When odour issues occur at an industrial site, rapid diagnosis must be done and a strategy defined to treat odour sources definitively.

Today, the sensory panel approach using dynamic olfactometry analysis is considered as the first approach to rank odour sources and subsequently to treat the most noxious odours. When investigating the source of the odour, an online monitoring system provides for the best available methodology. Conventional electronic nose (e-nose) technologies are designed to check odour variation and try to correlate results with a sensory approach (e.g., dynamic olfactometry using EN 13725 or ASTM 679-E04 methods). These approaches, however, have limitations, since the current e-nose solutions do not provide the gas composition via speciation and require the use of technologies that are highly susceptible to interference. Manual sampling techniques are susceptible to additional loses of sample because the molecules are often lost during sampling and transport of samples to the laboratory for analysis. Therefore, the need for online analysers able to monitor onsite odours constituents such as Volatile Organic Compounds (VOCs), sulphurs, and nitrogenous compounds is apparent.

In response to this need, Chromatotec has developed the solution for the online analysis of VOCs, sulphurs, and NH3. This solution redefines the capability with online monitoring specifically suited for the ‘odour’ monitoring industry. Chromatotec solutions provide the ability to quantify concentrations in parts per billion (ppb) or parts per trillion (ppt) in ambient air and process applications. Chromatotec has proven wrong the traditional thinking that no analytical solution can be more sensitive than human nose. Chromatotec is the global supplier of online measurement platforms capable of meeting the strictest guidance from regulators and industry and deploys its solutions worldwide for use in the ambient air, industrial, research, and energy monitoring sector. Chromatotec’s all-in-one, turn-key, vigiODOR solution can be deployed at any location, any environment, and any classification where odourant monitoring is required.

CANOPIA recovery centre located in Bayonne, France, has recently deployed Chromatotec’s vigiODOR solution. This site collects domestic waste from 200,000 citizens and converts it to compost, solid recovered fuel and biogas by utilising the VALORGA methanization process. The CANOPIA site treats 84,000 tons of waste and produces 30,000 tons of compost per year. The site covers over three acres with 0.25 acres dedicated to air treatment. Urbaser Environment designed and managed the construction of the entire site and currently manages the site through the VALORTEGIA subsidiary.

For Sebastien Cueillens, Project Director for Urbaser Environment organisation and in charge of the site management, odour is a crucial point. In the past, Mr. Cueillens had used e-nose technology with Metal Oxide Sensors (MOS) technologies and was disappointed by such technology as the data lacked information about gas composition. He stated, “The quantification of sulphurs is very important to verify the performance of the biologic digester. The VOCs are important to verify the performance of charcoal filters. The odour monitoring is important to verify that processes work properly and are compliant with the legislation. It is important for us to dissociate odour perceived by the neighbourhood from the potential odour generated on site. This is a crucial point as once we are sure that odour treatment works properly, we can focus on diffusing sources.”

Concentration trend for Sulphurs and some mercpatans on outlet odour control monitored with vigi e-nose

When asked about his interest in Chromatotec’s vigiODOR solution, Mr. Cueillens added: “We were looking for a solution able to monitor sulphurs and VOCs to facilitate our understanding about process variation. This was not possible with sensors-based electronic nose technology as such solutions did not help us to elaborate diagnosis of process malfunctions when odour concentration exceedance was observed on the effluent of the odour control system. Today, the Chromatotec solution with vigiODOR platform and vigi e-nose GC based technology give us the expected results.”

The vigiODOR solution is developed for online monitoring and modelling of the site contribution of the olfactory impact of the site, which allows for site mitigation procedures to treat and prevent odours. Odour events are better understood by using a scientific approach to determine sulphurs composition, VOCs concentration, and odour concentration measured according to EN13725. The measurement system performance evaluation is completed using the internal calibration (permeation tube) feature of the system, providing the correlation with olfactory response, field measurements, and impact forecasts. Spot measurement can be integrated into the online measurement cycle to demonstrate compliance with the odour concentration objectives defined in the French composting regulations (5 ouE/m3 not to be exceeded more than 175h per year (2% of time) in residential areas).

