ATMOSPHERIC EMISSION EVALUATION U.S. LIME HENDERSON, NEVADA TEST NO. 74 - LIM -4 U.S. ENVIRONMENTAL PROTECTION AGENCY OFFICE OF AIR QUALITY PLANNING & STANDARDS CONTRACT NO. 68-O2-O236 ------- U.S. LIME HENDERSON, NEVADA TABLE OF CONTENTS I. Discussion of Results « II. Procedure III. Clean-Up and Analysis IV. Process Description and Operation V. Computer Print-Outs °f Emission Data VI. Appendix - Field Data Sheets PAGE 1-6 7 - 8 9 - 10 11 - 12 13 - 20 21 - 43 (SECTIONS V AND VI ARE-NOT INCLUDED IN THIS REPORT) ------- VALENTINE, FISHER & TDMLINSDN CONSULTING ENGINEERS «.».M,N.A.C.,A.A.A.»., B.A..M.H., I.B.C. BZO LLOYD BUILDING or (zoe) 8ZS-C717 SEATTLE, WASHINGTON 98101 WM. M. VALENTINE, M.E. ARTHUR K. FISHER, M.E. GEORGE D. TOMLINSON, E.E. BR. ASSOCIATES WAYNE A. HANSON, M.E. DOUGLAS W. PASCOE, E.E. P. "CHIC" CICCHETTI December 26, 1974 ASSOCIATES! PHILIP W. WOODRUPF DENNIS W. FINLAYSON HENRY L. ROYCE, ILLUM. WILLIAM T. MCDONALD DEAN A. MANNIG ROGER C. HUNTLEY WESLEY D. SNOWDEN, P.E. INDRU J. PRIMLANI. M.E. PURPOSE Emissions samples were taken on the outlet duct at a lime hydrator located at Henderson, Nevada. The plant is owned and operated by U.S. Lime which is a division of Flintkote Co. The plant used a baghouse for particulate reduction purposes and was assumed to be one of the best controlled sources, in connection with this type of industrial process. Results of the tests are to be used by the EPA for evaluating and setting Nation-wide standards for this type of industrial process. SUMMARY The evaluation was performed on April 23/24, 19/4. The outlet grain loadings for the four samples were 0.0126, 0.0209, 0.0161, and 0.0186 for the respective runs. The grain loading was not corrected for COo. The average percent moisture for the four runs was 82.24%. The percent isokinetic for the four respective runs was 153%, 194%, 155%, and 140%. The standard cubic foot is defined at 70°F., 1 atmosphere pressure and dry. VALENTINE, FISHER & TOMLINSON Wesley D-xSttowden, P.E. Manager^JEnvironmental Services ------- DISCUSSION OF RESULTS The sampling team arrived on the afternoon of April 22, 1974. Due to U.S. Lime's early shutdown time of 4 P.M., work was not started until the morning of April 23, 1974. The sampling equipment was setup according to EPA Method 5 Procedures and a wet and dry bulb temperature was taken. The approximate moisture content of the stack gases was determined by using a high temperature psychrometric chart. This moisture content was 80%. A nomograph was then set up using the collected data. The standard EPA nomograph for isokinetic sampling is based upon a maximum moisture content of 50%. This made it necessary to interpolate several values in order to arrive at an approximate "K" value on the nomograph. A short 25-minute sample was taken to confirm the moisture content and isokinetic sampling rate. The moisture content agreed with the psychrometeric chart, but preliminary calculations showed the precent isokinetic well below 100%. This was attributed to the high moisture content of the stack gases. During the next 4 runs the air flow rate through the dry gas meter was hand calculated for each point. At the completion of each test the isokinetic sampling rate was calculated and adjustments were made. A review of the data summary shows that the ideal 100% _+ 10% isokinetic sampling rate was not reached. The isokinetic sampling rates for all of the five runs were substantially above 100%. This discrepancy can be accounted for by considering two factors. The nomograph used was intended for moisture contents from 0% to 50%. This made it necessary to interpolate several values in order to arrive at an approximate "K" value on the nomograph, as mentioned above. The second reason can be reviewed on the following graph. Curve No. 1 is comparing the percent moisture and the percent isokineLic lor Lhe first lest at U.S. Lime. For this run the "C" value was only approximated and the sample was run to determine isokinetic values and percent moisture. As can be seen the slope of the curve is quite steep in the area between 90% and 110% isokinetic which are the allowable limits of EPA Method 5. If the original determination of the percent moisture of the stack gases is in excess of +_ 3% • of the actual, the percent isokinetic will be beyond the allowable limits. This compares with a tolerance of + 11% moisture for stack gases in the vicinity of 5% moisture content (Curve No. 2) which is a more typical percent moisture. To demonstrate how the high moisture content could have