Anotec Technical Paper - Environmental Odour Control For Foundries

33RD National Foundry Convention. Australian Foundry Institute 13-17 October 2002 TECHNICAL PAPER: ENVIRONMENTAL ODOUR MANAGEMENT. Anotec Pty Ltd

which has been shown to remove up to 95% of Foundry odours.

ENVIRONMENTAL ODOUR MANAGEMENT

INTRODUCTION Anotec Odour Control formulations have been demonstrated to successfully reduce VOC emissions from sand handling operations, and abate odours from core room emissions in iron casting foundries. Anotec Pty Limited proposed a project to integrate two methodologies whereby odour emissions are collected and then treated. The project was undertaken at a few existing ferrous and nonferrous foundries to determine the economic feasibility and the effectiveness of the proposed methodologies in reducing odours and VOCs. The success of the Anotec Odour Control formulation for foundries has now been commercialised and used by foundries and other industries with similar operations to control VOCs and odours, a common nuisance.

Victoria Zavras and John Zavras Anotec Pty Limited ABSTRACT Industrial emissions to atmosphere have always been a significant focus of environmental regulation since the first Clean Air Act of Australia came into force. With current concerns about global warming, ozone depletion and the respiratory effects of fine particulates, air quality is a central feature of existing Australian legislation. Over the last 12 years, Anotec Pty Limited has engaged in investigating and promoting a phased odour abatement program for clients to proactively address odour concerns on a “stepby-step” basis. Anotec’s approach emphasises a prioritisation scheme that promotes cost management, optimises odour treatment efficiencies, and takes advantage of new technologies as they are proven and become available.

ANOTEC ODOUR CONTROL – THE TECHNOLOGY BEHIND THE TREATMENT A bulk of “odour neutralisers” currently marketed has a high concentration of essential oils. Anotec products are a surfactant induced absorption technology as evidenced from the GC/MS analysis conducted. This is in part why the Anotec product is NOT a masking agent as there is a REDUCTION in components present in odours. Some companies professing to be “odour control specialists” and ''environmentally friendly'' are using essential oils as a technology to treat malodours. The use of essential oils is not very environmentally friendly when you consider that trees need to be chopped down, squeezing out the oil and using this oil to reduce odours at an industrial site.

One such proven technology is the treatment of malodours emanating from foundry premises using scientifically formulated Anotec odour control solutions as a direct result of examining emission sources within the foundry namely cooling down after pouring and the introduction of an Anotec odour profiling product as a liquid additive to combat volatile emissions in binder resins. Emissions from pouring are usually uncontrolled and usually low level in concentration, and it is the purpose of this paper to introduce the implementation of an Anotec odour control formulation to be used with a suitable device to assist in this area in a cost effective and efficient manner.

These claims are old hypothetical technology which results in the waste of natural resources, is extremely expensive and unreliable for formulating purposes as essential oils have been proven to be impure, and on occasion of low quality and not reproducible.

The paper introduces Anotec Pty. Ltd. as an odour control company that has developed a scientifically proven, economical process

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A cleaner more scientific approach is the use of aroma chemicals and surfactant based technology. The components in the mix are reliable and all tests conducted by Anotec Pty Limited has revealed that there in no ''masking'' involved when using state-of-theart scientific instrumental and wet methods of analysis.

1. The collection of fumes by enclosing the emission source (in this case the moulds after pouring), and sample collection of all of foundry emissions (VOCs and other chemicals) by identifying the odour producing components within the complex odorous mixture and then to measure their threshold levels and concentration.

For example, if we look at rosemary oil, the chemical make up includes components such as geraniol, citronella and pine. Different batches of oils from different parts of the world have these components at different concentrations. There is no consistency in the raw product being used by formulators.

2. The above assists Anotec in providing a basis for calculating odour control alternatives after housekeeping and other pollution control methods have been assessed. 3. At the time of testing there was no need to determine the strength or presence of an odour via olfactometric means as the project undertaken by Anotec was community complaint driven.

