SCREENING STUDY FOR BACKGROUND INFORMATION AND SIGNIFICANT EMISSIONS FROM GYPSUM PRODUCT MANUFACTURING TASK ORDER NO. 14 CONTRACT NO. 68-02-0242 PREPARED FOR CONTROL SYSTEMS DIVISION ENVIRONMENTAL PROTECTION AGENCY SUBMITTED BY PROCESSES RESEARCH, INC. INDUSTRIAL PLANNING AND RESEARCH CINCINNATI, OHIO ------- PROCESSES RESEARCH, INC. INDUSTRIAL PLANNING AND RESEARCH SCREENING STUDY FOR BACKGROUND INFORMATION AND SIGNIFICANT EMISSIONS FROM GYPSUM PRODUCT MANUFACTURING Task Order No« 14 Contract No. 68-02-0242 May 25, 1973 Prepared for Control Systems Division Environmental Protection Agency Submitted by PROCESSES RESEARCH, INC. Industrial Planning and Research Cincinnati, Ohio ------- PROCESSES RESEARCH, INC. INDUSTRIAL PLANNING AND RESEARCH This report was furnished to the Environmental Protection Agency by Processes Research, Inc., Cincinnati, Ohio in fulfillment of Contract No. 68-02-0242. The contents of this report are reproduced herein as received from Processes Research, Inc. The opinions, findings, and conclusions expressed are those of the author and not necessarily those of the Environmental Protection Agency. ii ------- PROCESSES RESEARCH, INC. INDUSTRIAL PLANNING AND RESEARCH ABSTRACT The report deals with the atmospheric emissions that are produced during the operation of calcining gypsum and production of gypsum board products. The aver- age particulate emissions from these plants are between 25 and 40 pounds per hour with baghouse collectors and electrostatic precipitators generally being employed as control devices. Extrapolation of emissions from all plants indicate that total emissions are in the range of 80,000 tons per year. Emission of sulfur oxides is primarily dependent upon the sulfur content of the fuels being used for calcining and other operations, and production of nitrogen oxides is also a function of the combustion equipment and fuels used. Emission regulations relating to visible, particulate, sulfur oxide, and nitrogen oxide emissions are shown for nine states A description of a general process for production of calcined gypsum and gypsum board products is given with flow diagrams. A list of gypsum and/or gypsum pro- duct producers is shown along with total industry production capacity, best controlled plants and their control equipment, and emissions data from various production locations. A brief description of emission analysis, applicable con- trol technology, and economics of control equipment is included. iii ------- PROCESSES RESEARCH, INC. INDUSTRIAL PLANNING AND RESEARCH Section I II III IV V VI VII VIII IX X XI SCREENING STUDY FOR BACKGROUND INFORMATION AND SIGNIFICANT EMISSIONS FROM GYPSUM PRODUCT MANUFACTURING INDEX Title Purpose and Scope Summary Air Pollution Regulations Calcining of Gypsum Board Products Emissions, Analysis and Control List of Producers Data from Operating Plants Best Controlled Plants Forecast of Growth Information Sources Page 1 2 3 13 19 22 31 35 41 42 43 iv ------- PROCESSES RESEARCH, INC. INDUSTRIAL PLANNING AND RESEARCH SECTION I - PURPOSE AND SCOPE This report provides the Control Systems Division, Environmental Protection Agency, with preliminary qualitative and quantitative data related to the operation of plants for the production of gypsum and gypsum products. The general purposes of this preliminary study were to identify sources of atmospheric emissions in this industry, to identify and quantify such emissions and to evaluate the state of the art in terms of equipment currently employed for the control of such emissions. The scope of this preliminary report deals with the two major industry operations: A. Calcining of gypsum. B. Production of board products. ------- PROCESSES RESEARCH, INC. INDUSTRIAL PLANNING AND RESEARCH SECTION II - SUMMARY Review of the emissions data contained in this report will disclose that the "best controlled" gypsum calcining plants and board plants employ bag collec- tors and/or electrostatic precipitators. The average particulate emissions for these plants are in the range of 25 to 40 pounds per hour and these plants will generally comply with existing air pollution regulations. If all plants were so equipped, the total nationwide emissions of particu- lates would be on the order of 12,000 tons per year. Extrapolation of the data for all plants indicates that total emissions of particulates to atmosphere are in the range of 80,000 tons per year. ------- PROCESSES RESEARCH, INC. INDUSTRIAL PLANNING AND RESEARCH SECTION III - AIR POLLUTION REGULATIONS Gypsum product plants are located in 28 states. Ten of these states have been selected as representing a cross section of the areas in which these plants are located. A summary of the pertinent regulations of each of these states (with the exception of California) is given below. In California, each county has its own regulations and a county by county analysis of these regulations is not deemed to be appropriate for this report. The 10 states involved are: California Michigan Florida New Jersey Georgia New York Indiana Oklahoma Iowa Texas The regulations abstracted deal with: 1. Particulate Emissions from Process Sources. 2. Visible Emissions. 3. Emission of Nitrogen Oxides and Sulfur Oxides from Fuel Burning Operations. 