THE POSSIBILITY OF ENERGY RECOVERY FROM SPECIFIC WASTE STREAMS IN CYPRUS

Transcription

1 THE POSSIBILITY OF ENERGY RECOVERY FROM SPECIFIC WASTE STREAMS IN CYPRUS A. MENTZIS*, A. KARKAZI*, N. GARGOULAS*, S. SKOULAXINOU* AND N. KYTHREOTOU * EPEM SA, 141b Acharnon Str., , Athens, Greece Ministry of Agriculture, Natural Resources and Environment, Environment Service, Cyprus SUMMARY: This paper seeks to present the procedure and methodology that has been followed and the results that come up from the investigation of the potential energy recovery from various waste streams produced in Cyprus. Cyprus is one of the smallest in surface member states and meeds to identify alternative solutions to landfilling, since the available area that may be used for wast disposal in the island is very small. In this respect and considering that it is not always possible to reuse / recycle all the streams and all of the waste, energy recovery is an equally interesting perspective. The analysis revealed that there is opportunity to recover the energy content of several waste streams, combining the utilization of the existing energy intensive industries (mainly cement factories) and developing a medium scale WtE plant. 1. INTRODUCTION The need to divert waste from landfilling and maximize the utilization of material contained in waste is among the basic requirements of the EU waste management policy and legislation. According to the waste hierarchy, waste management practices are prioritized as follows: Waste reuse Waste recycling Utilization of the energy content of waste Safe disposal of waste treatment/utilization residues It is evident that energy reuse and recycling is not always technically feasible and financially viable. Therefore the utilization of the energy content of the waste constitutes a very interesting alternative. This is also correlated with the need to divert the energy needs from mineral fuel resources. Cyprus is one of the smallest, in surface and population, Member States of the EU and is characterized by intense tourist activity, while other fields of economic activities include agriculture and a small number of industrial facilities (active in power generation and cement production). Despite the fact that relatively small waste quantities are generated in the island, the small surface of Cyprus, combined with the significant land value, restricts to a great extend the area that may be used for waste disposal. As such, there is a need to reduce the waste to be Proceedings Venice 2010, Third International Symposium on Energy from Biomass and Waste Venice, Italy; 8-11 November by CISA, Environmental Sanitary Engineering Centre, Italy

2 disposed off as much as possible. In this framework, the possibility to implement systems for the energy utilization of various waste fractions generated in Cyprus was examined and the results are presented in this paper. 2. METHODOLOGY The waste streams that were examined in order to assess the possibility to utilize their energy content include: Treated municipal waste (RDF / SRF) Specific industrial waste Waste oils Used tires Sludge Agricultural waste The generated quantities distributed geographically were assessed, as well as the current waste management practices. Also, the existing and planned waste management and industrial infrastructure was examined, in order to identify the opportunities to use this infrastructure for the production of energy from the generated waste. Following the analysis of the current waste management status, alternative scenarios were developed for the energy recovery from the aforementioned waste streams. The scenarios were developed in two levels: Strategic level, in order to decide whether the energy recovery may occur in existing industrial infrastructure or in new WtE plants Technical level, in order to determine the technology that may be implemented in the case that the development of a new WtE plant is promoted The development of alternative scenarios was based on the following principles and information: Waste quantities and geographical distribution Grouping of generated waste, based on its characteristics and properties Current energy recovery practices location of existing infrastructure Economies of scale Flexibility and reference of WtE technologies A SWOT analysis was used for the comparative evaluation of the scenarios that were developed and the criteria used included: Technical criteria: o Potential to treat all waste streams required specification of input pretreatment needs o Amount of energy generated o Level of implementation internationally o Risks of implementation Environmental criteria: o Air emissions o Wastewater o solid and hazardous residues o Contribution in the reduction of global warming Social criteria: o Level of acceptance by citizens and competent authorities

3 Financial criteria: o Investment cost o Operational cost o Estimated income Following the comparative analysis of the scenarios an action plan was proposed including specifications for the waste treatment. 3. RESULTS OF THE ANALYSIS - DISCUSSION 3.1 Waste generation and treatment for energy recovery in Cyprus Data on current waste generation in Cyprus, for the streams under examination, were collected using various sources (e.g. existing studies, questionnaires, etc). Table 1 presents the quantities of the waste streams that may potentially be utilized for energy recovery. Currently in Cyprus a small percentage of the generated waste is used for energy recovery in the existing cement factories or in a new pyrolysis plant of used tires. The main streams used in these factories include: Waste oils bilge waters Used tires Sludge The regions of Nicosia, Limassol and Larnaka/Famagusta present similar potential for energy recovery from waste. Also, in Limassol and Larnaka/Famagusta regions most of the existing waste management units are already located or scheduled to be located (i.e. waste oils treatment plants, used tires pyrolysis plant, cement factories, SRF/RDF production plants etc). With respect to the needs for pre-treatment of the waste prior to energy recovery it is noted: Used tires need to be shredded Sludge needs to be dried RDF/SRF will be produced in municipal solid waste plants in a MBT facility. Then the RDF/SRF needs to be balled or put in pellets Used oils and bilge water are pre-treated in order to reduce the water content Table 1 - Distribution of waste that may be utilized for energy recovery per region. Annual waste quantity (tn) Waste type Nicosia Larnaka and Famagusta Limassol Pafos Waste from food industry Other organic waste Paper and wood industrial waste Sludge from industrial wastewater Used oils Oil residues bilge water Old tires Sewage sludge Products of rendering facilities Animal fat RDF/SRF

