Study the substitution of fossil fuels by RDF produced from municipal solid waste of HaNoi

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VNU UNIVERSITY OF SCIENCE TECHNISCHE UNIVERSITÄT DRESDEN N g u y en Bich Ngoc S T U D Y T H E S U B S T I T U T I O N O F F O S SIL F U E L S BY R D F P R O D U C E D F R O M M U N I C IP A L S O L ID W A S T E O F H A N O I Major: W aste M a n a g e m e n t and C ontam inated Site T reatm ent C ode M A S T E R T H E S IS S U P E R V IS O R : PR O F. DR. N G U Y E N THI D IE M T R A N G ĐAI HỌC QUỐC GIA HÀ NÔI TRUNG TAM THÓNG TIN THƯ VIÊN H anoi - 2011 ACKNOWLEDGEMENT I own my deepest Thi Diem Trang. believing, great gratitude to my supervisor Without I could her patiently not complete opportunities for this learning Prof. support thesis. new Nguyen She things and gave me as well as training myself. I would like Bilitewski, National to express Technische University Service (DAAD) for my thankfulness Universität and The German organizing this to Prof. Dresden, Vietnam Academic Exchange Master course. It is also an honor for me to study with devoted professors and lecturers the within this course. They knowledge but also a new vision, It is a pleasure possible Ms. to thank only gave me a new way of thinking. those who made this thesis Dang Ngoc Chau and my three friends Hop, Chuong. I am also grateful for Ms. of valuable her not comments and Tao, Tran Thi Nguyet because support during my thesis wri ting. I would like to thank my many of my colleagues for their encouragement during this course and for the time we spent together. The special thank goes to my parent and my I would like to show my gratitude to little sister for their love and endless support. Last my but not least, amant. Thank you for always standing helping me overcome difficult time. by my side and 2.3.1. CO 2 emission calculation ......................................................................... 36 2.3.2. Nitrous oxide em ission ............................................................................. 37 3. R e s u l t s a n d d i s c u s s i o n .......................................................................................... 38 3.1. RDF preparing process con tro l........................................................................38 3.1.1. Stabilization tim e ...................................................................................... 38 3.1.2. Tem perature .............................................................................................. 39 3.1.3. Leachate volume ........................................................................................ 41 3.1.4. Water co n ten t ............................................................................................ 42 3.2. RDF q u ality......................................................................................................... 44 3.2.1. R D F com position ..................................................................................... 44 3.2.2. Heating va lu e ........................................................................................... 45 3.3. GHGs estimation................................................................................................ 47 3.3.1. Pre-treatment ste p .................................................................................... 4 7 3.3.2. RDF utilization ste p ................................................................ ................ 48 3.3.3. Total GHGs em ission ................................................................................ 49 C o n c l u s i o n ..................................................................................................................................... 51 R e f e r e n c e s .....................................................................................................................................5 2 M aster Thesis L ist o f figures/ tobies L ist o f f ig u r e s Figure 1: Global energy consumption from 1985 to 2010 (million tons o f oil equivalent) [1 ] ....................................................................................................................9 Figure 2: Rotterdam product oil prices - US dollarsper barrel [ 1 ] ......................... 10 Figure 3: Natural gas price (dollars/Btu) [ 1 ] .............................................................11 Figure 4: Shares o f world primary energy [ 1] ...........................................................12 Figure 5: Electricity consumption in Vietnam (kWh per cap ita )............................ 13 Figure 6 : Share o f total primary energy supply in Vietnam in 200 8 ........................14 Figure 7: Waste composition o f Hanoi [2 0 ]................................................................ 15 Figure 8: Densified RDF (Saitama Prefectural Environmental Management Center, Ja p a n )..................................................................................................................20 Figure 9: Schematic Representation o f MBT Process [8 | ...................................... 23 Figure 10: Herhof Stabilat method [11]........................................................................25 Figure 11: Schematic diagram o f MBT CD.08 [14].................................................. 