Intricacies of VOC Measurement

Transcription

1 Intricacies of VOC Measurement PIOGA - Air Quality Compliance Training October 12, 2017 Presented by Timothy Rodak

2 What's in a Title? Intricacies of VOC Measurement In Reality Mysteries? Nightmares? Frustrations?

3 What is a VOC? Volatile Organic Compounds Definition per 40 CFR Part (s) (as of October 30, 2014) Volatile organic compounds (VOC) means any compound of carbon, excluding carbon monoxide, carbon dioxide, carbonic acid, metallic carbides or carbonates, and ammonium carbonate, which participates in atmospheric photochemical reactions.

4 What is a VOC? Although the same term VOC is used for both indoor and outdoor air quality, the term is defined differently to reflect its predominant concern in each context. This has created a misunderstanding in the marketplace and in the environmental community. In addition, the measured quantity and composition of VOCs in the air can vary significantly depending on the measurement methods used, which has generated additional confusion.

5 Easier Question: What is not a VOC? Answer: Methane Ethane Formaldehyde

6 How should VOC be measured? EPA says

7 How should VOC be measured? 40 CFR Part (s) (2) For purposes of determining compliance with emissions limits, VOC will be measured by the test methods in the approved State implementation plan (SIP) or 40 CFR part 60, appendix A, as applicable. (4) For purposes of Federal enforcement for a specific source, the EPA shall use the test methods specified in the applicable EPA-approved SIP, in a permit issued pursuant to a program approved or promulgated under title V of the Act, or under 40 CFR part 51, subpart I or appendix S, or under 40 CFR parts 52 or 60.

8 EPA Method 25A Total Hydrocarbons EPA Method 320 Methane, Ethane +

9 EPA Method 25A Total Hydrocarbons To do it right you have to know more than the method 1. Frequently Asked Questions (FAQs) for Method 25A How to report data, Caveat: Methane response factor PADEP Source Testing Manual, Revision 3.3, 2000 Section The entire sampling system prior to the flame ionization analyzer (FIA) must be heated to the higher of 248±25 F (120±14 C) or stack temperature. Heating above 400 F is not required.

10 EPA Method 25A Total Hydrocarbons To do it right you have to know more than the method 3. PADEP EPA Method 25A Notes (key points that are not mentioned in the method) /Pages/default.aspx

11 PADEP EPA Method 25A Notes 16 additional points Highlights: 1. higher of 248±25 F (120±14 C) or stack temperature. 2. Record temperatures of components at 15-minute intervals 3. heated portions of the analyzer should be at least 10 F hotter than the rest of the sampling system.

12 Possibly 7 or more components to record temperature every 15-minutes

13 EPA Method 320 Methane and Ethane + Speciation method using FTIR technology, Self-validating method, QA/QC 2. Can measure significant number of organics 3. Complex, requires highly trained personnel 4. Industry use and knowledge are increasing 5. Oversight and Agency scrutiny are also increasing

14 Focus: 40 CFR 60, Subpart JJJJ EPA Method 320 for VOC measurement 1. Table 2 to Subpart JJJJ of Part 60 Requirements for Performance Tests For Each You Must Using Stationary Internal Combustion Engine v. Measure VOC at the exhaust of the stationary internal combustion engine; Methods 25A and 18 Method 25A with HC Cutter Method 18 Method 320 ASTM Method

15 III. Summary of Amendments F. Standards of Performance for Stationary Spark Ignition Internal Combustion Engines (Subpart JJJJ) of Part 60

16 III. Summary of Amendments F. Standards of Performance for Stationary III. Summary of Amendments Spark Ignition Internal Combustion F. Standards Engines of Performance (Subpart JJJJ) for Stationary of Part 60 Spark Ignition Internal Combustion Engines (Subpart JJJJ) of Part 60

17 EPA Method 18 or 320 alone cannot be used to measure VOC lack of a consistent, demonstrable, and validated approach to measuring total VOC emissions. VOC Measurement Approach by Difference Method Total Hydrocarbons EPA Method 25A Methane/Ethane EPA Method 320 VOC = M25A M320

18 Use of the Difference Method It makes compliance testing fun again

19 Source: MKS Instruments, Inc. Certification Methods Errors in the Analysis of NMHC and VOCs in CNG-Based Engine Emissions

20 A Good Test Day A Bad Test Day Engine 1 Engine 2 THC (EPA M 25) ppm C3 VOC (M25A-320) ppm C3 THC (EPA M 25) ppm C3 VOC (M25A-320) ppm C3 Run 1 Run 2 Run g/bhp = 0.08 (Limit = 0.25)

21 Conclusions VOC defined by how its measured Testing requirements beyond the method (EPA Method 25A) Use of EPA Method 320 increasing Difference Method there are good days and bad days More to come

22 Intricacies of VOC Measurement Timothy Rodak