Carbon chain lengths are important to organic molecules. The shorter the length of the chain, the more volatile the molecule is. These carbon chains are in a liquid dispersion.

4. Testing for the strength of the odours recorded were not economically viable at the time and it was suggested that a trial of an Anotec odour control formulation be assessed for its removal efficiency once identification and concentration levels of the VOCs and other chemicals emitted from the area were determined. Anotec’s strong recommendation was to trial an Anotec formulation developed based on chemical fingerprinting of odour samples collected at each foundry.

The ability of a liquid to carry material in suspension is a function of minute electrical charges. As the electro-negative charge increases, more material can be carried in suspension. As the charge decreases, the particles move closer to each other and the liquid is able to carry less material. There is a point where the ability to carry material in suspension is exceeded, and particles begin to clump together with the heavier particles materials dropping out of the liquid and coagulating.

5. Once the general composition of the foundry odours are established Anotec conducted analytical tests using the odour control formulation derived from the chemical fingerprint of the raw odours emitted.

ANOTEC ODOUR CONTROL – FOUNDRIES In the year 2000 Anotec adopted the BATNEEC Policy (Best Available Technology Not Entailing Excessive Costs) to ensure that its clients are secure in the knowledge that all goods and services provided are effective, efficient and economical.

6. The objectives include determining the amount and kind of substance that could effectively reduce or eliminate the odours within a confined unit, the degree of dilution by ventilation or outside dispersal which would be needed to dilute a given odour from a source, the amount or percentage of odorants that must be removed from a space by methods such as the application of an Anotec Odour Control Product (OCPs, or 0307) or to lower the concentration of the odorants below the known perceptible threshold. Subjective methods in determining the odours are important but unnecessary for Anotec to engage in formulating an odour control solution. However, Anotec have suggested

It should be noted that Anotec Pty Limited are the suppliers of Anotec Odour Control Products developed by examining scientific data extrapolated from chemical analysis of composition and concentration levels of chemical constituents identified within an odorous mix.

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This is true for both qualitative and quantitative methods of odour analysis. The composition of an odour can range from a single chemical compound to a complex mixture of compounds. The components of the odour will often dictate the method of sampling. Therefore, insight as to which compounds or type of compounds may be contributing to the odour is desirable. Without this, a sampling method that can handle a broad range of compounds would be necessary.

that another form of subjective testing be used by requesting that the residents located in the vicinity of the foundry complete Odour Diaries or contribute to an Odour Detection Register. The points outlined above need to be addressed with all foundries looking at viable odour mitigation programs and was determined to be of benefit to Anotec and all the parties involved and/or concerned about foundry odours as it gave a clear indication of what is occurring at the foundry based on analysis of the said foundry site rather than relying on the results of tests conducted in other foundries using other formulations.

Several aspects should be considered when choosing an appropriate sampling method. The physical and chemical properties of the odorant will often determine which sampling method is desirable. Some of these properties are the polarity, volatility, and stability of the chemical compounds associated with the odour. To analyse the sample accurately, the composition of the odorant(s) must remain intact during sample collection. Condensation, adsorption, or permeation of the odorous compounds through the walls of the collection system can cause errors. For example, the boiling point of a chemical component in the odorous mix is 109 0 C, which means it is a liquid at ambient temperature. This physical property greatly influences the chemical component emissions and measurement. Elevated temperatures will dramatically increase this component’s emissions. When measuring compounds with high boiling points, it is important not to use sampling techniques that allow the sample to cool before it enters the analytical detector.

ANOTEC ODOUR ASSESSMENT VOCs are not a category of substances but a grouping of a wide range of organic chemical compounds to simplify reporting when these are present in ambient air or emissions. Many substances (eg natural gas) could strictly be classified as VOCs, but the term is reserved to characterise the presence of substances in polluted air (i.e. the term generally refers to the vapours or gases given off by the compounds rather than the liquid phase of the compounds). Effective management of odorous emissions requires a systematic method for odour assessment and sampling. This can involve a perceptual response method, an analytical instrument approach, or a process that uses elements of both approaches. Anotec usually recommends the latter. Regardless of how specific odorants are determined (chemically or via perception), managing odorous emissions and alleviating odour nuisance remains the desired end result of odour evaluations and assessments conducted.

