New Direct Flame Monitoring Technology to Help Operators Comply with Increasingly Stringent Flaring Regulations

Paper from the AFRC 2017 conference titled New Direct Flame Monitoring Technology to Help Operators Comply with Increasingly Stringent Flaring Regulations

Known shortcomings of current flare monitoring methods plus new EPA standards drove the need to develop a new direct flare combustion efficiency (CE) measurement and monitoring method - a technology that directly, autonomously, and continuously monitors flare performance in real time. This patented method, known as VISR, or Video Imaging Spectro-Radiometry, utilizes a multi-spectral infrared (IR) imager to simultaneously measure the relative concentrations of combustion products, carbon dioxide (CO2), and unburned hydrocarbons (HC) at the pixel level. Directly monitoring flare CE eliminates inaccuracies associated with the current practice of monitoring indirect parameters (heating value, velocity, etc.). Because VISR devices can operate autonomously, no aiming or manual data reduction is required. Remote measurement removes the need for contact with corrosive process streams, making VISR devices less costly to maintain and operate over time. This paper will discuss the VISR technology and how it can be used to generate continuous, real-time data on CE and smoke, allowing operators to optimize flare performance in real time.

NEW DIRECT FLAME MONITORING TECHNOLOGY TO HELP OPERATORS COMPLY WITH INCREASINGLY STRINGENT FLARING REGULATIONS Brian Duck Zeeco, Inc. Broken Arrow, Oklahoma, USA ABSTRACT Known shortcomings of current flare monitoring methods plus new EPA standards drove the need to develop a new direct flare combustion efficiency (CE) measurement and monitoring method - a technology that directly, autonomously, and continuously monitors flare performance in real time. This patented method, known as VISR, or Video Imaging Spectro-Radiometry, utilizes a multi-spectral infrared (IR) imager to simultaneously measure the relative concentrations of combustion products, carbon dioxide (CO ), and unburned hydrocarbons (HC) at the pixel level. Directly monitoring flare CE eliminates inaccuracies associated with the current practice of monitoring indirect parameters (heating value, velocity, etc.). Because VISR devices can operate autonomously, no aiming or manual data reduction is required. Remote measurement removes the need for contact with corrosive process streams, making VISR devices less costly to maintain and operate over time. This paper will discuss the VISR technology and how it can be used to generate continuous, real-time data on CE and smoke, allowing operators to optimize flare performance in real time. 2 Page 1 Table of Contents Table of Contents ................................................................................................................................. 2 Table of Tables ..................................................................................................................................... 2 Table of Figures.................................................................................................................................... 2 Introduction........................................................................................................................................... 3 Zeeco FlareGuardian .......................................................................................................................... 5 Testing and Validation ......................................................................................................................... 7 Results ................................................................................................................................................... 8 Discussion ............................................................................................................................................. 9 Conclusions ......................................................................................................................................... 10 Appendix ............................................................................................................................................. 11 TM Table of Tables Table 1 - Comparative Table showing EPA requirements and VISR .............................................. 6 Table 2 - Design Features and Benefits of Zeeco FlareGuardian monitoring system .................... 6 Table of Figures Figure 1 - Example of Air Assisted Flare .......................................................................................... 3 Figure 2 - Example of Sonic Process Flare ........................................................................................ 3 Figure 3a - Image of smokeless flaring .............................................................................................. 4 Figure 3b - VISR Image of smokeless flare ....................................................................................... 4 Figure 3c - Example of Smoking Flare System ................................................................................. 4 Figure 3d - VISR reported image of smoking flare ........................................................................... 