Toolkit for Identification and Quantification of Releases of Dioxins, Furans and Other Unintentional POPs
PART III Example Inventories
Example Inventory 8 Source Group 7 Production and Use of Chemicals and Consumer Goods
The purpose of this case study is to illustrate the process of inventory development, update and revision, focusing on the production and use of chemicals. This case study provides a hypothetical inventory example of a Country X, including practical details on updating and revision of the inventory to assess trends in releases over time.
Country X developed the baseline inventory of dioxins in 2004 to support the development of the action plan as required by Article 5 of the Stockholm Convention. Activity data for the different sources of dioxins were collected for the reference year 2004 (baseline year). Activity data were obtained from the statistic yearbook. The inventory is developed by applying the Toolkit 2005 methodology and the emission factors specified in the 2005 edition of the Toolkit.
In this sample inventory, the inventory development process for the chemical industry is detailed, and provides useful guidance on estimating PCDD/PCDF releases for this source group.
The baseline inventory of Country X was conducted in 2004 using data collected for the reference year 2004, according to the emission factors included in the Toolkit 2005 methodology.
For pentachlorophenol (PCP) and polychlorinated biphenyls (PCB), the production and use of PCP and PCB had been forbidden in Country X for many years, and thus no production of these chemicals occurred in the baseline year. For PCP-Na, the output was of 2,000 tons.
For chlorinated pesticides, 2,4,-dichlorophenoxy acetic acid (2,4-D) and 2,4,6-trichlorophenol were used as herbicides in Country X. The outputs of 2,4-D and 2,4,6-trichlorophenol in Country X in 2004 were of 16,000 and 800 tons respectively. No production of other chemicals listed in category 7b occurred in Country X in the baseline year 2004.
For chloranil, there were three plants in Country X in 2004. Plant A produced p-chloranil via chlorination of phenol. Plant B manufactured p-chloranil via hydroquinone, and Plant C produced o-chloranil via chlorination of phenol. The activity levels were of 300, 1,000, and 400 tons for Plants A, B, and C, respectively.
With regard to chlorobenzenes, the activity levels were of 6,000, 22,000 and 6,000 tons for p-dichlorobenzene, o-dichlorobenzene and 1,2,4-trichlorobenzene respectively.
In 2004, the production of alkali from the chlor-alkali industry in Country X was about 10.6 million tons. Among them, about 20,000 tons of alkali was produced using graphite anodes. The other alkali production in Country X was manufactured by membrane technology. No formation and emission of dioxins occurred during the production of chlorine/alkali by membrane technology.
The output of PVC was about 800,000 tons manufactured in modern plants (belonging to class 2 of EDC/VCM/PVC facilities) in Country X. About 4.53 million tons of PVC production belonged to class 3 (PVC only).
Release estimates were made by assuming a linear relation between the intensity of the activity and the emission resulting from this activity.
Release to Air
For source 7b, the emission factors to air were only available for class 2 and 3 of the EDC/VCM/PVC in Toolkit 2005 methodology. Releases to air from source 7b were calculated by using the following equation:
|Release of dioxins to air =||∑i=1,n activity levels for class i x emission factors to air for class i =|
|800 000 t × 0.4 μg TEQ/t (Modern plants, EDC/VCM or EDC/VCM/PVC) + 4 530 000 t × 0.0003 μg TEQ/t (PVC only) =|
|= 0.32 g|
Release to Water
For source 7b, the emission factors to water were only available for class 2 and 3 of the EDC/VCM/PVC in Toolkit 2005 methodology. Releases to water were calculated by using the following equation:
|Release of dioxins to water =||∑i=1,n activity levels for class i x emission factors to water for class i =|
|800 000 t × 0.5 μg TEQ/t (Modern plants, EDC/VCM or EDC/VCM/PVC) + 4 530 000 t × 0.03 μg TEQ/t (PVC only) =|
|= 0.536 g|
Release to Land
Emission factors were not available for dioxin release into land in the Toolkit 2005 methodology. Thus, no release into the land was expected for source 7b according to the Toolkit 2005 methodology.