1. PARTICULATE EMISSIONS FROM PROCESS SOURCES The allowable emission, in pounds per hour, is based on the process weight rate. Process weight is defined as the total weight of all materials introduced into any source operation. Solid fuels charged are considered as part of the process weight, but liquid and gaseous fuels and combustion air are not. The rate of allowable emission is shown in Table I. ------- TABLE I REGULATIONS APPLICABLE TO GENERAL PROCESS SOURCES RATE OF ALLOWABLE EMISSION. LBS PARTICULATE/HR Process Weight Rate, Lbs/Hr Florida Georgia* Indiana Iowa Michigan New Jersey' New York3 Oklahoma Texas 100 .55 .551 .551 .55 .55 .50 .551 .. 1,000 2.25 2.58 2.58 2.58 2.58 2.3 2.58 1.6 5.000 6.34 7.58 7.58 7.58 7.58 6.7 7.58 7.7 10,000 9.73 12.0 12.0 12.0 12.0 10.8 12.0 15.2 20 ,000 14.99 19.2 19.2 19.2 19.2 17.4 19.2 30.1 40,000 23.0 30.5 30.5 30.5 30.5 27.6 30.5 59.7 60,000 29.60 40.0 40.0 40.0 40.0 36.1 40.0 67.4 120,000 33.28 46.3 46.3 46.3 46.3 51.8 46.3 82.3 200,000 36.11 51.2 51.2 51.2 51.2 56.1 51.2 95.2 1,000,000 46.72 69.0 69.0 69.0 69.0 71.7 69.0 151.2 2,000,000 -- 77.6 77.6 77.6 77.6 78.3 77.6 184.4 6,000,000 — 92.7 92.7 92.7 92.7 90.24 92.7 252.3 ------- PROCESSES RESEARCH, INC. INDUSTRIAL PLANNING AND RESEARCH Notes for Table I 1. For new equipment only. For existing equipment the values are the same through 60,000 pounds per hour. For over 60,000 pounds per hour, the values are: Process Weight Rate Lbs/Hr 120,000 200,000 1,000,000 2,000,000 6,000,000 Allowable Emissions Lbs/Hr 63.5 89.7 262.0 414.0 873.0 2. New Jersey does not follow this format. Their format is: Allowable1* Emission Rate Lbs/Hr 0.5 1.0 6.0 12.0 24.0 30.0 a. Based on 99 percent collection efficiency. b. Based on 0.02 grains per scf. 3. Applies to sources with an environmental rating of B or C. Allowable emission rate from sources with an A or D rating is at the discretion of the Department of Environmental Conservation. Potential Emission Rate from Source Operation Lbs/Hr 50 or less 100 1,000 2,000 3,000 or more Allowable* Emission Rate Lbs/Hr 0.5 1.0 10.0 20.0 30.0 Source Gas Emitted From Source Operations Scfm 3,000 or less 6,000 35,000 70,000 140,000 175,000 or more ------- PROCESSES RESEARCH, INC. INDUSTRIAL PLANNING AND RESEARCH 2. VISIBLE EMISSIONS a_. Process Sources These emissions are graded on the basis of equivalent opacity which is the degree to which an emission, other than gray or black smoke, is partially or wholly impervious to rays of light and causes obstruction of an observer's view. This is expressed as an equivalent of the obstruction caused by a gray or black smoke emission of a given density as measured by a Ringelmann Smoke Chart. b_. Fuel Burning Operations Opacity is determined by use of a Ringelmann Smoke Chart. The Ringelmann Smoke Chart is published in the U. S. Bureau of Mines Information Circular No. 8333. The allowable opacities are shown in Table II. ------- PROCESSES RESEARCH, INC. INDUSTRIAL PLANNING AND RESEARCH TABLE II REGULATIONS APPLICABLE TO VISUAL EMISSIONS State Florida Georgia Indiana Iowa Michigan New Jersey New York Oklahoma Texas PARTICULATES Fuel Burning1 Percent Opacity 202 202 40 40 205 206 207 20 208 Industrial Processes Percent Opacity No visible discharges^ 104 40 40 205 20 207 20 208 Notes for Table II 1. When presence of uncombined water is the only reason for failure of emissions to meet limitation, these requirements do not apply. 2. For new equipment; 40 percent for existing equipment. 3. For sulfuric acid plants and nitric acid plants. Other plants not specified. 4. For new portland cement plants, new nitric acid plants, and new sul- furic acid plants. Other plants not specified. ------- PROCESSES RESEARCH, INC. INDUSTRIAL PLANNING AND RESEARCH 5. Proposed rule change. Existing regulation calls for 40 percent. 6. Applies to indirect heat exchangers with a rated hourly capacity of 200 mm Btu or greater gross heat input. If input is less than 200 mm Btu, no visible emissions are permitted. 7. May not exceed this value for more than 3 minutes out of any 60 minute time period. May not exceed 40 percent during this 3 minute period. 8. For new .installations. Thirty percent for existing installations. ------- PROCESSES RESEARCH, INC. INDUSTRIAL PLANNING AND RESEARCH 3. EMISSION OF NITROGEN OXIDES AND SULFUR OXIDES FROM FUEL BURNING OPERATIONS The rate of allowable emission is shown in Table III. However, enforce- ment of these regulations will undoubtedly be affected by the current uncertainty in regard to the reliability of analyses for nitrogen oxides (see Section VI). ------- Florida1 Georgia2 Indiana Iowa Michigan New Jersey New York Oklahoma Texas 14 TABLE III EMISSION OF NITROGEN OXIDES AND SULFUR OXIDES Nitrogen Oxides Lbs/MM Btu Heat Input Liquid Fuel 0.30 0.30 0.303 0.306 0.3011 0.30 (As N02) Solid Fuel 0.70 0.70 0.703 See Note 7 See Note 9 0.7011 0.70 See Note IS FROM FUEL BURNING OPERATIONS Sulfur Oxides Lbs/MM 'Btu Heat Input Gaseous Fuel 0.20 0.20 0.203 0.206 0.2011 0.20 (As S02) Liquid Solid Fuel Fuel 0.80 1.20 0.80 1.20 See Note 4 1.55 5.05 See Note 8 See Note 10 See Note 12 0.813 2.0 See Note 16 Gaseous Fuel •-_• 0.20 ------- PROCESSES RESEARCH, INC. INDUSTRIAL PLANNING AND RESEARCH Notes for Table III 1. New sources, maximum 2 hour average. All sources after July 1, 1975. 2. New sources. For existing sources: S = 4000F/L^s_\ " ^300 / Where S = S02 emitted, Ibs/hr hg = Stack height, ft n =» 3 for hs < 300 n = 2 for h ^-300 S f Varies from 0.8 to 3.0 depending upon heat input and location of source. 