Example Inventory 9 Source Group 8 Miscellaneous

This example inventory aims to illustrate the process of inventory development, update and revision for source group 8: Miscellaneous, source category 8b: Crematoria. This case study provides a hypothetical example of a country X that compiles inventory data for crematoria as part of the action plan within the National Implementation Plan (NIP) according to the Stockholm Convention on Persistent Organic Pollutants (POPs).

Baseline inventory

The baseline inventory of country X was conducted in 2005 by using data collected for 2004 (reference year); the amount of PCDD/PCDF releases to air and residue were calculated following the Standardized Toolkit for Identification and Quantification of Dioxin and Furan Releases, UNEP 2005. According to country X, cremation was mainly performed as a Buddhism tradition. Therefore, religion and death records were obtained from National Statistics in 2004, as well as the number and list of Buddhist temples that have cremation facilities. According to country X, 75.82% of deaths resulted in cremations. Questionnaires were sent to these temples to obtain more detailed information including the type and temperature of the burning chamber, as well as after burning chamber, duration of operation, dust abatement system, air pollution control system, type and amount of fuel, and number of cremations per year.

The crematoria were classified into 3 classes according to the technologies in use, based on the data obtained from questionnaires complemented by site visits as follows:

• Class 1 (no control) refers to the crematoria where the combustion temperature is below 850°C, with uncontrolled combustion air flow or no flue gas cleaning system in place. The coffin is decorated with plastic material or made of treated wood;
• Class 2 (medium control) refers to the crematoria where the combustion temperature is above 850°C, with controlled combustion air flow and only dust removal in place. The coffin does not contain plastic material or treated wood;
• Class 3 (optimal control) refers to the crematoria where the combustion temperature is above 850°C with controlled combustion air flow and air pollution control system (APCS) in operation.

The data for Class 1, 2 and 3 are segregated, then the activity rate or production (t/a) of crematoria in each class is multiplied by a PCDD/PCDF emission factor to obtain the amount of PCDD/PCDF releases to air and residue as illustrated in the table below:

PCDD/PCDF release from crematoria to environmental media

Class	Source Categories	Activity (t/a)	Annual release (g I-TEQ/a)
			Air	Water	Land	Product	Residue
	8 Miscellaneous
	8b Crematoria
1	No control	238,455	21.46				ND
2	Medium control	15,333	0.15				0.04
3	Optimal control	0	0.00				0.00
Total for Crematoria		253,788	21.61	0.00	0.00	0.00	0.04

Updating of the inventory and revising the baseline

he measures included in the action plan targeting crematoria are based on best available techniques considering both environmental aspects (e.g. appropriate air pollution control systems) and technology (e.g. minimum temperature, residence time and oxygen content requirements). Further to implementing these measures, country X needs to assess whether PCDD/PCDF releases from this source decreased over time. The inventory is thus updated in 2013 to evaluate the changes in releases as a result of implementing best available techniques and best available practices. Data were collected for 2010 (reference year). During the process of updating the inventory it was found that 20 new crematoria with optimal control for PCDD/PCDF (class 3) release were installed in various regions in country X. Questionnaires were sent to both new and existing crematoria to obtain up-to-date information regarding their production or activity rates, temperature and duration of cremation process, fuel use, air pollution control system and evaluate / reclassify these facilities according to their current technology profile and activity levels. The same approach as in the baseline inventory was thus applied and resulted in 30% of the crematoria which were classified as class 1 in the baseline inventory being upgraded to class 2, and 5% of the crematoria which were classified as class 2 in the baseline being upgraded to class 3.

The results show that although the number of facilities increased in country X from 2004 to 2010, PCDD/PCDF releases decreased over the same period of time as a result of phasing in best available techniques for crematoria:

Class	Source Categories	Activity (t/a)	Annual release (g I-TEQ/a)
			Air	Water	Land	Product	Residue
	8 Miscellaneous
	8b Crematoria
1	No control	99,000	8.91				ND
2	Medium control	152,000	1.52				0.38
3	Optimal control	50,000	0.02				0.12
Total for Crematoria		253,788	10.45				0.5

Country X also plans an own PCDD/PCDF measurement campaign to collect and analyze samples from several facilities and refine the emission factors used in estimating releases. Once the emission data are generated and new emission factors derived, country X will revise the inventory by applying the same set of revised emission factors based on own measurements, to enable consistent evaluation of trends in releases over time.

