MBUAPCD RULE 435 CONTROL OF NOX FROM KILNS
LAST REVISED 09/21/94

RULE 435.  CONTROL OF NITROGEN OXIDES FROM KILNS 
Adopted September 21, 1994


                                 CONTENTS


PART 1  GENERAL. . . . . . . . . . . . . . . . . . . . . . . . . . . . .  3
  1.1   Purpose. . . . . . . . . . . . . . . . . . . . . . . . . . . . .  3
  1.2   Applicability. . . . . . . . . . . . . . . . . . . . . . . . . .  3
  1.3   Exemptions . . . . . . . . . . . . . . . . . . . . . . . . . . .  3
  1.4   Effective Dates. . . . . . . . . . . . . . . . . . . . . . . . .  3
  1.5   References . . . . . . . . . . . . . . . . . . . . . . . . . . .  4

PART 2  DEFINITIONS. . . . . . . . . . . . . . . . . . . . . . . . . . .  4
  2.1   Calendar Year. . . . . . . . . . . . . . . . . . . . . . . . . .  4
  2.2   Clock-Hour Average Measurements. . . . . . . . . . . . . . . . .  4
  2.3   Combustion Modification. . . . . . . . . . . . . . . . . . . . .  4
  2.4   Continuous Emissions Monitoring System (CEMS). . . . . . . . . .  4
  2.5   Dolomite . . . . . . . . . . . . . . . . . . . . . . . . . . . .  5
  2.6   Dolomite Hearth Kiln . . . . . . . . . . . . . . . . . . . . . .  5
  2.7   Dolomite Rotary Kiln . . . . . . . . . . . . . . . . . . . . . .  5
  2.8   Emissions. . . . . . . . . . . . . . . . . . . . . . . . . . . .  5
  2.9   Excess Oxygen. . . . . . . . . . . . . . . . . . . . . . . . . .  5
  2.10    Hearth Kiln. . . . . . . . . . . . . . . . . . . . . . . . . .  5
  2.11    Heating Value. . . . . . . . . . . . . . . . . . . . . . . . .  5
  2.12    Kiln . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6
  2.13    Magnesia . . . . . . . . . . . . . . . . . . . . . . . . . . .  6
  2.14    Magnesia Hearth Kiln . . . . . . . . . . . . . . . . . . . . .  6
  2.15    Magnesia Rotary Kiln . . . . . . . . . . . . . . . . . . . . .  6
  2.16    Maximum Rated Capacity . . . . . . . . . . . . . . . . . . . .  6
  2.17    Nitrogen Oxides (NOx). . . . . . . . . . . . . . . . . . . . .  6
  2.18    Periclase. . . . . . . . . . . . . . . . . . . . . . . . . . .  7
  2.19    Portland Cement. . . . . . . . . . . . . . . . . . . . . . . .  7
  2.20    Preheater Precalciner Portland Cement Kiln . . . . . . . . . .  7
  2.21    Roller Mill. . . . . . . . . . . . . . . . . . . . . . . . . .  7
  2.22    Rotary Kiln. . . . . . . . . . . . . . . . . . . . . . . . . .  7
  2.23    Running 24-Hour Average Measurements . . . . . . . . . . . . .  7
  2.24    Shut-down. . . . . . . . . . . . . . . . . . . . . . . . . . .  7
  2.25    Start-up . . . . . . . . . . . . . . . . . . . . . . . . . . .  8
  2.26    Stoichiometric Combustion. . . . . . . . . . . . . . . . . . .  8
  2.27    Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  8

PART 3  REQUIREMENTS AND STANDARDS . . . . . . . . . . . . . . . . . . .  8
  3.1   Requirements for Preheater Precalciner Portland Cement
        Kilns. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  8
  3.2   Requirements for Dolomite Rotary Kilns . . . . . . . . . . . . .  8
  3.3   Requirements for Magnesia Rotary Kilns . . . . . . . . . . . . .  9
  3.4   Requirements for Dolomite Hearth Kilns . . . . . . . . . . . . .  9
  3.5   Requirements for Magnesia Hearth Kilns . . . . . . . . . . . . .  9
  3.6   Continuous Emissions Monitoring Systems (CEMS) . . . . . . . . .  9
  3.7   Source Test Requirements . . . . . . . . . . . . . . . . . . . . 10
  3.8   Calculation of Average Emissions . . . . . . . . . . . . . . . . 11

