fxEPA United States Environmental Protection Agency Industrial Environmental Research EPA-600/7-79-104a Laboratory April 1979 Research Triangle Park NIC 27711 Effects of Conditioning Agents on Emissions from Coal-fired Boilers: Test Report No. 1 Interagency Energy/Environment R&D Program Report ------- RESEARCH REPORTING SERIES Research reports of the Office of Research and Development, U.S. Environmental Protection Agency, have been grouped into nine series. These nine broad cate- gories were established to facilitate further development and application of en- vironmental technology. Elimination of traditional grouping was consciously planned to foster technology transfer and a maximum interface in related fields. The nine series are: 1. Environmental Health Effects Research 2. Environmental Protection Technology 3. Ecological Research 4. Environmental Monitoring 5. Socioeconomic Environmental Studies 6. Scientific and Technical Assessment Reports (STAR) 7. Interagency Energy-Environment Research and Development 8. "Special" Reports 9. Miscellaneous Reports This report has been assigned to the INTERAGENCY ENERGY-ENVIRONMENT RESEARCH AND DEVELOPMENT series. Reports in this series result from the effort funded under the 17-agency Federal Energy/Environment Research and Development Program. These studies relate to EPA's mission to protect the public health and welfare from adverse effects of pollutants associated with energy sys- tems. The goal of the Program is to assure the rapid development of domestic energy supplies in an environmentally-compatible manner by providing the nec- essary environmental data and control technology. Investigations include analy- ses of the transport of energy-related pollutants and their health and ecological effects; assessments of, and development of, control technologies for energy systems; and integrated assessments of a wide-range of energy-related environ- mental issues. EPA REVIEW NOTICE This report has been reviewed by the participating Federal Agencies, and approved for publication. Approval does not signify that the contents necessarily reflect the views and policies of the Government, nor does mention of trade names or commercial products constitute endorsement or recommendation for use. This document is available to the public through the National Technical Informa- tion Service, Springfield, Virginia 22161. ------- EPA-600/7-79-104a April 1979 Effects of Conditioning Agents on Emissions from Coal-fired Boilers: Test Report No. 1 by R.G. Patterson, P. Riersgard, R. Parker, and S. Calvert Air Pollution Technology, Inc. 4901 Morena Boulevard, Suite 402 San Diego, California 92117 Contract No. 68-02-2628 Program Element No. EHE624A EPA Project Officer: Leslie E. Sparks Industrial Environmental Research Laboratory Office of Energy, Minerals, and Industry Research Triangle Park, NC 27711 Prepared for U.S. ENVIRONMENTAL PROTECTION AGENCY Office of Research and Development Washington, DC 20460 ------- ABSTRACT A field performance test has been conducted on an electro- static precipitator (ESP) which uses sulfur trioxide as the con- ditioning agent. The ESP is located at an electric utilities power plant, burning approximately 1$ sulfur coal. Tests were conducted with and without injection of the conditioning agent. The ESP performance was characterized in terms of particle collection efficiency and the chemical com- position of particulate and gaseous emissions. Fly ash resis- tivity and duct opacity were also measured. Results show an average increase in overall efficiency from 80% to 95% with injection of the conditioning agent. This is accompanied by a decrease in fly ash resistivity, a decrease in opacity, and an increase in sulfur trioxide concentration entering and leaving the precipitator. 111 ------- CONTENTS Page Abstract iii Figures vi Tables vii Acknowledgment iy Sections 1. Introduction 1 2. Summary and Conclusions Results 3 Conclusions 5 3. Description of Test Plant Design 6 Operating Conditions . 9 Test Methods and Schedule 12 4. Test Results Collection Efficiency 15 ESP Performance Predictions 21 Flue Gas Composition 24 Elemental Analysis 27 Resistivity 32 Opacity 32 Coal Composition 35 5. Economics 38 References 40 IV ------- CONTENTS (continued) Page Appendices A. Particulate Sampling Methods 41 B. Particle Size Data 45 C. Particulate Sulfate Data 54 D. Input Data for the ESP Performance Model 56 E. Elemental Analysis Data 58 ------- FIGURES Number Page 1 Plant layout ..................... 7 2 ESP inlet section voltage-current relationships. ... 11 3 ESP outlet section voltage -current relationships ... 11 4 Inlet size distribution for conditioned tests showing 90% confidence intervals ........... 16 5 Inlet size distribution for baseline tests showing 90% confidence intervals ........... 17 6 Outlet size distribution for conditioned tests showing 90% confidence intervals ........... 18 7 Outlet size distribution for baseline tests showing 90% confidence intervals ........... 19 8 Grade penetration curves for S03 conditioned tests ......................... 22 9 Grade penetration curves for baseline tests ...... 23 10 Controlled condensation system ............ 26 11 SOa concentration of flue gas at ESP inlet ...... 29 12 Mass concentrations of major elements in fly ash with S03 conditioning ............... 30 13 Mass concentrations of major elements in fly ash from baseline test ................ 31 14 In-stack opacity probe ................ 34 15 Opacity in outlet duct ................ 36 Appendix A-l Modified EPA sampling train with in-stack cascade impactor ................... 43 VI ------- TABLES Number^ Page 1 Electrostatic Precipitator Design Information .... 8 2 Boiler Load Data 10 3 Summary of Overall Efficiencies 20 4 ESP Inlet Flue Gas Conditions 25 5 ESP Outlet Flue Gas Conditions 25 6 Concentration of S03 in Flue Gas 28 7 Inlet Fly Ash Resistivity 33 8 Chemical Analysis of Coal 37 9 Capital and Operating Costs 39 Appendices B-l Inlet and Outlet Particle Data for Run 1 46 B-2 Inlet and Outlet Particle Data for Run 2 46 B-3 Inlet and Outlet Particle Data for Run 12 47 B-4 Inlet and Outlet Particle Data for Run 13 47 B-5 Inlet and Outlet Particle Data for Run 14 48 B-6 Inlet and Outlet Particle Data for Run 16 48 B-7 Inlet and Outlet Particle Data for Run 17 49 B-8 Inlet and Outlet Particle Data for Run 21 49 B-9 Inlet and Outlet Particle Data for Run 23 50 B-10 Inlet and Outlet Particle Data for Run 24 50 VII ------- TABLES (continued) Number B-ll Inlet and Outlet Particle Data for Run 26 51 B-12 Inlet and Outlet Particle Data for Run 28 51 B-13 Inlet and Outlet Particle Data for Blank Run 3. . . 52 B-14 Inlet and Outlet Particle Data for Blank Run 5. . . 52 B-15 Inlet and Outlet Particle Data for Blank Run 10 . . 53 B-16 Inlet and Outlet Particle Data for Blank Run 19 . . 