Corrosion-enhanced activated carbon deodorization of malodorous gases from fish processing

doi:10.21203/rs.3.rs-4873508/v1

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Corrosion-enhanced activated carbon deodorization of malodorous gases from fish processing

https://doi.org/10.21203/rs.3.rs-4873508/v1

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Activated carbon adsorption is one of the most effective methods of deodorizing malodorous gases generated by fish processing. This paper proposes an innovative method of improving activated carbon adsorption of malodorous gases from the fish industry. The solution, which involves introducing a layer of corroding steel packing into the adsorption bed, provided the same high deodorization rate as activated carbon alone (nearly 100%). The innovation considerably extended the adsorbent service life. For gases with a concentration of 2,200 ou_E/m³, the efficiency of the activated carbon increases over ninefold. At a carbon price of 2,400 € per ton, gas treatment becomes considerably cheaper (a reduction of 3.59 € per 1 m³ treated gas, which translates to a final cost of 0.38 €). The steel packing can consist of recycled materials. If the corrosivity of the treated gases is similar to that of air, the packing can be reused repeatedly, even over dozens of years.

deodorization

odor emissions

adsorption

fish processing

malodorous gases

cost of sorbent

Development of civilization goes hand in hand with progressing environmental destruction. In recent years, however, there has been growing awareness of this threat, which has led to the development of new environmental protection technologies and the improvements to existing ones. The scope of this environmental protection is also being expanded to encompass more and more issues, including the identification and elimination of odor nuisance. Reduction of odor emissions caused by various growing industries poses yet another challenge for environmental engineering, made even more urgent by people's awareness of issues surrounding environmental protection and quality of life.

The food processing industry, including fish processing, is one of the more problematic branches of industry in terms of odor nuisance, generating a large number of formal complaints from the populace in Poland (Bujny and Maśliński, 2018; Jachnik, 2017; Ministerstwo Środowiska Departament Ochrony Powietrza i Klimatu, 2016). The main odor-producing pollutants in this industry are: nitrogen compounds, sulfur compounds, fatty acids, aldehydes, ketones and alcohols (Table 1). Out of all segments of the food industry, fish processing is considered to be one of the most problematic sources of malodorous emissions (Gospodarek et al., 2018; Wibowo et al., 2017). Though fresh raw fish themselves are relatively non-offensive in terms of smell, a number of foul-smelling gases are released into the air during their processing. Fresh raw fish have been found to contain only traces of odorous substances responsible for the so-called “fishy” smell (trimethylamine, pyridine). However, far more compounds are released during high-temperature processing, cold/hot smoking, and production waste processing/storage. These include ammonia, amines (including trimethylamine, pentane-1,5-diamine, also known as cadaverine, and tetramethylenediamine, also known as putrescine), aldehydes (including 2-methylpropanal, 2-methylbutanal, 3-methylbutanal), volatile fatty acids and sulfur compounds (including thiols and sulfides, e.g. dimethyl disulfide, dimethyl tridisulfide), and phenols (e.g. 2-methoxyphenol) (Ranau and Steinhart, 2004; Rutkowski et al., 1995; Zwoździak et al., 2016). Depending on the industry, odor concentrations can exceed 10³ ou_E/m³ (Szynkowska and Zawoździak, 2010; Zwoździak et al., 2016).

Table 1. Main odor-generating components present in gases from fish processing.