PART 4  ADMINISTRATIVE REQUIREMENTS. . . . . . . . . . . . . . . . . . . 12
  4.1   Implementation Plan. . . . . . . . . . . . . . . . . . . . . . . 12
  4.2   Schedule for Implementation of the Rule. . . . . . . . . . . . . 12
  4.3   Authority to Construct Application . . . . . . . . . . . . . . . 12
  4.4   Recordkeeping Requirements . . . . . . . . . . . . . . . . . . . 13
  4.5   Reporting Requirements . . . . . . . . . . . . . . . . . . . . . 13
  4.6   Required Test Methods. . . . . . . . . . . . . . . . . . . . . . 14





PART 1  GENERAL


1.1   Purpose

      The purpose of this Rule is to limit emissions of nitrogen
      oxides (NOx) resulting from operation of minerals processing
      kilns.


1.2   Applicability

      The provisions of this Rule shall apply to minerals processing
      kilns within the jurisdiction of the Monterey Bay Unified Air
      Pollution Control District (District).


1.3   Exemptions

  1.3.1   The provisions of this Rule shall not apply to facilities that
          emit less than a total of 100 tons of NOx per calendar
          year.

  1.3.2   The provisions of this Rule shall not apply to kilns that
          operate fewer than 100 hours during any calendar year.

  1.3.3   The provisions of this Rule shall not apply to dryers
          operating at temperatures below 800oF used to heat product
          for the purpose of releasing physically bound water.

  1.3.4   The provisions of this Rule shall not apply to kilns used
          exclusively in the production of ceramic ware, and with
          heat provided by firing with natural gas, propane, or
          electricity.

  1.3.5   The provisions of Sections 3.1.1, 3.1.2, 3.2, 3.3, 3.4, and
          3.5 of this Rule shall not apply during scheduled maintenance
          activities, start-up conditions, or shut-down conditions.

  1.3.6   If any kiln operates during a six month period but is not
          tested during that period as required by Section 3.7.2, the
          source testing shall be conducted during the next period of
          operation for that kiln.


1.4   Effective Dates

  1.4.1   The requirements of this Rule shall become effective
          December 21, 1994.  Implementation of the rule
          requirements shall be consistent with the deadlines provided
          in Part 4 of this Rule.

  1.4.2   This Rule shall terminate and be of no further force or
          effect upon approval by the United States Environmental
          Protection Agency (EPA) of the exemption request for
          relief from the requirement to adopt NOx reasonably
          available control technology (RACT) measures for the
          District's North Central Coast Air Basin, under the
          provisions of Section 182(f) of the federal Clean Air Act. 
          The North Central Coast Air Basin consists of Monterey,
          San Benito, and Santa Cruz counties.

 
1.5   References

      The requirements of this Rule result from the requirements of
      Section 182(b)(2) of the federal Clean Air Act (Title 42 United
      States Code Section 7401 et seq.)



PART 2  DEFINITIONS


2.1   Calendar Year

      A period of one year beginning and ending with the dates of
      January 1 and December 31.


2.2   Clock-Hour Average Measurements

      Measurements based upon a one-hour average computed from data
      points equally spaced over each clock-hour period.


2.3   Combustion Modification

      Any modification of the firing process in an affected unit,
      including changes to the primary or secondary combustion air
      or fuel flow systems, that results in a change of oxygen (O2),
      carbon monoxide (CO), and nitrogen oxides (NOx) emissions.


2.4   Continuous Emissions Monitoring System (CEMS)

      The total equipment necessary for the continuous determination
      and recordkeeping of process gas concentrations and emission
      rates.


2.5   Dolomite

      A mineral consisting of calcium magnesium carbonate,
      CaMg(CO3)2.


2.6   Dolomite Hearth Kiln

      Any hearth kiln that produces calcined dolomite or dead-burned
      dolomite from raw dolomite feed material.


2.7   Dolomite Rotary Kiln

      Any rotary kiln that produces calcined dolomite or dead-burned
      dolomite from raw dolomite feed material.