The ability to detect, identify, and quantify odours from foundries (such as during the cooling down of casts after pouring) is an essential tool in the assessment of odours and in the development of prevention and mitigation treatments. If there is some correlation between the concentration of odorants found by an analytical method and the odour itself, then this tool is most useful.

The need for odour sample collection is most likely to occur in the case of a well established and continuing facility that has been unable to resolve odour emissions. In this case, the foundry operators sought an analytical approach upon which to base a remediation program. The proper collection of air samples containing odorous compounds is essential for accurate analysis of the source of the odour.

Upon assessing foundries, it is generally understood that the major production operations in the foundry are raw material handling and preparation, metal melting, mould & core production, and casting and finishing. Anotec have determined that there are potential odour sources in all these areas

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requires the collection of raw odour samples. The raw odour samples were collected from directly above the casting line, not exceeding one meter and in the plume of the gaseous emission.

(some quite visible). The significant contributor of odours at the test sites was the cooling down of the casting stage. The assessment revealed that, ideally, fugitive emissions should be controlled by evacuation through a retrofitted capture hood using a suppression technique such as an Anotec misting system/gas cleaner. Emissions controlled by hoods and an evacuation treatment system should then, ideally, be vented via a vent stack. The basic concept of this suppression technique is to prevent the formation of pollutants by excluding ambient air contact with the molten surfaces. The system was to be constructed with an evacuated runner cover system and the local hooding to be ducted via the said vent stack.

During the assessment and collection of raw odour samples, it was determined that the emissions from the cooling moulds escalated in concentration levels between approximately 25 – 45 minutes after pouring. The Anotec formulation developed was based on the “peak” concentration levels detected during raw odour sampling. Once formulated, the Anotec odour control solution was tested on-site. Raw Odour results during the tests were also included to determine the removal efficiency of the formulation based on the emissions on that day and not on the emissions analysed for formulating purposes.

VOC (Volatile Organic Compounds) emissions result from core baking and occur during mould drying. Emissions from pouring consist of fumes, VOCs, and particulates from the mould and core materials when contacted by the molten steel. As the mould cools, emissions continue.

It should also be noted that the initial raw odour samples were collected prior the construction of an enclosure for the casting line. It was also noted that the concentration levels of the raw odour in the treatment assessment were somewhat higher due to lack of dilution with the ambient air and confinement within the constructed enclosure.

As mentioned, emissions from pouring are usually uncontrolled and usually low level in concentration, and it is the purpose of this paper to introduce the implementation of an Anotec odour control device to assist in this area.

The application or testing unit was specially designed based on Anotec’s specifications to ensure that the Anotec formulation is effectively applied in direct contact with the malodorous emission. To save on the hardship of using literally hundreds of metres of stainless steel pipe work, Anotec recommended the use of this unit. The model available can hold up to ten nozzles. It employs a multiple vane, positive displacement pump which can have the discharge pressure adjusted from 4 -14 bar. Elastomeric construction for pump, tank and solenoid valve is Viton. The control system incorporates a microprocessor with nonvolatile memory in case of power failure. The microprocessor programs were easily altered on site by simply downloading from a laptop computer the necessary program applicable to the testing site.

The odour assessment conducted revealed the need to emphasis that, ideally, all emission control techniques should involve an emission capture system to ensure effective and efficient treatment with the recommended Anotec formulation and deodorising system.

