CEM Istanbul, 14 th May 2014

Transcription

1 Predictive Emission Monitoring (PEM): Suitability and Application in View of U.S. EPA and European Regulatory Frameworks CEM Istanbul, 14 th May 2014 Thomas Eisenmann Dr. Roland Bianchin David Triebel Seite 1

2 Introduction Predictive Emission Monitoring Systems (PEMS) are used for continuous monitoring of emissions at stationary sources as an alternative and backup for Continuous Emission Monitoring Systems (CEMS, in Europe usually AMS - Automated Monitoring System). PEMS define the relationship between a number of characteristic process parameters of an emission source and the corresponding emission concentration. PEMS provide a reasonable alternative to CEMS (AMS) where there is a reliable and predictable correlation between plant operating conditions and emissions.

3 Introduction This is generally applicable to gas and oil fired plants, e.g. Boilers Turbines Reciprocal Internal Combustion Engines (RICE) Heaters Furnaces Ships Just to name a few

4 Introduction DAHS plus Emissions Model DCS Inputs (read only) Data Interface by bus systems (Modbus, Profibus, OPC etc.) D-DAS 2010 D-PEMS Control Control Building Emission Source NO x, CO, O 2 etc. Fuels: Gas, Oil etc. Fuel Flow DAHS: DCS: Data Acquisition & Handling System Distributed Control System

5 Regulatory Framework U.S. EPA CEMS as well as PEMS in the USA and countries following U.S. Environmental Protection Agency (EPA) regulations are mainly governed by 40 C(ode)F(ederal)R(egulation) Part 60 (Part 63) and 40 CFR Part 75. PEMS as Alternative Monitoring Method (AMS) is specifically addressed in Part 60 Performance Specification PS-16 and Part 75 Subpart E Alternative Monitoring Methods.

6 US EPA Part 60 New Source Performance Standard - NSPS, promulgated first 1971 Subparts for each type of source with e.g. subpart D covering boilers, GG covering stationary gas turbines and J Petroleum Refineries Industrial Units >100 mmbtu (about 29 MW), in some case also to smaller sources (e.g. Subpart Dc covering small industrial boilers) Requires Continuous Monitoring of Primary Pollutants (NOx, SO2, CO, Opacity and VOC) Part 60 is flanked by a series of test methods for emission measurements and 13 (17) Performance Specifications

7 Performance Specifications Performance specifications are used for evaluating the acceptability of CEMS (and PEMS) at the time of or soon after installation and whenever specified in the regulations; Quality assurance procedures in 40 CFR Part 60 Appendix F are used to evaluate the effectiveness of quality control (QC) and quality assurance (QA) procedures and the quality of data produced by any CEMS / PEMS.

8 US EPA Part 75 Continuous Emission Monitoring, originally published in 1993 Continuous Emission Monitoring (CEM) and reporting requirements under EPA s Acid Rain Program (ARP), instituted in 1990 under Title IV of the Clean Air Act Included is a cap and trade program as market-based approach to reducing emissions ARP regulates electricity generating units (EGUs) that burn fossil fuels and that serve a generator > 25 megawatts It requires continuous monitoring and reporting of SO 2 mass emissions, CO 2 mass emissions, NO x emission rate, and heat input Emissions data must be reported for each operating hour, without exception Each CEMS or PEMS must be equipped with an automated DAHS

9 Regulatory Framework Europe PEMS in compliance with pren (WG 37) PEMS Standard IED 2010/75/EU The Large Combustion Plant Directive LCPD (2001/80/EC) The Waste Incineration Directive WID (2000/76/EC) EN Applicability of QAL1? EN Applicability of minimum requirements as per Part 3 needs to be reviewed.

10 CEN / TC 264 WG 37 PEMS Standard CEN (European Committee for Standardization) established within the Technical Committee (TC) 264 Air Quality the working group WG37 Main stimulus came from the Netherlands. They use PEMS in particular for refinery / petrochemical applications The normative work started of from a Dutch draft and is entitled pren Predictive Emission Monitoring Systems (PEMS) Applicability Execution and Quality Assurance Legal basis is the EU directive EU for industrial emissions

11 CEN / TC 264 WG 37 PEMS Standard Four Task Groups: Building a PEMS QA of PEMS Validation of a PEMS U.S. EPA Part 60 (PS-16) as well as Part 75 (Subpart E) Generic example of execution and QA of a PEMS. WG37 standard must accommodate the one-of-a-kind uniqueness of PEMS focus for a primarily specific plant; on a certification for a specific plant (initial RATA). This is a particular challenge for dealing with EN15267 Part 3 and the array of questions concerning type tests; Detailed suitability of QAL2 test schemes of EN14181 will be investigated

12 VGB PEMS Project R&D project funded by VGB Power Tech, the European technical association for power and heat generation: Evaluation of the application of Predictive Emissions Monitoring Systems (PEMS) in Europe taking into account the boundary conditions of the Standards EN and EN Conducted at two combined cycle power plants in Germany Major objective was to compare PEMS with plant CEMS and the results of a QAL2 conducted by an independent, accredited stack tester Lessons learned gave good insight, where improvements can be achieved and what needs to be observed to successfully conduct the PEMS implementation process A detailed assessment of performance criteria in EN15267 Part 3 with respect to their applicability for PEMS can be found in the final report of TUEV Rheinland