3. For fuel burning equipment with a capacity of 250 mm Btu/hr or more. 4. Sulfur dioxide emission for new sources with a heat input of more than 250 mm Btu/hr shall comply with the Federal emission standards. For new sources with a heat input of 250 mm Btu/hr or less, and for existing equipment, the emission rate shall be limited to that expressed by: -0.33 Em * 17.0 Qrn Where Em = Maximum allowable SC^in the stack gases in Ibs/mm Btu heat input Qm = Heat input, mm Btu/hr 5. Maximum 2 hour average after January 1, 1975. From January 1, 1974 to January 1, 1975, the limits are 2.0 for liquid fuels and 6.0 for solid fuels. 6. Maximum 2 hour average, effective January 1, 1974. 7. No limits stated. 8. Limitations apply to steam generating stations only. 9. No limits stated. 11 ------- PROCESSES RESEARCH, INC. INDUSTRIAL PLANNING AND RESEARCH 10. Very involved method used for determining allowable S02 emission. See New Jersey Air Pollution Control Code, Chapter 8, Sections 2.2, 2.3, and 2.17. 11. Applies to installations with a heat input of more than 250 mm Btu/hr. 12. Limitations are placed on sulfur content of fuel rather than on emissions. 13. After July 1, 1975, limit is 0.3 Ibs/mm Btu. 14. All figures are based on a maximum 2 hour average. 15. Limitations apply to gas-fired steam generating units only. 16. For fuel burning units other than steam generators, limitations are based on ground level concentration averaged over a 30 minute period. They are: Galveston and Harris Counties - 0.28 ppm Jefferson and Orange Counties - 0.32 ppm Other counties - 0.40 ppm 12 ------- PROCESSES RESEARCH, INC. INDUSTRIAL PLANNING AND RESEARCH SECTION IV - CALCINING OF GYPSUM For the manufacture of gypsum products, the gypsum must be converted from calcium sulfate dihydrate (CaSO^ZI^O) to calcium sulfate hemihydrate (CaSO^»l/2H20) by calcining under controlled temperature conditions so that calcium sulfate anhydrite (CaSO^) is not produced. Strictly speaking, the term "gypsum" refers only to the dihydrate, but the term is almost universally used in referring to the hemihydrate and anhydrite as well. Block flow diagram No. 3411-A shows the relationship between steps in the process and composition of the gypsum. Gypsum is mined in both open pit and underground mines. Calcining plants are located near these mines or along a seaboard,or major waterway if imported gypsum is used. The run-of-mine gypsum is reduced in size and free water re- moved before calcining to remove the combined water. Referring to flow diagram No. 3411-B, a brief description of the process iis: v Run-of-mine gypsum is conveyed to a crusher feed bin. From this bin it passes over a vibrating screen to a crusher. The underflow from the screen and the discharge from the crusher are combined and conveyed to a crushed rock hopper. A portion of this material may be screened to provide the proper size rock to be sold for use as a Portland cement retarder. Rock from the hopper is fed to a surge bin from which it flows (or is conveyed) to a grinding mill. This mill is usually a Raymond type which grinds, classifies, and dries the rock. When calcining or drying gypsum, the mill is in a circuit in which the solid is subjected to hot gases during grinding. In this setup, the mill fan draws hot 13 ------- PROCESSES RESEARCH, INC. INDUSTRIAL PLANNING AND RESEARCH combustion gases through a flue from a furnace. From the mill the hot dust-laden gases exit through a duct to a cyclone collector, from which the finished product drops to a bin while any remaining dust is removed by a baghouse collector. The hot combustion gases are exhausted by a fan from the bag collector with part of the gas being recycled to the furnace. This is shown on flow diagram No. 3411-B1. The ground rock from the mill (80 percent O-OO mesh) is known as "land plaster" and may be sold as such for agricultural purposes. This material is conveyed to the land plaster bins which feed the calciners when further treatment is required„ Calcining is usually done batchwise in vertical kettles until the tempera- ture of the mass reaches a maximum of 320 to 340F. The calcined materials, known as "hot stucco" is then dropped to the hot pits. The stucco is then conveyed to stucco storage bins. Improperly calcined material may be conveyed to the stucco reject bin from where it is recycled back to the crushed rock storage bin. In some plants, continuous calcining is carried out in a Raymond mill. This simul- taneously crushes, classifies, removes the surface moisture, and calcines the gypsum. The finished stucco may be sold as such for use in various plasters, Keene's cement, etc. It is also the major raw material for a board products plant. If such a plant is built in conjunction with a calcining plant, the stucco is con- veyed to the feed bins of the board plant. The only air pollutants from this process are gypsum dust and stack gases from the heaters for the Raymond mills and from the calciners. The fuel used for the heaters and calciners may be gas or oil. If oil is used there may be SOX and NOX emissions. 14 ------- PROCESSES RESEARCH, INC. CINCINNATI, OHIO NEW YORK, N.Y. DRWG. 34II-A GYPSUM RCCK CASQq •2H20 PARTICIPATE PARTICULATE CRUSHING PARTICULATE - PLASTERS &CEMENTS SCREENING GRINDING DRYING (FREE WATER! ONLY) i PORTLAND CEMENT RETARDER CASCV2H20 -PARTICULATE LAND PLASTER CAS04-2H20 AGRICULTURAL GYPSUM -2H20 CALCINING PARTICULATE SOX,NOX STUCCO CAS04-'4H20 BOARD PRODUCTS PRODUCT BLOCK FLOW DIAGRAM 15 ------- RUN-OF- MINE ROCK HOPPER CRUSHER FEED BIN V ^ SCREEN TO ATM I II SCREENJV CEMENT ROCK \/ SURGE TANK CRUSHED ROCK STORAGE BIN ^ D ^ 7i if 1 ? s LAND PLASTER BIN fx \ Si s. 