ODOUR TESTING & RESULTS The initial step in assessing and formulating for an odour control solution involved the collection of “raw odour” samples. The significance of the raw odour results is twofold. One, to determine whether the emissions from the casting line after pouring are posing a chemical, odour or both issue and two, to formulate an odour control solution to significantly reduce or eliminate the concentration levels detected in the malodorous emission. Testing at all foundries

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The Testing Unit The unit is encased in a 2mm powder coated steel weather, vermin and vandal proof lockable enclosure. The suction lift of the pump should not exceed 1.6 metres and the static discharge head does not exceed 20 metres. Microprocessor commands pump start. The solenoid will open, releasing pressurised liquid to nozzles There is pressure relief by-pass that maintains the system pressure while pump is operating. The solenoid closes, pump turns off, and pressure relief solenoid opens eliminating spray line pressure allowing the control unit to only operate when needed, reducing running costs. In the case of power failure there is an in-built battery backup to maintain program integrity. A programmable asymmetric recycler controls the operation of a solenoid valve, which will release an amount of Anotec 0307, determined to most effectively neutralise the malodour, to the spray nozzle.

The Application / Testing Unit

The Application Nozzle

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RAW ODOUR (MAJOR ODOUR CONTRIBUTORS) Component (ppb)

10 minutes

20 minutes

45 minutes

2-butanone acetone benzene ethanol hexane m- and p-xylene methanol methyl formate o-xylene toluene

389 22 1897 81.7 87 42.6 626 192 1.2 190.5

326 38 26432 26.9 103.1 98.2 253.8 1.6 0.5 2185

802 95.4 14396 598.4 311.9 701 1954.5 1985.9 3.6 4339

RAW ODOUR AND TREATMENT WITH ANOTEC FORMULATION Component Raw Odour Treated Odour (ppb) 2-butanone acetone benzene ethanol hexane m- and p-xylene methanol methyl formate o-xylene toluene

956.2 103.8 38349 2585 412.5 902.8 2385 1659.2 5.9 3862

43 12 400 53.3 49.5 30 93 87 0 39.2 determined for all foundries assessed during raw odour sampling. Having said this, the following should be noted:

The results show that the chemical components identified in all samples collected of the odorous emissions from the casting line are directly attributable to the chemical makeup of the moulds.

The concentration levels recorded where from within the enclosure and were not indicative of the odours exiting the stack. Any fugitive odours escaping from the foundry are not attributable to the casting line after treatment but were directly linked to other processes taking place within the foundry. One nozzle was used in the trial to examine a “worst case scenario” using the Anotec 0307 formulation and get a better understanding of the effects one nozzle would have on the stack emissions. The removal efficiency using Anotec 0307 for foundry emissions is between 80 -95%. Dispersion of emissions via the stack should be looked at further. This will also have a significant affect on the emissions exiting the building (dilution). Anotec believe

Initially, due to the extremely high temperatures, any VOCs would have been partially combusted yielding a low concentration level at 10 minutes. Therefore, it can be surmised that there are no obvious odours emanating from the casting line immediately after pouring has been completed. The results also show that the concentration levels of the compounds identified were within perceptible limits and are suitable for treatment using an Anotec odour control formulation and that any toxic emissions are not enduring and are below the acceptable threshold limit. The latter was also

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that the trial was successful in reducing the concentration levels of each of the components identified within the collection unit. That the results show that, logically, if was a significant reduction in the chemical components then it is safe to assume that the chemical odours were also significantly reduced. After treatment with the Anotec formulation, any emissions from the stack/ducts will not constitute an odour nuisance within the community. Further investigation may need to be conducted to design an odour management program for foundries that includes the successful collection of emissions from within the site for effective and economical treatment via two or three exit points. Fugitive odours are the main contributor to the odour complaints registered with local council or regulatory authorities. Once these issues have been addressed Anotec believe that the foundry industry will be in a better position to assure the community of compliance with any regulations pertaining to odour emissions. Total time taken to conduct the project in each foundry was approximately 3 – 5 hours.