GROUP OF COMPOUNDS	COMPOUND NAME	DETECTION THRESHOLD [ppm]
Nitrogen compounds	ammonia	0,040 (Rutkowski et al., 1995) 0.018 (Kośmider et al., 2002)
	trimethylamine	0.004 (Zwoździak et al., 2016) 0.002 (Kośmider et al., 2002)
	dimethylamine	0.034 (Kośmider et al., 2002)
	metyloamina	0.02 (Kośmider et al., 2002)
	ethylamine	10 (Amoore and Hautala, 1983)
	trimethylamine oxide	-
	putrescine (1,4-diaminobutane; tetramethyldiamine)	-
	cadaverine (pentane-1,5-diamine)	-
	indole (2,3-benzopyrrole)	0.000032 (Kośmider et al., 2002)
	skatol (4-methyl-2,3-benzopyrrole)	0,017 (Rutkowski et al., 1995) 0.000565 (Kośmider et al., 2002)
	pyridine (azine)	0.084 (Kośmider et al., 2002)
Sulfur compounds	hydrogen sulfide	0,009 (Rutkowski et al., 1995) 0.007 (Zwoździak et al., 2016) 0.018 (Kośmider et al., 2002)
	methanethiol (methyl mercaptan)	0.001 (Kośmider et al., 2002)
	ethanethiol (ethyl mercaptan)	0.0011 (Kośmider et al., 2002)
	dimetylosulfide (siarczek dimetylu, sulfide dimetylowy, tioesterdimetylowy, 2-tiapropane)	0.002 (Zwoździak et al., 2016) 0.0023 (Kośmider et al., 2002)
	dimethyl disulfide	-
	sulphur dioxide	2 (Amoore and Hautala, 1983)
Fatty acids	acetic (ethyl acid)	0,224 (Rutkowski et al., 1995)
	butyric (butanoic)	0,0003 (Rutkowski et al., 1995) 0.004 (Kośmider et al., 2002)
	isobutyric (2-methylpropionic)	0.020 (Kośmider et al., 2002)
	valerian (pentanoic)	0,002 (Rutkowski et al., 1995) 0.005 (Kośmider et al., 2002)
	isovaleric (3 - methylbutane)	0,001 (Rutkowski et al., 1995) 0.002 (Kośmider et al., 2002)
	butyl
	caproic (hexanoic)	0,008 (Rutkowski et al., 1995) 0.012 (Kośmider et al., 2002)
	isocaproic (4 - methylpentane)	0.016 (Kośmider et al., 2002)
	propionic	0,015 (Rutkowski et al., 1995)
Aldehydes	acetaldehyde (ethanal)	0.002 (Kośmider et al., 2002) 100 (Amoore and Hautala, 1983)
	propionaldehyde (propanal)	0.042 (Zwoździak et al., 2016)
	butylaldehyde (butanal)	-
	isobutyraldehyde (3 - methylpropanal)	-
	benzaldehyde	-
	2-methylpropanal	-
	2-methylbutanal	-
Ketones	acetone (propane-2-on)	-
	diacetil (butane-2,3-dion)	-
	butanone (butan-2-on)	-
Alcohols	ethanol	78,415 (Zwoździak et al., 2016)
Alcohols	cyclohexanol	50 (Amoore and Hautala, 1983)

There are multiple methods of deodorizing such gasses (Chung, 2007; Ranau and Steinhart, 2004; Wysocka et al., 2019; Wysocka and Namieśnik, 2018). Known solutions can be divided into two basic groups:

technologies to avoid emissions - preventive technologies
methods consisting in emission blocking or dilution of emitted gases
a methodical solution that allows for the removal of odors from the stream of emitted gases – deodorization technologies.

The purpose of preventive technologies is to prevent the formation of odor-causing pollution. They should be applied first. But preventing the formation and emission of odorous substances is sometimes difficult or even impossible to carry out. In this case, the methods consisting in emission blocking or dilution of emitted gases are used. If this type of treatment does not bring any effect, the deodorization technologies remain.

There are different deodorization technologies available, which are based on: absorption, adsorption, biological processes, thermal neutralization, non-thermal oxidation or introduction of the admixtures that change odor character. Although steps are being taken to deodorize gases generated by fish industry, these interventions are often insufficient. Therefore, methods are being sought to increase the deodorization efficiency of such gases. Each with the methods own strengths and weaknesses (Table 2).

Table 2. Advantages and disadvantages of the popular gas deodorization methods.

Deodorization method

Disadvantages

Advantages

absorption

- problem of absorbent regeneration or utilization

- high costs of pumping

- if additional chemicals are used, they must be topped up

- corrosion of installation

- further stages of gas treatment are often required

- low investment and operating costs

- treatment of gases containing high odorant concentrations

- possibility of recovery of absorbed compounds

adsorption

- problem of adsorbent regeneration or utilization

- it is often only one of gas treatment stages

- possibility of recovery of adsorbed compounds

biological gas treatment

- treated gases must contain biodegradable components

- treated gases must be characterized by parameters guaranteeing biological activity (pH, temperature, presence of acid precursors) etc.

- treated gases must not contain excessive amount of toxic substances

- problem with an excessive amount of biomass - installation overgrowth

- required stability of gas treatment parameters

- a large surface area of the installation (for biofiltration)

- low investment and operating costs

- possible to treat gases with low odorant concentrations

- high effectiveness when biological material is well selected

thermal neutralization

- high operating costs (due to the high energy consumption and the necessity of gas enrichment or catalyst addition

- a high content of inflammable pollutants is required

- generation of secondary pollutants

- risk of corrosion and deposits on the installation

- simple design and operation of the installation

- waste-free process

- ensures high effectiveness of deodorization

- possibility of deodorizing gases with a broad range of odour-generating compounds

non-thermal oxidation

- operation with strongly oxidizing agents

- corrosion of the installation

- it is often necessary to remove ozone from treated gases (e.g. ozonisation processes or UV processes)