'v / — ... .... , > STUCCO REJECT BIN ELECTROSTATIC PKECI PITATOR 1- /I'TO ATM r i IT RAYMOND MILL CALCINER HOT PIT TO BOARD PLANT ^^-""^^ CEMENT ROCK LOADING TYPICAL GYPSUM PRODUCTS PLANT CRUSHING,- MILLING, AND CALCINING DRWG. 3411-B PROCESSES RESEARCH, INC. CINCINNATI, OHIO NEW YORK, N.Y. ------- EXHAUST GASES RECYCLED GASES RAYMOND MILL FURNACE MAKE-UP AIR FAN 17 DRWG34II-BI PROCESSES RESEARCH, INC. CINCINNATI, OHIO NEW YORK, N.Y. ------- PROCESSES RESEARCH, INC. INDUSTRIAL PLANNING AND RESEARCH The major sources of emission and types of pollutants are: Source Pollutant Primary crusher Dust Crushed rock screen Dust Crushed rock bin Dust Crushed rock feeder Dust Grinding mill Gas fired Dust Oil fired Dust S02 NOX Calciners Gas fired Dust Oil fired Dust S02 NOX Land plaster bin Dust Stucco reject elevator Dust Emissions from the grinding mill, land plaster bin, calciners, and stucco reject elevator may be too hot to be sent to a baghouse and the dust is too fine to be collected efficiently in a cyclone. Therefore, they are usually conveyed to an electrostatic precipitator. If the calciners and grinding mill heaters are oil fired, the exhaust gases from the precipitator may have to be scrubbed to bring the S02 down to acceptable levels. The dust from the primary crushing and screening operations is usually collected in cyclone units. It is usually necessary to supplement these with baghouse units or a precipitator for additional cleanup« 18 ------- PROCESSES RESEARCH, INC. INDUSTRIAL PLANNING AND RESEARCH SECTION V - BOARD PRODUCTS In manufacturing board products from gypsum, water ±s mixed with the stucco and various materials are added to impart the required properties to the finished product. The nature of these additives will vary, depending upon whether the finished product is wallboard, acoustical board, insulating board, etc. A typical process for making wallboard is shown on flow Diagram 3411-C. Referring to this flow diagram, a brief description of the process is: Stucco from the hot pits is conveyed to the stucco storage bins in the board plant. No attempt is made to cool this stucco since the elevated temperature will not affect the process adversely. The stucco is conveyed by a screw con- veyor to an elevator and discharged to a vibrating screen. Any agglomerates which may have formed are screened out and returned to the screw conveyor where the shearing action of the conveyor will break them up. The underflow from the screen flows to a transfer conveyor. Various additivies such as starch, vermicu- lite, chopped glass fiber, and ground scrap are also added in this conveyor. This mixture is conveyed to a mixer where foamed soap from a foam generator and a mixture of asphalt, potash, and water from a Hydrapulper are also added. This material is thoroughly mixed to form a thick slurry, or paste, which is fed to the board machine. In the board machine the paste is fed uniformly onto a liner paper. A top paper liner is applied under a pair of nip rolls and edge folders. This sand- wich is then conveyed on a flat belt conveyor until the core hardens - usually about 6 minutes. The board is then cut automatically by a revolving knife. 19 ------- N> O TO ATM BAGHOUSE UJ O V 1 MANUAL "S r S <\ a:\ 0 x cc \ SOAP SOLUTI.OJ GLASS FIBER ROVING CUTTER : _£_ TO WASTECTRUCK) »LATH TO STOkAGE ABOARD TO STORAGE DRYER CUT OFF KNIFE BOARD MACHINE TYPICAL GYPSUM PRODUCTS PLANT BOARD AND LATH PRODUCTION PAPER FEEDER DRWG. 34II-C PROCESSES RESEARCH, INC. CINCINNATI, OHIO NEW YORK, N.Y. ------- PROCESSES RESEARCH, INC. INDUSTRIAL PLANNING AND RESEARCH The cut boards are automatically turned over and passed through a long, four- section kiln dryer. The boards leaving the dryer are turned face to face and end sawed to give smooth, straight ends. They are then bundled and stacked in preparation for shipping or warehousing. With minor modifications in operations, lath and sheathing can be made on the same equipment. The process is the same as described for wallboard. The only air pollutants from this process are gypsum dust and wallboard dust, which are essentially the same thing. Dusts from the stucco handling system, the additives elevator, and the mixer, go directly to a baghouse. Dust from the board-forming machine goes to a cyclone collector. The solids from this collector flow to the Hydrapulper and the air goes to the baghouse. Solids from the baghouse are recycled to the stucco feed screw. Dust from the end saws goes to a cyclone or baghouse collector. The collected dust may be recycled as an additive or may be discarded. Air from the collector is discharged to the atmosphere. 21 ------- PROCESSES RESEARCH, INC. INDUSTRIAL PLANNING AND RESEARCH SECTION VI - EMISSIONS, ANALYSIS AND CONTROL A. ANALYSIS The determination of the quantity of emissions from a gypsum products plant is facilitated by the fact that most emissions are carried in airstreams which are moved by blowers. Few natural draft stacks are involved. These blowers are usually used as exhausters on the downstream side of dust collection equipment. The most accurate method in general use to determine the quantity of air moved by a blower is a duct traverse using a standard pitot tube (Ref. 3b). Frequently it is possible to make a close approximation of the flow rate by measuring the operating horsepower of the blower and the differential head across the blower. The flow rate can be found from the performance curve. The accuracy will depend on the characteristic curve for the blower. The determination of the quantity of particulate matter carried in any stream is best made by passing a known quantity of