2.8   Emissions

      The quantitative rate of releases of air contaminants to the
      atmosphere from an emission point, as measured by the
      continuous emission monitoring system, source tests, or as
      calculated by the methods specified in an applicable rule,
      regulation, or permit to operate.


2.9   Excess Oxygen

      Oxygen concentration, measured in percent, remaining after a
      fuel has been completely burned; or the oxygen supplied in
      addition to that required for stoichiometric combustion.


2.10    Hearth Kiln

      A vertical kiln in which feed material is introduced in the top
      and moves down through a series of horizontal sections, or
      hearths.


2.11    Heating Value

      The quantity of heat obtained from the combustion of one unit of
      fuel.  For the purposes of calculating operating limits
      specified in Sections 3.1.2, 3.2, 3.3, 3.4, and 3.5, heating
      values of 12,000 BTU per pound of coal; 139,400 BTU per
      gallon of number 2 fuel oil; 153,165 BTU per gallon of
      number 6 fuel oil; and 1,050 BTU per standard cubic foot of
      natural gas shall be used.  Alternately, the owner or operator
      of an affected unit may submit applicable heating values obtained
      from certified fuel analyses.


2.12    Kiln

      A device for producing a chemical change (loss of chemically
      bound water, oxidation, or reduction) in feed materials by high
      temperature combustion of any fuel in the presence of the feed
      materials.


2.13    Magnesia

      An oxide of magnesium, MgO, commonly used in refractory
      products, cements, insulation, fertilizers, and rubber products.


2.14    Magnesia Hearth Kiln

      Any hearth kiln that fires magnesium hydroxide to produce
      magnesia.


2.15    Magnesia Rotary Kiln

      Any rotary kiln that fires magnesium hydroxide to produce
      magnesia or periclase.


2.16    Maximum Rated Capacity

      The maximum design heat input of a unit at the highest heating
      value of the fuel used.


2.17    Nitrogen Oxides (NOx)

      The sum of the molecular forms of nitrogen oxide and nitrogen
      dioxide.  When measured or calculated, the total of the two
      molecular forms are collectively expressed as nitrogen dioxide
      (NO2).


2.18    Periclase

      A crystalline, refractory material, which is produced from
      magnesium hydroxide and additives.


2.19    Portland Cement

      A hydraulic cement made by calcining a mixture of argillaceous
      (clay), calcareous (calcium) minerals and other additives.


2.20    Preheater Precalciner Portland Cement Kiln

      An energy efficient kiln that utilizes a suspension preheater
      precalciner and a rotary kiln system to produce Portland
      cement.


2.21    Roller Mill

      The grinding process in a Portland cement manufacturing
      process which performs drying, secondary crushing, and size
      classification of kiln feed materials.


2.22    Rotary Kiln

      A horizontal kiln in which feed material moves from one end to
      the other end of a slightly-inclined, rotating, cylindrical shell.


2.23    Running 24-Hour Average Measurements

      Measurements averaged over any consecutive twenty-four (24)
      hour period.  Each 24-hour average value shall be computed
      from clock-hour average measurements.


2.24    Shut-down

      That period of time during which a kiln is allowed to cool
      from operating temperature to a lower temperature or until
      combustion ceases, not to exceed 36 hours.


2.25    Start-up

      That period of time during which a kiln is heated to operating
      temperature from a lower temperature, not to exceed 36 hours
      from introduction of feed material into the kiln system.


2.26    Stoichiometric Combustion

      Combustion occurring with the theoretically chemically correct
      ratio of air to fuel necessary to completely burn the fuel with
      no excess oxygen.


2.27    Unit

      Any kiln as defined in Sections 1.2 and 2.12 herein.



PART 3  REQUIREMENTS AND STANDARDS


3.1   Requirements for Preheater Precalciner Portland Cement Kilns

  3.1.1   Each preheater precalciner Portland cement kiln shall be
          equipped with a digital process feedback controller which
          maintains oxygen concentrations as measured at the third
          stage of the kiln by the continuous emissions monitors
          specified in Section 3.6 equal to or less than two and
          one-half (2.5) percent for any running 24-hour averaging
          period.

  3.1.2   Each preheater precalciner Portland cement kiln shall not
          exceed a firing rate of 3.4 million British Thermal Units
          per ton (MMBTU/ton) of product produced for any running
          24-hour averaging period.  Continuous fuel use and product
          logs, as specified in Section 4.4.1.3, shall be maintained
          to verify compliance with this firing rate.