The Anotec formulation was applied via the misting system whereby it scrubbed the malodorous air stream to render it nonvolatile, significantly reduced in intensity and/or eliminated. It is evident based on these results that Anotec works by counteraction neutralisation, as quoted from the Odour Control Waste Water Facilities Manual of Practice No. 22 "...Neutralisation by counteraction is achieved when no resultant odour, pleasant or unpleasant, is sensed." Anotec also utilises current techniques as discussed in the manual that was prepared by the Task Force on Odour Control under the direction of the Facilities Development Committee and Technical Practice Committee. Olfactometry conducted using Anotec formulations on malodours has revealed that there is no increase in raw odour units after treatment and GC/MS analysis supports this as the chemical components of the odorous mix are significantly reduced. Masking agents. The concept of using perfumes to combat odours is one that has been around for over thirty years. However, aromatherapy, as it is called, works very much the same as any ordinary masking agent. That is, the product relies heavily on its perfumes to disguise the perception of a bad odour. In some instances masking agents have been quite successful in covering up malodours temporarily. The key words here are “covering up” and “temporarily”. Masking agents are not in themselves harmful but are deemed by Anotec as being ineffectual in industries where there are high level concentration of odours and continuous emissions.

There are applications for masking agents within the community that have proven to be quite successful. However these products are suitable for intermittent and temporary odours. Masking agents cover one smell with another. As a result, they must be strong, and may be almost as objectionable as the foundry odour. Masking agents are normally used as vaporised material injected into the air.

Pouring and Sampling

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ranging from a strong to weak variation of the same product.

Masking agents may be prohibitively expensive if used for more than small amounts of waste. It should also be noted that the organic chemical composition of most masking agents makes them susceptible to degradation by the micro organisms indigenous to manure. Therefore, the odour control capacity of most masking agents may be too short lived for practical use in metal casting production environments.

Testing during the trials at the foundries showed that the chemical make up of most emissions are virtually identical. However, having said this, the concentration levels are what differed within each sample taken during raw odour emission collection. Based on all testing to date, Anotec envisage in the near future, formulating an odour control product that will be suitable for ferrous and nonferrous foundries respectively based solely on raw odour analysis.

Of interest during the trials was that the inclusion of a volatile signature to the Anotec formulation did not interfere with the overall results. The Olfactometry conducted did not show an increase in odour units when applied.

The process works on emissions collected and passed through an exhaust flue. A sample of the emission is collected and a complete chemical analysis done of its constituents. On the basis of this analysis, Anotec prepare an Odour Control Product (OCP) which will react with the chemicals in the emission, reducing them to non-odorous, non-toxic residues. The OCP is introduced into the exhaust stream via an atomised spray. Analysis of the exhaust stream after treatment confirms the effectiveness of the process.

The approach Anotec has taken towards significantly reducing and/or eliminating odours from processes within the foundry industry is achievable, economical and most importantly effective. It is definitely the more preferred approach to counteract the odour problems when source control is not possible. The various ways to address the problem includes facilitating ventilation, the use of Anotec’s odour control formulations and effective collection of emissions. To date, Anotec’s odour control technology although quite sophisticated can be effortlessly implemented without major changes taking place within the foundry or any disruption to manufacturing. A variety of specially formulated Anotec products are available to dissociate the unique chemical components (i.e. the odour properties) in each type of emission identified in various industries. The usages of such specialised Anotec formulations are quite common in industrial and commercial applications since the sources of odours are more diverse.

The process has been conducted at several Australian Foundries using portable dosing equipment as well as existing and custom built equipment on-site. Emissions were collected from moulding lines which used Phenolic resin bonded sand. Treatment with Anotec OCP not only reduced the concentration of odour producing chemicals, but also had a similar effect on substances such as Benzene. Anotec have adopted the BATNEEC Policy (Best Available Technology Not Entailing Excessive Costs) to ensure that its clients receive goods and services that are effective, efficient and economical.

CONCLUSION

Anotec Pty.Ltd welcome the opportunity to discuss the scientific data supporting our claim that Anotec odour control successfully treats foundry malodours. Removal efficiency using the Anotec Foundry Formulation is on average > 90%.

There is no such thing as “broad spectrum” odour control. Where odour control products are concerned, it is virtually impossible to control all forms of odours with the same product. This can only be achieved if different dilutions of the same product were to be made available – that is,

As published and presented at the Australian Foundry Institute National Convention 2002

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