Category: Odour Monitoring

Whether we’re talking about chemical storage tanks, lagoons of slurry or food manufacturing, we design every odour control system to achieve a measured removal rate in ouE/m3. Additionally, every odour control system has a flow rate measured in m3/hr, which lets us calculate the system’s treatment capacity.

This article will explore these odour control measurements so you can estimate the odour unit capacity and removal rates of your systems.

Odour control unit capacity

Odour control systems process a maximum airflow volume measured in m3/hr (cubic meters per hour). We estimate m3/hr requirements based on the operational capacity of the plant/site.

Another unit of measurement is ouE/m3 (One European Odour Unit per hour), which is the number of odorants evaporated into one cubic metre of gas. ouE/m3 sets the target for the odour removal efficiency, defining outlet concentration.

Understanding m3/hr

Simply, m3/hr is how many cubic metres of air the odour control unit will process in an hour. A higher m3/hr means it has a higher capacity.

However, a higher capacity is not always desirable, especially in smaller systems, because a higher capacity means a more extensive, more complex system, which increases cost. Thus, finding a balance between capacity and size is crucial.

A standard odour control unit has a capacity of 50 m3/hr to 1,000 m3/hr, which sounds like a lot. Still, it is nothing relatively speaking – OSIL’s CCU (Containerised Carbon Unit) treats 6,000 m3/hr to 45,000m3 /hr with a stackable design.

The ability of an odour control system to treat airflow volumes depends on four key factors:

•  System size

• Adsorbent selection

• Adsorptive capacity

• Process conditions – temperature, chemical constituents, moisture

There is more to satisfying a required m3/hr than pumping lots of air through an extensive system; the odour control system needs to treat the air effectively and achieve a desired ouE/m3 (odour concentration).

Understanding ouE/m3

Simply, ouE/M3 is how we measure odour control unit capacity. It is an objective measure of odour concentration (the amount of odour).

All odour control systems take contaminated air gas and treat it mechanically, chemically, or biologically. ouE/M3 can be measured before and after treatment to determine the efficiency of odour removal.

OSIL and most other odour control experts use ouE/m3 because it is the European standardised method of conducting olfactometry. It accurately tells us the concentration of odours, so we can measure removal rates and efficacy.

In odour monitoring and olfactometry, ouE/m3 measurements are usually described with the following notation:

C98, 1-hour = x ouE/m3 w

• x: Limit concentration in ouE

•1-hour: the average time the concentration is calculated

• 98: the percentile that is used to derive concentration value

This notation is used in odour monitoring to define odour concentrations, allowing us to measure tiny concentrations. This is helpful when designing mitigation measures and fine-tuning the performance of odour control systems.

Find out more

Want to find out more about odour control solutions? Contact us today and speak with one of our experts. Just call +44 (0)1543 506855.

To choose the right odour control technology, first, we need to identify the types of odour you produce and the concentration of the odours.

Many processes produce predictable odorous compounds as by-products, like hydrogen sulphide and ammonia. However, we still need to figure out the makeup of the compounds to choose the right odour control solution.

Odour monitoring and sampling

For existing processes, we use odour monitoring, a scientific process that detects and collects data about odours such as concentration and type.

The following data sets are useful:

• F – Frequency
• I – Intensity
• D – Duration
• O – Offensiveness
• L – Location / R – Receptor

Techniques for acquiring data include olfactometry, which requires physical sampling and analysis in a lab, instrumental odour monitoring systems (electronic noses that collect data and send it to a control centre) and the human nose using trained experts.

Odour sampling and analysis is taken further by Gas Chromatography-Mass Spectrometry (GC/MS), which tells us the gas components at a molecular level. GC/MS is crucial when odours are complex and not easily identifiable.

Pre-build processes 

For pre-build processes, odour control should be built into the process to integrate the technology and solution fully.

When specifying odour control systems for new processes, we consider the types and concentrations of odours that are predicted to be produced, air and flow rate, available site space, maintenance requirements and treatment location.

We know what technologies work for odours through experience and fieldwork, not to mention the vast scientific research over the years. Your build will have specifications, so we’ll specify technologies that meet your demands.

