First draft Part II default Emission Factors, Source Group 7 Chemicals and Consumer Goods


Annex 48 Complementary information to source category 7b Chemical Industry



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Annex 48 Complementary information to source category 7b Chemical Industry


Overview of recent revisions

No revision to emission factors was made.


Derivation of emission factors

Release to Air

Most studies on the chemical industry have shown that only minor releases of PCDD/PCDF to the air result from manufacture of the listed products.


In general, air releases of PCDD/PCDF will be of concern at the local level. It is usually an issue of occupational exposure/worker hygiene, workplace design, and provision of suitable protective clothes – eventually including filter masks - to potentially exposed workers.
Higher air release may result from chemicals in use but these are hard to quantify and will depend on local conditions. Other air releases may occur from incineration of residues from the chemical production processes. These are likely to be accounted for as hazardous waste incineration and dealt with in source group 1b.
Release to Water

Releases of PCDD/PCDF to water and to sewer can result where effluents are discharged and not recycled within the process. The PCDD/PCDF are likely to be strongly bound to solid material or associated with oily phases of the effluents. The release of PCDD/PCDF will depend on the process used, the amount of effluent produced and effluent treatment in place.


It is not possible to provide emission factors for releases to water as they are dependent on site-specific factors.
For each process it is important to identify effluent releases, to note where in the process they come from, to identify treatment applied and to note where the effluent is released to (sewer, river, settling pond, etc.). If data is available on the amount of effluent and on composition this is valuable also.
Releases may also occur where products are used. In the case of product use it may be possible to estimate the amount of product released to water and therefore estimate the release of PCDD/PCDF. In other cases it is valuable to note where releases to water may be occurring from product use.
Release to Land

Releases of PCDD/PCDF to land are only likely from production processes where residues from the production processes are disposed by simple dumping on land. No emission factors can be given and any such practice should be noted with information gathered on the amount and source of the residue where possible.


Releases to land from product use are possible, especially for pesticides. If good information is available on the use of contaminated chemicals it may be possible to estimate the releases to land. In other cases note the possible releases to land and gather data on the product uses.
Release in Products and from Product Use and Disposal

For each of the chemicals listed in below, data is provided on concentrations of PCDD/PCDF in the products (where these are available). This can be combined with production data and import/export information to estimate a flow of PCDD/PCDF in the product.


The releases from the product to the environment will depend on the uses of the chemical and disposal of materials treated with the product. Where possible data should be gathered on the main uses, the amounts used, the nature of the industry or domestic uses and the handling and treatment of materials, which have been treated.
Release in Residues

Residues from chemical production may contain PCDD/PCDF. The levels will depend on the process used and purification applied. There are many possible residue streams. Those of interest will include by-products (especially the denser oily residues from purification), sludge from effluent treatment, etc. Concentrations of PCDD/PCDF can vary widely from ng TEQ/kg to mg TEQ/kg. No general factors can be provided.


It is useful to gather data on residues produced at chemical production sites. It is also helpful to note how the residues are treated and disposed of.
Residues may also arise from product use or formulation. It may be possible to estimate the amount of a contaminated product ending up in a residue.
Chlorine Production

Release to Air

From the process, no release of PCDD/PCDF to air is expected.


Release to Water

Releases of PCDD/PCDF to water will depend on the effluent treatment applied. PCDD/PCDF are likely to be tightly bound to particles and the efficiency with which these are captured is likely to influence any release to water. No general emission factor can be provided. Information on the sources, quantities and treatment applied to effluents should be gathered.


Release in Products

Chlorine gas does not contain PCDD/PCDF. Thus, the emission factor for chlorine is zero.



Release in Residues

Most PCDD/PCDF contamination will be found in the residues. There are data available from Germany (Hagenmaier and She 1994), Sweden (Rappe et al. 1991), and from China (Xu et al. 2000, Wu 2000). The concentrations in the graphite sludge were as follows: up to 3,985 μg I-TEQ/kg in a sample from Germany, from 13 to 28 μg N-TEQ/kg in three samples from Sweden (Rappe et al. 1991), and 21.65 μg I-TEQ/kg in one sample from China (Xu et al. 2000). For the Chinese dioxin release inventory, it is assumed that on average 50 kg of graphite sludge is generated per ton of alkali produced. With a default concentration of 20 μg TEQ/kg graphite sludge, an emission factor of 1,000 μg TEQ/t of chloralkali is proposed.


Ethylene Dichloride or 1,2-Dichloroethane (EDC)

Release to Air

Emissions to air from these processes come mainly from incineration. Incineration is used to control exhaust gases from the various steps of the process with various furnace types such as thermal oxidizers, rotary kiln, liquid injection incinerators and fluidized-bed incinerators. Due to the HCl content in the exhaust gases, it is expected that the incinerators are equipped at least with a cooling system and a caustic quench to neutralize HCl.


