EXPERIENCE IN LANDFILL MINING IN MALLORCA (BALEARIC ISLANDS - SPAIN) THE PHILOSOPHY OF THE PERPETUAL LANDFILL

Transcription

1 EXPERIENCE IN LANDFILL MINING IN MALLORCA (BALEARIC ISLANDS - SPAIN) THE PHILOSOPHY OF THE PERPETUAL LANDFILL may 2012 Old Monastery of Saint Augustine Bergamo Italy A. Canaleta G. Ripoll TIRME, S.A. - Palma de Mallorca Balearic Islands - Spain

2 INDEX 0.1. The waste management model in Mallorca 0.2. Landfill mining - The opportunity 0.3. Refuse Dump Zone Studies and landfill mining test and energy recovery of the CDWr 0.5. Cost-benefit balance 0.6. Conclusions 21/05/

3 0.1. THE WASTE MANAGEMENT MODEL IN MALLORCA may 2012-Italy

4 MALLORCA REMARKABLE FACTS Demographic density: double than Spanish average GENERAL ASPECTS Annual tourism input supposes almost 10 million visitors Extension of the island: Km 2 Density of population: 230 inhabitants/km 2 Urban waste generation: 2,02 Kg/inhab/day 21/05/2012 Economy based on service sector, with a contribution of ca. 80 % to the GNP (Gross National Product), being the most important economic sector the tourism High seasonality in waste production 4

5 EVOLUTION of WASTE MANAGEMENT MODEL PDSGRUM (1990) (20/09/90 Decree 87/1990) Management model based only and exclusively on the incineration of MSW PDSGRUM (2000) (18/02/00 Decree 21/2000) "Multiprocessing" model: selection packaging, composting, anaerobic digestion, incineration and landfilling. Sewage sludge incorporated into the system Baseline situation Waste managed directly by the municipalities. Final Destination: 100% landfill Continuity model which incorporates the treatment of CDWr. The main goal is landfilling of PDSGRUM (2006) 06/02/06 is zero waste from the whole system. It also incorporates a solar drying plant for the treatment of sewage sludge. 21/05/2012 SUM2012 SYMPOSIUM ON URBAN MINING 5

6 ACTUAL SITUATION: MSW TREATMENT FACILITIES EXISTING IN MALLORCA 5 Transfer Stations 3 Sewage-sludge composting plants OFMW composting plant 21/05/ Light-Packaging Sorting Plant - Plant for Anaerobic Digestion of wastes - Composting Plant - WTE Plant with slag treatment and security landfill - Solar drying plant for sewage sludge 6

7 WTE PLANT SECURITY LANDFILL SOLAR DRYING PLANT SLAG TREATMENT PLANT 21/05/2012 SUM2012 SYMPOSIUM ON URBAN MINING 7

8 Anaerobic Digestion Plant Composting Plant Light Packaging Sorting Plant Environmental Education Center 21/05/

9 TRANSFER STATION SEWAGE SLUGDE COMPOSTING PLANTS FOMW COMPOSTING PLANT 21/05/

10 0.2. LANDFILL MINING - THE OPPORTUNITY may 2012-Italy

11 WHY WE CONSIDERED THE OPTION OF LANDFILL MINING? DAILY DEMOGRAPHIC PRESSURE The strong seasonal nature of the generation of waste due to the great affluence of tourists in summer months. Mallorca receives about 10 million visitors a year The decrease, in relation to predictions, of construction and demolition waste due to the global economic crisis. 1-1 Year Population Census Floating population Demographic pressure index Average floating population is calculated to be inhabitants (period: ) ? ? 21/05/

12 WASTE GENERATION AND FREE CAPACITY Waste generation: Free capacity: Aprox t/y -30% 21/05/

13 WASTE HIERARCHY (4R) Prevencion REDUCTION / PREVENTION LANDFILL MINING PREPARATION Reutilización FOR REUSE Reciclaje RECYCLING Recuperación OTHER RECOVERY Deposito DISPOSAL 21/05/