53 C-l Results of Particulate Sulfate Tests 55 D-l Input Data for the ESP Performance Model 57 E-l Minimum Sensitivities of Elements 59 E-2 Results of Elemental Analysis of Fly Ash on Cascade Impactor Substrates 60 Vlll ------- ACKNOWLEDGMENT A.P.T. wishes to express its appreciation to Dr. H.J. White who provided valuable consultation, and to Dr. Leslie Sparks, the EPA Project Officer, for excellent coordination and technical assistance in support of this test program. The assistance and coordination provided by plant personnel at the test site also is sincerely appreciated. IX ------- SECTION 1 INTRODUCTION The Particulate Technology Branch of the U.S. EPA In- dustrial Environmental Research Laboratory, Research Triangle Park, NC has contracted with A.P.T., Inc. to conduct a series of field test performance evaluations of electrostatic preci- pitators (ESP) which use flue gas conditioning agents to im- prove their performance. This report presents the results of the first field test conducted at an electric utilities power plant which burns low sulfur coal. Sulfur trioxide injection is used to condition the flue gas before it enters the electro- static precipitator. Flue gas conditioning agents are used primarily for main- taining high particulate collection efficiency in electrostatic precipitators operating on high electrical resistivity fly ash resulting from the combustion of low sulfur coals. Flue gas conditioning is not usually designed into a new installation but rather is used as a corrective measure for a precipitator which is unable to meet emission or opacity standards. Many potential conditioning agents have been investigated and a number are available commercially. Conditioning agents may be injected in the boiler or may be injected downstream from the air preheater. Their effectiveness will depend to some extent on the flue gas composition and temperature. The improved collection efficiency associated with flue gas conditioning generally is attributed to a decrease in the fly ash electrical resistivity. However, other mechanisms such as an increase in space charge and a reduction in rapping re- entrainment losses may be more important than resistivity in some situations. ------- This test program is being conducted to obtain an exten- sive data base for evaluating the effectiveness of various conditioning agents. It is planned that each test will provide sufficient data to identify the important mechanisms in effect and to quantify any additional process emissions which result from the use of the conditioning system. ------- SECTION 2 SUMMARY AND CONCLUSIONS A field performance test has been conducted on an ESP which uses sulfur trioxide injection for flue gas conditioning. The ESP is located at an electric utilities power plant, burning approximately 1% sulfur coal. Tests were conducted with and without injection of the conditioning agent. The ESP performance was characterized in terms of overall and grade particle collection efficiency and the chemical composition of particulate and gaseous emissions. Fly ash resistivity and in-stack opacity were also measured. RESULTS The ESP has a design efficiency of 951 when burning high sulfur coal. When low sulfur coal is burned, the precipitator cannot maintain its design efficiency without gas conditioning. During the unconditioned tests it was observed that sparking was much more frequent than during the conditioned tests. The overall and grade collection efficiencies were deter- mined from particle size and mass data obtained using in-stack cascade impactors. Overall efficiencies were also obtained using a modification of EPA Method 5. The overall mass ef- ficiency when S03 injection was used for gas conditioning averaged 94.91. Without S03 injection, the average efficiency decreased to 80.2%. The grade penetration curves showed im- proved collection for all particle sizes measured (from about 0.3 to 5 ym dia.) when the conditioning agent was used. How- ever, the improvement appears to be more pronounced for the larger particle sizes. The measured overall and grade efficiencies compared well with the ESP performance model (Sparks, 1978) for conditioned and baseline tests. ------- Elemental analyses of certain cascade impactor particulate samples (outlet only) were conducted for the conditioned and baseline tests. The conditioned tests showed an increase in the mass of sulfur leaving the ESP as particulate (2.5 mg/DNm3) relative to the baseline tests (0.4 mg/DNm3). Mass emissions of all other elements analyzed were lower in the conditioned tests than in the baseline tests. This is consistent with the lower overall penetration measured for the conditioned tests. In-situ fly ash electrical resistivity was measured using a point-to-plane probe at the ESP inlet for the baseline and conditioned tests. The average resistivity for the baseline case was 1.7 x 1011 ft-cm. When S03 conditioning was used, the average resistivity decreased to 4.7 x 1010 fi-cm. The opacity of the flue gas was measured in the outlet duct of the ESP for the conditioned and baseline tests. The average opacity was 401 during the conditioned tests and 80% during the baseline tests. Sulfur trioxide concentrations were determined at the ESP inlet and outlet using the controlled condensation method (Maddelone, 1977). The average S03 concentration during the conditioned tests was 10.9 ppm at the inlet and 8.1 ppm at the outlet. Theoretically, from a material balance, 32 ppm of S03 were injected. The equivalent of approximately 24 ppm S03 was accounted for on the fly ash. During the baseline tests the S03 concentration averaged 1.6 ppm at the inlet and 1.0 ppm at the outlet. The sulfur content of the fly ash leaving the ESP decreased from 2.5 mg/DNm3 for the con- ditioned tests to 0.4 mg/DNm3 for the baseline tests. The S02 concentration in the flue gas varied from about 650 to 800 ppm at the inlet and from about 600 to 700 ppm at the outlet. The lower concentration at the outlet may have been caused by in-leakage of air. This hypothesis is consis- tent with an observed increase in 02 concentration at the outlet. The unconditioned (baseline) tests showed about 13% ------- less S02 at the inlet and outlet, however fluctuations in the sulfur content of the coal are more than enough to account for the observed change in S02 concentration. Coal samples were analyzed for the conditioned and base- line tests. The sulfur content averaged 1.1 wt I during the conditioned tests and 0.8 wt \ during the baseline tests. Otherwise, the samples were very similar with about 11 wt % ash and very low levels of alkali metals (Na, K, Li, Ca). CONCLUSIONS The results of this field test clearly indicate that the S03 flue gas conditioning system successfully increased the ESP efficiency from about 801 to near the design efficiency of 95% when low sulfur coal fly ash is being collected. The mechanism for improvement appears to be, at least in part, a decrease in fly ash resistivity. This is consistent with the observation of a higher sparking rate during the baseline tests. The grade efficiency curves indicate a more pronounced improvement in collection of large particles. This could be the result of a reduction in reentrainment associated with use of the conditioning agent. There was no significant change in S02 concentration associated with use of the S03 conditioning system. Observed S02 fluctuations could be accounted for by variations in the sulfur content of the coal. The sulfur content of the fly ash and the outlet concentration of S03 increased signifi- cantly when the conditioning agent was injected. ------- SECTION 3 DESCRIPTION OF TEST PLANT DESIGN The plant has six power