The US survey of EDC/VCM and PVC plants (US-EPA 2000, Vinyl Institute 1998) evaluated results from 22 incinerators within the industry. The emissions were lowest for vent gases from combustors at PVC only production sites (note: no liquid residue streams). The emission factors for vent and liquid/vent combustion were highly variable and varied four orders of magnitude for similar combustors. For the Toolkit, the average emission were taken to calculate the emission factors for the combustion of vent gases only and liquid and vents based on EDC production as shown in Table 64.
The data in Table 64 are based on EDC or PVC production data from the U.S. industry. The 2002 US-EPA TRI data for PCDD/PCDF releases to air from 22 facilities convert into emission factors between 0 μg TEQ/t of EDC and 3 μg TEQ/t of EDC with an average of 0.4 μg TEQ/t of EDC (US-EPA 2004, Carroll 2004, Dyke et al. 2004). The emission factor for PVC stand-alone plants were taken from US-EPA 2000, Vinyl Institute 1998.
An alternative approach would be to use emission factors based on the amount of waste fed. Also in this case, releases from vent gas and liquid waste/vent gas incinerators at combined EDC/VCM plants showed variable emissions, which ranged from 1.3 and 14 μg TEQ/t of waste feed.
Since the combustor design and operation is most critical it is suggested that an estimate of the amount of waste burned is made and this is treated as hazardous waste incineration (1b Hazardous Waste Incineration).
Release to Water

The manufacture of EDC/VCM and PVC uses considerable amounts of process water, which either leaves the plant or is recycled as far as possible back into the EDC/VCM/PVC manufacturing process. The process water that cannot be recycled may be discharged without further treatment or directed into a wastewater treatment process. This typically reduces BODY (biological oxygen demand) and total suspended solids as well as adjusting the pH to meet water guidelines.


At modern US facilities PCDD/PCDF concentrations in wastewaters from PVC sites only were close to detection limit. The overall mean concentrations were 0.88 pg I-TEQ/L (ND=0) and 4.7 pg I-TEQ/L (ND=½ DL). An emission factor of 0.03 μg TEQ/t of PVC has been derived for wastewaters from modern PVC plants (US EPA 2000, Vinyl Institute 1998).
At EDC/VCM plants, all samples had quantifiable concentrations with mean values of 0.42 pg TEQ/L (ND=0) and 4.4 pg TEQ/L (ND=½ DL) (US EPA 2000, Vinyl Institute 1998). Emission factors for EDC/VCM and EDC/VCM/PVC plants ranged from 0 g TEQ/t of EDC/VCM/PVC to 2.5 μg TEQ/t of product. For this Toolkit, the mean of 0.5 μg TEQ/t of EDC for wastewaters from EDC/VCM plants was chosen as default emission factor for modern plants (US-EPA 2004, Carroll 2004, Dyke et al. 2004).
For EDC/VCM and EDC/VCM/PVC plants, it is assumed that the amounts of PCDD/PCDF released to the environment with wastewater rather depends on the efficiency of the waste water treatment system - especially its capability to remove spent catalyst solids – rather than on the process applied.
For old and poorly controlled systems formation of PCDD/PCDF may be higher and releases to water may be higher as well due to poor water treatment systems. However, presently, no emission factor can be given.
Release in Products

PCDD/PCDF concentrations in PVC products are low; most samples showed no detectable PCDD/PCDF. An overall mean concentration of 0.3 ng I-TEQ/kg should be used for the Toolkit. In EDC, only in one sample 0.03 ng I-TEQ/kg (ND=0) could be detected. Emission factors for old PVC and EDC products cannot be given due to the lack of authentic samples.


Release in Residues

The main residues of interest are: heavy ends from EDC purification, spent catalyst (from fixed bed plants) and wastewater treatment sludge. Each of these residues may be handled and disposed of in a number of ways, which will affect releases to the environment.