the stream through a flash- fired glass fiber filter which is weighed before and after the sample is taken (Ref. 3b). The highest temperature of any of these streams from a gypsum plant is below the temperature limit of the filters and filter holders available. In making these determinations, it is important that isokinetic sampling tech- niques are used. Since the only S02 which will be emitted from a gypsum plant will be from a combustion process using oil, the simplest way to determine it is to analyze the oil for sulfur content. All of this sulfur will be converted to S02 so the total emission of SO2 will depend on the firing rate. 22 ------- PROCESSES RESEARCH, INC. INDUSTRIAL PLANNING AND RESEARCH The problem of measuring nitrogen oxides, especially in the presence of sulfur oxides, is being extensively studied by many organizations. None of the methods now available give completely satisfactory results (Ref. 3b, 4 and 5). However, some of the newer methods seem promising. One of these is the electrochemical sensor equipped to determine both S0£ and NOX. In this unit, the 802 is not differentiated by the NOX sensor but the NOX does not interfere with the SO2 sensor. Both sensors are used and the NOX measurement is corrected to allow for the S0£ level. In using this method the sample must be filtered and cooled. This could be done in conjunction with the test for particulate matter. In a properly fired unit, carbon monoxide should not be present in the outlet gases. It is the only one of the fixed gases which is a pollutant. The classical procedure for measuring it is to pass the gas sample over hot iodine pentoxide and titrate the iodine liberated. Carbon monoxide is also measured by gas chromatography and by nondispersive infrared (NDIR) analyzers. The NDIR analyzers have rapid response and good sensitivity but tend to drift so that fairly frequent zeroing and calibration may be necessary. All of these methods require that the sample be filtered and cooled. In discussion with gypsum manufacturers in the United States, it has been determined that no fluorine bearing gypsum (byproduct of phosphoric acid manufacture) is used to produce commercial gypsum, wall board, .and associated products. Therefore, in regard to the gypsum industry, emissions of fluorines and fluorides are not considered to be a problem. 23 ------- PROCESSES RESEARCH, INC. INDUSTRIAL PLANNING AND RESEARCH B. CONTROL The best way to control 802 is to use a low sulfur fuel. If this is not feasible the S02 may be removed from the stack gas by wet scrubbing» One system uses a lime slurry which reacts with the S02 to form sulfates and sul- fites (Ref. 3a). This, of course, precludes recovery of the SQ2. Another systems uses a hot solution of potassium sulfite (1^803) for scrubbing (Ref. 3a) . The sulfite reacts with 802 to form potassium bisulfite. Cooling the hot bi- sulfite solution converts the bisulfite (KHS03> to the pyrosulfite (1^8205) which is concentrated and steam stripped to produce 802 an<^ potassium sulfite. The latter is reused in the scrubber. This system requires close temperature control and uses about four pounds of steam for each pound of 802 recovered. The reduction of nitrogen oxides to less than 200 ppm in an effluent stream is very difficult. Much of the current technology involves scrubbing with alkaline solutions but this is of limited value because of the low solubility of nitrogen oxides in water (Ref. 3a). This problem is also being extensively in- vestigated by several organizations. The most efficient equipment for the collection of particulate matter is the electrostatic precipitator. It is also the most expensive and is used in gypsum plants only when the effluent is too hot to be collected in a baghouse. The use of cyclone collectors and baghouses should be satisfactory if proper units are chosen for the various services. Wet collectors are usually avoided since they convert an air pollution problem to a water pollution problem. Both baghouse collectors and electrostatic precipitators used to collect gypsum dust have collection efficiencies of 95 to 99 percent. The cost information relating to these two types of equipment are presented in the following tables. 24 ------- PROCESSES RESEARCH, INC. INDUSTRIAL PLANNING AND RESEARCH TABLE IV BAGHOUSE COLLECTOR Rate: 40,000 acfm Costs: FOB (including fan, starter, and 40 horsepower motor) $40,000 Erected $50,000 Operating per year $ 3,200 Maintenance per year $ 8,000 Capital (12.8 percent of erected cost) $ 6,400 Total annual cost $17,600 Sources: "Estimating the Cost of Gas Cleaning Plants" Chemical Engineering, December 13, 1971, Pg 86-96. "A Manual of Electrostatic Precipitator Technology - Part II - Application Areas." NATIC No. PB-196-381 25 ------- Table V Electrostatic Precipitator Installations in Gypsum Plants (Period 1935-1969) Pptr. Contract Year (s) 1935-1939 1940-1944 1945-1949 1950-1954 1955-1959 1960-1964 1965-1969 Five (5) No. of Install. 4 3 3 18 20 10 1 Year Period Indicated No. of Pptrs. 5 3 3 25 21 11 2 Total Gas Volume (ICfacfm) 100 56 77.5 545.5 607.6 351.6 80 Average Volume /Year During Period (10 acfm) 20 11.2 15.5 109 121.5 70.3 16.0 Weighted Design Efficiency on acfm Basis (%) 98.5 98.6 96.5 97.5 97.7 99. 15 99.0 Grand Totals 59 70 1818.2 NOTES: The statistics in this table include precipitators on rock dryers, kettles, rotary calciners, holoflite calciners, and combinations of calciners and kettles with dryer and grinding mill vent gases. 