generating units and a seventh unit under construction. Testing was performed on unit No. 3 which has a boiler rated at 44 megawatts. Unit No. 3 has a maximum operating capacity of 58 megawatts producing 10,000 kPa (1,450 psi) steam at 540°C (1,005°F). The location of the S03 injection ports, and inlet and outlet sampling ports is shown in Figure 1. The ESP, installed downstream from the air preheater (Ljlingstrom type) , has a design efficiency of 95% when burning high sulfur coal. It is preceded by a bank of axial entry cy- clones of undetermined efficiency. The ESP consists of two sections in series; i.e., an inlet and an outlet section. Each has a transformer-rectifier (T/R) set which can be electrically isolated into a right and left subsection. The wire current is full wave rectified. Design information for the ESP is given in Table 1. The configuration of the precipitator can be seen in Figure 1. The flue gas flows through the axial entry cyclones where it is directed upward past the S03 injection nozzles into a bend with turning vanes. There is a diverging section immediately before the ESP. Downstream from the ESP the flue gas converges and is directed upward and over the top of the precipitator to the induced draft fan. Turning vanes are provided to improve flow distribution. The eight inlet sampling ports are at the upstream edge of the diverging section before the ESP. The four outlet ports are located immediately following the bend over the precipitator. ------- OUTLET PORTS FLOW CYCLONES Figure 1. Plant lavout. ------- TABLE 1. ELECTROSTATIC PRECIPITATOR DESIGN INFORMATION Startup date Design gas flow Design gas velocity Design specific collector area Design efficiency Precipitation rate Overall configuration Plates Wires Electrical 1972 104 actual m3/s (217,000 actual ft3/min) 1.05 m/s (3.4 ft/s) 36 m2 per actual m3/s (182 ft2 per 1000 actual ft3/min) 95% IV - 0.084 m/s (0.274 ft/s) G 2 series chambers 3 electrical sections in parallel per chamber 36 parallel gas passages 37 plates per chamber (cold rolled steel sheets) plate height - 9.5 m (31 ft) plate length each section - 2.7 m (9 ft) for total length in direction of flow of 5.5m (18 ft) plate-to-plate spacing - 0.23 m (9 in.) total surface area of plates - 3,730 m2 (40,180 ft2) 12 equally spaced wires per gas passage wire diameter - 2.8 mm (0.11 in.) wires are hanging type, placed in the center 16.4 mm (1/4 in.) of the plate-plate space 2 transformer-rectifier sets which were electrically insolatable into 6 subsections maximum power consumption - -50 kW ------- Fly ash is removed from the wires and plates by vibrators which operate for about one minute every five minutes. The col- lected ash falls into hoppers beneath the ESP. The manually acti- vated ash handling system pulls the ash from the hoppers with suction from a water ejector nozzle and deposits it in a silo. The silo is emptied by truck. The S03 injection system converts hot vaporized S02 and air into S03 over a vanadium pentoxide (V05) catalyst. It is injected into the flue gas downstream from the air preheater and cyclone at 490°C (920°F) through five rows of nozzles. The flue gas is ap- proximately 160°C (320°F) at the injection point. The S02 is stored in bulk liquid form and consumed at a constant rate of approximately 46 Ibs/hr at full load of 58 MW. For 100% con- version of S02 to S03, this corresponds to a maximum addition of 32 ppm of S03 to the flue gas stream. OPERATING CONDITIONS The unit was operated at full load for the duration of the test. It was controlled to produce a constant steam rate. Full load was limited by the air intake dampers. The maximum design flow of the ESP was 104 m3/s (217,000 ACFM). The flow during the test was slightly lower at 102 m3/s (217,000 ACFM). As can be seen from Table 2, the power output of the plant increased on January 31. This was caused by chlorination of the conden- sers; a cleaning operation which makes the condensers more ef- ficient, thus enabling higher output from the turbines for the same steam rate. Voltage current relationships were determined for the ESP during both the conditioned and baseline test periods (Figures 2 and 3). The normal operating point at both the inlet and out- let of the ESP was a voltage of 50 kV and a current density of o 24 nA/cm . The test data were generated by adjusting the primary voltage manually and recording the resulting primary and secondary currents. A secondary voltage meter was not available so that secondary voltage had to be calculated from the power transmitted that is: ------- TABLE 2. BOILER LOAD DATA Date Boiler Load MW 1/25/78 1/26/78 1/27/78 1/31/78 2/1/78 2/5/78 2/6/78 2/7/78 57.5 57.5 57.5 58 58 5 5 58.5 58.4 58.4 10 ------- 6 u E- i—< CO H Z tu OS OS E o CO w Q f- Z uu OS os u 35 30 25 20 15 10 5 0 D 1/31/78 CONDITIONED 2/7/78 BASELINE O 0 o J_ _L _L 30 35 40 45 50 SECONDARY VOLTAGE, DC kV 55 60 Figure 2. ESP inlet section voltage-current relat ionships. 30 25 20 15 10 5 0 D 1/31/78 CONDITIONED A 2/7/78 BASELINE 30 35 40 45 50 SECONDARY VOLTAGE, DC kV 55 60 Figure 3. ESP outlet section voltage-current relat ionships . 11 ------- V2 = 0.85 (1) I2 where Vi § V2 = primary and secondary voltages, V Ii § I2 = primary and secondary currents, A 0.85 = efficiency assumed for the transformer - rectifier set Two factors contribute to the scatter of data on the curves: 1) sparking, particularly during the unconditioned (baseline) tests, made the meters jump continually so that they were very difficult to read accurately; 2) the lack of a secondary voltage meter necessitated calculations which multiplied the errors in- herent in the meter readings. The current-voltage relationships for the inlet and outlet sections of the ESP are shown in Figures 2 and 3,respectively. The solid lines represent least squares fits to the data. The inlet section shows a marked shift to the right for the condi- tioned case compared to the baseline case. This shift implies a higher operating voltage is possible for a given current when the conditioning agent is used. This is consistent with the ef- fect anticipated with a decrease in fly ash resistivity. The outlet section (Figure 3) does not show any clear trends. No spark meter was available but the sparking was clearly increased during the unconditioned case. Sparking persisted to the lowest secondary voltage. TEST METHODS AND SCHEDULE Field tests of the ESP were conducted with and without in- jection of the flue gas conditioning agent. Variances were ob- tained from the proper agencies for periods covering the un- conditioned tests. The field test spanned the period January 25 to February 7, 1978. Testing of the conditioned case started on January 25 and ended on February 2. The boiler unit was shut down three days for boiler tube repairs (January 28, 29, 30) during this time. 12 ------- A three-day deconditioning period allowed the ESP to come to steady state before the baseline (unconditioned) tests, which started February 5 and lasted through February 7. The particulate analyses included size, mass, resistivity and chemical composition. Size distributions were obtained at the inlet and the outlet of the ESP with calibrated cascade im- pactors. A modified EPA Method 5 train was used for total mass