For combined EDC/VCM plants concentrations in wastewater treatment sludge ranged from 100 to 5,900 μg I-TEQ/t of product (VI 1998). Sites using fixed-bed technology were usually lower but these sites produced spent catalyst (in fluidized bed processes, this is released with the water and is being collected in the wastewater treatment sludge). Overall average emission factors were approximately 2 μg I-TEQ/t (EDC production). For fixed bed plants most PCDD/PCDF may be expected to be associated with the spent catalyst. Sludge from sites where PVC only is being produced has an emission factor of 0.02 μg TEQ/t of PVC. Solid emissions, as spent catalyst and wastewater treatment solids taken together at EDC and combined EDC/PVC sites will be ca. 2.0 μg TEQ/t of product (US-EPA 2000, Vinyl Institute 1998).
Concentrations of PCDD/PCDF can be much higher in some residue streams, such as heavy ends from EDC purification. For example, Stringer et al. (1995) reported concentrations from 3,000 ng TEQ/kg to 5,000,000 ng TEQ/kg in wastes from PVC manufacture. Clearly the potential for releases from these streams depends on the way the materials are handled and disposed of. The amount of residue produced should be estimated if possible. In many cases these residues are incinerated on-site or by commercial hazardous waste incinerators to make an estimate of releases from this activity see 1b - Hazardous waste incineration. In a few cases residues have been either disposed of in underground stores (Dyke et al. 1997) and in some cases may be used as feedstock for solvent production.
If the residues are disposed of by dumping or are used as a feedstock for another process this should be noted. UK data showed that halogen-organic wastes contained 100 μg I-TEQ/t (expressed per unit of EDC production). This factor can be used to make initial estimates of the amount of PCDD/PCDF in these streams – the fate of the residue streams must be identified.

Annex 49 Complementary information to source category 7c Petroleum Industry


Overview of recent revisions

No revision to emission factors was made.


Derivation of emission factors

Release to Air

Presently, only emissions to air can be estimated by applying the same emission factor as for burning and flaring of landfill and biogas. The emissions from the reactivation of the catalyst cannot yet be quantified.


Release to Water

The amount of wastewater generated in the catalytic reforming process is around 190 kg/t of feedstock. The wastewater contains high levels of oil, suspended solids. Emissions of PCDD/PCDF to water may occur upon discharge of the wastewater. However, no data are available at present. Any discharge of wastewater should be noted.


Release in Residues

Spent catalyst fines may be generated from the fine particle abatement systems. Spent catalyst generated is around 20-25 tons per year for a 5-million-tons-per-year refinery. Typically, spent catalyst is sent back for recycling or regeneration.


From the wastewater treatment, sludge can be generated. There are no PCDD/PCDF concentrations available at present; however, concentrations of pyrene and benzo[a]pyrene in the low mg/kg range have been detected (BREF 2000b).

Annex 50 Complementary information to source category 7d Textile Production


Overview of recent revisions

No revision to emission factors was made.


Derivation of emission factors

Release to Air

There is no indication of relevant PCDD/PCDF emissions to the air from textile plants and thus, no emission factor will be given. The emissions from the generation of steam and power should be accounted for in Source Group 3.


Release to Water

There are no data available and no emission factors could be generated. When German finishing processes were investigated, no quantifiable concentrations have been found. Releases to water will depend on the materials and chemicals used or applied, both in the process and to the raw materials and also on the water treatment. There is evidence for potential releases where there are poor controls on the discharges and large quantities of certain chemicals.


Release in Products

There is no simple indicator to identify dioxin-contaminated fibers, wools or textiles: whereas in most samples of raw textiles, concentrations below 1 ng I-TEQ/kg were detected (means around 0.2 ng I-TEQ/kg), there were also highly contaminated samples found. For example, 244 ng I-TEQ/kg were detected in bleached polyester, 370 ng I-TEQ/kg in blue cotton (Horstmann 1994), and 86 ng I-TEQ/kg in wool (Mayer 1997). The homologue profiles of all highly contaminated samples were dominated by the higher chlorinated PCDD and PCDF (Cl7 and Cl8). These are indicators for either the biocide pentachlorophenol or chloranil-based dyestuffs as the source of the contamination. However, several analyses confirmed that there is no correlation between PCP and PCDD/PCDF concentrations in textiles although the dioxin patterns gave strong indications that PCP should be the source. These findings make sense as PCP is water-soluble and will be removed in the finishing process and final washing processes whereas the PCDD/PCDF adsorb to the fiber and will stay in the textile (Horstmann and McLachlan 1995b, Klasmeier and McLachlan 1998).


Release in Residues

Depending on the factors described above, sludge from water treatment or from process steps may contain PCDD/PCDF. At present, there are no measured data available.



Annex 51 Complementary information to source category 7e Leather Refining


No revision to emission factors was made.

CASE STUDIES



Case Study 8 Example inventory for source group 7 Production and Use of Chemicals and Consumer Goods


To be developed

1Hyperlink to the case study 8 Example of Inventory fro Source Group 7

2 Section V.C Production of pulp, pg. 11.

3 Section V.C Production of pulp, pg. 11

4 Hyperlink to Annex 47 containing derivation of EFs for source category.

5 Hyperlink to Annex 48 containing derivation of EFs for source category.

6 Hyperlink to Annex 49 containing derivation of EFs for source category.

7 Section VI.J Textile industry. Pg 11.

8 Hyperlink to Annex 50 containing derivation of EFs for source category.

9 Hyperlink to Annex 51 containing derivation of EFs for source category.




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