13 Some Other PEMS Relevant Activities Another working group, WG 9 Quality assurance of automated measuring systems (Amendment to EN14181:2004) within TC 264 is related to WG 37. It is working on a draft standard for data acquisition and handling systems (DAHS). To address communication and digital interfaces, a quite significant issue also for PEMS and their integration in plant-wide IT networks, the Association of German Engineers VDI has published a series of guideline documents as VDI 4201, Part1-4

14 Practical Minimum Performance Requirements I Best model selectable and application specific to provide the best fit to a plant process and the most economical way. Components: NO x / O 2 / CO / SO 2 / CO 2 / NH 3 / HC / VOC / HCHO / others as needed. Model parameters individual per component Units: Any unit wanted by the operator or stipulated by environmental regulation (ppm, mg/nm 3, g/gj, etc.). Ranges only limited by used analyzer for the training data set. Model building incorporating data from multiple analyzers and multiple ranges. Ranges fully adjustable. Sensor Validation System: Determination of defective and erroneous process sensors and inputs. PS-16 requires it daily, recommended is once per minute. Redundant sensors and analysis of reliable inputs.

15 Practical Minimum Performance Requirements II Accuracy and precision as per PS-16 /Subpart E / CEMS standard Measurement frequency 1 sec. Response time: 99,9 % less than 1 sec. Data availability 99 % + Executable on standard server and workstation hardware Visualization (graphic user interface - GUI) By means of a data acquisition systems, but also own (simple graphic representation) Prevention of data manipulation and unauthorized reproduction of licenses, e.g. log file recording immutably all modification of software or model, model encryption, new revision number, license key etc. All standard interfaces, e.g. OPC, ModBus, Profibus etc.

16 Quality Assurance PEMS is an Analyzer! Measure Sensor Validation Relative Accuracy Audit RAA Relative Accuracy Test Audit RATA EN QAL1 EN QAL 2 EN QAL 3 EN 14181AST Frequency Once per minute, minimum daily Quarterly / Monthly Annual Uncertainty: PEMS Model Building Initial calibration Periodic checks at regular intervals Annual

17 Quality Assurance EPA Part 60 Initial certification Sensor Validation Quarterly RAAs Subsequent RAAs Yearly RATA According PS-16 (continual compliance): Minimum 27-run (9 runs at three operating levels of the key parameter that most affects emissions ) relative accuracy test (RAA). Minimum daily check, recommended once per minute or once per monitoring cycle. RAAs in the first year after initial certification: At least three 30- minute portable analyzer or reference method (RM) determinations*. Step 3 All quarterly RAAs passed in the first year and the RATA in the second year: One may elect to perform a single mid-year RAA in the second year. Step 4 Yearly Relative Accuracy Test Audit (RATA): Minimum 9-runs at the normal operating level. Step 5 Step 2 Step 1 *The average of the portable analyzer or Reference Method determinations must not differ from the PEMS average value by more than 10 percent or the test is failed

18 Quality Assurance EPA Part 75 Subpart E Alternative Monitoring System (AMS) Compliance Approval 720 operating hour demonstration that the AMS has same or better precision, reliability, accessibility, and timeliness (PRAT) as a CEMS Data Availability Valid paired data for at least 90 % of the minimum 720 operating hours Reliability Valid one-hour averages for minimum 95.0 % of operating hours for one year Sensor Validation System shall include an alarm to inform the operator when sensors need repair and when the PEMS is out-ofcontrol. Sensor failure test. RAA & RATA Semi-annual or annual RATA 3-run (minimum) RAAs in every month in which the unit operates for at least 56 hours (may be only for ozone season May- September or waived for a three-month RAA) Normal operating levels

19 Summary and Comparison PEMS CEMS Common Features Continuous Plant Types Accuracy / Precision Quality assurance Data Acquisition CEMS / PEMS Both methods can be used for continuous emissions monitoring. For all oil- and gas-fired sources. Accuracy and precision are comparable provided that the same quality assurance is applied. Securing data quality with procedures of EN14181 / requirements of EN (EU) as well as Part 60 / Part 75 RATA / RAA (USA) For data representation and reporting of monitoring results, use of data acquisition and handling systems.

20 Summary and Comparison PEMS CEMS Differences CEMS PEMS Hardware Application Cost Quality assurance Gas Analyzers Accessories like probes, heated lines, racks, shelters etc. needed CEMS more universally applicable: Plants fired with variable solid fuels Components like particulate matter and Hg Standard server hardware with means for data back-up and securing data integrity Basically not suitable for solid, moisture absorbing fuels Not applicable at e.g. waste incinerators Restricted for coal-fired plants Capital cost: Approximately 50 % of a comparable CEMS. In case of model transferability or for ex-proof areas, cost difference may even be much higher Operations and maintenance: Approximately % of CEMS cost Quality assurance: No cost difference EU: Type approval U.S. Daily Zero and Span Check (Part 60) EU: EN may not be reasonably applicable due to the plant specific, oneof-a-kind characteristic of PEMS U.S. Sensor Validation System (PS-16, Subpart E). Resilience to input failures.

21 Predictive Emission Monitoring (PEM): Suitability and Application in View of U.S. EPA and European Regulatory Frameworks CEM Istanbul, 14 th May 2014 Seite 22