determinations. The resistivity of the particulate fly ash entering the ESP was monitored with an in-situ point-to-plane resistivity probe. Plume opacity in the outlet duct of the ESP was measured using a modified opacity meter and was recorded on a continuous basis. Coal samples were obtained daily and analyzed to characterize the coal composition during the testing period. Information on the ESP design, maintenance and operation were obtained from power plant personnel through survey forms and personal communications. The current-voltage relationships for each section of the ESP were determined for conditioned and unconditioned tests. Annual operating and maintenance costs were obtained for the ESP, flue gas conditioning equipment and chemicals Samples of particulate matter collected with a cascade im- pactor at the ESP inlet and outlet were analyzed to determine the elemental composition as a function of particle size. The amount of particulate sulfate collected on the impactor substrates was determined with an acid-base titration using bromophenol blue as the indicator. Ion excited X-ray emission analysis was used to determine the elemental composition. The flue gas velocity and static pressure were measured at the inlet and outlet using calibrated S-type pitot tubes. The molecular weight and density of the gas was determined by measur- ing the gas composition and temperature. The concentration of water vapor was determined from measurements of the wet and dry bulb temperature in the stack. 13 ------- S02 concentrations entering and leaving the ESP were deter- mined using a Du Pont S02 stack analyzer (model 459). The output from the S02 analyzer was recorded on a continuous basis during the field test. The concentration of S03 entering and leaving the ESP was determined with the controlled condensation method as described by Maddelone (1977). 14 ------- SECTION 4 TEST RESULTS COLLECTION EFFICIENCY Overall and fractional collection efficiencies were deter- mined from particle size and mass data obtained using in-stack cascade impactors. Overall efficiencies were also obtained using a modification of EPA Method 5 (M5). The sampling trains and procedures are presented in Appendix "A". Particle size distributions at the ESP inlet are presented in Figures 4 and 5 for the conditioned and baseline tests,res- pectively. The inlet size distributions were very consistent with a geometric mass median diameter (MMD) of 8.5 ym* and a geometric standard deviation of about 4. The size distributions at the ESP outlet are presented in Figures 6 and 7 for the conditioned and baseline tests. The out- let particles were smaller for the conditioned tests (MMD = 2.2 ym, a = 3.7) than for the has el ine tests (MMD = 3.7 ym, a =4.1). c> & A summary of the overall efficiencies is presented in Table 3. The modified M5 test results give somewhat higher mass load- ings than do the impactor results. Inlet run "2-M5" is suspect because the nozzle tip may have contacted a layer of fly ash on the bottom of the duct. The average efficiency data show an in- crease from 80.2% to 94.9% associated with injection of the con- ditioning agent. * The convention used in this report is that physical particle diameters are shown as ym and aerodynamic particle diameters are shown as ymA. The physical particle diameter is related to the aerodynamic particle diameter by: d = d (p C')^2 pa p p where d = aerodynamic particle diameter, ymA; p = particle density, g/cm3 pa p d = physical particle diameter, ym; C1 = Cunningham slip correction " factor, dimensionless 15 ------- OS w w a P-I PL, U i—i LO 10.0 9.0 8.0 7.0 6.0 5. 0 4.0 3.0 2.0 1.0 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0. 2 0.1 II H-CH h-CM H-CH I-CH i-CH 1 1 I l 1 1 II 0.2 0.5 1 2 5 10 20 30 40 50 60 70 80 CUMULATIVE MASS UNDERSIZE, I Figure 4. Inlet size distribution for conditioned tests showing 901 confidence intervals. * Density assumed to be 2.3 g/cm3 16 ------- * E Di w H W i— i o PJ *— J o 1 — 1 H Oi ^ i — i C/} >- o: d, 1U . 9. 8. 7. 6. 5. 4. 3. 2. 1. 0. 0. 0. 0. 0. 0. 0. 0. 0. u 0 0 0 0 0 0 0 0 0 9 8 7 6 5 4 3 2 1 _ i 1 I i I ill h|OH' ' _ — ~ - - •™ ^ K)H — — _ K>H — t-OH — _ - - - — i-CH ~ — _ OH " ill i i i i i 1 i i 0.2 0.5 1 2 5 10 20 30 40 50 60 70 80 CUMULATIVE MASS UNDERSIZE, % Figure 5. Inlet size distribution for baseline tests showing 90% confidence intervals. * Density assumed to be 2.3 g/cm3 17 ------- W E-H W U i— ( H u i— i CO >-> 20 10 0.2 I o T 1— hCH hCM l-CH h-CH I I I I 5 10 20 30 40 50 60 70 80 CUMULATIVE MASS UNDERSIZE, % Figure 6. Outlet size distribution for conditioned tests showing 901 confidence intervals. * Density assumed to be 2.3 g/cm3 18 ------- OS PJ Q W i—i H O, U CO a: a. 20 10 0.2 j. _L _L J. 5 10 20 30 40 50 60 CUMULATIVE MASS UNDERSIZE, I 70 80 Figure 7. Outlet size distribution for baseline tests showing 901 confidence intervals * Density assumed to be 2.3 g/cm3 I 19 ------- TABLE 3. SUMMARY OF OVERALL EFFICIENCIES Run # With S03 1 2 12 13 14 16 1-M5* 2-M5* Average Standard Without S03 17 21 23 24 26 28 3-M5* Average Standard Inlet Concentration mg/DNm3 2,535 2,500 2,375 2,605 2,525 3,139 2,289 12,590 Deviation 2,297 2,470 2,483 2,595 2,449 2,154 4,179 Deviation Outlet Concentration mg/DNm3 104.8 105.3 127.9 145.1 136.3 101.4 265.6 208.3 588.3 428.2 503.3 514.1 426.6 510.2 605.5 Overall Efficiency % 95.9 95.8 94.6 94.4 94.6 96.8 88.4 98.3 94.9 2.9 74.4 82.7 79.7 80.2 82.6 76.3 85.5 80.2 3.8 * Modified EPA Method 5 20 ------- Grade penetration curves were computed from the simultan- eous inlet and outlet test data. The computation was based on a logarithmic spline fit to the cumulative mass concentration curves obtained from the cascade impactor data (Lawless, 1978). The results are presented as Figures 8 and 9. The conditioned tests show considerably lower penetration (higher efficiency) than the baseline tests. The improvement is particularly apparent for large particles. Each day one impactor run was made to collect a particulate sample for sulfate analysis. The fly ash on the substrate was analyzed with an acid/base titration using Bromophenol Blue as the indicator. The results showed the sulfate concentration to be below the detectable limit of 1 ppm. One exception was the final filter of the outlet impactor which showed measurable amounts of SOi; on some runs. However, this may have been an ar- tifact resulting from condensation of moisture in the probe. Moisture which collected on the probe wall may have contained sulfate ions. When the sampling ended, the liquid could have drained down to the final filter as the probe was being withdrawn, The final filter was wet after some runs. The detailed table of results is presented in Appendix "C". ESP PERFORMANCE PREDICTIONS Performance of the precipitator was predicted using a cal- culator program which models ESP performance (Sparks, 1978). The predicted performance is based on a model developed by Southern Research Institute (Gooch, 1975). The predicted baseline overall efficiency of the ESP is 79.9%, which compares with the measured value of 80.8%. When the resistivity of the fly ash is reduced to the conditioned level of 4.7 x 1010 fi-cm, the predicted over- all efficiency is 92.9%. The measured overall efficiency was 94.9% Grade penetration curves were calculated with the program and are shown in Figures 8 and 9. These figures show a slightly higher penetration than the measured values. 