- high energy consumption (e.g. UV generators)

- it is possible to treat only compounds which are susceptible to oxidation (it is difficult to remove dimethyl sulphite)

- low investment and operating costs

- waste-free process

- disinfection of treated gases

- the small size of devices and a small decrease in the pressure of the flowing gas (plasma technology)

introduction of admixtures changing the character of the odour

- can be used only for non-toxic odourants

- possibility of weakening defence reactions of people exposed to the substances

- high dependence on weather conditions (temperature, speed and direction of wind)

- treated gases must contain only low odourant concentrations

- low investment costs

- easy operation

- immediate effect

A popular method of deodorization is adsorption on activated carbon. It is very efficient method, but requires frequent replacement of the sorption bed (activated carbon) (Szynkowska et al., 2009). In adsorption processes, the problem of odorous pollutants is transferred from one medium (treated gas) to another one (sorbent). Therefore, it is necessary to combine these processes with appropriate sorbent utilization/regeneration processes. To reduce the cost of sorbent utilization/regeneration, new methods are being sought to increase the effectiveness of the deodorization. One common method in this respect is activated carbon adsorption. This paper proposes a method to enhance deodorization by harnessing emergent corrosion. The modernization consisted in introducing corroding steel elements to an impregnated activated carbon bed.

Gases generated by a food substance (smoked fish) served as the specimen. The food product was stored in a 30 dm³ barrel for three days (Fig. 1) prior the commencement of the experiment. Before the gases were harnessed, the barrel was purged with air to stabilize the odor concentration.

90 dm³ air was blown through, after which the gas was supplied to the adsorber for deodorization (Fig. 2).

Air with malodorous pollutants (odor concentration – 2200 ou_E/m³) was supplied via peristaltic pumps which fed 25 dm³/h of air to each experimental fixture. Deodorization was carried out concurrently in four adsorbers equipped with fixed packing on a grate. Two of the adsorbers were loaded with activated carbon (Table 3), the other two – with activated carbon (Table 3) combined with corroding steel elements. Activated carbon was loaded to 62 mm (59 g mass). The supplemental steel packing was made of black steel wire (GCA GT5 NA K – PN-80/M-80028) with a contact surface of 12.70 cm² (223 g mass)

Tab. 3. Parameters of the KOH-activated carbon

PARAMETER	VALUE
granulation diameter	4 mm
BET surface	1000 m²/g
CTC	> 60%
moisture	< 15%
minimum hardness	94%
pH	> 10
KOH content	about 7%
bulk density	540 ± 30 g/dm³

Odor concentration in the pre- and post-deodorization trials was determined by a group of panelists with the YES/NO method applying dynamic olfactometry. The group was selected following guidelines of the standard PN-EN 13725(2007). Gases were subjected to olfactometric analysis immediately after collection.

As already mentioned, adsorption, especially adsorption on activated carbon, is a popular method due to its low technological complexity and ease of use (Schlegelmilch et al., 2005). Also, the Best Available Techniques (BAT) Reference Document for the treatment of waste (including waste from the fish industry) identifies adsorption as one of the most effective end-of-pipe deodorization techniques. Adsorption processes are able to reduce the emission of odors by 70 - 99%. The most popular sorbent is activated carbon, which after the adsorption process is most often utilized in the combustion process (Pinasseau et al., 2018).

Table 4. Techniques for neutralizing odors by the End-of-pipe method proposed in the BREF for waste treatment (including waste from the fish industry) (Pinasseau et al., 2018)

TECHNIQUE	EFFICIENCY (%)
Adsorption	70% – 99%
Water absorption	60% – 85%
Alkaline oxygen absorption	80% – 90%
Combustion (non-catalytic)	98% – 99.9%
Catalytic combustion	80% – 95%
Biofiltration	70% – 99%
Bioscrubbing	70% – 80%
Biotrickling	70% – 90%
Moving-bed trickling filter	> 90%

During the research conducted as part of this article, the adsorption on activated carbon of gases contaminated with odor compounds, which are characteristic of fish processing, ensured practically 100% efficiency (Fig. 3).