affected over isokinetic Values, the following conditions could apply. If the same nomograph setting was used on Run No. 2 as on Run No. 1 the percent isokinetic for Run No. 2 would have been approximately 98% based upon the moisture correction. If the same nomograph setting was used on Run No. 3 the percent isokinetic would have been approximately 160% isokinetic. The conclusion is that when sampling stack gases with this high of moisture content continuous monitoring of the percent moisture with a wet bulb, dry bulb and psychrometric chart is necessary and the nomograph or equations should be readily available to make adjustments in the sampling flow rate. The existing outlet duct was modified with a duct extension, (Figure 3)_ and sampling was accomplished with this extension. A total of twelve (12) sampling points were selected, three (3) traverses with 4 points each, in the square stack. Data readings were taken every two and one-half minutes with 5 minutes per point for a total of one hour per sample. Due to the extremely high moisture content of the flue gases the impinger section of the sampling train would become completely filled with condensed water in approximately 30 minutes. ffSr ------- DISCUSSION OF RESULTS PAGE TWO . When this occured the sampling train was stopped and the backhalf of the sampling train (impingers) was completely removed and a new section installed. Approximately 25 pounds of ice were required for each one hour run, due to the high heat content of the nearly saturated gases. COo readings were taken during each run with a Fyrite. The maximum value which could accurately be read was 20% C0_. Any value greater than this had to be read by visually extending the scale and interpolating the values. Due to the extremely high moisture content a correction was made for the moisture added to the fryrite solution, which could result in higher readings. The Fyrite was zeroed and a C0~ reading was taken. After reading the C02 concentration, the Fyrite solution was released and allowed to return to its neutral level. The difference between the original zero and this final neutral level was deducted from the CO 2 reading and was assumed to be the fraction added by the water vapor. This correction quantity never exceeded 1% (X>2 and in most cases was zero. The outlet grain loadings were 0.0126, 0.0209, 0.0161 and 0.0186 grains per standard cubic foot for Runs 2 through 5. Run No. 2 has a substantially lower grain loading >than the other three runs. This can be accounted for because of two factors. . Approximately 660 ml of sample was lost, thus only 1610 ml of the original 2270 ml was analyzed. An approximate value for the particulate lost was calculated by determining the concentration of the particulate in the remaining solution and multiplying it times the quantity of solution lost. This can be considered only an approximation, as a review of ths iiiipiriSvsr "CiGhcc of the othsr runs indic-itcc thct the "articulate vcs not evenly distributed throughout the various sample bottles. The second point is that no acetone wash of the impingers and bubblers was performed •on this run. ------- EFFE.CT Or MOISTURE! CONTENT OF STACK 6AS ON /SO/C-//VE77C TOL.ERA/VCC /SO- yields 3i~/ 'if I I .© „•*,,.«>., lo lo •KV-v1" ±31, /VIOIS. -i L- J ------- DATA SUMMARY LIME HYDRATOR - U.S. LIME . HENDERSON, NEVADA RUN NO. 1** 2 3 4 5 AIR ACFM 5367 6175 5791 5378 5895 FLOW SCFM 683 939 581 675 539 PERCENT MOISTURE 80.4 76.2 86.4' 80.7 85.7 PERCENT ISOKINETIC 114 153 194 155 140 OUTLET GRAIN LOADING (FRONT HALF)*GR/SCF - 0.0126 0.0209 0.0161 0.0186 PMR (FRONT HALF)* LB/HR - 0.102 0.104 0.093 0.086 Data based on particulate collected in front half of sampling train, uncorrected for non-isokinetic conditions. Calculated using ratio of front half particulate to Pt of data print-out. Sample collected to determine % moisture. Particulate collected was not analyzed. ------- ^4 ^e- k. SIDE/ELEV. FRONT ELEV. PLAN SAMPLING PORT PROVISIONS HYDRATED LIME FACILITY U S L IME CO. ES-1 ------- PROCEDURE (PARTICULATE SAMPLING TRAIN) Stack gas sampling equipment designed by the United States Environmental Protection Agency (EPA), Office of Air Programs was used on this evaluation. A schematic of the sampling equipment is included in this report. Sampling was performed according to the following: Sampling ports were selected and installed. The number of sampling points were determined considering the number of duct diameters between obstructions in the duct up stream and down stream of the sampling