APMM Unit Recommendations/Considerations for AQP Un it Reasonable Progress

Determination for Devon Energy Blaine County #1 Com pressor Station Prepared by Claudia Smith
Emission Limit for 5,500 HP Ingersoll Rand 616 Natu ral Gas-Fired Compressor Engines
AP-42 specifies a NO x emission factor of 2.21 lbs/MMBtu for rich-burn na tural gas-fired reciprocating internal combustion engines. Based o n 90% control efficiency typically predicted for NSCR add-on control equipment, that would trans late to a controlled emission factor of 0.22 lbs/MMBtu

. The APMM unit typically sets emission limits as a m ass per unit time limit, such as lbs/hr.
Review of the permit analysis for a since modified version of Montana DEQ’s air pollution control permit for this facility (permit number 162 6-05) indicated that uncontrolled NO x emissions from these engines were estimated at 956. 13 tpy, or 218.06 lbs/hr. Considering 90% control efficiency, that would translate to a contr olled emission rate of 95.6 tpy or 21.8 lbs/hr

. Typical MRR Permit Requirements for Rich Burn Natur al Gas-Fired Engines with NSCR
Note: emission limit is typically a short term mass per unit time limit, such as lbs/hr (this could be calculated and recorded as a rolling 30-day aver age).
Work Practice and Operational Requirements

1. Each engine shall be equipped with a non-selective catalytic reduction (NSCR - three way catalyst) with air-to-fuel ratio control system capable of reducing uncontrolled emissions of NO x by at least 90% at maximum operating rate (90% to 110% of engine capacity at site elevation).

2. Install a temperature-sensing device (i.e. thermoco uple or resistance temperature detectors) before the catalyst in order to monitor the inlet temperatures of the catalyst for each engine.

3. The engine exhaust temperature at the inlet to the catalyst for each engine, shall be maintained at all times the engine operates at at l east 750oF and no more than 1250oF in accordance with manufacturer’s specifications. [Comment: The catalyst inlet temperature is important; it has to be hot enough t o work, but not so hot as to damage the catalyst – the actual temperature range would b e dependent on the specifications of the manufacturer of the control – the range above i s what is found in MACT ZZZZ for rich burn RICE with NSCR].

4. Install gauges before and after the catalyst for ea ch engine in order to monitor pressure drop across the catalyst. The pressure drop shall not change by more than ± 2” water at 100% load plus or minus 10% from the pressure drop across the catalyst measured during the initial performance test. [Comment: Pressure drop is a good indication of ca talyst operation; too low, the catalyst may be blown out; too high and it may be clogged].

5. Follow, for each engine and its respective catalyst , the manufacturer’s recommendedAPMM Unit Recommendations/Considerations for AQP Un it Reasonable Progress

Determination for Devon Energy Blaine County #1 Com pressor Station Prepared by Claudia Smith
maintenance schedule and procedures to ensure optim um performance of each engine and catalyst.

6. All engines shall be fired only with natural gas. The natural gas shall be pipeline-quality in all respects except that the CO 2 concentration in the gas shall not be required to be within pipeline-quality.

[Note: The purpose of requirement 6, above, is to ensure that there are no contaminants in the fuel that might foul the catalyst. In general, pip eline-quality natural gas is (1) within ± 5% of the heating value of pure methane, or 1,010 Btu/per cub ic foot under standard atmospheric conditions, and (2) free of water and toxic or corr osive contaminants. However, CO 2 is not a potential foulant of the catalyst and has therefore been excluded from the requirement.]

Testing Requirements

1. An initial performance test shall be conducted for each engine for measuring NO x emissions from the engines to demonstrate initial c ompliance with the emission limits. The initial performance test shall be conducted wit hin 90 calendar days of the effective date of the permit (or in this case, the reasonable progress determina tion?)

. 2. Upon change out of the catalyst for each engine a performance test shall be conducted for measuring NO x from the engines to demonstrate compliance with th e emission limits and re-establish temperature and pressure correlations. The performance test shall be conducted within 90 calendar days of the date of th e catalyst change out.
3. The performance tests for NO x shall be conducted in accordance with the test met hods specified in 40 CFR Part 60, Appendix A. EPA Refer ence Method 7E shall be used to measure NO x emissions.