21 ------- 1.0 o o rt (H o t—I H W W OH 0.1 0.01 I i I 13 I l l I I l I I I I l I i 0.2 10 PARTICLE DIAMETER, ym Figure 8. Grade penetration curves for S03 conditioned tests. * Density assumed to be 2.3 g/cm3 22 ------- 1. 0 * c o u rt ?-i M-i O h-H E- E- U4 z PJ OH 0.1 0.01 0.2 I I I I I I I I IIIi i l PREDICTED NUJN NO.2 8 - 17. 23 N 26 v 21 \ 24 1 I I I I I I 10 PARTICLE DIAMETER, Figure 9- Grade penetration curves for baseline tests. * Density assumed to be 2.3 g/cm3 23 ------- The parameters input to the program are derived from data obtained during the test period. These are shown in Table D-l in Appendix "D". FLUE GAS COMPOSITION The flue gases were sampled with an Orsat analyzer, a Du Pont S02 analyzer and a controlled condensation sulfate system (CCS) . The CCS was used to measure the quantity of S03. Flue gas velocity was determined with calibrated S-type pitot tubes. The velocity was measured at 48 points over the cross-sec- tion of the ducts. The velocity varied erratically over the test period at both inlet and outlet, as shown in Table 4. This may have been caused by turbulence from the downstream turning vanes. The concentrations of 02, C02, H20, and S02 are shown in Tables 4 and 5 for the inlet and outlet. The 02 concentration is higher at the outlet (Table 5) than the inlet (Table 4). Dis- crepancies may be attributed to in-leakage of air since the ESP operates at a negative pressure of 3.2 kPa (13" W.C.). Using the average 02 concentrations, an in-leakage rate of 7.5% was com- puted between the inlet and outlet of the ESP. This compares well with the leakage rate computed by comparing S02 concentrations The concentrations of S03entering and leaving the ESP was determined by the controlled condensation system (CCS) as des- cribed by Maddelone (1977). A schematic of the CCS is shown in Figure 10. This method is designed to operate at high temperature. The sampling probe is maintained at a temperature of 315°C (600°F) and the quartz filter holder is heated by a heating mantle so that a gas outlet temperature of 290°C (550°F) is maintained. This temperature is required to ensure that H2SOi»will not condense in the filter holder. The separation of S03 from S02 is achieved by cooling the gas stream below the dew point of H2SOi, but above the H20 dew point, thus preventing interference from SOa. The con- densed acid was then titrated with 0.2 N NaOH using Bromophenol Blue as the indicator. The probe nozzle was turned downstream during the sampling period to reduce the quantity of large particles reaching the 24 ------- TABLE 4. ESP INLET FLUE GAS CONDITIONS (DAILY AVERAGE) Date 1/25/78 1/26/78 1/27/78 1/31/78 2/1/78 2/5/78 2/6/78 2/7/78 Date 1/25/78 1/26/78 1/27/78 1/31/78 2/1/78 2/5/78 2/6/78 2/7/78 Flue Gas Temperature °C 142 139 145 133 146 135 147 -- TABLE 5. ESP Flue Gas Temperature °C 144 -- 145 147 152 146 -- — Flue Gas Composition, %02 %C02 %H20 6.1 5.5 6.6 4.4 14.1 4.0 3.9 14.6 4.5 5.0 14.0 5.6 4.5 14.2 4.4 4.7 14.2 OUTLET FLUE GAS CONDITIONS Flue Gas Composition, %02 %C02 %H20 2.2 6.2 4.0 4.9 5.3 14.0 5.0 4.8 6.1 6.0 13.0 Vol. /Vol. S02 ppm 730 710 720 730 840 650 680 670 (DAILY AVERAGE) Vol. /Vol. S02 ppm 700 650 660 680 680 600 620 620 Average Velocity m/s 5.8 5.2 5.0 5.9 5.5 5.7 5.2 -- Average Velocity m/s 8.8 8.9 9.2 9.6 8.7 8.8 8.8 — ------- QUARTZ LINED HEATED PROBE POWER SUPPLIES CONSTANT TEMPERATURE BATH GRAHAM CONDENSER QUARTZ FILTER HOLDER WITH HEATING MANTLE SILICA GEL SAMPLING TRAIN ICE CHEST WITH IMPINGERS Figure 10. Controlled condensation system. ------- filter. If the amount of material on the filter is kept small, the overall recovery of the CCS is better. The results of the CCS analysis are shown in Table 6. The concentration of S03 was higher at the inlet in both cases im- plying that the fly ash is adsorbing S03 in the ESP. For the conditioned tests, the measured level of S03 was 10.9 ppm at the inlet. This is less than the 32 ppm calculated from the S02 in- jection rate. The remaining sulfate may be on the surface of the fly ash. S02 entering and leaving the ESP was determined using a Du Pont S02 stack analyzer (Model 459). The output from the S02 analyzer was recorded on a continuous basis during the field test period. The S02 analyzer was switched from the ESP inlet to the outlet at one-hour intervals. The inlet S02 concentration is plotted for the test period in Figure 11. The conditioned tests show a reasonably steady concentration of 700 to 770 ppm (at the inlet). During the baseline tests the S02 concentration was about 670 ppm. The lower S02 concentration is most likely a re- sult of the lower sulfur content in the coal during the baseline tests. ELEMENTAL ANALYSIS The elemental composition of the particulates at the ESP out- let was determined as a function of particle size. The particu- lates were collected on 1.0 mil Mylar film substrates coated with Apiezon "L" grease in a cascade impactor. These substrates were then analyzed for chemical composition with proton induced -ray fluorescence (Ensor et al., 1968). Mylar substrates coated with Apiezon "L" grease exhibit a low background of trace elements when analyzed. The results of the analysis, as received, are shown in Ap- pendix "E". Figures 12 and 13 show the flue gas concentration for the detectable elements with particle size as the parameter. These figures show that the concentration of particulate sulfur increased from 0.4 to 2.5 mg/DNm3 when the conditioning agent was injected. 27 ------- TABLE 6. CONCENTRATION OF S03 IN FLUE GAS S03 Concentration With Conditioning Agent, ppm by vol. S03 Concentration Without Conditioning Agent, ppm by vol. Run Number 1 2 3 4 5 Avg. a g Inlet 6.4 14.6 11.6 * * 10.9 4.1 Outlet * 5.8 8.0 9.1 9.5 8.1 1.7 Run Number 1 2 3 4 5 6 7 Avg. a g Inlet * 4.4 1.6 1.7 * 2.0 1.2 2.2 1.3 Outlet * 1.1 * 0.7 0.9 1.1 1.0 1.0 0.2 28 ------- 1-0 vo Cu CL E- W C U O in 1000 900 800 700 600 500 400 300 1 JAN 25 26 27 28 29 30 31 FEB1 DATE Figure 11. S02 concentration of flue gas at ESP inlet. ------- 6 n STAGE CUT DIAMETER § 4 I— t H < OS W 7 U J o u lIlL ll.llll ..L... .Ill I... Si S K Ca Ti Al Fe Zn Figure 12. Mass concentrations of major elements in fly ash with S03 conditioning. 30 ------- U 7 6 en e § 5 DC I 4 H OS H W u 3 o 2 1 0 ll, 1 r 1 1 Cl ^^•••^^^HV — Ill STAGE JT DIAMETER -32 ymA -14 ymA ~ 5 . 3 ymA ~2.6 ymA -1.5 ymA ~0. 