28 Figure 12: Heat value o f RDF product - MBT CD.08method [ 14]........................29 Figure 13: RDF composition for 3 barrels....................................................................31 Figure 14: RDF sample preparing process.................................................................. 32 Figure 15: Waste barrel......... .......................................................................................... 33 Figure 16: Temperature in stabilization barrels.......................................................... 39 Figure 17: Composting temperature depending on C:N r a tio ................................. 40 Figure 18: Temperature differences in stabilization barrels..................................... 41 Figure 19: Leachate v o lu m e ...........................................................................................42 Figure 20: Water co n te n t................................................................................................ 43 Figure 21: Waste input composition (left) and estimated RDF output composition (right) - (a) sample 1, (b) sample 2, (c) sample 3 ....................................................45 Figure 22: Gross heating value comparison with fossil fuel and RDF from different studies............................................................................................................... 47 Figure 23: GHGs emission from RDF sample compare with fossil fuel (kg C 0 2.Cq ,'MJ) [ 9 ] .............................................................................................................................50 6 L ist o f figures/ tables M aster Thesis L i s t OF TABLES Table 1: Waste composition in Hanoi in 1995 and 2003 [20]...................................15 Table 2: MSW eeneration and collection rate in cities/towns in Vietnam ............. 16 Table 3: Type o f refuse derived fuel........................................................................... 18 Fable 4: Typical RDF composition in some resions [8] .........................................20 Table 5: Quality o f RDF from household and industrial sources [8] .....................21 Table 6 : Quality o f RDF in some Europe Countries [17]..........................................22 Table 7: Conversion rate for RDF production according to treatment process and country.............................................................................................................................. 26 Table 8: Annual RDF production from MSW in some countries [1]................... 27 Table 9: Waste input characteristics for RDF production (Đặng Ngọc Châu experiment) [6] ............................................................................................................... 29 Table 10: Comparison RDF product quality [6, 14]...................................................30 Table 11: Waste input com position...............................................................................32 Table 12: Characteristics o f waste fraction (Vietnam based) [9 ].............................35 Table 13: GW P according to IPCC [18]....................................................................... 36 Table 14: Stabilization tim e.............................................................................................38 Table 15: Reduction o f waste fraction after composting [1 6]..................................44 Tabic 16: Heating value................................................................................................... 46 Table 17: C 0 2 emission from combustion process (kg/kg R D F)............................ 48 7 M a ster Thesis Introduction In t r o d u c t i o n Vietnam is one o f the most rapidly developing countries in last decades. High density o f population and quickly growing o f living standard as well as consumerism give Vietnam more and more challenges. One o f them is the growth o f energy demand in all sectors. Prices of electricity and gasoline - two main energy sources in Vietnam - are constantly increasing in recent years. Clean and renewable energy has become an interesting topic which draws much attention from the society as well as the scientific community. Another side-effect o f development which is also brought by consumerism and high population is rapid increase o f solid waste generation. However, an efficient solution for solid waste management especially municipal solid waste management is still a challenge in Vietnam. One reason is that waste management in Vietnam lacks separation at source. To cope with those problems, energy from waste is being studied and considered a solution. There are several ways for converting waste into energy which have different requirement on technology and finance. One o f them is RDF production by bio-stabilization method which is considered as a suitable way when investment is limited and there is not waste separation at source. There are several researches on this topic in Vietnam which showed possibility o f implementation bio-stabilization as RDF production method in Vietnam. Based on previous study, this research “Study the substitution of fossil fuels by RDF produced from municipal solid waste of Hanoi” was carried out with the following objectives: • Assessment of bio-stabilization process in RDF producing. • Study the influence o f waste composition on RDF quality. • Evaluation of Green House Gases (GHG) emission and other RDF quality parameter to assess the possibility o f substitution RDF for fossil fuel. 8 M aster Thesis 1. Theoretical background 1. T h e o r e t i c a l b a c k g r o u n d 1.1. Situation o f global energy consu m ption /. /. 