Available technologies

Once we know more about the odours you produce, we can look at specifying technologies that will deal with them. Here are a few available technologies:

• ChemKlean (wet scrubbing) – Removes odours from air gas streams using a liquid chemical absorbent. Specified for basic odour control applications like inlet works. 
• LavaRok (biofiltration) – A biological filter made from pumice stone with bacteria that turns biodegradable compounds into food.
• Tube vents and a passive filter – Specified for vent gases and tanks to absorb hydrogen sulphide and other noxious odours produced in sewage treatment.
• OdaCompact (two-stage treatment) – Two stages of odour treatment in a single tower, combining LavaRok biofiltration with CuCarb dry media filters. 
• CCU (Containerised Carbon Unit) – A stackable, containerised odour control system that uses activated carbon adsorption with CuCarb filters.  

Localised vs centralised odour control

Sometimes, the right technology setup depends on the floorplan of the site, with site space also a factor in sizing and specifying odour control systems.

Localised odour control includes several smaller odour control systems located close to the emission source, eliminating complex pipes and ductwork.

Centralised odour control includes ductwork to move contaminated air into a central, large odour control system, which can be located externally.

For multi-stage treatments, we can also combine localised and centralised odour control. In this setup, localised systems might scrub non-organic odorous compounds to prepare the air gas stream for final polishing in a larger biological system.

Speak to one of our odour control experts today to find out more about how we size and specify the right odour control solutions for our customers.

Petrol and fuel refineries produce a variety of odorous compounds including sulphides, mercaptans and hydrocarbon compounds.

These refinery odours can seep into the atmosphere and cause nuisance complaints, damaging the refinery’s reputation.

Inevitably, completely getting rid of petrol and fuel refinery odours isn’t possible – like all odours, we can only control and manage them.   

Thankfully, petrol and fuel refinery odours can be efficiently dealt with using modern filtration systems that remove, absorb and adsorb odorous compounds.

Such systems need to be properly sized and specified for the application, but first, it is necessary to analyse odours and monitor them so that we can evaluate odour problems and devise accurate, efficient and effective solutions.

Odour monitoring

Data logging

Odour monitoring involves using sensors to monitor the sources of odours so we can evaluate the extent and types of odour produced. Armed with this information, we can at least offer basic advice on appropriate solutions.

Olfactometry

Olfactometry is an in-depth, lab-based odour analysis that detects and measures key odour-generating compounds. It measures the concentration of odours with an odour number that determines the strength of the odour.

Gas Chromatography Mass Spectrometry (GC-MS)

GC-MS combines gas chromatography (which tells us the various components of an odour) with mass spectrometry (which tells us the mass-to-charge ratio of one or more molecules present in a sample), giving us an odour breakdown.

Odour control systems

To get rid of odours at petrol and fuel refineries, we can use a variety of odour control systems in either single or multi-stage treatment processes:

Passive filters (adsorption)

High-quality ‘passives’ offer effective hydrogen sulphide and VOC removal. Oil and chemical storage tanks, vents and containers are prime applications.

Our passive filters have a disposable/refillable filter, and the carbon media can be tweaked to remove different odours. For example, impregnated carbon can be used to remove NH3 (ammonia) with high efficacy.

Dry scrubbing (adsorption)

OSIL’s activated carbon dry scrubbers offer effective hydrogen sulphide, VOC and ammonia removal at high flow rates. Dry scrubbers are a good solution for petrol and fuel refineries that produce significant volumes of organic odours.

Our dry scrubbers can operate as a single standalone unit or as a polishing unit downstream of biological or chemical treatment systems.

Wet scrubbing (absorption)

Wet scrubbers remove contaminants from air gas streams with a liquid absorbent (water with chemical additives). Our ChemKlean® Scrubbing System can be utilised for inlet works and exhaust gases for petrol and fuel production processes.

Wet scrubbing is often paired with a biological treatment, or the OdaCompact® system, a space-saving system that combines LavaRok® biofiltration dry media.

Biological systems (degradation)

Biotrickling filters and biofilters are two types of biological system that use a biomass to remove organic compounds from air gas streams.

Our systems use LavaRok® for the media bed. The big benefit of LavaRok® biofiltration for refinery odour control is it produces no contaminated sludge as a by-product, so it significantly reduces waste.

Providing odorous compounds are biodegradable, biological systems will treat large volumes of air with excellent efficiency.

Biological treatments can be used in refineries to remove odours from gas flaring systems, bitumen production and septic water areas.

Find out more

If your refinery is looking into odour control solutions, contact us today for a chat about how we can help you meet your goals.