75ymA ~0.40ymA „ iniii, i "* 1 - - - 1111 — iiiiiii Al Si Ca Ti Fe Zn Figure 13. Mass concentrations of major elements in fly ash from baseline test. 31 ------- RESISTIVITY Dust resistivity is defined as the resistance of the dust layer to electrical current, measured in ft-cm. The dust re- sistivity was measured at the outlet with the Southern Research Institute in-situ point-to-plane resistivity probe (Smith et al. , 1977) The dust resistivity is determined from, A V ' = £r (2) where p = dust resistivity, Q-cm A = plate surface area, cm V = voltage, V t = dust layer thickness, cm I = current, A Table 7 shows the results of the dust resistivity measure- ments during the conditioned and baseline tests. With S03 con- ditioning, the average resistivity decreased by a factor of four, from 1.7 x 10nn-cm to 4.7 x 1010n-cm. The corresponding precipitation rate, W , increased with 6 the conditioning from 0.05 m/s (0.15 ft/s) to 0.08 m/s (0.27 ft/s). Fly ash resistivity and precipitation rate data, from previous field performance tests predicted precipitation rates of 0.05 m/s (0.16 ft/s) and 0.09 m/s (0.28 ft/s) for the above resistivities (White, 1974). The good agreement between ob- served and predicted values indicates both the representative nature of this test and the functional relationship that exists between resistivity and precipitator efficiency. OPACITY The opacity in the outlet duct of the ESP was monitored continuously during the tests with a Lear-Siegler RM4 opacity meter modified for portable use. A schematic of the probe is shown in Figure 14. 32 ------- TABLE 7. INLET FLY ASH RESISTIVITY Temperature Resistivity Date °C (°F) ^-cm With conditioning agent 1/26 121 (250) 3.9 x 1010 1/27 132 (270) 7.6 x 1010 1/31 137 (279) 1.5 x 1010 2/1 139 (283) 5.7 X 1010 Without conditioning agent Average 4.7 x 1010 a 2.6 x 1010 g 2/5 133 (272) 1.5 x 10n 2/5 137 (278) 1.6 x 10n 2/6 136 (277) 2.0 x 10n 2/6 137 (278) 1.3 x 1011 2/7 142 (287) 2.3 x 10n 2/7 142 (288) 1.7 x 10n Average 1.7 x B 0.4 x 1011 33 ------- i i RETROFLECTOR FLUE GkS PATH HANDLE LEAR SIEGLER TRANSMISSOMETER Figure 14. In-stack opacity probe. ------- During the conditioned test, the opacity was in the range of 401, as shown in Figure 15. The gap during the conditioned test is from a shutdown of the No. 3 unit. The opacity rose to the limit of the scale set on the opacity meter after injection of the conditioning agent was stopped. After switching to a higher range, the opacity measured approximately 80%. COAL COMPOSITION Coal samples were withdrawn from the coal entering the pul- verizers every two hours to obtain five or six samples per day. These samples were mixed and a portion taken for analysis. The size of the coal entering the pulverizers ranged from 1 mm to 3 cm in diameter. Plant analyses of the coal were also made available and are included in Table 8. The sulfur concentrations of the samples taken by A.P.T. show some deviation from plant data. This may be attributable to different sampling times. The conditioned period shows a higher level of sulfur. This increased sulfur content would cause a higher concentration of S02 in the flue gas, as was observed. 35 ------- cx o 90 80 70 60 50 40 30 20 10 SO2 TURNED OFF I I JAN 25 26 27 28 29 30 31 FEB 1 DATE Figure 15. Opacity in outlet duct, ------- TABLE 8. CHEMICAL ANALYSIS OF COAL Analyte Sodium Potassium Lithium Calcium Magnesium Sulfur Sulfur*' Ash* Volatile hydrocarbons* Fixed carbon* Heat content* Sample from Conditioned Period _ Dry wt. % 0.013 0.06 0.00019 0.19 0.02 1.09 0.88 10.7 33.5 SOrJoules/kg (13,OOOBtu/lb) Sample from Unconditioned Period Dry wt. % 0.016 0.06 0.00014 0.18 0.02 0.78 0.85 11.1 33.6 55.7 30rjoules/kg (13,100Btu/lb) *Averages of daily data received from the plant 37 ------- SECTION 5 ECONOMICS The ESP for unit No. 3 was put on line in 1972 at a cost of $1.4 million. It normally operates at full load capacity of 58 megawatts. The flue gas conditioning system was in- stalled two years later. The cost of the S03 system was not available. The summary of the available cost data shown in Table 9 is based on dollar values as of the first half of 1977. Maintenance and operating costs for the ESP shown do not reflect the cost of power to supply the high voltage. 38 ------- TABLE 9. CAPITAL AND OPERATING COSTS UNIT NO. 3 1977 COSTS A. Installed capital costs: ESP, $24 per kW, Total $1,358,000; on-line 1972 Conditioning equipment: Total $ *; on-line 1974 B. Annual operation and maintenance costs (Does not include electric power or chemical cost): ESP $57,693 Conditioning equipment $ 2,845 C. Chemical costs: Conditioning agent, unit cost $160/ton (with freight) $140/ton (freight not included) yearly consumption 55,600 kg/year yearly cost $9,814 D. Average unit costs: ESP Gas conditioning 0.159 mills/kW-hr 0.035 mills/kW-hr (including S02 cost) 0.0078 mills/kW-hr (without S02 cost) * This value not supplied by plant records 39 ------- REFERENCES Ensor, D. S., T. A. Cahill, and L. E. Sparks, "Elemental Analysis of Fly Ash from Combustion of a Low Sulfur Coal," APCA Meeting 1968, Paper No. 75-33.7, June 1975. Gooch, J. P., J. R. McDonald, S. Oglesby, Jr., "A Mathematical Model of Electrostatic Precipitation," EPA 650/2075-037 April 1975. ' Lawless, P. A., "Analysis of Cascade Impactor Data for Calculating Particle Penetration," Research Triangle Institute, EPA Con tract No. 68-02-2612, Task 36, 1978. Maddelone, R. et al., "Process Measurement Procedures: Sulfuric Acid Emissions," February 1977. Smith, W. B. et al., "Procedures Manual for Electrostatic Precini tator Evaluation," EPA Contract No. 68-02-2131, Southern Research Institute, March 1977. Sparks, L. E. "SR-52 Programmable Calculator Programs for Venturi Scrubbers and Electro-Static Precipitators " EPA 600/7-78-0?* March 1978. UZ6 White, H. J. "Resistivity Problems in Electrostatic Precip- itation," APCA, Vol. 24, No. 4, April 1974. 40 ------- APPENDIX "A" PARTICULATE SAMPLING METHODS 41 ------- APPENDIX "A". PARTICIPATE SAMPLING METHODS CASCADE IMPACTOR TEST METHOD Cascade impactor measurements were taken at the inlet and outlet of the ESP to determine the collection efficiency as a function of particle size. Calibrated UW Mk III cascade impactors were used. A schematic is shown in Figure A-l. The particle mass entering and leaving the ESP was deter- mined from the sum of the mass collected on all the stages (in- cluding the nozzle of the in-situ cascade impactor). Greased Mylar and Reeve Angel glass fiber substrates were used. Substrates were baked at 205°C (400°F) for four hours and desiccated for two hours prior to weighing. To minimize weight loss and trace element contamination with greased substrates, Apiezon L grease was used. Blank test runs with twenty minutes of exposure to the actual flue gas were performed to confirm no weight gain on Reeve Angel substrates in the presence of S02. The elemental composition of the fly ash was determined as a function of particle diameter. Fly ash samples were taken at the ESP outlet for this purpose daily. Particulate samples were obtained with a UW Mk III cascade impactor using 1 mil Mylar sub- strates, coated with Apiezon L grease. The Mylar substrates and Apiezon L grease were shown to have a low background of trace elements. Particulate sulfate entering and leaving the ESP was obtained from the chemical analysis of the cascade impactor substrates (Reeve Angel glass fiber substrates). This was done on one inlet and one outlet run per day, as the same set of substrates could not be used for both chemical and gravimetric analysis. The particulate sample was dissolved in C02-free distilled water and the amount of sulfate present was determined by a ti- tration with NaOH with Bromophenol Blue as indicator. 