The vigiODOR solution is the comprehensive odour monitoring system incorporating a multiplexer (stream selector) that automatically collects process gas from three odour control systems: bio filtration, charcoal filters, and waste reception area. The analysis is done by an automatic gas chromatograph (vigi e-nose) integrated in an environmentally controlled shelter. The standalone, all-in-one system includes an automatic calibration module and gas generators, alleviating the need for traditional support equipment (gas bottles, regulators, etc.).

Concentration trend for tVOCs on outlet odor control monitored with vigi e-nose

The vigi e-nose analyser monitors 14 specific sulphurs such as H2S, Mercaptans, sulphides such as DMS DMDS, SO2. In addition, the solution monitors VOCs producing data specific to odour intensity and concentrations measured locally in accordance with EN 13725. Concentrations are tracked at ppb or ppt levels, all lower than what the human nose can detect.

To evaluate the chemical and odour impact of the source on the neighbourhood, the topography, meteo, and concentrations monitored by the analyser are input into the dispersion modelling software developed with our partner, Numtech. The meteo data, source origin contribution, analytical data, and alarms are centralised on the vigiODOR platform installed on the local server (cloud-based solutions available as well). The solution was preconfigured to provide for rapid access of the data (see vigiODOR interface image).

The vigiODOR platform is engineered specifically to adapt to our customer’s needs. Besides the CANOPIA methanization centre, the solution is widely deployed at several sites including waste water treatment plants in Paris, Dubai, Poland, US, and Asia. This unique solution provides the ability to monitor and forecast in real-time the dispersion of odour and gas plumes (H2S, NH3, VOC, TBM, etc.) around industrial sites.

When connected to the network of vigi e-nose analysers and on-site weather station, the solution provides key, real-time information to optimise facility operations and efficiently manage chemical and olfactory pollution. The solution provides a real-time display of discharge and atmospheric dispersion. The system’s “Forecasting Mode” provides forecasts of up to 48 hours in advance enabling warning activation or production programs re-adjustment. The latest generation dispersion models (e.g., simple Gaussian model, ADMS reference model, latest-generation Lagrangian model) is integrated into the platform. The solution’s “Service Mode” (SaaS) provides the same level of information and display and requires only a simple subscription and an Internet connection. The complete, decision-support tool provides real-time display of plume by emission levels and weather conditions, odour and specific pollutant gas concentration profiles at emission source, and receptor points with relative contribution of the different sources. This centralises the visualisation of analysers and meteorological data from the on-site installed station. To provide intelligent measurement, the solution provides warnings from configurable threshold overruns on emission points or on pre-defined receptor points (neighbourhood, sensible sites, property lines) with data archiving for statistics calculations on historic data (e.g., exposition frequency, percentiles, monthly or annual means, etc.). Reports are automatic and accessible for non-experts in gas chromatography or dispersion software. Results are provided at a glance with automatic data validation. The analyser integrates an internal permeation tube with a specific stable standard analysed after each analysis.

vigiODOR interface with dynamic plume for sulphurs and contribution of odour source in addition to meteo data

The Chromatotec vigi e-nose concentration as depicted below provides a solution with increased responsiveness to the risk of odour nuisance with e-mail alerts when exceeding 5 ouE/m3 on one of the nine receptor points or on the source emission. It gives Sulphurs and VOCs profiles in addition to odour profile with automatic reports and alerts on site on each source monitored or on neighbourhood.

The solution can be considered as a tracking system for the performance of the odour treatment facility by the continuous measurement of odour, VOCs, and sulphur gas. It allows identification of the sources causing environmental odours. The solution enables transparent communication for the sharing of information on odour management with the authorities, if required. Annual, monthly and daily automated reports provide the necessary data to assess the odour and chemical impact of the site and to facilitate odour understanding.