26 ------- Table VI Summary of Performance Data on Gypsum Plant Electrostatic Precipitators Calciner Calciner Combination Kettles Rock Dryers (Rotary) (Holoflite) . Kettle, Dryer, Mill Critical Parameter Max Min Max Min Max Min Max Min Max Min 1. Gas Volume/Precipitator 13.6 2.9 43.0 10.8 82.5 29.8 16.6 7.6 60.2 9.0 (acfm in thousands) 2. Precipitator Efficiency 99.90 94.38 99.85 97.2099.82 99.14 99.90 98.20 99.96 93.76 (per cent) 3. Gas Velocity in Precipitator 5.5 1.5 7.5 3.1 7.9 4.2 2.8 1.4 7.4 3.0 (fps) •VJ 4. Precipitator Dust Concentration 48.0 4.8 156 4.6 46.3 32.9 62.6 30.8 63.9 7.7 ; (gr/scfd) 5. Precipitator Input Power 828 124 282 69 174 62 983 576 390 65 (watts/1000 acfm) 6. Precipitator Avg. Field 12.8 8.8 15.0 9.0 13.0 8.1 15.5 9.8 13.4 8.0 Strength (kV/in.) 7. Gas Moisture 47.6 19.0 17.4 3.6 35.2 14.2 54.0 17.6 22.2 6.7 (per cent by volume) 8. Gas Temperature 342 220 240 125 - 339 200 250 140 (°F) 9. Precipitator Performance 2.39 0.74 2.06 0.89 1.45 1.03 1.39 0.47 2.39 0.40 Ratio (R) ------- PROCESSES RESEARCH, INC. INDUSTRIAL PLANNING AND RESEARCH Economics. Table VII shows erected and FOB costs for precipitators installed in gypsum plants over the period 1959-1967. The costs per acfm range from $0.89 to $1.03 for 99.0% collection efficiency, and from $1.43 to $1.53 for 99.5%. Erected costs vary from $1.38 to $3.62 per acfm. Table VIII lists the maintenance costs for two precipitators installed in gypsum plants. The fan costs were based on a pressure drop of 1/2" W.G. in the precipitator. The plant was assumed to operate 8000 hours per year with elec- tricity costs estimated at $0.0075 per kWh. 28 ------- PROCESSES RESEARCH, INC. INDUSTRIAL PLANNING AND RESEARCH Table VII Gypsum Industry Economics Year 1959 1960 1961 1962 1964 1965 1967 Type Cost FOB Erected FOB Erected FOB FOB Erected FOB Design Design Total Cost/Unit Volume Volume Efficiency Cost ($ /acfm) (1000'sacfm) (%) (10? $) 40 40 40 40 40 36 36 36 40 27 40 99.0 99.0 99.0 99.7 99.0 99.5 99.5 99.5 99.0 99.0 99.0 39.5 55.2 38.7 90.1 35.7 55.0 51.3 56.3 36.0 97.8 41.0 0.99 1,38 0.97 2.25 0.89 1.53 1.43 1.57 0.90 3.62 1.03 29 ------- PROCESSES RESEARCH, Lsrc. INDUSTRIAL PLANNING AND RESEARCH Table VIII Maintenance Data for Precipitators Installed on Gypsum Calciners Prod. Rate tons/hr. 17-17 60-90 Gas Flow, acfm 16,600 35,000 Precipitator Power, kW 12.2 13.5 No. of Maintenance Periods/year 3-4 3-4 Man hours/year 70-90 70-90 Maintenance Labor Costs 480 480 Fan Power, kW 2 1. 04 2.19 Power Costs - Fan, $/yr. 62.25 131.25 Power Costs - Precipitator, $ /yr. 730 810 Capital Costs,4 $/yr. 8,600 9,350 Total Annual Costs 9. 872. 25 10, 771. 25 i Based on $6. 00 per hour Based on 1/2" W. G. pressure drop Based on Power Costs at $0. 0075 per kWh Based on 12. 8% of total Erected Costs 30 ------- PROCESSES RESEARCH, INC. INDUSTRIAL PLANNING AND RESEARCH SECTION VII - LIST OF PRODUCERS Gypsum and/or gypsum products are produced in twenty-eight of the conter- minous states at 79 locations. Six major producers account for sixty-nine, or 87-1/2 percent, of these installations. There is no breakdown available showing the nominal capacity or production for any of these producers. However, the latest data (1971) available for the overall industry shows this breakdown (Ref. 6): Product Capacity Uncalcined Short Tons Portland cement retarder 3,349,018 Agricultural gypsum 849,970 Fillers and unclassified 106,003 Total 4,304,991 Calcined Plasters Building Plasters Regular basecoat 381,471 Mill-mixed basecoat 188,556 Veneer plaster 89,723 Gouging, molding, and Keene's cement 75,251 Roof-deck concrete 180.803 Total 915,804 Industrial Plasters 268,212 Board Products .MSF Lath 477,403 Veneer base 292,257 Gypsum sheathing 272,269 Regular gypsum board 9,014,908 Type X gypsum board 1,766,483 Predecorated wallboard 122,361 Total (MSF) 11,945,681 31 ------- PROCESSES RESEARCH, INC. INDUSTRIAL PLANNING AND RESEARCH If all of the board products averaged out at 1/2 inch thickness, which gives a weight of 2 pounds per square foot, the tonnage of board products is the same as the thousands of square feet produced. Using this assumption, the total ton- nage of gypsum and gypsum products produced in 1971 is 17,434,688 short tons. This is in close agreement with the apparent supply of crude gypsum which was estimated at 16,688,235 short tons (including imports) in 1971 (Ref» 6). The seven major producers and the location of their installations are: Company The Celotex Corporation The Flintkote Company Georgia-Pacific Corporation Gypsum Division Johns-Manville Corporation Kaiser Cement and Gypsum Corp, State Iowa New Jersey Ohio Texas Wyoming California Georgia Nevada New Jersey Texas Delaware Georgia Iowa Kansas Michigan New York Texas Utah Wyoming Nevada Arizona California Florida New Jersey Washington City Fort Dodge Edgewater Port Clinton Hamlin Cody Fremont Savannah Las Vegas Camden Sweetwater Wilmington Brunswick Fort Dodge Blue Rapids Grand Rapids Akron Buchanan Quanah Sigurd Lovell Las Vegas Florence Antioch Long Beach Jacksonville Delanco Seattle 32 ------- PROCESSES RESEARCH, INC. INDUSTRIAL PLANNING AND RESEARCH Company National Gypsum Company United States Gypsum Company State Arizona California Connecticut Florida Georgia Illinois Indiana Iowa Kansas Louisiana Maryland Michigan New Hampshire New Jersey New York Ohio Texas California Florida Indiana Iowa Louisiana Maryland Massachusetts Michigan Montana Nevada New York Ohio Oklahoma Pennsylvania Texas Utah Virginia City Phoenix Long Beach Richmond New Haven Tampa Garden City