Conclusion

When updating the PCDD/PCDF inventory, it is necessary to review the baseline or previous inventories to maintain consistency over time and ensure that the estimates obtained are comparable over time. Data quality is important; therefore, it is also essential to revise and update data obtained from national statistics, questionnaires and site visits. More specifically, it is important to note all factors such as the type of wood used in making the coffin, the preservatives used in treating the wood, plastic decorations added to the coffin, which would contribute to higher emissions of PCDD/PCDF to air and residue.

Introduction

Dioxin and furans emitted by the dry cleaning processes are found in the residues from distillation of the solvents and in filters. The emission factors for PCDD/PCDF found in the literature are usually expressed relative to the amount of residue from the solvent recycling process. Depending on the efficiency of stills, the bottoms range from a dry powder to a wet sludge that contains some solvent and the filtered material.

As shown in the Toolkit, a ton of residue from a dry cleaning machine may contain from 50 µg TEQ to 3000 µg TEQ of PCDD/PCDF depending on the nature of the cloths and tissues treated and the amount of contamination they contain.

To evaluate emissions of PCDD/PCDF from the dry cleaning industry at a country level using the Toolkit method, one has to estimate the amount of residues generated and the relative nature of the tissues cleaned (heavy or contaminated textiles/normal textiles). In nearly all countries it is difficult to find such data to complete the inventory.

In case of lacking data, the following considerations may help in the estimation of these values:

• In a U.S. EPA study, it was reported that an average dry cleaning machine (35 lb cloths per hour/ 4200 lb per month) generates an average of 407 lb of residues from the bottom of the still; an approximation of the amount of residues generated might be 1kg/10 kg of textiles;
• The ratio of heavy textiles to normal textiles treated in dry cleaning laundries is varying from country to country; an expert judgment is needed according to local practices;
• Last generation dry cleaning processes use less than 10 kg of solvent per ton of textiles;
• Residues of dry cleaning contain less than 1% of solvent (new dry cleaning processes).

Example 1

In country A, the total installed dry cleaning capacity is 2500 kg/h and the activity is 3600 t/year of which 60% are heavy textiles. The total amount of residues is estimated at 360 t/year and the PCDD/PCDF releases in residues are:

• From heavy textiles : 60% x 360 t/y x 3000 μg TEQ = 0.648 g TEQ
• From light textiles : 40% x 360 t/y x 50 μg TEQ = 0.0072 g TEQ

Emissions in residues for dry cleaning category are 0.6552 g TEQ/year. Total emissions for this category are 0.6552 g TEQ/year as there is no emission through other media.

Example 2

In country B, there is not enough information concerning the production rate but we know there are at least 60 dry cleaning laundries in the country. We can assume the average production rate is 24 000kg/year/laundry (4200 lb/month) and their release rate is 2.4 t/year. The ratio between the two categories of textiles treated is not really known but a local expert estimated that it would be about 1/1.$

PCDD/PCDF releases in residues are:

• From heavy textiles : 50 % x 60 x 2.4 x 3000 = 0.216 g TEQ
• From light textiles : 50% x 60 x 2.4 x 50 = 0.0036 g TEQ

Total emissions for dry cleaning category are 0.2196 g TEQ

Example 3

In country C, there is no data concerning the production rate and the residues generation for the dry cleaning category, but it is known, from official statistics, that the average annual imported quantities of solvent for use in dry cleaning (perchloroethylene, Stoddard solvent, other brand names) are stable at about 500 tons per year. Assuming an average consumption of 10kg/ton of textiles treated in dry cleaning processes, a production rate of about 50 000 t is estimated, which will generate about 500 tons of residue.

PCDD/PCDF releases in residues are:

• From heavy textiles: 50% x 500 t/y x 3 000 μg TEQ = 0.75 g TEQ
• From light textiles: 50% x 500 t/y x 50 μg TEQ = 0.0125 g TEQ

Total PCDD/PCDF emissions from dry cleaning are of 0.7625 g TEQ.