Considering the particularities of odor nuisances, the problem of offensive gases emitted by fish processing plants can be eliminated at this deodorization rate. Failure to deodorize (degrade) malodorous compounds below the odor detection threshold would mean that the problem of public complaints would persist. According to the definition of the odor detection threshold, even levels slightly above the threshold would be noticed by 50% of the population. Therefore, there has been a push for methods which would provide a nearly 100% deodorization rate. Despite the 100% deodorization rate of activated carbon, it may be inadequate for fish industry gases. Activated carbon provides 100% deodorization, but at low efficiency. The present study has shown that the adsorption capacity of the bed is quite quickly exhausted. After just 1.5 h, the deodorization rate dropped below the target level (100%) and did not exceed 99.4% (Fig. 3). The odor concentration at the outflow was around 10 ou_E/m³(Fig. 4) and, as can be expected, increased over time (Fig. 4).

Although the present study was conducted over a short period of time, it is clear that deodorization of fish processing gases requires significant input of adsorption material. 59 g of activated carbon were used per 40 dm³ of the treated gas (until breakthrough). At a price of 2,400 € per ton, this translates to 3.59 € per 1 m³ of the treated gas. Apart from the limited commercial viability, waste from deodorization can be a problem as well. Higher amounts of adsorbent generate more waste, which requires later disposal. Although the disposal process itself does not present a major technological hurdle, it does generate additional economic and environmental costs. Therefore, in order to reduce costs and the amount of the resultant waste, it is proposed that the adsorbent material be supported with a layer of corrosive steel packing.

Corrosion refers to the destruction of a material as a result of chemical or electrochemical action of the environment, with electrochemical corrosion being the most common. It entails a series of electrochemical processes involving the flow of charges (anodic and cathodic processes) and the formation of associated reaction products (Baszkiewicz and Kamiński, 2006). Both the electrode processes and the corrosion products can reduce the odor nuisance of gases by reacting with their constituent malodorous substances (Wysocka and Boguszewicz, 2019; Wysocka and Obremski, 2017). The present study shows that natural corrosion contributed to better deodorization performance, with a ninefold increase in the treated volume of fish processing malodorous gases at almost 100% deodorization. Only after 375 m³ gas had been treated (Fig. 4) did the breakthrough occur, which is when the deodorization rate dropped from 100% to 99.4%. The presented deodorization set-up, loaded with 59 g activated carbon, can remove virtually 100% odor concentration from 375 dm³ malodorous gas at a concentration of 2,200 ou_E/m³(Fig. 4). This means that the activated carbon efficiency increased over ninefold, which generates considerable saving in treatment cost – a reduction of 3.21 € per 1 m³ treated gas, which translates to a final cost of 0.38 €.

It should be also noted that the steel packing can be reused after the depleted activated carbon is replaced. The continued usability of the steel packing is determined purely by its rate of corrosion, which in turn depends on the type of the gas treated. The rate of corrosion in polluted air ranges from 200 to 1,500 g× m^-2× year^-1 (Głuszko, 2008). At this corrosivity, a single batch of steel packing can be reused over dozens of years.

Though the scale of the experiment and the time of deodorization were both fairly limited, they do clearly indicate that a corroding layer of steel can expedite adsorption on an activated carbon sorbent. The present study may inspire further research on the subject, and falls in line with the current push towards reusing spent materials. The steel packing can consist of recycled materials, and higher degrees of steel corrosion are more effective in supporting deodorization (Wysocka, 2020).

In pursuit of methods for deodorizing malodorous gases generated by fish processing, it is important to consider existing and commonly used methods based on activated carbon adsorption. Such methods can remove virtually 100% of the odor concentration in highly unpleasant malodorous gases. However, one of their primary disadvantages lies in the cost of the adsorption material. This article proposes supplementing the material with an additional layer of corroding steel, which can considerably extend the time to bed exhaustion. This can greatly extend the service time of an activated carbon bed (and thus significantly reduce operating costs) while maintaining virtually 100% deodorization. The experiment shows that enriching a bed with a layer of corroding steel increases the efficiency of the bed more than ninefold. At a carbon price of 2,400 € per ton and a concentration of 2,200 ou_E/m³, this improved performance greatly reduces the cost of gas treatment (savings of 3.21 € per 1 m³ treated gas). Furthermore, if the corrosivity of the treated gases is similar to that of air, a single steel packing layer can be reused over dozens of years.

