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French treatment - A comprehensive assessment of 42 recent MSW incinerators Between 1993 and 2000, the French Agency for Environment and Energy Management (ADEME) played a key role in the construction and upgrading of 42 municipal solid waste incinerators in France. A study carried out in 2001 assessed technical, environmental and economic aspects of these plants. Erwan Autret In 2000, France produced an estimated 45.6 million tonnes of municipal solid waste (MSW).1 As of January 2003, France had 123 municipal solid waste incinerators (MSWIs) in operation with a total installed capacity of the order of 12 million tonnes.2 Over the past 10 years, the performance of French MSWIs has improved considerably to meet the requirements set out in EU directives and to minimize environmental impacts and health risks. Numerous small MSWIs have closed following the implementation of European directives 89/369/EEC and 89/429/EEC governing the incineration of non-hazardous waste (including municipal waste). On the other hand, a new generation of incinerators has emerged. Between 1993 and 2000, 42 MSWIs were constructed or completely refurbished in France at a total cost of ¿1.9 billion. The incineration of both hazardous and non-hazardous waste in Member States is now covered by new legislation, Directive 2000/76/EC,3 which will be fully implemented by 2005. France had 123 municipal solid waste incinerators in operation in 2003 By helping to fund these works, the French Agency for Environment and Energy Management, ADEME, has played a major role in the development of incineration in France. Total aid from ADEME between 1993 and 2000 was ¿107 million, i.e. 5.7% of the required investment in the 42 MSWIs. In 2001, ADEME asked the consultancy company, Trivalor, to carry out a comprehensive assessment of the operation of these units.4 This article summarizes the technical, environmental and economic assessments from this study. Technical and environmental assessments Of the 42 units studied in 2001, 31 had been operating for more than a year and 11 were either under construction (start-up planned for 2002 and 2003) or had been in operation for less than a year (start-up planned during 2001). 74% of the units were new installations and 26% were extensions of existing facilities. The total capacity of the 42 MSWIs was 4.7 million tonnes/year compared with a total capacity of all French facilities in 2001 of 11.2 million tonnes/year (i.e. they represent 42% of national capacity). The average throughput of the 42 MSWIs was around 110,000 tonnes/year, while over 40% of units had a capacity of between 75,000 tonnes/year and 130,000 tonnes/year. There were as many units with a capacity less than 70,000 tonnes/year as with a capacity greater than 200,000 tonnes/year. Time from initial studies to start-up Taking a project from initial studies to start-up required seven years on average. This duration can be broken down into three equal parts as follows: Saint-Ouen MSWI; France has 123 MSWIs in operation with a total installed capacity of the order of 12 million tonnes. PHOTO: ROLAND BOURGUET/ADEME 1998 28 months from the initial studies to the consultation with the builders or delegates 28 months from the consultation phase to obtaining authorization (includes definition of legal structure, miscellaneous formalities, public inquiries, etc.) 28 months from the beginning of construction work to industrial start-up The performance of French MSWIs has improved considerably over the past ten years Despite growing NIMBYism and legal challenges, these procedures had not got longer since 1993. In addition, the type of legal structure - public service delegation or public ownership - was not found to affect the duration of procedures. Type of waste processed While municipal solid waste incinerators are, obviously, used mainly for processing municipal waste (80% of waste incinerated), the 42 units had diversified to an increasing extent - both in terms of the types of waste accepted (see Table 1) and quantities processed. TABLE 1. Types of waste processed by the 42 MSWIs Type Processed by MSWIs in operation Processed by MSWIs under construction Municipal solid waste 100% 100% Non-hazardous industrial waste 77% 82% Sewage sludge 23% 36% Healthcare wastea 29% 9% Refuse fr om sorting or separate collection facilities 35% 55% Refuse from composting facilities 19% 27% Others (bulky waste, unsorted waste, etc.) 29% 27% a According to French regulations, healthcare waste can be incinerated, under