Device used to sniff out out industrial emissions

Scientists are developing ‘electronic nose’ sensor technology for measuring and predicting the dispersal of odours from industrial plants into the community.

Odotech, a spin-out from Polytechnique Montréal, is working with clients in the UK, including Yorkshire Water, other waste water treatment plants, and some breweries. The data gathered will help plant managers optimise deployment of scrubbing methods, and time certain operational processes according to the weather.

‘Certainly in North America, 70% of air quality complaints are odour-related, so it’s a real quality of life issue for nearby residents and the wider community,’ said Thierry Pagé, Odotech’s President. ‘Those people, you want them happy, I haven’t seen a lot of plant managers that don’t want to be a good neighbour, and so we enable that, they don’t have to wait for the phonecall that there’s a problem, they are the first ones to know and they can act accordingly.’

So-called electronic noses for have been developed previously for detecting explosives, determining food quality and more recently in medicine for identifying residues predictive of lung cancer for example. The team however, saw a niche for the technology in industry.

‘Basically we have 16 sensors that will react to the same chemical compounds as the human nose does. Based on the reaction of those 16 sensors we generate a fingerprint, so we will need to teach to the electronic nose to be able to recognise different odours, so this is odour of biogas say, this is the odour of sludge,’ Pagé said.

‘The technology is so different from what’s existing on the market — with specific gas sensors, you can tell a plant manager you’ve got 2ppm [parts per million] of this chemical compound, but what he wants to know is does it smell or not?’

For any particular plant, traditional environmental capture is first used, and culprit odours are characterised in the laboratory and thresholds set by human volunteers. A sensor unit is then deployed in the immediate vicinity of the plant, along with a microweather station.

The combined data from these two inputs is processed at a control centre by Odotech’s proprietary software, ultimately allowing the operator to ‘see’ the odour plume in real time and make predictions about how it will spread on an hour-by-hour, day-by-day basis.

This can provide a number of strategic advantages for plant managers. Currently odours can be dealt with by using scrubbers and biofilters, which are extremely expensive to deploy. If, for example, there is a strong wind and the plumage is predicted to disperse and dilute odour in an area without residents, the plant manager can perform certain processes at that time with no need for any post cleaning. It can also help to ‘diagnose’ problem odours and provide confirmation where odours are coming from.

‘Many of our clients reside in industrial complexes where you have multiple neighbours that are also emitting odours and generally it’s the biggest site that gets fingered. If a neighbour keeps calling saying: “I keep smelling your plant,” do you just take the blame and assume it’s you? With this system you can look at what going on and say: “You know what, all day the wind has been blowing South, it’s impossible that’s the odour are coming from me. Maybe it’s the municipal waste site over there”,’ Pagé said.

While the technology is able to generate fingerprints for hundreds of different odours the majority of complaints centre around hydrogen sulphide-type odours and volatile organic compounds. Although as Page points out even a chocolate factory can create problems when the odour is not there by choice.