Waukegan Shoals Fort Dodge Medicine Lodge Westwego Baltimore National City Portsmouth Burlington Bronx Clarence Center Lorain Rotan Plaster City Santa Fe Springs Jacksonville East Chicago Shoals Fort Dodge Sperry New Orleans Baltimore Boston Alabaster River Rouge Lewistown Empire New Brighton (S.I.) Oakfield Stony Point Gypsum Southard Philadelphia Galena Park Sweetwater Sigurd Norfolk Saltville 33 ------- PROCESSES RESEARCH, INC. INDUSTRIAL PLANNING AND RESEARCH Of the 81 installations, 46 (or 56.8 percent) are located in, or very close to, standard metropolitan statistical areas. These include: East Coast 21 Gulf Coast 4 West Coast 7 Fort Dodge, Iowa 4 East Chicago, Indiana 1 Buffalo, New York 3 Sandusky, Ohio 2 Sweetwater, Texas 4 46 34 ------- PROCESSES RESEARCH, INC. INDUSTRIAL PLANNING AND RESEARCH SECTION VIII -DATA FROM OPERATING PLANTS The data shown in Tables IX and X were obtained from the plants indicated. 35 ------- TABLE IX EMISSIONS FROM CALCINING OPERATIONS PLANT DATA Date Company and Location Constructed Celotex Corp. Cody, Wyoming 1962 Edgewater, New Jersey 1958 Fort Dodge, Iowa 1958 Hamlin, Texas cas 1945 Port Clinton, Ohio ca. 1945 The Flintkote Co. Fremont, California 1965 Savannah, Georgia 1964 Georgia-Pacific Corp. Buchanan, New York 1969 Level1, Wyoming 1967 Grand Rapids Gypsum Co. Grand Rapids, Michigan 1970' Johns-Manvllle Corp. Florence, Arizona 1955 Las Vegas, Nevada 1965 Kaiser Gypsum Co. Jacksonville, Florida 1964 Delanco, New Jersey 1966 National Gypsum Co. Richmond, California 1964 Fort Dodge, Iowa 1940 Clarence Center, New York 1940 Long Beach, California 1965 United States Gypsum Co. Shoals, Indiana 1955 Stony Point, New York 1956 Baltimore. Maryland 1962 Dust Emission. Lbs/Hr Total 40 40 40 400 35 .02 Grains Per scf 0.5 0.84 0.56 35 0.2 4.3 45.5 45 0.45 7.6 12.6 0.9 5307 ,96 5.11 Dust Collection Equip. Fuel Burning S02 Emission Lbs/Hr Note 1 Note 1 Note 1 Note 1 Note 1 Negl. Negl. Negl. Negl. Negl. Negl. Negl. 1.33 Note 5 0 0 (61) 6 0 Negl. Negl. Negl. N°x Emission Negl. Negl. Negl. Negl. Negl. Negl. Note 4 Note 4 Negl. Negl. Negl. Negl. Negl. Negl. Negl. Fuel Used Note 1 Note 1 Note 1 Note 1 Note 1 Gas2 Gas Gas Gas Gas Gas ------- PROCESSES RESEARCH, INC. INDUSTRIAL PLANNING AND RESEARCH Notes for Table IX 1. S(>2 from low sulfur fuel meets. Federal standards. 2. No. 2 fule oil standby. 3. Also use a wet scrubber. 4. Unknown. 5. Unknown. Low sulfur fuel is used. 6. Quantity reported as 250 tons per year. Quantity shown is calculated using 8160 operating hours per year. 7. Board plant built in 1920. 37 ------- TABLE X EMISSIONS FROM BOARD PLANT OPERATIONS Company and Location Celotex Corp. Cody, Wyoming Edgewater, New Jersey Fort Dodge, Iowa Hamlln, Texas Fort Clinton, Ohio The Fllntkote Co. Freemont, California Savannah, Georgia Georgia-Pacific Corp. Buchanan, New York Love11, Wyoming Grand Rapids Gypsum Co. Grand Raplda, Michigan Kaiser Gypsum Co. Jacksonville, Florida Delanco, New Jersey National Gypsum Co. Richmond, California Fort Dodge, Iowa Clarence Center, New York Long Beach, California United States Gypsum Co. Shoals, Indiana Stony Point, New York Baltimore, Maryland Paper Dust .01 .01 15.4 Dust Emission. Lbs/Hr End Trim Board Dust Drying Total 30 5 5 30 Note 1 Note 3 0.5 .18 .19 .18 .19 5 33.3 14 2.8 2.6 2.1 2.9 3.6 19 12.8 9.9 Dust Collection Equip. Cyclones Baghouse . P X X X X Note 2 X X X X X5 X X X X X X X X X X X X X X X X Fuel Burning SC7 NOx Emission Emission Lbs/Hr^ Lbs/ Negl. Negl. Negl. Negl. Negl. Negl. Negl. Negl. Negl. Negl. 12.5 Negl. Negl. Negl. (94.4)' Negl. Negl. Negl. Negl. Negl. Negl. Negl. Negl. Negl. Negl. Negl. Negl. Negl. Negl. Note 6 Negl. Negl. Negl. Negl. Negl. Negl. Negl. Negl. Gas Gas Gas Gas Gas Gas* Gas" Gas Gas Gas Gas Gas Gas" Gas4 ------- PROCESSES RESEARCH, INC. INDUSTRIAL PLANNING AND RESEARCH Notes for Table X 1. None reported. 2. Closed system. 3. 99 percent of particles greater than 0.5 microns collected. 4. No. 2 fuel oil standby. 5. Also use a wet scrubber. 6. Quantity of NOX emission unknown. 7. Quantity reported as 340 tons per year. Quantity shown is calculated using 7200 operating hours per year. 39 ------- PROCESSES RESEARCH, INC. INDUSTRIAL PLANNING AND RESEARCH A rough estimate of nationwide particulate contamination from gypsum product plants can be made by using an average dust emission figure. From the data available this is 340 Ibs/hr for crushing, grinding, and calcining oper- ations, and 10.3 Ibs/hr for board plants. An average board line will produce 400 square feet per minute, or 4000*40) 365 . 210j2M mf per yMr Since approximately 12,000,000 MSF per year are produced (see Section VII), the total emission for board lines is (1°'3) = 588 Ibs Per hour nationwide. The total quantity of gypsum processed is approximately 17,500,000 tons per year. The average plant will process about 1000 tons of rock per day. Therefore, the approximate total emission for rock processing, is \l>50°>0™ (340) - 16,300 Ibs per hour nationwide 3o!> This is based on continuous three-shift operation. If the mill is operated on a one-shift basis, the dust emission rate would be three times this. Thus, the total dust emission rate could be as high as 49,500 pounds per hour on a nationwide basis. 