specific circumstances, together with municipal waste (i.e. maximum of 10% of healthcare incinerated). The study found that: when sizing the plant, greater account was taken of non-hazardous industrial waste (processed in over 80% of the latest installations) an increase in the proportion of sewage sludge processed - a waste for which local authorities are responsible (almost 40% of new projects affected) energy recovery was being integrated into the waste management system as evidenced by the more systematic factoring in of refuse from sorting and separate collection facilities (35% and 55% for existing and new units, respectively) and composting facilities the sharp decrease in the processing of healthcare waste, which - apart from some regional exceptions - can be processed adequately using existing capacity Plant operations All plants generally operated at full capacity, mainly because installations are not generally oversized and facilities sometimes reach saturation point due to non-hazardous industrial waste or waste from local authorities outside their standard territory. The average load ratio (ratio of tonnage processed to theoretical annual tonnage for 7500 operating hours annually) was 93% and, apart from two exceptions, all installations had a load ratio of over 80%. The highest load ratios were observed in installations with low capacities (i.e. load ratios of >95% for capacities <100,000 tonnes/year). Certain equipment used to optimize operations is now becoming commonplace, e.g. balers used for temporary storage in bales and bulky waste crushers. Emissions Gaseous emissions from the 31 operating MSWIs were analysed in terms of four levels of performance (see Table 2). The results of this analysis are given in Table 3 in terms of numbers of installations and the total tonnage incinerated that reached/did not reach the four performance levels. TABLE 2. Levels of performance selected for the analysis of gaseous emissions Performance level Deadline for existing plants Deadline for new plants Directives 89/369/EEC and 89/429/EEC End-1996 for installations >6 tonnes/hour End-2000 for installations <6 tonnes/hour 8 March 1991 Dust and acid gasesa 2005 24 February 1997 Dioxinsa 2005 24 February 1997 NOxa 2005 2002 a As defined by Directive 2000/76/EC. ign="top" bgcolor="#DDE7E7"> TABLE 3. Analysis of gaseous emissions Performance level Numbers of units Total tonnage Reached Not reached Reached Not reached Directives 89/369/EEC and 89/429/EEC 100%   100%   Dust and acid gasesa 55% 45% 67% 33% Dioxinsa 55% 45% 50% 50% NOxa 10% 90% 10% 90% a As defined by Directive 2000/76/EC. All sites achieved the emission limits demanded by Directives 89/369/EEC and 89/429/EEC. Table 3 shows that 55% of sites (representing 67% of tonnage) were operating in 2001 within the limits for dust and acid gas emissions set by Directive 2000/76/EC. However, flue gas treatment did not appear to have any influence at those plants that had not yet reached these emission levels. The MSWI at Argenteuil, outside Paris, has a treatment capacity of about 170,000 tonnes per year. Completed in 1998, this incinerator is optimized to recover both electric and thermal energy, supplying heat to more than 5500 households. PHOTO: A. PARINET/ADEME 2000 In respect of dioxins, 55% of sites (representing 50% of tonnage) had emission levels of less than 0.1 ng/Nm3. Emission levels were less than 1 ng/Nm3 in over half the other units. There was a clear difference in terms of performance between the various types of flue gas treatment; over 70% of sites not operating within the 0.1 ng/Nm3 threshold used wet processes. Installing dioxin treatment equipment on dry or semi-wet treatment systems already equipped with a fabric filter is a relatively simple operation and one that had already been performed in the majority of cases. Three sites - one of which was at the delivery phase in 2001 - were equipped with a nitrogen oxide (NOx) treatment system. Comprehensive work was being undertaken to meet the performance levels for 2005 demanded by Directive 2000/76/EC. All the 11 sites under construction have been designed to operate within the Directive's limits, except for NOx, for which treatment was not required at the time of the construction. Seven of the 11 sites have, however, been designed to generate NOx emissions of less than 200 mg/Nm3. In respect of certain other pollutants, guaranteed levels for these new units were well within the requirements of Directive 2000/76/EC. Energy recovery All the 42 MSWIs recovered energy generated