14 0.3. REFUSE DUMP OF ZONE may 2012-Italy

15 REFUSE DUMP OF ZONE 2 The landfill is divided into four sectors or landfill cells according to the topography of the land. The facility is composed of: Waterproofing system and leachate collection system. Leachate collection tanks. I II The surface area of this facility is approximately 142,000 m 2. III 285,780 t have been dumped: of which 206,962 t are CDW refuse and 78,827 t capping aggregates. Calculated density is 0.76 t/m 3 and volume occupied is 377,268 m 3. IV 21/05/

16 0.4. STUDIES AND LANDFILL MINING TEST AND ENERGY RECOVERY OF THE CDWr may 2012-Italy

17 STUDIES AND LANDFILL MINING TEST The project was divided into 3 stages: Stage 1: Viability study Stage 2: Validation of the working hypothesis of the viability study 1) Characterization and determination of the LHV of the waste 2) Pilot extraction test 3) Screening performance test 4) Loading and transport 5) Energy recovery from waste Stage 3: Industrial mining test and energy recovery from CDWr. 21/05/

18 CHARACTERIZATION OF CDW REFUSE The materials dumped in cells I and II are made up of 3 typologies: Construction and demolition waste refuse (CDWr) Aggregates (natural and recycled) that separate the layers of waste. Selected aggregate material which makes up the screed dikes built to date. Fuel fraction % weight Non-fuel fraction % weight Paper and cardboard 5,5 Stones and building materials 5,2 Plastics (not package) 8,6 Metals 3,9 Rubber, cables covers, hoses 1,5 Glass 0,7 Wood 48,6 Ceramics 0,2 Textile 5,1 Plaster 0,5 Styrofoam, foams 3,3 Fine fraction 15 Fine fraction 1,9 TOTAL 74,5 TOTAL 25,5 21/05/2012 SUM2012 SYMPOSIUM ON URBAN MINING 18

19 LOWER HEATING VALUE (LHV) In order to determine the LHV of the waste dumped, the columns of waste in cells I and II were divided into three layers This differentiation was based on the operating system used. Cell I + Cell II Initial date Operating stage End date Operating system Waste (tonnes) Aggregates (tonnes) % aggregates Depth (m) Layer 1 October 2007 Simultaneous Operation cells I and II June 2009 Filled with a capping layer of cm every 2 m of waste. 87, Layer 2 November 2006 Cell I September 2007 System of cells with weekly covering 82, Layer 3 June 2006 Initial operating TIRME in cell I October 2006 Filled with a capping layer of cm every 2 m of waste. 37, Layer 1 Layer 2 Layer 3 21/05/2012 SUM2012 SYMPOSIUM ON URBAN MINING 19

20 LOWER HEATING VALUE (LHV) Three probes were conducted on the whole column (Probes A, B, C) to collect samples of the waste and to determine the LHV in an external laboratory Sample Depth (m) Fuel fraction (%) Non-fuel fraction (%) LHV (Kcal/kg) Layer 1 0 a ,895 Layer 2 5 a ,310 Layer 3 11 a , LHV vs depth Layer 1 Layer 2 Layer LHV (Kcal/kg) Depth (m) LHV (Kcal/kg) LHV after pre-treat waste LHV optimal (Kcal/kg) Probe A 21/05/2012 SUM2012 SYMPOSIUM ON URBAN MINING 20

21 EXTRACTION and SCREENING TESTS Layer 1: Only considered removing the layers of capping aggregates with mechanical means. Aggregate separation was not expected to be totally efficient, although from the tests we succeeded in separating 80% of the aggregates. Layer 2: Screening test were carried out to improve energy content, obtaining yields of up to 40% of the separation of the fine fraction through trommeling with a 40 mm mesh. This pre-treatment enabled us to gain approximately 300 kcal/kg of waste as this fine fraction is basically 70% inorganic matter. 21/05/2012 SUM2012 SYMPOSIUM ON URBAN MINING 21