4. All tests for NO x emissions must meet the following requirements:
(a) All tests shall be performed at a maximum opera ting rate (90% to 110% of engine capacity at site elevation).
(b) During each test run, data shall be collected o n all parameters necessary to document how NO x emissions in pounds per hour were measured or calc ulated (such as test run length, minimum sample volume, vo lumetric flow rate, moisture and oxygen corrections, etc.). The temperature at the inlet to the catalyst and the pressure drop across the catalyst shall also be mea sured and recorded during each test run for each engine.
(c) Each source test shall consist of at least thre e 1-hour or longer valid test runs. Emission results shall be reported as the arithmeti c average of all valid test runs and shall be in terms of the emission limits (pound s per hour) and grams per horsepower-hour.APMM Unit Recommendations/Considerations for AQP Un it Reasonable Progress

Determination for Devon Energy Blaine County #1 Com pressor Station Prepared by Claudia Smith
(d) A source test plan for NO x emissions shall be submitted to EPA at least 45 calendar days prior to the scheduled performance te st.
(e) The source test plan shall include and address the following elements:
(i) Purpose of the test;
(ii) Engines and catalysts to be tested;
(iii) Expected engine operating rate(s) during test ; (iv) Schedule/dates for test;
(v) Sampling and analysis procedures (sampling loca tions, test methods, laboratory identification);
(vi) Quality assurance plan (calibration procedures and frequency, sample recovery and field documentation, chain of custody procedures); and
(vii) Data processing and reporting (descrip tion of data handling and

quality control procedures, report content).
Monitoring Requirements

1. Measure NO x emissions from each engine at least semi-annually or once every 6 month period to demonstrate compliance with the emission limits. To meet this requirement, measure NOx emissions from the engines using a port able analyzer and a monitoring protocol approved by EPA. Submit the analyzer spec ifications and monitoring protocol to EPA for approval within 45 calendar days of the effective date of the permit (or in this case, the reasonable progress determination?) . Monitoring for NO x emissions shall commence during the first complete calendar quarter following the permittee’s submittal of the initial performance test results for NO x to EPA.

2. Measure the engine exhaust temperature at the inlet to the oxidation catalyst at least once per week. The pressure drop across the oxidation c atalyst shall be measured monthly. Each temperature-sensing device shall be accurate t o within plus or minus 0.75% of span and the pressure sensing devices shall be accurate to within plus or minus 0.1 inches of
water.

II.E. Recordkeeping Requirements [40 CFR 71.6(a)(3)(ii)]

1. Comply with the following recordkeeping requirem ents:
(a) Records shall be kept of all temperature and pr essure measurements required by this permit.
(b) Records shall be kept of vendor specifications for the thermocouples and pressure gauges.APMM Unit Recommendations/Considerations for AQP Un it Reasonable Progress

Determination for Devon Energy Blaine County #1 Com pressor Station Prepared by Claudia Smith
(c) Records shall be kept of vendor specifications for the NSCR catalyst and the airto-fuel ratio controller on each engine.

(d) Records shall be kept that are sufficient to de monstrate that the fuel for the engines is pipeline-quality natural gas in all resp ects, with the exception of the CO 2 concentration in the natural gas.
2. Records shall be kept of all required testing an d monitoring. The records shall include the following:
(a) The date, place, and time of sampling or measu rements;
(b) The date(s) analyses were performed;
(c) The company or entity that performed the analys es; (d) The analytical techniques or methods used;

(e) The results of such analyses or measurements; a nd
(f) The operating conditions as existing at the tim e of sampling or measurement.
3. Records of all required monitoring data and supp ort information shall be maintained for a period of at least 5 years from the date of the mon itoring sample, measurement, or report. These records shall be made available upon request by EPA Region 8. Support information includes all calibration and maintenanc e records, all original strip-chart recordings for continuous monitoring instrumentatio n, and copies of all reports required.
II.F. Reporting Requirements [40 CFR 71.6(a)(3)(iii)]
Submit to EPA a written report of the results of th e required performance tests. This report shall be submitted within 90 calendar days of the date of testing completion.