ports. Stack pressure, temperature moisture content and maximum velocity head readings were measured. An EPA designed nomograph was set up using this data and the correct nozzle diameter was selected using the nomograph. The sampling train was prepared as follows: An impinger was filled with approximately 500 gram of silica gel and weighed to the nearest 0.1 gram. A filter (MSA 1106-BH) was labeled and dessicated for at least 24 hours and weighed to the nearest 0.5 mg. 100 milligrams of water was placed in the first and second impingers. The third impinger was left dry. All three impingers were then weighed individually to the nearest 0.1 gram and recorded. • A leak test.was preformed on the assembled sampling train. The leak rate did not exceed O.Q2- cfm at a vacuum of 24 inches Hg. The probe was heated so tliau the gas i_euip£i'aLui.*t at the probe cutlc-t was approximately 250 F. The filter was heated to approximately 250°F. to avoid condensation of moisture on the filter. Crushed ice was placed around the impingers at the beginning of the test with new ice being added as.required to keep the gases leaving the satapling train below 70°F. The train was operated as follows: The Probe was inserted into the stack to the first traverse point with the nozzle tip pointing directly into the gas stream. The pump was started and immediately adjusted to sample at isokinetic velocities. Equal time was spent . at selected points of equal elemental areas of the duct with the pertinent data being recorded from each time interval. The EPA nomograph was used to maintain isokinetic sampling throughout the sampling period. At the conclusion of the run the pump was turned off, the probe was removed, and the final readings were recorded. Clean up of the sample train and analysis of the samples was performed according to the enclosed clean up and analysis procedure. ------- PROCEDURE (continued) The weight of the dust per volume and weight of dust per time were calculated as follows: The Concentration Method: The condentration of dust entering the sampling nozzle is calculated and then multiplied by the volumetric flow rate of the stack gases to obtain the Pollutant Mass Rate (PMR). Concentration in Nozzle x Volumetric Flow Rate = Pollutant Mass Rate On Concentration Basis. (I>T/VOLSTD) x QQS = PMRp Assuming the nozzle velocity is greater than the average stack gas velocity (V greater than V ), the calculated Pollutant Mass Rate will be less than the true Pollutant Mass Rate because the heavier dust particles will leave their streamline and not enter the nozzle. If \'n is less than V then the calculated PMR will be greater than the true PMR. ------- CLEM-UP AND ANALYSIS Clean-up of the EPA train was performed by carefully removing the filter and placing it in a container marked "Run X, Container A". Distilled water and brushes were used to clean the nozzle, glass probe and pre-filter connections. The water wash was placed in a container marked "Run X, Container B". The volume of water in the impinger and bubblers (glassware) was weighed in their respective containers to the nearest 0.1 gram. The original weights which included approximately 100 ml. of water in the bubbler and 100 ml. of water in the impinger were then subtracted and the difference added with the water weight gain of the silica gel. This represented the amount of water collected during the run. The water from the glassware and a water rinse oi: the glassware was placed in a container marked "Run X, Container C". An acetone rinse of the glassware and all post-filter glassware (not including the silica gel container) was performed and placed in a container marked "Run X, Container D". Analysis of the samples in each container was performed according to the following: Run X, Container A - Transfer the filter and any loose particulate from the sample container to a tared glass weighing dish and desiccated for.24 hours in a desiccator or constant humidity chamber containing a saturated solution of calcium chloride or its equivalent. Weighed to a constant weight and report the results to the nearest 0.1 milligram. Run X, Container B - Measure tne volume to the nearest 0.1 milliliter. Transfer water washings from container into a tared beaker and evaporate to dryness at ambient temperature and pressure. Desiccate for 24 hours and weigh to a constant weight. Report the result to the nearest 0.1 milligram. Run X, Container C - Measure the volume to the nearest 0.1 milliliter. Extract organic particulate from the water solution with three 25 milliliter