4 The waste streams under examination were grouped as follows: Group 1: Waste of high organic content and calorific value: o Sludge o Products of rendering facilities o Animal fat Group 2: Liquid waste: o Waste oils o Bilge waters Group 3: Solid waste of high calorific value: o Paper and wood industrial waste o Used tires Group 4: Solid waste of low calorific value: o Waste from food industry other organic waste Group 5: Special waste streams: o RDF / SRF 3.2 Examination of alternative scenarios Considering the results of the analysis of waste streams and quantities, the alternative scenarios were developed, based also on the following: The size of Cyprus and the waste quantities generated restrict the viability of a new WtE plant for each of the waste groups identified. Hence, the operation of 1 new WtE unit will be examined There is in operation a pyrolysis plant for used tires One of the cement factories already utilizes significant waste quantities for energy recovery (used oils and bilge waters, sludge, tires etc), while it schedules the development of a new unit, which will be in position to accept bigger waste quantities In terms of WtE technologies, the most commonly used technology is incineration, while gasification and pyrolysis have been significantly expanded in the last years, and plasma is the most recent technology Based on the above, the following alternative scenarios for the recovery of energy from waste in Cyprus were examined: Scenario 1: Construction and operation of 1 WtE plant in Larnaka/Famagusta or Limassol region. This scenario is further split in the following sub-scenarios concerning the technology to be implemented: o Scenario 1a: Incineration o Scenario 1b: Pyrolysis o Scenario 1c: Gasification o Scenario 1a: Plasma Scenario 2: energy recovery from waste using a new WtE plant (of smaller capacity than the one in Scenario 1) and the scheduled cement plant Scenario 3: maximization of the energy recovery of waste in the scheduled cement plant Table 2 presents the main characteristics of each alternative scenario.

5 Table 2 - Characteristics and requirements of alternative scenarios Pretreatment requirements Financial data Energy recovery References Social acceptance Scenario 1a Scenario 1b Scenario 1c Scenario 1d Scenario 2 Scenario 3 Requires shredding, drying, etc Investment cost: m Operation cost: /tn Revenues: 30,8 m ή 44 /tn Commercially most developed technology Negative social perception in relation to incineration of MSW. The WtE for streams other than MSW may be easier Requires shredding, sieving, drying, etc Investment cost: m Operation cost: /tn Revenues: 32,4 m ή 46,2 /tn Under development. No references of large capacities or for cotreatment of various waste streams As all new technologies several reservations appear. As WtE technology it faces similar reactions as in Scenario 1 Homogenization Investment cost: m Operation cost: /tn Revenues: 43,4 m ή 62 /tn Under development with several references. There are references of large capacities and treatment of various waste streams As all new technologies several reservations appear. As WtE technology it faces similar reactions as in Scenario 1 Small requirements Investment cost: m Operation cost: /tn Revenues: 46,2 m ή 66 /tn Most novel technology As all new technologies several reservations appear. As WtE technology it faces similar reactions as in Scenario 1 Pre-treatment to reach the specifications of cement factory Investment cost: m Operation cost: /tn Revenues: 19,3 m ή 39,5 /tn Substitution of tn/year pet coke or tn/year Heavy fuel oil Similar to scenario 1 The cement and pyrolysis plant operate without social reactions. Concerning the new plant reactions are similar to Scenario 1 Pre-treatment to reach the specifications of cement factory ΜWHr/year Substitution of tn/year pet coke or tn/year Heavy fuel oil The cement and pyrolysis plant operate without social reactions.