Release in Products
PCDD/PCDF releases in product were the dominant release route for source 7b. The emission of dioxins in product from source 7b was estimated to be 157.57 g according to the equation described below.
|Release of dioxins to products =||∑i=1,n activity levels for class i x emission factors to products for class i =|
|2 000 t × 500 μg TEQ/t (PCP-Na) + 800 t × 700 μg TEQ/t (2,4,6-trichlorophenol) + 16 000 t × 700 μg TEQ/t (2,4-D) + 300 t × 400 000 μg TEQ/t (p-chloranil via chlorination of phenol) + 1 000 t × 100 μg TEQ/t (p-chloranil via hydroquinone) + 400 t × 60 000 μg TEQ/t (o-chloranil via chlorination of phenol) + 6 000 t × 39 μg TEQ/t (p-dichlorobenzene) + 800 000 t × 0.03 μg TEQ/t (Modern plants, EDC/VCM or EDC/VCM/PVC) + 4 530 000 t × 0.1 μg TEQ/t (PVC only)|
|= 157.57 g|
Release in Residues
PCDD/PCDF releases in residues were significant in 2005. The emission factors of dioxins in residues from source 7b were available for production of chlorobenzenes, Chlorine/alkali, and ECD/VCM/PVC production according to the Toolkit 2005 methodology. Thus, the estimated release of PCDD/PCDF in residues from source 7b was of 46.91 g.
|Release of dioxins to residues =||∑i=1,n activity levels for class i x emission factors to residues for class i =|
6 000 t × 3 000 μg TEQ/t (1,2,4-trichlorobenzene) + 20 000 t × 1 000 μg TEQ/t (Chlor-alkali production using graphite anodes) + 800 000 t × 10 μg TEQ/t (Modern plants, EDC/VCM or EDC/VCM/PVC) + 4 530 000 t × 0.2 μg TEQ/t (PVC only) =
|= 46.91 g|
The total dioxin release from source 7b by five different release routes was calculated to be 205.33 g. The emission inventory for source 7b is presented in the following table.
Total dioxin release = Release to Air + Release to Water + Release to Land + Release in Products + Release in Residues = 0.32 g + 0.536 g + 157.57 g + 46.91 g = 205.33 g
Baseline inventory (reference year 2004)
|Source category 7b||Production||Annual release|
|t/a||g TEQ/a||g TEQ/a||g TEQ/a||g TEQ/a||g TEQ/a|
|7b||Production and Use of Chemicals||Air||Water||Land||Product||Residue|
|1||European, American production (chlorination of phenol with Cl2)||0||0|
|2||Chinese production (thermolysis of HCH)||0||0|
|1||Low chlorinated, e.g., Clophen A30, Aroclor 1242||0|
|Medium chlorinated, e.g., Clophen A40, Aroclor 1248||0||0|
|Medium chlorinated, e.g., Clophen A50, Aroclor 1254||0||0|
|4||High chlorinated, e.g., Clophen A60, Aroclor 1260||0||0|
|1||Pure 2,4,5-Trichlorophenoxy acetic acid (2,4,5-T)||0||0|
|4||2,4-Dichlorophenoxy acetic acid (2,4-D)||16,000||11.200|
|2,4,6-Trichlorophenyl-4’-nitrophenyl ether (CNP = chloronitrofen )||0||0|
|1||p-chloranil via chlorination of phenol||300||120.000|
|2||p-chloranil via hydrochinone||1,000||0.100|
|3||Dyestuffs on chloranil basis (old process, Class 1)||0||0|
|4||o-chloranil via chlorination of phenol||400||24.000|
|Chlor-alkali production using graphite anodes||20,000||20|
|1||Old technology, EDC/VCM, PVC||0||0|
|2||Modern plants, EDC/VCM or EDC/VCM/PVC||800,000||0.32||0.400||0.024||8|
|Category 7b (Total per vector)||0.321||0.536||157.571||46.906|
|Category 7b (Grand total)||205.33|
The updated inventory of Country X was developed using data of activity levels collected for the reference year 2010, according to the updated emission factors in Toolkit 2013. The revised Toolkit includes important structural changes to the classification of sources in the chemical industry sector, new or revised emission factors for a number of sources, as well as additional source categories and classes.