4 Figure 4 - Zeeco FlareGuardian monitoring system in use during validation testing ..................... 5 Figure 5 - Example of testing Setup for FlareGuardian Validation .................................................. 7 Figure 6 - Flare CE Validation of FlareGuardian vs. Extractive Sampling Method ....................... 8 Page 2 Introduction The changing government regulations imposed on refineries, gas processing facilities, petrochemical manufacturers, and OEM vendors demand constant adaptation to meet requirements. Across the globe, facilities are scrutinized for their emissions contributions to our global environment and are soon to be held to even more stringent standards. Since its inception, the United States Environmental Protection Agency (EPA) has been actively involved in various flare system enforcement initiatives to reduce the emissions from flares. Some examples of industrial flares can be seen below in Figures 1 & 2. Figure 1 - Example of Air Assisted Flare Figure 2 - Example of Sonic Process Flare In December 2015, the EPA imposed well-defined flaring regulations regarding emissions in the new Refinery Risk and Technology Review (RTR) Rule. To comply with this updated regulation, flare performance is required to be monitored by strict, defined parameters that currently can only be determined using indirect measurement methods or labor-intensive extractive sampling techniques. Recent testing has shown that the latest EPA methodology for monitoring combustion efficiency (CE) by way of calculating the combustion zone net heating value (CZNHV) varies greatly and invites questions regarding the efficacy of this method. Also, of the few other measurement methods known to measure CE as required to comply with new regulations, none have been credited with being timely, effective in cost or results, or easy to operate and manage. For example, extractive sampling techniques are effective and accurate, but require tremendous effort and labor to produce results. Measuring surrogate parameters (indirect monitoring) requires substantial financial investment in specialized components to ensure compliance (gas chromatographs, BTU analyzers, ultrasonic flowmeters, etc.). Consequently, results do not produce a direct measurement of a flare's performance or any real-time data. A method that will comply with the EPA's newest regulations and optimize flare performance requires a more long-term, simplified, and accurate solution. In this paper, we will discuss how the implementation of new technology utilized in Zeeco's FlareGuardian monitoring system can generate real-time continuous monitoring to meet this demand and satisfy compliance with ease. TM Page 3 VISR Technology Other technology exists to directly monitor flare systems, but most cannot produce results to verify regulation compliance. Those technologies can have tremendous shortcomings as well; for instance, while the use of infrared (IR) flame or pilot monitors can provide imagery capable of determining the presence of a flame, no flare performance or efficiency measurements can be derived with these devices. When "Passive Fourier Transform IR" methods (PFTIR) are employed, they can provide data to comply with regulations but are limited to a single line of sight approximate to wind direction for a flaring event and must be continuously manned and adjusted to monitor CE. With the use of patented Video Imaging Spectro-Radiometry (VISR) technology, achieving real-time measurement of flare efficiency and hydrocarbon (HC) /combustion product emissions is simplified. VISR technology provides a direct flare CE measurement while simultaneously minimizing the chance of calculation errors common to indirect measurement technologies. VISR's multispectral imaging system utilizes a specialized micro-lens array and bandpass filtering systems to generate CE and performance information in real time. This capability utilized in conjunction with complex flame behavior algorithms, permits VISR devices to convert the filtered signals identifying chemical species and combustion products into data images to deliver detailed, accurate measurements of a flare's performance. Figures 3a-3d below illustrate the capabilities of VISR to produce filter-specific imaging to achieve this function. Figure 3a - Image of Smokeless Flaring Figure 3b - VISR Image of Smokeless Flare Figure 3c - Example of Smoking Flare System Figure 3d - VISR Reported Image of Smoking Flare Page 4 VISR's capabilities to recognize chemical species in distinct wavelength spectrums (CO2, CO, HC, etc.) at the pixel level produces comparative measurements within the flame envelope. Over a measurement frequency of 30 Hertz (Hz), VISR reports in one (1) second averaged intervals of flare performance and other parameters (smoke production, flame surface area, etc.). Environmental effects such as ultraviolet (UV) and infrared (IR) interference from sunlight in the field of view have essentially no effect on the measurement capabilities of a VISR system. In addition, rain and fog do not prevent this technology from obtaining accurate measurements, ensuring consistent data and performance of the device over various conditions. FlareGuardian TM To take full advantage of the advancements made by VISR technology, Zeeco has produced