42 ------- THERMOMETER CASCADE IMPACTOR IMPINGER TRAIN STACK WALL I I | THERMOMETERS ICEBATH ROTAMETER VACUUM GAUGE ORIFICE METER DRY GAS METER VACUUM PUMP SILICA GEL DRYER Figure A-l. Modified EPA sampling train with in-stack cascade impactor. ------- EPA METHOD 5 MEASUREMENTS EPA Method 5 measurements were made to determine accurate overall mass collection efficiencies. The location of the test ports in the duct were such that a standard Method 5 would re- quire 48 five-minute samples. The sampling time was reduced from five minutes to three minutes each to expedite the test. The molecular weight and gas density were determined with a standard Orsat analysis, according to EPA Method 3. 500 mg SAMPLE FOR BIOASSAY TESTING Particulate samples (500 mg) were collected at the ESP outlet with one sample collected for each test condition (that is, with and without flue gas conditioning). During the conditioned test a sample was scooped from the fly ash pile at the outlet. During the baseline tests a Method 5 train was used to collect a sample on a filter. These samples were forwarded to the EPA project officer. 44 ------- APPENDIX "B" PARTICLE SIZE DATA 45 ------- TABLE B-l. INLET AND OUTLET PARTICLE DATA FOR RUN #1 Taken 1/25/78 at 11:50 am IMPACTOR STAGE NUMBER Precutter § Nozzle 1 2 3 4 5 6 7 Filter S amp 1 e Volume (DNm3) INLET M cum (mg/DNm3) 2,510 2,240 1,830 1,680 965 391 123 34.9 21.4 d pc (ymA) 30.9 13.5 5.24 2.70 1.57 0.89 0.50 d P (ym) 20.26 8.80 3.34 1.67 0.92 0.48 0.23 0.0373 OUTLET M cum (mg/DNm3) 105 80.2 72.9 70.0 60.4 31.5 11.7 4.76 2.56 d pc (ymA) 22.3 9.77 3.78 1.88 1.13 0.64 0.36 d p (ym) 14.6 6.32 2.37 1.12 0.63 0.31 0.14 0.273 TABLE B-2. INLET AND OUTLET PARTICLE DATA FOR RUN #7 Taken 1/27/78 at 2:40 pm IMPACTOR STAGE NUMBER Precutter § Nozzle 1 2 3 4 5 6 7 Filter Sample Volume (DNm3) INLET M cum (mg/DNm3) 2,490 2,120 1,570 1,370 655 328 197 59.8 22.8 d pc (ymA) 33.5 14.7 5.68 2.93 1.71 0.96 0.55 d P (ym) 21.99 9.57 3.63 1.82 1.02 0.52 0.26 0.0351 OUTLET cum (mg/DNm3) 105 81.1 71.3 67.4 55.2 30.4 14.8 6.41 3.62 V (ymA) 23.6 10.3 4.00 1.99 1.20 0.68 0.38 dP (ym) 15.4 6.70 2.52 1.20 0.68 0.34 0.15 0.359 N: 20°C, 1 atm; (P ; ymA = 46 P =2.3g/cm3 ------- TABLE B-3. INLET AND OUTLET PARTICLE DATA FOR RUN #12 Taken 1/31/78 at 1:40 pm IMPACTOR STAGE NUMBER Precutter fj Nozzle 1 2 3 4 5 6 7 Filter Sample Volume (DNm3) INLET M cum (mg/DNm3) 2,380 2,260 1,470 1,050 486 185 70.2 25.1 20.1 d pc (umA) 31.2 13.7 5.29 2.72 1.58 0.91 0.47 d P (urn) 20.45 8.90 3.37 1.68 0.93 0.49 0.21 0.0399 OUTLET M cum (mg/DNm3) 128 102 83.6 77.7 61.3 40.3 27.0 20.9 20.1 d pc (umA) 23. 5 10.3 3.99 1.92 1.18 0.84 0.37 d p (pm) 15.38 6.67 2.51 1.15 0.67 0.44 0.14 0.556 TABLE B-4. INLET AND OUTLET PARTICLE DATA FOR RUN #13 Taken 1/31/78 at 2:25 pm IMPACTOR STAGE NUMBER Precutter § Nozzle 1 2 3 4 5 6 7 Filter Sample Volume (DNm3) INLET M cum (mg/DNm3) 2,260 2,370 1,620 1,160 557 222 85.6 22.7 7.56 d PC (ymA) 31.2 13.7 5.29 2.72 1.59 0.90 0.51 d P (vim) 20.45 8.90 3.37 1.68 0.93 0.49 0.23 0.0397 OUTLET M mcum (mg/DNm3) 145 123 106 93.9 70.3 40.5 20.3 9.39 5.16 d PC (ymA) 23.7 10.4 4.02 2.00 1.21 0.68 0.38 d P (um) 15.3 6.74 2.53 1.20 0.68 0.34 0.15 0.543 N: 20°C, 1 atm;dpa = dp (pp ^; ymA 47 ; p = 2.3 g/cm3 p ------- TABLE B-5. INLET AND OUTLET PARTICLE DATA FOR RUN #14 Taken 1/31/78 at 4:20 pm IMPACTOR STAGE NUMBER Precutter § Nozzle 1 2 3 4 5 6 7 Filter S amp 1 e Volume (DNm3) INLET M cum (mg/DNm3) 2,530 2,400 1,610 1,280 429 195 87.7 37.6 10.0 d pc (ymA) 31.4 13.8 5.32 2.74 1.59 0.91 0.47 d P (vim) 20.59 8.96 3.39 1.68 0.93 0.49 0.21 0.0399 OUTLET M cum (mg/DNm3) 136 112 102 96.5 82.7 55.3 40.4 33.9 32.0 d pc (ymA) 23.5 10.3 3.98 1.92 1.17 0.84 0.37 d p (ym) 15.38 6.67 2.51 1.15 0.67 0.44 0.14 0.369 TABLE B-6. INLET AND OUTLET PARTICLE DATA FOR RUN #16 Taken 2/1/78 at 4:10 pm IMPACTOR STAGE NUMBER Precutter § Nozzle 1 2 3 4 5 6 7 Filter Sample Volume (DNm3) INLET M cum (mg/DNm3) 3,150 2,780 1,910 1,600 713 287 69.6 13.9 8. 36 V (ymA) 33.1 14.5 5.62 2.89 1.69 0.95 0.54 d P (ym) 21.73 9.45 3.59 1.79 1.00 0.52 0.25 0.0359 OUTLET M cum (mg/DNm3) 101 79.2 73.7 72.2 50.5 24.0 8.78 2.87 1.08 t d pc (ymA) 22.0 9.63 3.72 1.85 1.12 0.63 0.35 d p (ym) 14.37 6.23 2.33 1.10 0.63 0.31 0.13 0.558 N: 20°C, 1 atm; (p C')55; ymA=ym(g/cm3)!s; p = 2.3g/cm3 48 ------- TABLE B-7. INLET AND OUTLET PARTICLE DATA FOR RUN #17 Taken 2/5/78 at 8:15 am IMPACTOR STAGE NUMBER Precutter § Nozzle 1 2 3 4 5 6 7 Filter S amp 1 e Volume (DNm3) INLET M cum (mg/DNm3) 2,280 2,110 1,550 1,180 774 393 155 49.5 6.19 d pc (ymA) 35.3 15.4 5.98 3.08 1.78 1.03 0.53 d P (ym) 23.1 10.1 3.83 1.92 1.06 0.57 0.24 0.0323 OUTLET M cum (mg/DNm3) 588 398 365 344 208 84.0 26.0 7.59 4.34 d pc (ymA) 23.6 10.3 4.00 1.93 1.18 0.84 0.37 H p (ym) 15.4 6.70 2.52 1.16 0.67 0.44 0.14 0.369 TABLE B-8. INLET AND OUTLET PARTICLE DATA FOR RUN #21 Taken 2/5/78 at 2:30 pm IMPACTOR STAGE NUMBER Precutter § Nozzle 1 2 3 4 5 6 7 Filter Sample Volume (DNm3) INLET M cum (mg/DNm3) 2,440 2,180 1,490 1,360 675 296 104 32.0 2.67 dpc (ymA) 32.6 14.3 5.53 2.85 1.65 0.95 0.49 dP (ym) 21.4 9.31 3.53 1.77 0.98 0.52 0.22 0.0375 OUTLET cum (mg/DNm3) 428 290 253 214 136 67.9 25.2 8.85 7.87 V (ymA) 23.7 10.4 4.01 1.93 1.18 0.84 0.37 dP (ym) 15.98 6.72 2.53 1.16 0.67 0.44 0.14 0.305 N: 20°C, 1 atm; ^ ; ymA = ym(g/cm3)!s; p = 2.3 g/cm3 49 ------- TABLE B-9. INLET AND OUTLET PARTICLE DATA FOR RUN #23 Taken 2/5/78 at 4:45 pm IMPACTOR STAGE NUMBER Precutter § Nozzle 1 2 3 4 5 6 7 Filter S amp 1 e Volume (DNm3) INLET M cum (mg/DNm3) 2,550 2,340 1,720 1,580 811 339 144 16.9 2.82 d pc (ymA) 33.6 14.7 5.69 2.93 1.70 0.98 0.51 d P (ym) 22.0 9.58 3.64 1.82 1.01 0.54 0.23 0.0354 OUTLET M cum (mg/DNm3) 503 365 348 336 203 117 59.0 32.6 27.4 d P (ymA) 23.6 10.3 3.99 1.92 1.18 0.84 0.37 d P (ym) 15.41 6.69 2.51 1.15 0.67 0.44 0.14 0.307 TABLE B-10. INLET AND OUTLET PARTICLE DATA FOR RUN #24 Taken 2/6/78 at 1:10 pm IMPACTOR STAGE NUMBER Precutter § Nozzle 1 2 3 4 5 6 7 Filter Sample Volume (DNm3) INLET cum (mg/DNm3) 2,570 2,200 1,570 1,270 658 379 196 32.2 7.43 d pc (ymA) 31.9 14.0 5.40 2.78 1.62 0.92 0.52 d P (ym) 20.9 9.09 3.44 1.72 0.96 0.50 0.24 0.0404 OUTLET M cum (mg/DNm3) 514 403 360 304 282 178 128 109 104 d pc (ymA) 22.7 9.93 3.84 1.91 1.15 0.65 0.36 d P (ym) 14.83 6.43 2.41 1.14 0.65 0.32 0.14 0.334 N: 20°C, 1 atm; d = dp (PpC')% ; ymA= ym(g/cm3)Js; pp= 2.3 g/cm3 50 ------- TABLE B-ll INLET AND OUTLET PARTICLE DATA FOR RUN #26 Taken 2/6/78 at 4:00 pm IMP ACTOR STAGE NUMBER Precutter § Nozzle 1 2 3 4 5 6 7 Filter S amp 1 e Volume (DNm3) INLET M cum (mg/DNm3) 2,470 2,270 1,600 1,400 597 173 51. 7 18.1 7.75 d pc (ymA) 32.4 14.2 5.50 2.83 1.65 0.93 0.53 d P (ym) 21.3 9.25 3.51 1.75 0.98 0.51 0.24 0.0387 OUTLET M cum (mg/DNm3) 427 356 272 259 141 91.5 34.5 11.7 7.91 d pc (pmA) 23.2 10.2 3.94 1.96 1.18 0.66 0.38 d P (urn) 15.21 6.59 2.48 1.18 0.67 0.33 0.15 0.316 TABLE B-12, INLET AND OUTLET PARTICLE DATA FOR RUN #28 Taken 2/6/78 at 6:10 pm IMPACTOR STAGE NUMBER Precutter § Nozzle 1 2 3 4 5 6 7 Filter Sample Volume (DNm3) INLET M cum (mg/DNm3) 2,150 1,940 1,330 926 483 212 66.5 15.3 12.8 d pc (ymA) 32.3 14.1 5.47 2.82 1.64 0.93 0.53 d P (ym) 21.2 9.21 3.49 1.75 0.97 0.51 0.24 i 0.0391 OUTLET M cum (mg/DNm3) 510 354 312 301 174 87.9 33.4 10.8 8.20 d pc (ymA) 22.7 10.4 4. 01 2.00 1.20 0.68 0.38 d P (ym) 14.82 6.72 2.53 1.20 0.68 0.34 0.15 0.305 N: 20°C, 1 atm; dna = dn (pn C ' ) pa p p ymA = ym(g/cm3 ) \ P = 2 . 