Recently Odotech was presented an interesting scenario. A client in the Pacific Northwest wanted to start shipping sulphur from their site. The issue raised a number of eyebrows locally as the site is surrounded by a combination of water, industry (oil refinery) and residential housing. Furthermore, local air quality authorities were concerned that the sulphur emissions - in particular Hydrogen Sulphide (H2S) - would have a negative impact on the quality of life of local residents.
The scenario is interesting for a number of reasons. Sulphur is one of the most recognizable odors. The infamous rotten egg smell can come from many potential sources, including a refinery, tidal sea waters, waste water treatment plants to name but a few.
Knowing that there were other sulphur emitters in the area, the client’s concern was the following:
“How do we know that the sulphur odor emission is coming from our site, when in fact the odor could be coming from an industrial neighbour or simply low tide?”
The OdoWatch sytems can in fact be that useful tool to assist in measurement of odor, be it in low emission or high emission situations. The electronic noses record the odour data while a weather station records the meteorological data. The OdoWatch system then calculates the dispersion of the odor with respect to the operator’s site. Picture a Google map with a color coded dispersion plume super imposed, allowing the operator to determine the impact of his odors on surrounding neighbours.
In this particular case, Odotech, the client and the local air authority worked together to develop an air monitoring plan to address the needs of all stakeholders.
The result was the installation of an OdoWatch system that permits our client to monitor H2S emissions 24 hours a day. During the times when there was no loading of sulphur the OdoWatch system gives the client the necessary data to monitor “background” sulphur emissions - those already in the air from other sources such as the refinery and the sea bed at low tide. When the sulphur loading occurs, the client is now much better equipped to monitored their contribution to the sulphur emission total in the air, and in some cases apply appropriate measures. It also permits the client act proactively to prevent odor events and defend themselves in cases when they are not emitting any odor what so ever.
However, it has been scientifically demonstrated over the last decade that H2S is only partially responsible for the odors perceived offsite. Monitoring H2S for odor problems may lead to underestimations of the odor intensity or completely missing the contribution of other odorous compounds (VOCs, ammonia & amines, other sulfurous compounds, etc). We invite you to read these blogs:
Olfactometric quantification is essential for quantifying the overall odor level (odor concentration). Many operators today recognize the value of odor monitoring expressed in odor units for understanding odor complaints and improving their production processes. (http://blog.odotech.com/bid/51233/Pima-County-Marks-1-Year-of-Odor-Management-Innovation). However, there is a continuity problem in switching from H2S to Odor monitoring. How to relate the H2S historical data to the new Odor measurements ?
It is now possible to bridge the gap between H2S and Odor real-time monitoring by merging OdoWatch (odor monitoring with eNoses) with the new OdoSulf technology (H2S monitoring). Simultaneous H2S and Odor on the same platform is made easy with two 100% compatible technologies.
OdoSulf is the first automated system designed specifically for Hydrogen Sulfide (H2S) emissions with atmospheric dispersion plume display. The sulfNoses (H2S detectors) can measure H2S down to 2 ppb at the perimeter and up to 100 ppm at the emission source. The system delivers a real-time H2S atmospheric plume display. The data are then archived for future reference.
It is now possible with one air quality monitoring system to track real-time Odor and H2S. The eNoses and H2S monitors can be located at the sources and/or at the fenceline for the SulfNose. But all the sensors are integrated in one software to get H2S plumes and Odor plumes simultaneously and fenceline H2S logs. You can get alerted when odors are leaving your site, and know how far and were they travel.
Some of the possible uses of this combined H2S-Odor approach:
- Insure regulatory compliance (Track the H2S values at the property boundaries)
- Reduce the cost and impact of air quality & Odor investigations
- Improve community relations
- Monitor the effectiveness of abatement actions taken
- Optimize process
- Manage proactively
- Manage off-site impacts and complaints
- The sulfNoses + eNoses at the emission sources plus real-time modeling quickly determine whether or not the H2S from the facility is causing an off-site impact at complaint location
- In case of an alert, they show immediately which of the site sources needs action.
- Access historical data as needed.
- Monitor trends or address complaints.
- Quantify H2S/Odor to optimize H2S/Odor emission controls.
- Implementation of controls can be prioritized.