during waste incineration (see Table 4). Energy recovery by CHP was more common in extensions to existing sites. For the new projects, which were often located far from potential users, the breakdown was 33% CHP recovery and 66% recovery as electricity. TABLE 4. Analysis of energy recovery for new and existing MSWIs Number of units Proportion of capacity Type of energy recovery 2 2% All thermal (i.e. heat) 16 45% Combined heat and power (CHP) 24 53% All electricity Energy recovery ratios were found to be in line with forecasts. In respect of thermal recovery, forecast and actual energy recovery ratios exceeded 90%. In respect of CHP recovery, the average forecast energy recovery ratio was 58% compared with an average actual ratio of 54%. In respect of 'all electric' recovery, the average forecast energy recovery ratio was 22.5% compared with an average actual ratio of 21.8%. A more detailed analysis based on 80% of the tonnage processed in the 32 operating MSWIs revealed that 967 GWh of electricity was produced in 2001; this represented 53% of the electricity produced by incineration plants in France. Sales of heat energy totalled 1049 GWh/year, i.e. 29% of the total thermal energy recovered by MSWIs in France. Tables 5 and 6 compare the performances of the 42 units studied compared with all French facilities. TABLE 5. Energy recovery performances of CHP facilities in kWh/tonne   Overall French facilities in operation in 2000 with capacity >3 tonnes/hour Units in operation (13 units) Forecast figures for units under construction (3 units) Total energy recovery 815 992 1326 Of which: Heat for own use 101 153 366 Heat sold 546 629 578 Electricity for own use 61 71 82 Electricity sold 107 139 300 TABLE 6. Energy recovery performances of all-electric facilities in kWh/tonne   Overall French facilities in operation in 2000 with capacity >3 tonnes/hour Units in operation (18 units) Forecast figures for units under construction (6 units) Total production 368 418 528 Of which: Own use 83 89 98 Sold 285 329 430 A significant overall improvement in energy recovery was observed. This trend was confirmed by the increase in the forecast average energy recovery ratio. On certain existing sites, an all-electric recovery ratio of 550 kWh/tonne of waste incinerated was sometimes reached. Moreover, four other sites had ratios of over 480 kWh/tonne of waste incinerated. In respect of installations under construction, the average forecast recovery ratio reached 25%. The reasons for this phenomenon include: increased net calorific value for the 'mix' incinerated improved turbine efficiency in the power range in question optimized exploitation. Economic assessment The costs indicated do not include tax or subsidies. Increasing capital costs Investment costs rose significantly between 1993 and 2000. Average investment was ¿3.60 million per tonne/hour for the 10 latest units in 2001 compared with ¿2.65 million per tonne/hour in 1993. This increase is mainly due to: increased civil engineering costs architectural constraints the development of plant automation the introduction of new equipment and facilities (for temporary storage in bales, for handling sewage sludge and for crushing bulky waste). Variations in operating costs were due mainly to local conditions In view of the number of mergers and acquisitions among the construction companies and the relatively small number of projects in France, it is important to remain vigilant with regard to the evolution of investment costs over the coming years. Average operating costs Operating costs can be broken down into three main items: operating expenses (personnel, insurance, consumables, heavy maintenance, replacement, etc.), which represented an average of ¿33/tonne (standard deviation of ¿4.6/tonne) for operating installations cost of residue removal, which included the removal of air pollution control (APC) residues and bottom ash, and represented an average of ¿13/tonne (standard deviation of ¿5/tonne) energy earnings, which amounted on average, to ¿14/tonne (standard deviation of ¿4/tonne). The average net operating cost (average operating expenses + residue removal - energy earnings) was ¿32/tonne. However, there was a wide range of operating costs within the sample studied: the lowest cost was ¿18/tonne and the highest cost was ¿42/tonne the standard deviation was ¿8.4/tonne 30% of units had a cost per tonne (< ¿25/tonne) more than 20% lower than the average 20% of units had a cost per tonne (< ¿39/tonne) more than 20% higher than the average. The storage of reagents