3.2   Requirements for Dolomite Rotary Kilns

      Each dolomite rotary kiln shall not exceed a firing rate of
      7.50 MMBTU/ton of product produced for any running 24-hour
      averaging period.  Continuous fuel use and product logs, as
      specified in Section 4.4.1.3, shall be maintained to verify
      compliance with this firing rate.  Annual NOx emissions shall be
      calculated by the District based upon these fuel use records and
      source test results as specified in Section 3.7.2.


3.3   Requirements for Magnesia Rotary Kilns

      Each magnesia rotary kiln shall not exceed a firing rate of
      26.5 MMBTU/ton of product produced for any running 24-hour
      averaging period.  Continuous fuel use and product logs, as
      specified in Section 4.4.1.3, shall be maintained to verify
      compliance with this firing rate.  Annual NOx emissions shall be
      calculated by the District based upon these fuel use records and
      source test results as specified in Section 3.7.2.


3.4   Requirements for Dolomite Hearth Kilns

      Each dolomite hearth kiln shall not exceed a firing rate of
      23.5 MMBTU/ton of product produced for any running 24-hour
      averaging period.  Continuous fuel use and product logs, as
      specified in Section 4.4.1.3, shall be maintained to verify
      compliance with this firing rate.  Annual NOx emissions shall be
      calculated by the District based upon these fuel use records and
      source test results as specified in Section 3.7.2.


3.5   Requirements for Magnesia Hearth Kilns

      Each magnesia hearth kiln shall not exceed a firing rate of
      23.5 MMBTU/ton of product produced for any running 24-hour
      averaging period.  Continuous fuel use and product logs, as
      specified in Section 4.4.1.3, shall be maintained to verify
      compliance with this firing rate.  Annual NOx emissions shall be
      calculated by the District based upon these fuel use records and
      source test results as specified in Section 3.7.2.


3.6   Continuous Emissions Monitoring Systems (CEMS) 

  3.6.1   Each preheater precalciner Portland cement kiln shall be
          operated with a continuous emissions monitoring system
          (CEMS) for determining and recording continuous NOx
          concentrations in the stack gases.  CEMS shall also be
          operated for determining and recording continuous CO at
          the preheater exit and O2 concentrations at the third stage
          of the kiln.  NOx emissions shall be calculated as NO2.

  3.6.2   Each CEMS shall be installed, certified, maintained, and
          operated consistent with a District-approved implementation
          plan as described Section 4.1; and, except for those
          specified in Section 3.6.3, shall meet the following
          federal specifications:

    3.6.2.1   40 Code of Federal Regulations (CFR) Part 60, Appendix
              B, Spec. 4 (Environmental Protection Agency (EPA)
              Performance Specification 4, "Specifications and
              Test Procedures for CO Continuous Emission
              Monitoring Systems in Stationary Sources");

    3.6.2.2   40 CFR Part 60, Appendix B, Spec. 3 (EPA Performance
              Specification 3, "Specifications and Test Procedures
              for O2 and CO2 Continuous Emission Monitoring Systems
              in Stationary Sources"); and

    3.6.2.3   40 CFR Part 60, Appendix B, Spec. 2 (EPA Performance
              Specification 2, "Specifications and Test Procedures
              for SO2 and NOx Continuous Emission Monitoring
              Systems in Stationary Sources").

  3.6.3   CEMS required for monitoring CO and O2 concentrations
          for each precalciner Portland cement kiln shall be
          maintained in a good working condition with proper
          calibration and maintenance records, consistent with a
          District-approved plan submitted in accordance with
          Section 4.1.  

  3.6.4   Operators of each CEMS, except those specified in Section
          3.6.3, must follow the EPA quality assurance procedures
          of 40 CFR Part 60, Appendix F (Quality Assurance
          Procedures "Procedure 1.  Quality Assurance
          Requirements for Gas Continuous Emission Monitoring
          Systems Used for Compliance Determination").

  3.6.5   Each CEMS subject to this Rule shall complete a minimum of
          one cycle of operation (sampling, analyzing, and recording
          data) for each successive 15-minute period.

