Open Path FTIR Deployment at Fort McKay Station in 2014

Transcription

1 Open Path FTIR Deployment at Fort McKay Station in 2014 An AEMERA Funded Project Dr. Long Fu 1, Dr. Quamrul Huda 1, Dr. Bonnie Leung 1 Longdong Zhang 2, Dr. Zaher Hashisho 2 1 Alberta Environmental Monitoring, Evaluation and Reporting Agency 2 Department of Civil and Environmental Engineering, University of Alberta

2 Outline Background Methodology Principles of Open Path FTIR (OP-FTIR) Site description Results & Discussion Hourly results and comparison Select 5-min Non-Methane-HydroCarbon (NMHC) results and comparison Conclusions

3 Background Under the Joint Oil Sands Monitoring (JOSM) program, AEMERA deployed an OP-FTIR instrument for monitoring Volatile Organic Compounds (VOC) and other gas species simultaneously and continuously in Fort McKay to: enhance science-based monitoring for improved characterization of the state of the environment and collect the information necessary to understand cumulative effects (JOSM Plan); support resolution of odour and air quality concerns in residential communities in the oil sands region; and improve the characterization of VOC and Green House Gases (GHG) emissions in the oil sands regions.

4 Background (cont d) OP-FTIR originated in the 1970s and became mature in the 1990s. It has been used by U.S. EPA and other organizations in a variety of areas. Advantages: Emission Inventories & others Environmental Compliance (Russwurm et al., 2002) (Hashmonay et al., 2012) Fence-line monitoring OP-FTIR Multicompounds; Continuous; Automated; Long-term Loss prevention Workplace safety Accidental spills Multi-compounds can be measured simultaneously and continuously. It s automated, easy to set up and maintain. Path averaged digital samples allow real-time and also post-measurement data analyses. Low cost for long term deployment.

5 Methodology (cont d) Credit: A monostatic OP-FTIR (RAM2000 G2; KASSAY FSI, ITT Corp.) was used in this project. Standard procedures: U.S. EPA Method TO-16 and ASTM E (2013).

6 Methodology (cont d) FTIR 177 x 2 m FTIR OP-FTIR at AMS1 in Fort McKay Retroreflector 3.1 m 1.5 m Retro-reflector August 22, 2014 October 15, 2014 (54 days). Round-trip pathlength was 354 m; Sampling frequency was 1-min/sample, continuously; Heights of FTIR and retroreflector was 3.1 m and 1.5 m, respectively.

7 Results & Discussion Hourly results of CH 4 from OP-FTIR were consistent with those from 55i (Thermo Fisher Scientific) at AMS1, with ratios of OP-FTIR/55i ranging from 0.8 to ppm; average and median = 1.9 ppm (same as in Edmonton) High (>= 2.4 ppm) CH 4 conc. under SSW Conc. Rose CH4 OP-FTIR CH4 55i CH4 Conc. (ppm) _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _0026 Date_Time (MMDD_HHMM)

8 How are composite concentrations calculated? e.g., 3 days hourly data Hour Day 1 Day 2 Day 3 Composite Conc. (average)

9 Results & Discussion (cont d) Count CH4 OP-FTIR CH4 55i CH4 OP-FTIR Temp. AMS1 Composite Conc. (ppm) Composite Time (HH) Count Composite Conc. (ppm) Composite Time (HH) Temp. ( o C) Consistent composite diurnal variation patterns were observed by both OP-FTIR and 55i, with correlation coefficient (R) = Composite CH 4 concentration was reversely (R = -0.92) correlated with composite temperature, indicating that the CH 4 source(s) was most likely local, at least for most of the time during the field campaign.

10 Results & Discussion (cont d) Conc. (ppb) n-butane n-octane Ammonia Formaldehyde Methanol 0822_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _0528 Date_Time (MMDD_HHMM) Compound n-butane (ppb) n-octane (ppb) Ammonia (ppb) Formaldehyde (ppb) Methanol (ppb) Min Max Average Median No. of Hours Quantified AAAQOG (1-hour) NA NA 2, ,000 Total Hours 1300 (54 days) Total Effective Hours 1080 (83% of total hours)

11 Results & Discussion (cont d) 5-min results for non-methane-hydrocarbon (NMHC) episodes on 7 select days when both OP-FTIR and 55i detected NMHC will be discussed as follows. NMHC is continuously monitored by AMS1 using 55i. It is reported as CH 4 equivalent. E.g., 1 ppm propane (C 3 H 8 ) equals to 3 ppm CH 4. 55i does not provide speciation information. In contrast, OP-FTIR provides speciation information, but it does not measure NMHC directly.

