costs for hypothetical new and retrofit 500 MW installations. Another paper summarized* a comprehensive EPRI cost study, includ- ing that (a) FGD costs were currently lower (when corrected for inflation) than for pre- vious studies, (b) a number of technolo- gies were very close in costs per ton of SO2 removed, and (c) 30% reduction in wet FGD costs were obtainable by pro- cess simplification; e.g., no spare mod- ules, single absorbers. A third paper detailed design changes to reduce FGD retrofit costs, while a fourth paper discussed the role of economics in compliance planning strategies. The next two papers discussed retrofit cost consid- erations specific to the Tennessee Valley Authority system and to 200 candidate retrofit boilers nationwide, respectively. The latter paper also compared proposed U.S. retrofit economics to actual costs ex- perienced in recent West German retro- fits. A seventh paper focused on second- generation wet FGD technologies as ret- rofit choices while the eighth and final paper discussed strategies to comply with imminent acid rain legislative requirements. Furnace Sorbent Injection Emphasis was on design and operation of full-scale facilities. The first paper de- scribed furnace lime injection on a 65 MWt stoker-fired boiler in West Germany followed by a second reaction stage with humid if ication upstream of an electrostatic precipitator (ESP) for 90% SO2 removal. Three papers in this session which de- scribed experimental studies for limestone and lime sorbents injected into furnaces, while another paper detailed large pilot furnace injection on a 15 MWt tangential prototype boiler. Three papers described activities at three demonstration sites. Results were presented for lime injection at the 105 MW Edgewater and 61 MWe Whitewater Valley sites, reporting up to 50 and 72% SO2 removal, respectively. Plans for the 180 MWe demonstration at the Yorktown No. 2 tangentially fired boiler, to start up in 1992, were discussed in the final paper of this session. Byproduct Utilization In Session 3B, Byproduct Utilization, eight papers were presented for waste handling, disposal and re-use in wet FGD, spray dryer FGD, furnace sorbent injec- tion, and new technologies. Three papers dealt specifically with limestone/lime wet FGD sludge utilization as paving materi- als, aggregates, structural concrete, gyp- sum, and fertilizer. Other papers discussed potential byproducts from advanced new technologies such as gypsum and ammo- nium sulfite. Two papers dealt with spe- cific experience in byproduct/waste man- agement efforts: one for the Ohio Edison system and one covering recent experi- ence in West Germany. FSI Recycle The Furnace Sorbent Injection (FSI) Recycle Session (4A) consisted of four presentations on the increased utilization of calcium sorbents for in-furnace injec- tion. One paper discussed dust collector recycle of dry sorbent with additives; an- other discussed similar recycle but by re- slurrying and re-injection as a slurry into the furnace. Two other papers discussed more novel reactivation schemes prior to recycleone process (ARA) steam-treats collected solids prior to recycle into the flue gas, while another (ADVACATE) con- verts waste solids into calcium silicate prior to reinjection into ductwork. Wet FGD Reliability Session 4B, Wet FGD Reliability, con- sisted of eight papers covering: designing systems for load swing (cy- cling) service protective linings for scrubber com- ponents corrosion prevention/control effects of additives on materials of construction duct conversion downstream of FGD alternatives to gas reheat for duct corrosion prevention Spray Dryers Session 4C focused on large pilot- and full-scale commercial applications of spray dryer technology. Two papers covered pilot experience at TVA's Shawnee facility and EPRI's High Sulfur Test Center. One paper described operating experience on an 865 MWe unit using eight absorbers; a second described vendor experience with spray dryers worldwide. The effect of spray dryer operation on ESP performance was discussed in the remaining papers. Wet Full-Scale Operation Session 5 covered the mainstream topic of FGD symposia, that of full-scale oper- ating experiences of wet lime/limestone scrubbers. The session began with an overview of chemical additives for im- proved operation by the Session Chair- man. Nine papers followed on : thiosulfate additives on three com- mercial FGD units sodium formate addition on pilot- and full-scale scrubbers performance evaluation of magne- sium/lime, limestone, gypsum byproduct, and limestone low sulfur coal FGD operations evaluation of a Chiyoda wet scrub- ber system scale prevention on a commercial FGD system laboratory evaluation of additive losses in FGD process modifications to improve FGD performance Emerging Technologies, Combined SO^NO, Technologies, and Wet FGD Vendor Designs Sessions 6A, 6B, and 6C were "mini- sessions" consisting of abbreviated pre- sentations of new developments in SO control, specialized topics thought to be of less general interest than conventional FGD technology. The purpose of these sessions was to expose new concepts, while minimizing the time, thus allowing ------- many topics to be discussed. Sessions and topics covered were: Emerging Technologies: Parsons FGD process FGD process using cement kiln waste ISPRA Mark 13A process plasma-jet SO2 conversion CANSOLV FGD process anion-exchange resin dechlorini- zation synergistic reactor for SO2 control Combined SOx/NOx Technologies: overview report on SOx/NOx control lime-urea hydrate injection NOXSO process combined SOx/NOx control by cata- lytic system combined SOx/NOx control in a wet limestone scrubber combined SOx/NOx by fixed-bed dry sorbent dry sorbent injection SOx/NO con- trol Wet FGD Vendor Designs: Flakt wet FGD systems West German FGD systems Babcock-Hitachi "Intelligent" scrub- ber KRC-Noell wet FGD system Pure air FGD process Chiyoda wet FGD system Post-Combustion Dry Technologies Session 7A, Post-Combustion Dry Tech- nologies, focused on efforts to develop lower cost retrofit technologies using dry sorbents injected into the post-combus- tion flue gas. These papers included two discussions of dry sodium injection, four papers discussing calcium injection, one paper documenting a combined calcium/ sodium dry injection system, and one pa- per describing a spray dryer within an ESP (E-SOJ. Wet FGD Research Session 7B, Wet FGD Research, cov- ers the laboratory- and small-pilot-scale research on wet FGD being conducted primarily at EPRI and its member compa- nies. Topics included mist eliminator per- formance, limestone utilization, process ad- ditives, crystallization studies, combined SOx/NOx control in wet scrubbers, and pro- cess/economic models developed for in- dustry. Poster Session Although not presented formally at the podium, the 1990 SO2 Symposium con- ducted a large poster session where FGD- related subjects were discussed face to face between the author and audience. Of these, 13 submitted technical papers which are included in the proceedings. These topics are heavily oriented toward research programs and vary from fly ash effects on SO2 control, process models, improved FGD components, additives, and corrosion control. Also papers for non- utility applications, especially waste incin- erator FGD, were presented in this ses- sion. &LI.S. GOVERNMENT PRINTING OFFICE: 1991 - 548-02H/40030 ------- |