  3.6.6   CEMS data files shall be maintained by the operator and
          made available for District inspection upon request,
          according to the provisions of Section 4.4 of this Rule.


3.7   Source Test Requirements

  3.7.1   Source testing shall be performed at least once each year
          to verify compliance with the requirements of Sections
          3.1.1 and 3.1.2.  The source tests shall be performed in
          accordance with the methods detailed in Section 4.6 and, in
          addition, be consistent with the facility's District-issued
          Permit to Operate and the District Source Testing
          Procedures Manual.

  3.7.2   For any kiln which operates within a given six calendar
          month period, from either January 1st through June 30th or
          from July 1st through December 31st, source testing shall be
          performed during that six month period to establish NOx
          emissions for affected units specified in Sections 3.2,
          3.3, 3.4, and 3.5.  The results from each source test
          shall be used to establish an emission factor relating NOx
          emissions to fuel use (pounds NOx per MMBTU) that shall be
          used to calculate NOx emissions for the following six month
          period.  The source tests shall be performed in
          accordance with the methods detailed in Section 4.6 and
          consistent with the District Source Testing Procedures
          Manual.

    3.7.2.1   The owner/operator of any kiln subject to Section
              3.7.2 may petition the Air Pollution Control Officer
              (APCO) of the District to reduce the frequency of such
              testing to an annual basis, if it can be demonstrated to
              the satisfaction of the APCO that consistent emission
              factors have been derived from at least two years of
              compliance testing.

  3.7.3   Emissions determinations shall be conducted on units
          operating at a production rate of at least 90 percent of
          maximum standard production.  All emissions
          determinations shall be conducted on units in an operating
          condition typical of normal production.  Emissions
          testing, however, shall not be performed during start-up,
          shut-down, or breakdown conditions.


3.8   Calculation of Average Emissions, Fuel Use, and Production
      Rates

  3.8.1   For CEMS, average emissions shall be calculated as
          clock-hour averages.  Clock-hour average emissions
          shall be used to compute running 24-hour concentrations to
          demonstrate compliance with Sections 3.1.1 and 3.1.2. 
          Conversions shall be calculated according to the
          procedures within 40 CFR Part 75, Appendix F (Conversion
          Procedures).

  3.8.2   CEM data recorded during periods of CEMS breakdowns,
          repairs, scheduled maintenance, calibration checks, and
          zero and span adjustments shall not be included in the
          calculated averages.  Missing data shall be estimated
          following the procedures of 40 CFR Part 75, Appendix C
          (Missing Data Statistical Estimation Procedures).

  3.8.3   For kilns subject to the requirements of Sections 3.1.2,
          3.2, 3.3, 3.4, and 3.5, average fuel use and production
          rates shall be measured as clock-hour averages.  Clock-
          hour average fuel use and product rate measurements shall
          be used to calculate running 24-hour average rates.  

  3.8.4   For determining compliance with the limits set forth in
          Sections 3.1.2, 3.2, 3.3, 3.4, and 3.5, 24-hour fuel use
          rates shall be converted to BTUs using the heating values
          specified in Section 2.11.



PART 4  ADMINISTRATIVE REQUIREMENTS


4.1   Implementation Plan

  4.1.1   By December 31, 1995, the owner or operator of each
          affected source shall submit for approval to the Air
          Pollution Control Officer an implementation plan for
          compliance with the provisions of this Rule.

  4.1.2   Each implementation plan shall propose the actions and
          alternatives which will be taken to meet the requirements
          of this Rule.  At a minimum, each implementation plan shall
          include:

    4.1.2.1   A list of kilns subject to this Rule, including kiln and
              burner manufacturer, applicable model numbers,
              maximum rated capacity for each kiln, and the feed and
              product materials.

    4.1.2.2   A description of the process control equipment that
              shall be used to achieve the excess oxygen requirements
              of this Rule.

    4.1.2.3   A description of the CEMS proposed to meet the
              requirements of this Rule, including make and model
              number of the CEM equipment, proposed location of
              sample ports, a schedule and description of scheduled
              maintenance, zero and span checks, calibration
              activities, and certification protocols.

    4.1.2.4   A schedule for implementation which shows increments
              of progress by which the source will be brought into
              compliance and certification of final compliance by
              December 31, 1996.