The activity levels of chemicals production are the same as in the baseline year and the corresponding release estimates are summarized in the following table using the Toolkit 2013 and corresponding emission factors.
Updated inventory (reference year 2010)
|Class||Source categories||Production||Annual release|
|t/a||g TEQ/a||g TEQ/a||g TEQ/a||g TEQ/a||g TEQ/a|
|7b||Chlorinated Inorganic Chemicals||0.0||0.0||0.0||0.0||20.0|
|Elemental chlorine production (per ton ECU)||20'000||0||0||0||0||20|
|1||Chlor-alkali production using graphite anodes||20'000||20|
|2||Chlor-alkali production using titanium electrodes|
|7c||Chlorinated Aliphatic Chemicals||0.5||0.4||0.0||0.0||0.4|
|EDC/VCM and EDC/VCM/PVC (per ton EDC)||800'000||0.040||0.400||0.000||0.000||0.076|
|1a||With fixed-bed oxychlorination catalyst||0.000||0.000||0.000||0.000|
|1b||With fluidized-bed oxychlorination catalyst||0.000||0.000||0.000||0.000|
|2a||With fixed-bed oxychlorination catalyst||0.000||0.000||0.000||0.000|
|2b||With fluidized-bed oxychlorination catalyst||0.000||0.000||0.000||0.000|
|3a||With fixed-bed oxychlorination catalyst||
|3b||With fluidized-bed oxychlorination catalyst||0.000||0.000||0.000|
|PVC only (per ton PVC product)||4'530'000||0.453||0.014||0.000||0.000||0.281|
|7d||Chlorinated Aromatic Chemicals (per ton product)||0.0||0.0||0.0||455.4||0.0|
|1||Low chlorinated, Clophen A30, Aroclor 1242||0.000|
|2||Medium chlorinated, Clophen A40, Aroclor 1248||0.000|
|3||Medium chlorinated, Clophen A50, Aroclor 1254||0.000|
|4||High chlorinated, Clophen A60, Aroclor 1260||0.000|
|PCP and PCP-Na||2'000||0.000||0.000||0.000||25.000||0.000|
|2,4,5-T and 2,4,6-trichlorophenol||800||0.000||0.000||0.000||0.560||0.000|
|2,4-D and derivatives||16'000||0.000||0.000||0.000||2.720||0.000|
|1||Direct chlorination of phenol||1'000||400.000|
|2||Chlorination of hydroquinone with minimal purification||0.000|
|3||Chlorination of hydroquinone with moderate purification||1'000||26.000|
|4||Chlorination of hydroquinone with advanced purification||0.000|
|Phthalocyanine dyes and pigments||0||0.000||0.000||0.000||0.000||0.000|
|Dioxazine dyes and pigments||0||0.000||0.000||0.000||0.000||0.000|
|7e||Other Chlorinated and Non-Chlorinated Chemical (per ton product)||0.0||0.0||0.0||0.0||0.0|
|TiCl4 and TiO2||0||0.000||0.000||0.000||0.000||0.000|
Chemicals Industry (categories 7b through 7e)
Chemicals Industry (Grand total)
Although the activity rates remained at constant rates since 2004, the difference between the baseline and updated releases is consequent: 476.63 - 205.33 = 271.3 g TEQ. In particular, releases in product are twice as high as baseline values. This is only due to the changes in the Toolkit emission factors, as the activity rates remained at constant levels since 2004. To ensure consistent results over time, the baseline release estimates need to be revised according to the Toolkit 2013 set of emission factors, ensuring that the difference between the 2010 and 2004 values is, as expected, null.
New data and information have been integrated in the revised 2013 edition of the Toolkit, and important changes have been made to emission factors and the classification of sources for the chemical industry. The updating of the inventory for this source group needs to be accompanied by the revision of the baseline values to enable assessment of consistent trends in releases over time.