a VISR-based product called FlareGuardian to meet the demand for an efficient, accurate, and compliant direct flare monitoring system. An illustration of the testing setup of a Zeeco FlareGuardian unit can be seen in Fig. 4. Figure 4 - Zeeco FlareGuardian Monitoring System In Use During Validation Testing Table 1 below shows the high-level requirements of the RTR rule in relation to industrial flaring. Because the legislation does not clearly define the methodologies to verify compliance, CE measurement via direct monitoring devices such as FlareGuardian will eliminate many of the hardships faced by companies otherwise forced to employ and substantiate measurement via "alternative options." Page 5 Table 1 - Comparative Table showing EPA Requirements and VISR As illustrated, FlareGuardian offers the capability to meet all requirements and ensure compliance while avoiding costly measurement techniques and reducing the time required to adjust in the field - consequently improving flare efficiency. Table 2 explains the full benefits of employing Zeeco's FlareGuardian flare monitoring system: FlareGuardian Benefits and Design Aspects -Provides real-time combustion efficiency, smoke index, flame stability, flame footprint, heat release, and pilot status for a complete picture of flare performance -Autonomous data collection (PLC or DCS) for optimized flare performance -Simplifies monitoring, reporting, and compliance activities -Patented technology -Remote mounted, non-contact monitoring -More accurate results versus indirect monitoring -Eliminates the need for monitoring surrogate parameters -Smoke index (SI) assist in achieving incipient smoke conditions day and night -Short measurement cycle enables quick response and minimizes cost for supplemental fuel, steam, or air -Industrial interface allows for closed loop flare operation and control based on direct combustion efficiency and smoke index values Table 2 - Design Features and Benefits of Zeeco FlareGuardian Monitoring System Page 6 -Easy installation and maintenance, uninterrupted production processes, and no calibrations Direct measurement for flame CE avoids exposing equipment to corrosive process streams and prevents the use of expensive, unreliable solutions for data collection. An autonomous solution allows for independent monitoring and adjustment to flaring conditions, minimizing the use of operator intervention. VISR devices such as FlareGuardian hold the potential to directly, autonomously, and continuously monitor flare performance in real time. Thus, this data is readily available to review and execute critical adjustment decisions (i.e. adjustments in supplemental fuel, steam, or air) for flaring scenarios to maintain compliance and meet federal and local regulation criteria. Once online, FlareGuardian begins to report directly to the user system performance parameters in a dashboard structured report for ease of interpretation. Filtered imagery of the flame, real-time calculation, and report of CE, indications of smoking, and other parameters can be viewed without an operator needing to attend the flare itself. In the next section, we will review and discuss the validation of the FlareGuardian device against current approved EPA methods of flaring efficacy, thereby demonstrating that the use of VISR technology can generate unparalleled data quality and further optimize performance of flaring systems in real time. Testing and Validation Extensive testing and validation has occurred at Zeeco's testing facility to determine the feasibility of the FlareGuardian system. In November 2014, full scale experimentation was conducted near Tulsa, Oklahoma at Zeeco, Inc.'s testing facility. An example of the testing setup can be seen in Figure 5. Figure 5 - Example of Testing Setup for FlareGuardian Validation A total of 39 test points was observed measuring CE for two separate methods (extractive sampling against FlareGuardian VISR monitoring). Validation was performed on three separate Zeeco, Inc. production flare tips as follows. This selection was made to show the diversity of measurement capabilities using FlareGuardian: Page 7 ➢ Zeeco Model QFS, 16", steam assisted ➢ Zeeco Model AFDS, 10", air assisted ➢ Zeeco Model MPGF, multi-point sonic flare, pressure assisted For this experiment, flares were evaluated by FlareGuardian at a distance of 300 feet from the base of each flare stack. DRE and CE were measured to validate the results from the FlareGuardian monitor against that derived by extractive sampling. Using the methods consistent with the standard EPA methods for stack testing, a sampling hood was suspended over the flare using a crane setup as depicted in Figure 5. Gas samples were transported back to a stable trailer monitoring facility on site and continuously analyzed for presence of combustion products (carbon dioxide and carbon monoxide), oxygen content, and unburned hydrocarbons. Results The results of the testing performed by Zeeco, Inc. are shown graphically in Figure 6. The average CE difference between the two methods for all reported tests was 0.50%. Measurement of CE between extractive sampling and FlareGuardian were highly consistent, varying only in regions where poor combustion efficiency was achieved. The full data set with all measured