3 g/cm 51 ------- TABLE B-13. INLET AND OUTLET PARTICLE DATA FOR BLANK RUN #3 Taken 1/25/78 at 3:45 pm IMPACTOR STAGE NUMBER Probe Pre-filter 1 2 3 4 5 6 7 Filter Sample Volume (DNm3) INLET Loading mg 17.6 151.0 -0.1 -0.3 -0.4 -0.3 -0.3 -0.6 -0.3 -0.4 V (ymA) 26.8 11.8 4.45 2.28 1.29 0.72 0.42 0.051 OUTLET Loading mg 7.7 41.0 0.0 -0.1 -0.3 -0.1 -0.3 -0.2 -0.3 0.0 d pc (ymA) 21.3 9.3 3.49 1.82 1.02 0.57 0.33 0.349 TABLE B-14. INLET AND OUTLET PARTICLE DATA FOR BLANK RUN #5 Taken 1/27/78 at 9:10 am IMPACTOR STAGE NUMBER Probe Pre-filter 1 2 3 4 5 6 7 Filter Sample Volume (DNm3) INLET Loading mg 8.9 105.6 0.0 -2.0 -0.1 -0.1 0.0 -0.2 0.0 0.0 V (ymA) 28.9 12.7 4.80 2.47 1.39 0.78 0.45 0.044 OUTLET Loading mg 13.0 29.6 0.0 -0.2 -0.2 0.0 0.0 -0.1 0.0 35.9 V (ymA) 20.6 9.1 3.4 1.8 0.99 0.55 0.32 0.410 N: 20°C, 1 atm; d dp (pp 52 Pp=2.3g/cm3 ------- TABLE B-15. INLET AND OUTLET PARTICLE DATA FOR BLANK RUN #10 Taken 1/31/78 at 8:25 am IMPACTOR STAGE NUMBER Probe Pre-filter 1 2 3 4 5 6 7 Filter Sample Volume (DNm3) INLET Loading mg 5.2 160.1 0.1 -0.1 -0.2 -0.2 -0.2 -0.1 -0.3 0.0 A v (ymA) 28.3 12.4 4.69 2.41 1.36 0. 76 0.44 0.047 OUTLET Loading mg 13.8 58.5 0.0 -0.1 0.0 0.0 -0.1 -0.1 -0.2 10.4 d V (ymA) 20.4 8.92 3.34 1.73 0.98 0.55 0.32 0.583 TABLE B-16. INLET AND OUTLET PARTICLE DATA FOR BLANK RUN #19 Taken 2/5/78 at 10:30 am IMPACTOR STAGE NUMBER Probe Pre-f ilter 1 2 3 4 5 6 7 Filter S amp 1 e Volume (DNm3) INLET Loading mg 14.2 122.2 0.3 0.0 0.0 -0.1 0.0 0.0 0.0 0.1 V CymA) 26.6 11.7 4.42 2,28 1.29 0.72 0.42 0.042 OUTLET Loading rag 36.1 87.5 0.1 0.3 0.3 0.3 0.1 0.1 0.0 6.3 dpc (ymA) 20.6 9.1 3.4 1.8 1.0 0.55 0.32 0.168 N: 20°C, 1 atm; d = dp (pp ; ymA = ymCg/cm3)31; pp = 2.3 g/cm3 53 ------- APPENDIX "C" PARTICULATE SULFATE DATA 54 ------- TABLE C-l. RESULTS OF PARTICULATE SULFATE TESTS, mg/DNm3 OF GAS SAMPLED Run No. Stage 1 2 3 4 5 6 7 Filter Conditioned Tests 2 Inlet 2.10 1.05 0.90 0.30 0.30 0.30 0.30 0.30 Outlet 1.49 0.21 0.17 0.23 0.27 0.19 0.19 0.15 8 Inlet 1.14 0.33 1.14 0.49 0.33 0.65 0.65 0.49 Outlet 0.13 0.08 0.14 0.18 0.14 0.16 0.13 0.14 Baseline Tests 11 Inlet * * * * * 2.60 * * Outlet 1.09 0.23 * * * * * * 18 Inlet 1.08 * * * * * * * Outlet 0.09 * * * * * * 0.33 22 Inlet * * * * * * * * Outlet * * * * * * * 6.72 29 Inlet * * * * * * * * Outlet * * * * * * * 0.28 Ul t/1 * Below detectable limit ------- APPENDIX "D" INPUT DATA FOR THE ESP PERFORMANCE MODEL 56 ------- TABLE D-l. INPUT DATA FOR THE ESP PERFORMANCE MODEL PROGRAM* Case Baseline 0.1-2 ym Baseline 2-20 ym S03 Conditioning 0.1-2 ym SOj Conditioning 2-20 ym d Pi 8.5 8.5 8.5 8.5 a g 4.0 4.0 4.0 4.0 a 1.16 0.948 2.85 2.25 b 0.300 0.817 1.06 2.33 c 0.212 -3.50x10-* 0.486 0.00265 y^c 0.36 0.36 0.36 0.36 a 0.25 0.25 0.25 0.25 N 2 2 2 2 S 0.1 0.1 0.1 0.1 di 0.1 2 0.1 2 df 2.0 20 2 20 Ad 0.1 1 0.1 1 Enter Data Mass mean particle diameter, d ( ym) Number of baffled sections, Ng t & Geometric standard deviation, a Sneakage-reentrainment fraction, S o First curve fit parameter for migration velocity, a Initial particle diameter, d^ (ym) Second curve fit parameter for migration velocity, b Final particle diameter, df (ym) Third curve fit parameter for migration velocity, c Particle diameter increment, Ad (ym) Specific collector area, A /Q,, (cm2/Acm3/sec) Normalized standard deviation of gas velocity distribution, a Sparks (1978) ------- APPENDIX "E" ELEMENTAL ANALYSIS DATA 58 ------- APPENDIX "E". ELEMENTAL ANALYSIS DATA Thirty elements were included in the UC Davis X-ray Analysis of the cascade impactor substrates. Of these thirty only eight were present in significant amounts. Table E-l lists the thirty elements and representative minimum resis- tivities. Table E-2 presents the weight per substrate area, by cascade impactor stage, for the eight elements which were present in large enough amounts to be of interest. TABLE E-l. MINIMUM SENSITIVITIES OF ELEMENTS, ng/cmz Na 2,158 V 172 Hg 725 Mg 615 Cr 149 Pb 864 Al 653 Mn 150 Sn 374 Si 613 Fe 157 Ag 1,856 S 470 Co 151 Br 459 Cl 443 Ni 116 Rb 740 K 279 Cu 89 Sr 1,013 Ca 198 Zn 107 Zr 1,502 Ba 550 Pt 566 Mo 2,351 Ti 168 Au 652 Pd 4,660 59 ------- TABLE E-2. RESULTS OF ELEMENTAL ANALYSIS OF FLY ASH ON CASCADE IMPACTOR SUBSTRATES 00 3 4-> 16* 1 2 3 4 5 6 7 34** 1 2 3 4 5 6 7 24** 1 2 3 4 5 6 7 ng/cm2 Al 2430 2657 8322 2836 2920 206 *** 60832 21055 25877 25513 4621 4628 1750 *** 11464 32192 37295 10990 3922 ^1539 Si 5147 6870 15504 5222 5351 855 *** 101540 37357 40427 41872 8201 8921 3483 1509 21887 52636 60104 20011 7084 2953 S 5665 8467 2543 4739 5904 4116 4399 *** 1427 261 467 350 506 286 1133 3113 679 *** 397 565 400 K 1434 1201 4276 1273 1562 510 148 21842 6452 9008 8380 1796 1686 743 5550 2923 10957 13488 3988 1530 655 Ca 3513 4365 4507 3926 2560 1508 1562 16813 12073 7398 7562 3886 4415 3817 7763 6252 9717 10504 6607 5410 1713 Ti 1940 1312 5180 1606 2212 784 604 29718 7032 10654 8568 2102 2046 1056 8802 3384 12378 14556 4372 1998 519 Fe 22088 20449 33215 10695 15078 5436 2100 201947 34750 62852 49857 12375 13017 5520 56112 17258 82818 99906 27685 11698 5211 Zn 244 277 266 166 257 155 165 1480 348 464 388 154 472 106 598 236 420 597 316 183 141 * Conditioned test ** Baseline test *** Below significant limit 60 ------- TECHNICAL REPORT DATA (Please read Inunctions on the reverse before completing) 1. REPORT NO. EPA-600/7-79-104a 2. 3. RECIPIENT'S ACCESSION NO. 4. TITLE AND SUBTITLE Effects of Conditioning Agents on Emissions from Coal-fired Boilers: Test Report No. 1 5. REPORT DATE April 1979 6. PERFORMING ORGANIZATION CODE 7. AUTHOR(S) R.G.Patterson, P.Riersgard, R.Parker, and S. Calvert 8. PERFORMING ORGANIZATION REPORT NO. 9. PERFORMING ORGANIZATION NAME AND ADDRESS Air Pollution Technology, Inc. 4901 Morena Boulevard, Suite 402 San Diego, California 92117 10. PROGRAM ELEMENT NO. EHE624A 11. CONTRACT/GRANT NO. 68-02-2628 12. SPONSORING AGENCY NAME AND ADDRESS EPA, Office of Research and Development Industrial Environmental Research Laboratory Research Triangle Park, NC 27711 13. TYPE OF REPORT AND PERIOC C Task Final; 1/78 - 4/78 COVERED 14. SPONSORING AGENCY CODE EPA/600/13 ,5. SUPPLEMENTARY NOTES T£RL_RTp j, 16. The report gives results of a field performance test of an electrostatic precipitator (ESP) which uses SOS an the conditioning agent. The ESP is at an electric utility power plant, burning approximately 1% sulfur coal. Tests were conducted with and without injection of the SO3. The ESP performance was characterized in terms of particle collection efficiency and the chemical composition of particulate and gaseous emissions. Fly ash resistivity and dust opacity were also measured. Results show an average increase in overall efficiency from 80% to 95% with injection of the SOS. This is accompanied by a decrease in fly ash resistivity, a decrease in opacity, and an increase in SOS concentration entering and leaving the ESP. Approximately 80% of the injected SOS escaped the ESP. 7. KEY WORDS AND DOCUMENT ANALYSIS DESCRIPTORS Pollution Flue Gases Treatment Coal Combustion Sulfur Trioxide Electrostatic Pre- cipitation Fly Ash Electrical Resisti- vity Opacity b.lDENTIFIERS/OPEN ENDED TERMS Pollution Control Stationary Sources Conditioning Agents c. COSATl Field/Group 13B 21B 14B 21D 07B 13H 20C 18. DISTRIBUTION STATEMENT Unlimited 19. SECURITY CLASS (ThisReport) Unclassified 21. NO. OF PAGES 71 20. SECURITY CLASS (This page) Unclassified 22. PRICE EPA Form 2220-1 (9-73) 61 ------- |