40 ------- PROCESSES RESEARCH, INC. INDUSTRIAL PLANNING AND RESEARCH SECTION IX - BEST CONTROLLED PLANTS The best controlled plants are the latest ones built, and are equipped with baghouses or electrostatic precipitators or a combination of the two. Among these are: The Celotex Corporation Cody, Wyoming The Flintkote Co. Savannagh, Georgia Georgia-Pacific Corporation Buchanan, New York Grand Rapids Gypsum Co. Grand Rapids, Michigan Johns-Manville Corporation Florence, Arizona Las Vegas, Nevada Kaiser Gypsum Co. Delanco, New Jersey National Gypsum Co. Long Beach, California United States Gypsum Co. Baltimore, Maryland The quantity of emissions for these plants and the type of control equip- ment in use is shown in Tables IX and X. A baghouse collector costs approximately five times as much as a comparable cyclone collector. An electrostatic precipitator can be installed at a cost comparable to a baghouse if the flow quantity is high. The minimum flow rate for an industrial type precipitator is approximately 50,000 absolute cubic feet per minute. 41 ------- PROCESSES RESEARCH, INC. INDUSTRIAL PLANNING AND RESEARCH SECTION X - FORECAST OF GROWTH The demand for gypsum products is directly related to the housing industry. For the past five years the domestic production of crude gypsum has leveled off at 10 to 10.5 million short tons per year, with the balance of the crude supplied as imports. Conceivably, this situation could continue for the next few years and present gypsum producers attach a low probability to the possibility of new gypsum plants in the short term. Current indications of a rising trend in the housing industry could, however, lead to expansion of existing plants or possibly to new gypsum board plants in the near future. 42 ------- PROCESSES RESEARCH, INC. INDUSTRIAL PLANNING AND RESEARCH SECTION XI - INFORMATION SOURCES COMPANIES AND ORGANIZATIONS CONTACTED Celotex Corp. 1500 N. Dale Mabry Tampa, Florida 33607 (813) 872-3111 Flintkote Co. 400 WestChester Ave0 White Plains, New York 10604 (914) 761-7400 Georgia-Pacific Corp. 900 S. W. Fifth Street Portland, Oregon 97207 (503) 222-5561 Johns-Manville Corp. Greenwood Plaza Denver, Colorado (303) 770-1000 Kaiser Gypsum Co. 300 Lakeside Drive Oakland, California 94612 (415) 271-2211 National Gypsum Co. 325 Delaware Avenue Buffalo, New York 14202 (716) 852-5880 United States Gypsum Co. 101 South Wacker Drive Chicago, Illinois 60606 (312) 321-3400 The Gypsum Association 201 N. Wells Street Chicago, Illinois 60606 (312) 726-5675 Grand Rapids Gypsum Co. 1007 N. Division Ave. Grand Rapids, Michigan (616) 459-6183 49501 Marion M. Hambrick Vice President of Operations J. E. Krebs Project Engineer Vincent J0 Tretter, Jr. Senior Environmental Engineer Edmund M. Fenner Director of Technical Relations Robert Costa Vice President and General Manager W. A. Schmidt Chief Dust Control Engineer John F. Schroder Manager of Environmental Protection F. J. Rogers Manager, Administrative Services Not contacted. Data obtained through the Gypsum Association 43 ------- PROCESSES RESEARCH, INC. INDUSTRIAL PLANNING AND RESEARCH B. EQUIPMENT COMPANIES The Coe Manufacturing Co. Painesville, Ohio 44077 The Ehrsam Co. 300 N. Cedar Abilene, Kansas 67410 Combustion Engineering Co. Raymond Division 427 W. Randolph St. Chicago, Illinois 60606 C. STATES (Air Pollution Regulations) California California Air Resources Board 1108 14th Street Sacramento, California 95814 Florida Department of Pollution Control Suite 300, Tallahassee Bank Building 315 South Calhoun St. Tallahassee, Florida 32301 Georgia Georgia Department of Public Health 47 Trinity Avenue S.W. Atlanta, Georgia 30334 Indiana Air Pollution Control Board 1330 Vest Michigan St. Indianapolis, Indiana 46206 ATT: Mr. Perry E. Miller Technical Secretary 44 ------- PROCESSES RESEARCH, INC. INDUSTRIAL PLANNING AND RESEARCH Iowa Iowa Air Pollution Control Commission Iowa State Department of Health Lucas State Office Building Des Moines, Iowa 50319 ATT: Mr. Charles Campbell Michigan Bureau of Industrial Health and Air Pollution Control Department of Public Health 3500 N. Logan Lansing, Michigan 48914 New Jersey New Jersey State Department of Environmental Protection Bureau of Air Pollution Control P. 0. Box 1390 Trenton, New Jersey 08625 New York New York State Department of Environmental Conservation 41 State Street Albany, New York 12207 Oklahoma Environmental Health Services Air Pollution Control Division Oklahoma State Department of Health 3400 N. Eastern Oklahoma City, Oklahoma 73105 Oregon Department of Environmental Quality 1400 Southwest Fifth Avenue Portland, Oregon 97201 ATT: Mr. H. M. Patterson Chief, Air Quality Control Texas Texas Air Control Board 1100 West 49th Street Austin, Texas 78756 45 ------- PROCESSES RESEARCH, INC. INDUSTRIAL PLANNING AND RESEARCH D. PUBLICATIONS 1. American Petroleum Institute Engineering Reports Cyclone Dust Collectors, 1955 Removal of Particulate Matter from Gaseous Wastes - Filtration, 1961 Electrostatic Precipitators, 1961 2. Chemical Economics Handbook - Standford Research Institute, July 1971 3. Chemical Engineering Deskbook a_. Environmental Engineering, June 1971 b_. Environmental Engineering, May 1972 4. Combustion, August 1972 5. Environmental Science and Technology, October 1972 6. Mineral Industry Surveys - Gypsum (Quarterly) U. S. Bureau of Mines, 1971 7. Minerals Yearbook - U. S. Bureau of Mines, 1970 8. Pit and Quarry, August 1961 9. Pit and Quarry Handbook, 1971-72 10. Rock Products, November 1960 11. Rock Products, June 1966 E. PLANT VISITS National Gypsum Co.» Shoals, Indiana United States Gypsum Co., Shoals, Indiana Georgia-Pacific Corp., Buchanan, New York United States Gypsum Co., Stony Point, New York December 4, 1972 December 4, 1972 December 6, 1972 December 6, 1972 46 ------- |