parameters can be found in Appendix 1. Figure 6 - Flare CE Validation of FlareGuardian vs. Extractive Sampling Method Based on the individual percent difference against the extractive method reference, the data suggests that FlareGuardian holds a more conservative calculation basis for calculating CE. As federal regulations for compliant CE exist at 96.5%, even in accounting for a conservative calculation, the difference between extractive sampling and VISR are minimal. Based on the data, it can be inferred that excellent repeatability and accuracy exists between FlareGuardian and extractive sampling, thus promoting the use of VISR in flaring applications moving forward. Page 8 Discussion Current measurement methods possess certain pitfalls, such as high capital cost, extensive servicing of all components, constant re-calibration of devices, exposure to corrosive process conditions, and higher labor investment to ensure compliance with mandated regulations. Also, since the EPA RTR rule is accompanied by time-dependent monitoring constraints, a problem is created when striving to comply while using methods that do not provide real-time results. Surrogate parameter measurement is dependent on multiple process components to report data in a multitude of timeframes, which can create prohibitive delays in obtaining results for relative flaring performance. During this composite time delay, flaring process conditions could change dramatically and possibly negate any compliance corrective action, a problem which is not experienced by the real-time data reporting provided with VISR devices. FlareGuardian simplifies monitoring and reduces the involvement of plant operators to ensure compliance and flare efficacy. Currently, the EPA RTR rule has been derived to govern flaring applications in the US refining industry. With the compliance deadline approaching in the near future, refineries will be required by law to meet these evaluation parameters regardless of the technology employed. More extensive coverage of operations will be in the line of sight for future regulation, such as chemical plants, midstream operations, and further upstream exploration and production efforts. As these regulations progress, so should the technology behind remaining compliant, such as developments like the VISR-based FlareGuardian system. Page 9 Conclusions Available data supports that the use of VISR technology has been validated and will soon emerge not only in the industry but also with regulatory agencies as the best available technology for flare monitoring. VISR-based products such as FlareGuardian will enable operators to reduce flaring emissions, improve flare performance, and troubleshoot flaring systems, giving them a means to control CE and optimize performance in real time. Page 10 Appendix No. (A) (B) (C) (D) (E) (F) CE - EX CE - FS CE % Diff SI (G) 1 AFDS Propane (100%) 7994 33.29 - 259 99.94 97.40 -2.54 2.85 21.13 2 AFDS Propane (100%) 7994 33.29 - 259 99.99 98.80 -1.19 2.46 19.45 3 AFDS Propane (100%) 7994 33.29 - 259 99.98 98.70 -1.28 4.58 19.37 4 AFDS Propane (100%) 6670 39.89 - 221 99.99 98.80 -1.19 2.87 17.63 5 AFDS Propane (100%) 6670 39.89 - 221 99.97 98.60 -1.37 2.70 18.84 6 AFDS Propane (100%) 5278 50.42 - 178 99.97 99.20 -0.77 2.66 19.83 7 AFDS Propane (100%) 5278 50.42 - 178 99.95 99.20 -0.75 2.50 20.03 8 AFDS Propane (100%) 3063 86.87 - 107 99.33 99.00 -0.33 0.72 20.53 9 AFDS Propane (100%) 3063 86.87 - 107 99.77 98.70 -1.07 1.44 18.94 17 QFS Propylene (100%) 4910 - 0.48 1031 99.86 99.90 -0.86 3.99 19.93 18 QFS Propylene (100%) 4910 - 0.48 1031 99.90 99.00 -0.80 2.24 19.98 21 MPGF Propane (100%) 5079 - - - 100.00 99.90 -0.10 0.24 18.77 22 MPGF Propane (100%) 5079 - - - 100.00 99.70 -0.30 0.27 18.07 23 MPGF Propylene (100%) 4952 - - - 100.00 99.90 -0.10 1.41 17.92 24 MPGF Propylene (100%) 4952 - - - 100.00 99.90 -0.10 1.36 17.38 25 MPGF Propane/N (50/50) 2448 - - - 99.97 99.30 -0.67 0.23 19.48 2 Page 11 26 MPGF Propane/N (50/50) 2448 - - - 99.99 99.80 -0.19 0.35 18.19 27 MPGF Natural Gas (100%) 3300 - - - 100.00 99.80 -0.20 0.26 17.03 28 MPGF Natural Gas (100%) 3300 - - - 100.00 99.90 -0.10 0.32 15.76 29 QFS Propane (100%) 4640 - 0.52 1035 99.99 98.70 -1.29 0.56 19.91 30 QFS Propane (100%) 4640 - 0.52 1035 99.97 99.10 -0.87 0.70 17.60 31 QFS Propane (100%) 1879 - 1.25 571 97.75 97.50 -0.25 0.46 19.90 32 QFS Propane (100%) 1879 - 1.25 571 67.48 77.20 9.72 0.83 20.24 34 QFS Propane (100%) 1537 - 1.53 489 59.99 73.60 13.61 0.17 19.94 36 QFS Propane (100%) 1537 - 1.53 489 70.57 76.60 6.03 0.15 18.75 37 QFS Propane (100%) 1537 - 1.53 489 83.15 85.10 1.95 0.21 18.38 38 QFS Propane (100%) 3328 - 0.71 850 99.67 99.01 -0.57 0.40 17.38 39 QFS Propane (100%) 3328 - 0.71 850 99.82 99.40 -0.42 0.46 18.86 2 Average CE difference between the two methods - all 28 tests: 0.50% Number of tests with oxygen <19.5% (indication for good extraction): 18 Average CE difference between the two methods - 18 tests with oxygen <19.5%: -0.10% Where, (A) = Flare Tip Type (AIR, MPGF, or STEAM) (B) = Fuel Type Used and Composition (C) = Fuel Flow Rate, In LB/HR (D) = Stoichiometric Air Percentage (SA %) Page 12 (E) = Steam-to-HC Ratio (lb /lb ) steam HC (F) = Combustion Zone Net Heating Value (CZNHV, BTU/FT ) 3 (G) = Average O in extracted sample (%) 2 Page 13