6 Following the development of the alternative scenarios a SWOT analysis was used in order to evaluate them comparatively. The main results of the analysis include: Scenario 1a appears to have an overall good performance due to: o The potential to treat multiple waste streams o The significant international experience o The lower cost compared to the other alternatives o The significant amount of energy produced o The relatively low level of uncertainties regarding its implemention Significant disadvantages are the generation of hazardous residues, as well as the negative public perception concerning incineration. Scenario 1b appears to have an overall average performance due to: o The high pre-treatment requirements o The low level of international experience and the high level of uncertainties o The high investment and operation cost o The generation of hazardous residues A significant advantage is the production of high amount of energy. Scenario 1c appears to have a relatively good performance due to: o The significant amount of energy produced o The relatively low level of uncertainties regarding its implemention o The relatively high international experience o The significant evolution and development seen in recent years Significant disadvantages are the high investment cost and the generation of hazardous residues. Scenario 1d appears to have an overall bad performance due to: o The small level of implementation at international level, a fact that increases the uncertainties concerning the results of its implementation (e.g. high energy recovery rate, reduced emissions etc) o The high cost Based on the above, it is considered that this scenario is not appropriate to be implemented in Cyprus. Scenario 2 appears to have an overall good performance due to: o The lower cost compared to other scenarios o The significant amount of energy produced, as well as the substitution of conventional fuels o The significant contribution in the reduction of the global warming phenomenon o The relatively positive social acceptance A significant disadvantage is that the alternative options on waste treatment (new plant and existing infrastructure) act competitively. Scenario 3 appears to have an overall good performance due to: o The cost is borne by the operators of the cement plant and the pyrolysis facility o The substitution of conventional fuel o The significant contribution in the reduction of the global warming phenomenon o The relatively positive social acceptance o The fact that this practice is already know and implemented in Cyprus A significant disadvantage is that the system s success is depending exclusively in the private operators of the plants.

7 The analysis revealed the conclusion that scenario 3 is the least cost intensive for the authorities as all costs are borne by the private operators. However, the fact that the system will be based on the operation of the private facilities posed significant risks to its success, as the operators may require technical specifications or financial reimbursements aiming at higher profit and not at the successful implementation of the system. Therefore, it is considered suitable for the authorities to seek for a flexible system consisting of a small dedicated WtE plant, which together with the existing facilities (cement production and pyrolysis) will maximize the energy utilization of the waste. This scenario (scenario 2) provides this flexibility, as 3 alternative waste utilization options will be implemented: Utilization in WtE plant Utilization in the cement production plant Utilization of used tires in the pyrolysis plant An important disadvantage of this system is that the alternative options are competitive to each other, since their revenues depend on the waste input. In this framework, in the case that the construction of the new WtE plant is decided, it is proposed to implement the technology of incineration, which is the most widely implemented, with high energy recovery and lower cost, compared to the alternative WtE technologies. Alternatively, the gasification appears to have similar cost to incineration and a relatively high level of implementation. 4. CONCLUSIONS Following the final decision concerning the development of the system for energy recovery from the waste generated in Cyprus, the following actions need to be implemented, in order for the system to be successfully developed: Discussion with the operators of the existing facilities in order to determine the waste quantity and streams that they can treat, as well as their technical and financial requirements Final decisions on the works that will be implemented for the management of MSW, in terms of locations and technologies, since these decisions affect the location of the new WtE plant, as well as the input quantities (in relation to RDF / SRF) Maturation of the WtE plant in relation to the environmental, feasibility and detailed design studies that need to be developed, as well as to the establishment of the technical specifications of the input waste and the specifications related with each stage of the waste management cycle (from collection to final disposal of the residues) Determination of the sources of the funds that will be used for the construction of the WtE plant (PPP or public and EU funds etc) Implementation of a public campaign in order to minimize the negative reactions towards the energy utilization of waste Moreover, as soon as the system of energy recovery from waste is established, the development of a separate administrative unit should be examined in order: To monitor the energy recovery actions (collection, transportation, treatment) To monitor the operation of the WtE plants and their environmental performance To monitor the collaboration of the operators of the plants with all stakeholders To monitor the financial viability of the system and contribute in the establishment of the tariff policy To collaborate with the waste producers and managers for the system optimization To monitor the technological and legislative developments in order to improve the system

8 In any case, first of all the dedication of developing the waste utilization system is needed by all stakeholders and especially by the central administration. In this respect, several discussions and round tables with all stakeholders (ministries, waste producers, potential waste users etc) will be required, in order to establish the basic principles and constituents of the system of energy recovery from waste. REFERENCES DEFRA UK (2007) Advanced Thermal Treatment of Municipal Solid Waste. EC (2008) Green Bible. Ecoprog GmbH ( ) Waste Incineration Plants in Europe. Environment Agency (2007) Treatment of non hazardous wastes for landfill. Environment Agency (2002) Waste Pre-Treatment: A Review. EPEM S.A. (2008a) Technical Assistance for the Construction and operation for 25 years of a waste treatment plant and energy production plant in Imathia Prefecture. EPEM S.A. (2008b) Framework Contract for the elaboration of studies for the treatment and utilization of waste in Thessaloniki Prefecture. EPEM S.A. (2005) Study for the development of a MBT plant for municipal solid waste in Western Macedonia Region. Juniper Consultancy Ltd. ( ) Ratings for Waste Processes and Suppliers. Juniper Consultancy Ltd. (2008a) Plasma, Its role in waste processing, A Decision Maker's Guide. Juniper Consultancy Ltd. (2008b) Juniper Ratings Report, Application: Gasification, version 2.0, September Rand T. et. al. (2000) Municipal Solid Waste Incineration, A Decision Maker's Guide, The World Bank, Washington D.C. UK Environment Agency, Waste Technology Data Centre, WORLD BANK (2000) Decision Makers Guide to Incineration of Municipal Solid Waste.