12 Results & Discussion (cont d) OP-FTIR cannot differentiate alkanes with very close carbon numbers (e.g., n-butane (C 4 H 10 ) and n-pentane (C 5 H 12 )) due to their closely resembled IR spectra. Therefore, n- butane (C 4 H 10 ) and n-octane (C 8 H 18 ) are used as surrogates for alkanes (U.S. EPA 2009). Thus, NMHC (OP-FTIR) can be estimated using concentrations of n- butane (C 4 H 10 ) and n-octane (C 8 H 18 ) to compare with NMHC (55i). (U.S. EPA 2009) As a result, [NMHC] OP-FTIR (as CH 4 equivalent) = 4 x [n-butane, C 4 H 10 ] + 8 x [n-octane, C 8 H 18 ], if the alkanes are truly a mixture of n-butane and n-octane.

13 WD ( o ) Conc. (ppb) _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _1635 Date_Time (MMDD_HHMM) Episodes mainly under northerly wind 0903_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _1635 Date_Time (MMDD_HHMM) NMHC (OP-FTIR, factors 4 and 8) Calculated NMHC (55i) Directly measured

14 Conc. (ppb) _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _1635 Date_Time (MMDD_HHMM) NMHC (OP-FTIR, best fit) NMHC (55i) NMHC by OP-FTIR = 3 x [n-butane (propane)] + 0 x [n-octane] (factor 3, propane (C 3 H 8 )). OP-FTIR and 55i results were more consistent than the case of using factors 4 and 8 for OP-FTIR NMHC. The difference between the results could be due to: Estimated NMHC using n-butane and n-octane concentrations (OP-FTIR) vs. directly measured NMHC (55i). Path averaged (OP-FTIR) vs. point sampling (55i) Continuous sampling (OP-FTIR) vs. sampling-analysis (70 sec)-sampling (55i) Close but different locations

15 Results & Discussion (cont d) NMHC concentration trends were consistent for the major episodes observed. OP-FTIR was a compliment to 55i with speciation information. 55i could give real-time readings of NMHC at low concentrations (50 ppb level) while OP-FTIR requires post-measurement analysis at this level. No odour complaint was recorded in Fort McKay area during the field campaign (almost 2 months).

16 NMHC Conc. (ppb) NMHC (OP-FTIR) NMHC (55i) CH4 (OP-FTIR) :36 16:48 18:00 19:12 20:24 Time (HH:MM CH4 Conc. (ppm) A closer look at the major NMHC episode on September 6 th, 2014: R = 0.95 between NMHC (OP-FTIR) and NMHC (55i). Highly correlated. Ratio of NMHC (OP-FTIR)/NMHC (55i) ranged from 1.0 to 1.8 (median = 1.2, for data values > 50 ppb). 55i has a detection limit of 50 ppb. R = 0.07 between NMHC (OP-FTIR) and CH 4 (OP-FTIR). Not correlated. R = 0.22 between NMHC (55i) and CH 4 (55i) results for data from August 1, 2014 to October 31, Sources of CH 4 and NMHC are probably separate.

17 Conclusions Average CH 4 conc. was 1.9 ppm. High CH 4 conc. (>= 2.4 ppm) were detected under south-south-westerly wind. VOC detected were dominated by alkanes, with average conc. of 24.1 ppb, 16.2 ppb, 5.1 ppb and 10.2 ppb for n-butane, n-octane, formaldehyde and methanol, respectively. Ammonia average concentration was 10.1 ppb. These concentrations are well below those in AAAQOG (when applicable). High NMHC were detected under northerly wind. CH 4 and NMHC results were consistent between OP-FTIR and 55i. OP-FTIR demonstrated its capability in monitoring multi-compounds simultaneously and continuously in the oil sands region. More field campaigns for longer time periods in the oil sands region are necessary to have a better understanding of odour complaints and air emissions from oil sands operations.

18 Acknowledgement Our sincere thanks are due to: AEMERA for the funding support. WBEA for the field support and data sharing. AITF for the logistic support.

19 Thank you Questions?