Author Contribution

Izabela Wysocka and Anna Lipińska are the only authors of the article titled " Corrosion-enhanced activated carbon deodorization of malodorous gases from fish processing". Individual contributions from individual authors:.1. Conceptualization – 100% Izabela Wysocka2. Methodology – 100% Izabela Wysocka3. Validation – 100% Izabela Wysocka4. Formal analysis – 100% Izabela Wysocka 5. Investigation – 80% Anna Lipińska and 20% Izabela Wysocka6. Data curation – 100% Izabela Wysocka7. Writing - Original Draft – 100% Izabela Wysocka8. Writing – review & editing – 100% Izabela Wysocka9. Visualization – 100% Izabela Wysocka10. Supervision – 100% Izabela WysockaThe authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Baszkiewicz, J., Kamiński, M.: Korozja materiałów. Oficyna Wydawnicza Politechniki Warszawskiej (2006)
Bujny, J., Maśliński, M.: Zwalczanie uciążliwości zapachowych w świetle aktualnie obowiązujących przepisów prawnych. Finanse Komunalne, 23–40. (2018)
Chung, Y.-C.: Evaluation of gas removal and bacterial community diversity in a biofilter developed to treat composting exhaust gases. J. Hazard. Mater. 144, 377–385 (2007)
Gospodarek, M., Rybarczyka, P., Gębicki, J.: Aktualny stan prawny w zakresie przeciwdziałania uciążliwościom zapachowym, XIV Konferencja Dla Miasta i Środowiska -. Problemy Unieszkodliwiania Odpadów, Warszawa (2018)
Głuszko, M.: Zagadnienia ochrony antykorozyjnej konstrukcji stalowych oraz urządzeń elektroenergetycznych eksploatowanych w warunkach atmosferycznych / Problems of anticorrosion protection of steel structures and electro energetic equipment exploited in atmospheric conditions. IEl, Warszawa (2008)
Jachnik, E.: Prawne aspekty ochrony zapachowej jakości powietrza. Przegląd Prawa Rolnego, 149–163. (2017)
Ministerstwo Środowiska: Departament Ochrony Powietrza i Klimatu. Kodeks przeciwdziałania uciążliwości zapachowej (2016)
Pinasseau, A., Zerger, B., Roth, J., Canova, M., Roudier, S.: Best available techniques (BAT) reference document for waste treatment: Industrial Emissions Directive 2010/75/EU (integrated pollution prevention and control). Publications Office of the European Union (2018)
PN-EN 13725: Jakość powietrza. Oznaczanie stężenia zapachowego metodą olfaktometrii dynamicznej. (2007)
Ranau, R., Steinhart, H.: Identification and evaluation of volatile odor-active pollutants from different odor emission sources in the food industry. Eur. Food Res. Technol. 220, 226–231 (2004)
Rutkowski, J.D., Kośmider, J., Szklarczyk, M.: Substancje odorotwórcze w środowisku. Państwowa Inspekcja Ochrony Środowiska, Warszawa (1995)
Schlegelmilch, M., Streese, J., Stegmann, R.: Odour management and treatment technologies: An overview. Waste Manage. 25, 928–939 (2005)
Szynkowska, M., Zawoździak, J.: Współczesna problematyka odorów. WNT, Warszawa. (2010)
Szynkowska, M.I., Wojciechowska, E., Węglińska, A., Paryjczak, T.: Odourus emission. An environmental protection issue (Odory. Aktualny problem w ochronie środowiska). Przemysł Chemiczny. 88/6, 712–720 (2009)
Wibowo, T.S., Purwanto, P., Yulianto, B.: Environmental management efforts at fillet fish processing industry in coastal fishing port Tegalsari Tegal—Indonesia. Adv. Sci. Lett. 23, 2542–2544 (2017)
Wysocka, I.: Wykorzystanie korozji żelaza w ograniczaniu emisji zapachowych / Utilizing iron corrosion in reducing odour emissions. Wydawnictwo Polskiej Akademii Nauk, Warszawa (2020)
Wysocka, I., Boguszewicz, A.: Effectiveness of removal of odorous compounds from a poultry farm in a water scrubber with sand filling. J. Ecol. Eng. 20, 141–145 (2019)
Wysocka, I., Gębicki, J., Namieśnik, J.: Technologies for deodorization of malodorous gases. Environmental Science and Pollution Research International (2019)
Wysocka, I., Namieśnik, J.: Technologie dezodoryzacji gazów złowonnych. Analityka: Nauka i Praktyka 4, 42–48. (2018)
Wysocka, I., Obremski, B.M.: Zastosowanie procesów korozyjnych w absorpcyjnej metodzie oczyszczania gazów złowonnych pochodzących znad osadów ściekowych. Forum Eksploatatora. 5/2017(92), 50–52 (2017)
Zwoździak, J., Dziewa, M., Szałata, Ł., Kwiecińska, K., Cuske, M., Piechocka, A., Bartosik, M.: Lista substancji i związków chemicznych, które są przyczyną uciążliwości zapachowej. Narodowy Fundusz Ochrony Środowiska i Gospodarki Wodnej (2016)

No competing interests reported.

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Corrosion-enhanced activated carbon deodorization of malodorous gases from fish processing

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