portions of chloroform and three 25 milliliter portions of ethyl ether. Combine the ether and chloroform extracts and transfer to a tared beaker. Evaporate until no solvent remains at about 70°F. This can be accomplished by blowing air that has been filtered through activated charcoal over the sample. Desiccate for 24 hours and weigh to a constant weight. Report the results to the nearest 0.1 milligram. After the extraction, evaporate the remaining water to dryness and report the results to the nearest 0.1 milligram. i Run X, Container D - Measure the volume to the nearest 0.1 milliliter. Transfer the acetone washings to a tared beaker and evaporate to dryness at ambient temperature and pressure. Desiccate for 24 hours and weigh to a constant weight. Report the results to the nearest 0.1 milligram. Blanks were taken on the deionized water, ether and chloroform and subtracted from the respective sample volumes. The filter paper used with the EPA train was a Mine Safety Appliance 1106 BH, heat treated glass fiber filter mat. ------- The following sample identification numbers were assigned to samples collected at U.S. Lime Company, Henderson, Nevada: RUN NO. ANALYSIS // 2A 2B 2C 2CX 2D 3A 3B 3C 3C 3D" x 4A 4B 4C AC 4D~ x CLEAN-UP // 13A 13B 13C 13D 14A 14B 14C 14D ISA 15B 15C 15D DESCRIPTION Filter Front Half Acetone Wash Back Half Water Ether-Chloroform Extraction Back Half Acetone Wash * Filter Front Half Acetone Wash Back Half Water Ether-Chloroform Extraction Back Half Acetone Wash Filter Front Half Acetone Wash Back Half Water Ether-Chloroform Extraction Back Half Acetone Wash 5A 5B 50 5CX 5D 16A 16B Ifir. 16D Filter Front Half Acetone Wash Back Half Water Ether-Chloroform Extraction Back Half Acetone Wash ------- PROCESS DESCRIPTION AND PROCESSS Limestone consists primarily of calcium carbonate or combinations of calcium and magnesium carbonate with varying amounts of impurities. Lime is calcined or burned form of limestone, commonly divided into two basic products - quicklime and hydrated lime. Calcination expels carbon dioxide from the raw limestone, leaving calcium oxide (quicklime). With the addition of water, calcium hydroxide (hydrated lime) is formed. The basic processes in production are (1) quarrying the limestone raw material, (2) preparing the limestone for kilns by crushing and sizing, (3) calcining the limestone, and (4) optionally processing the quicklime further by additional crushing and sizing and then hydration. The Flintkote Company dolomitic lime plant at Henderson, Nevada, operates a pressure hydration unit controled by a baghouse. To prevent condensation of moisture on the bag filters, the offgases from the hydrator are heated to between 300 and 350°F. by a gas burner before passing through the baghouse. The pressure drop across the bag- house ranged from 2.3 to 4.1 in H20. The gas exiting from the baghouse contains approximately 79% H20 and 15% C02. This gas exits through the fan exhaust directly to the atmosphere. A summary of the operating variables is presented in the following Table. Process feed rates were not obtained because the isokinetic sampling was not successful. For these tests an extension duct was added to allow sampling according to EPA prescribed methods. Addition of this ducting increased back pressure on the baghouse and resulted in condensation of water vapor on the filters. The exhaust fan shaft speed was increased from the normal rate of 1835 RPM to 2080 RPM to overcome the condensation problem. Sampling performed consisted of four one-hour particulate samples. More extensive testing was abandoned when calculations indicated that sampling could not be performed in accordance with EPA requirements for 90 to 110 percent isokinetic flow. The extremely high moisture content, approximately 80% by volume, was the source of this difficulty. Future attempts to sample this plant must be preceded by a revision of EPA particulate sampling procedures. Visual observation of the residual plume indicates that the baghouse is doing a very good job of controlling particulate emissions. A five minute .collection of hydrate caught in the baghouse indicated that it was recovering approximately 100 pounds of lime per hour. ------- SUMMARY OF PRESSURE HYDRATOR AND BAGHOUSE OPERATING DATA DURING SAMPLING Date 4/24/74 4/24/74 4/25/74 Test No. 11 3, 4, & 5 Lime Feed Rate (tons/hr) Water Feed Rate (tons/hr) Hydrated Feed Rate (tons/hr) Baghouse Pressure Drop (inches H20) 3.9-4.1 3.3-3.5 2.3-3.35 Baghouse Inlet Temp. (°F) 318-356 324-347 305-351 12 ------- |