4.2   Schedule for Implementation of the Rule

      By December 31, 1996, the owner or operator of each affected
      unit shall comply with the requirements of this Rule.


4.3   Authority to Construct Application

      Within 30 days following approval of the implementation plan by
      the Air Pollution Control Officer, the owner or operator of
      each affected kiln shall submit a complete application for any
      Authority to Construct required for the installation of any
      equipment necessary to comply with Sections 3.1, 3.2, 3.3,
      3.4, and 3.5 herein, or CEMS equipment necessary to comply
      with Section 3.6 of this Rule.


4.4   Recordkeeping Requirements

  4.4.1   The owner or operator of each affected kiln shall
          maintain permanent hourly and applicable running average
          records (running 24-hour average emissions or running 24-
          hour average fuel and production rates) in a District-
          approved format for a period of five years after creation
          and shall make these records available for inspection by
          the Air Pollution Control Officer upon request.  As an
          alternative, the records may be kept in a District-approved
          electronic format.  The records shall include, but not be
          limited to:

    4.4.1.1   The dates, times, and durations of any start-up, shut-
              down, or breakdown periods.

    4.4.1.2   Clock-hour and running 24-hour average records of
              concentrations of CO, NOx, and percent O2, based upon
              data collected from the CEMS for any preheater
              precalciner cement kiln.

    4.4.1.3   Clock-hour and running 24-hour average records of
              the type, quantity, and heat content of fuel burned in the
              affected unit, the quantity (in tons) of product
              produced, and the ratio of heat input to product
              produced for affected units specified in Sections
              3.1.2, 3.2, 3.3, 3.4, and 3.5.

    4.4.1.4   Monthly NOx emissions calculated from the 24-hour
              average records of fuel use and the most current
              District-approved emission factor established by
              source testing as specified in Section 3.7.2.

    4.4.1.5   Records of maintenance, zero and span checks,
              breakdowns, calibrations, and certifications of each
              CEMS.

  4.4.2   For any CEMS subject to this Rule, records of all raw and
          processed data for parameters measured shall be
          maintained for a period of five years after creation and
          shall be made available for inspection by the Air Pollution
          Control Officer upon request.  


4.5   Reporting Requirements

      Quarterly summary reports of data collected during each
      calendar quarter under the provisions of Section 4.4 shall be
      submitted in a District-approved format to the District within
      45 days after the end of each calendar quarter.  The
      summaries must include, but are not limited to: 

  4.5.1   The maximum daily running 24-hour average concentrations
          of CO, NOx, and percent of O2 for each preheater
          precalciner Portland cement kiln which operated during the
          reporting quarter.

  4.5.2   The running 24-hour average fuel use and production rates
          for each kiln specified in Sections 3.1, 3.2, 3.3, 3.4,
          and 3.5, and operated during the reporting quarter.

  4.5.3   The quarterly NOx emissions for units specified in
          Sections 3.1, 3.2, 3.3, 3.4, and 3.5.

4.6   Required Test Methods

  4.6.1   O2 concentrations in stack gases during stationary source
          tests shall be demonstrated using EPA Method 3A,
          "Determination of O2 and CO2 Concentrations in Emissions
          from Stationary Sources (Instrumental Analyzer
          Procedure)" or California Air Resources Board (CARB)
          Method 100, "Procedures for Continuous Gaseous Emission
          Stack Sampling" (Stack Gas Oxygen).

  4.6.2   NOx concentrations in stack gases during stationary
          source tests shall be demonstrated using EPA Method 7E,
          "Determination of Nitrogen Oxides Emissions from
          Stationary Sources (Instrumental Analyzer Procedure)"
          or CARB Method 100, "Procedures for Continuous Gaseous
          Emission Stack Sampling" (Stack Gas NOx).

  4.6.3   CO concentrations in stack gases during stationary source
          tests shall be demonstrated using EPA Method 10,
          "Determination of Carbon Monoxide Emissions from
          Stationary Sources" or CARB Method 100, "Procedures
          for Continuous Gaseous Emission Stack Sampling" (Stack
          Gas CO).

  4.6.4   CO concentrations at the preheater exit of each preheater
          precalciner Portland cement kiln shall be demonstrated
          following methods detailed in the District-approved plan
          specified in Section 4.1.2
                                 * * * * *