22 EXTRACTION and SCREENING TESTS In order to avoid large gas pockets that could be found to have accumulated among the waste, the excavation was carried out in fine layers. This operating method favoured the practically immediate elimination of gases, thus decreasing the risk of handling the mass of waste For the extraction and loading of the lorries a tracked excavator, a front end loader and a back-hoe were used. 21/05/2012 SUM2012 SYMPOSIUM ON URBAN MINING 22

23 ENERGY RECOVERY FROM RECLAIMED WASTE The waste was excavated and transported to the incinerator where controlled combustion was carried out for 12 hours with the aim of determining the impact of the process. The LHV of layer 1 oscillated between kcal/kg, an acceptable value for its recovery. Layer 2 pretreatment its recovery was ruled out by low LHV. In parallel with the combustion tests, ash and slag samples were collected from both lines. Analyses carried out did not show any significant differences with respect to historical values. Parameter Units Regular waste Mined waste LHV Kcal/Kg Temperature in the furnace ºC Steam production t/h CO (boiler output) mg/m O 2 (boiler output) % HCl (boiler output) mg/nm SO 2 (boiler output) mg/nm /05/2012 SUM2012 SYMPOSIUM ON URBAN MINING 23

24 INDUSTRIAL TEST OF LANDFILL MINING Over 80,000 tonnes were reclaimed and treated, corresponding to layer 1. Optimization of transport costs was a critical point in the mining operation. The distance between DR Z2 and the WTE plant is 60 km. Large capacity lorries (90 m 3 ) with moving floors were used along with other lower capacity vehicles. In the peak period, more than 1000 tonnes of CDWr have been transported daily. THE FUTURE? Viability of metal separation and improving Layer 2 s LHV. 21/05/2012 SUM2012 SYMPOSIUM ON URBAN MINING 24

25 0.5. COST-BENEFIT BALANCE may 2012-Italy

26 COST-BENEFIT BALANCE ENVIRONMENTAL VALUE SOCIAL VALUE STRATEGIC VALUE ECONOMIC VALUE Extraction Screening Load Transport Treatment Energy recovery 21/05/2012 SUM2012 SYMPOSIUM ON URBAN MINING 26

27 0.6. CONCLUSIONS may 2012-Italy

28 CONCLUSIONS (I) The characteristics of the waste treatment model established in Mallorca through the Executive Plans allow us to recover this waste. Thereby, it is possible to make up for the decrease in waste, brought about by the crisis in the construction industry, with materials that are currently found dumped in DR Z2. From the preliminary studies, we obtained the necessary data to be able to assess the viability of mining on an industrial scale, by ruling out excavation in layer 3, proposing prior screening in layer 2 and direct excavation of layer 1 with mechanical separation of the capping aggregates. The separation of aggregates in layer 1 is not complete although it is possible to achieve separation percentages close to 80%. Pre-treatment by screening for layer 2 produces a rise in LHV of approximately 300 kcal/kg. A record of all the operations carried out during the landfill period made it possible to develop this work and successfully determine the key parameters in the mining process. 21/05/2012 SUM2012 SYMPOSIUM ON URBAN MINING 28

29 CONCLUSIONS (II) Mining cells I and II of DR Z2 and subsequent energy recovery is totally viable. Environmentally, these operations do not generate significant changes that can affect the environment negatively. In the long term, the elimination of the waste is evidently an improvement for the environment. The recovery of the energy contained in the waste is close to 170 GWht and is equivalent to substituting 14,600 Tep. This means a drop in consumption of around 100,000 barrels of oil or providing electricity to 11,000 people for one year (OSE 2008). Once DR Z2 has been excavated and following the philosophy of the perpetual landfill, there will be a considerable volume of perfectly conditioned landfill site available. 21/05/2012 SUM2012 SYMPOSIUM ON URBAN MINING 29

30 THANKS FOR YOUR ATTENTION