for flue gas treatment at Bellegarde MSWI. Between 1993 and 2000, 42 MSWIs were constructed or completely refurbished in France at a total cost of ¿1.9 bill ion. PHOTO: ROLAND BOURGUET/ADEME 1998 Unlike investment costs, the evolution of operating costs in existing plants could not be clearly explained by detailed item-by-item analysis of spending. The size of units, in particular, did not seem to affect operating costs. This suggests that variations in operating costs were due mainly to local conditions affecting the sale of by-products and energy. Installations engaged in 'all-electric' energy recovery sold electricity to the French electricity company, EDF, at an average price of 4.3 Eurocents/kWh. Apart from a few exceptional cases, all the electricity sold was priced at between 3.3 and 4.6 Eurocents/kWh. In addition, there was a near-linear relationship between electricity earnings and tonnage processed. Average earnings amounted to ¿13.10/tonne processed, with a standard deviation of ¿4/tonne. ABOVE LEFT Slag conveyors at the Saint Saulve MSWI. The 42 units in France had diversified to an increasing extent, both in terms of the types of waste accepted and quantities processed. PHOTO: ROLAND BOURGUET/ADEME 1996 ABOVE RIGHT A technician makes air emission measurements at the Saint Saulve MSWI. All MSWI facilities in France achieve the emission limits demanded by Directives 89/369/EEC and 89/429/EEC. PHOTO: ROLAND BOURGUET/ADEME 1996 For installations engaged in CHP, average energy earnings totalled ¿15.70/tonne processed, with a standard deviation of ¿7.50/tonne. This was 20% more than for all-electric energy recovery. Electricity and heat earnings per tonne of waste processed were variable since they depended on the EDF purchase price, the preferred energy recovery mode and the efficiency of energy recovery. Overall, the sale of heat raised an average of ¿9.80/tonne (standard deviation of ¿5.90/tonne), i.e. more than 60% of total energy earnings. The sale of electricity raised an average of ¿5.90/tonne (standard deviation of ¿4.40/tonne). Total average costs were calculated to be ¿78/tonne Total average costs A total average cost (capital + operating) for the operational units was calculated to be ¿78/tonne. This calculation assumed: Investment (on the basis of ¿3.6 million per tonnes/hour) borrowed for 15 years at 6% for a plant operating 8000 hours/year), i.e. ¿46/tonne Operation (average total expenses + residue removal - energy earnings), i.e. ¿32/tonne. This amount excluded any subsidies and self-financing, and was for an installation with characteristics equivalent to the average of those observed among the sample of 31 operational installations. This amount was, furthermore, per tonne treated and independent of differential pricing in respect of the local authority and other customers. Labour requirements Incineration plants have low labour requirements and generate few jobs. The 31 plants in operation generated around 0.3 jobs per 1000 tonne/year of capacity. The ratio appeared to be decreasing in respect of installations under construction (0.27 jobs per 1000 tonnes/year). This downward trend, which required confirmation when the new installations were up and running could be due to the increasing automation of plants. The 42 units studied represent a total of some 1350 jobs (created or transferred). The level of skills required by staff has risen in line with the modernization and growing sophistication of the processes. Conclusion Out of the total of 123 MSWIs operating today in France, 42 were constructed between 1993 and 2000 with the help of ADEME. These 42 units not only meet current European standards (Directives 89/369/EEC and 89/429/EEC), but also partially anticipate the requirements of the new Directive on waste incineration (2000/76/EC). The next challenge is for all the MSWIs to meet the compliance deadline of December 2005 set out in Directive 2000/76/EC. Comprehensive construction works and investments will help to minimize environmental impacts and health risks for a better sustainable development. References www.ademe.fr www.environnement.gouv.fr 2000/76/EC on the incineration of waste. Official Journal of the European Communities. 28 December 2000.L332. p. 91. europa.eu.int/comm/environment/wasteinc/ ADEME Municipal Waste Division. Thermal treatment of municipal solid waste: assessment of the 42 French facilities funded by ADEME. September 2002.   Erwan Autret is Project Manager at Ademe, based in Angers, France. Fax: +33 2 41 20 42 00 e-mail: erwan.autret@ademe.fr