1. Global energy consumption In history, the world energy consumption is constantly increasing except some periods when it slightly reduced mainly due to economic problem. In 2010, global energy consumption rebounded strongly, driven by economic recovery. The growth in energy consumption was broad-based, with mature OECD economies joining non-OECD countries in growing at above-average rates. All forms o f energy has grown strongly, with growth in fossil fuels in 2010 suggesting that global C 0 2 emissions from energy use grew at the fastest rate since 1969. [1] W orld c o n su m p tio n Minor, tcmntt o» 130£K 9 Cod 9 RanawaMe* 1200C ■ Hytfroeiectriaty * f'iuctov energy ■ 1100C N a tu ral g a s ■ Ol 10003 900C 7000 eox 5000 aooc Figure 1: Global energy consumption from 1985 to 2010 (million tons of oil equivalent) [1] Figure 1 shows the trend o f energy consumption in the world. After falling for two consecutive years, global oil consumption grew by 2.7 million barrels per day (b/d), or 3.1%, to reach a record level o f 87.4 million b/d. This was the largest percentage increase since 2004 but still the weakest global growth rate among fossil fuels. World natural gas consumption grew by 7.4% - the most 9 M aster Thesis 1. Theoretical background rapid increase since 1984. On the other hand, coal consumption also grew by 7.6% in 2010. Coal now accounts for 29.6% o f global energy consumption, up from 25.6% 10 years ago. Energy price developments were mixed. Oil prices remained in the $70-80 range for much o f the year before rising in the fourth quarter. With the OPEC production cuts implemented in 2008/09 still in place, average oil prices for the year as a whole were the second-highest on record. (Figure 2) [1] H Gasoline ■ Gas oil ■ Heavy fu el Oil 160 à 150 140 130 120 ñ j 110 1 100 i J r k M r J * / H 93 94 9S / J V v J Ar 96 97 ,y . <Ì A . 98 99 > k - s -s s 00 ot J\ J1 J / á A ft / 90 J / J 70 w 1 V 1 1 60 50 40 / / k - 80 30 20 10 02 03 04 os 06 07 OB 09 10 0 Figure 2: Rotterdam product oil prices - u s dollars per barrel [1] According to 2011 Beyond Petroleum (BP) report, natural gas prices in 2010 grew strongly in the UK and in markets indexed to oil prices (including much o f the world’s LNG); but prices remained weak in North America - where shale gas production continued to increase - and in continental Europe (partly due to a growing share o f spot-priced deliveries) (see Figure 3). Coal prices remained weak in Japan and North America, but rose strongly in Europe due to coal production grew robustly in the u s and Asia but fell in the European Union(EU). In recent years, people have witnessed a rapid growth o f non-fossil energy. Global hydroelectric and nuclear output each saw the strongest increases since 2004. Hydroelectric output grew by 5.3%, with China accounting for more than 60% o f global growth due to a combination o f new capacity and wet weather. 10 M a ste r Thesis 1. Theoretical background Worldwide nuclear output grew by 2%, with three-quarters o f the increase coming from OECD countries. French nuclear output rose by 4.4%, accounting for the largest volumetric increase in the world. Other renewable energy sources continued to grow rapidly. [ 1] Figure 3: Natural gas price (dollars/Btu) [1| Global biofuels production in 2010 grew by 13.8%, or 240,000 b/d, constituting one o f the largest sources of liquids production growth in the world. Growth was driven by the US (+140,000 b/d, or 17%) and Brazil (+50,000 b/d, or 11.5%). Renewable energy used in power generation grew by 15.5%, driven by continued robust growth in wind energy (+22.7%). The increase in wind energy in turn was driven by China and the US, which together accounted for nearly 70% o f global growth. These forms o f renewable energy accounted for 1.8% o f global energy consumption, up from 0 .6% in 2000. [ 1] 1.1.2. Change in share o f world prim ary energy When looking at the share of world primary energy, oil, coal and natural gas are three main sources o f energy. In the past 20 years, percentage o f oil in total primary energy consumption is reduced rapidly. Energy crisis, high oil price and environmental problems are making people looking for new sources o f energy which is more sustainable. Hydro and nuclear energy are popular non-fossil energy sources nowadays. However, both o f them showed their disadvantages. 11 M aster Thesis 1. Theoretical background Especially after nuclear crisis in Japan, March 2011, people have to look for new clean and safe energy. C ontributions to gro w th S hares o f w o rld p rim a ry en erg y 50% 0 i| 2.5 9i ■ R enew ables* 40% 2m ■ Hydro H Nuclear 30% ■ Coal 20 % 1.0% ■ Gas 10% 0.59c Hydro M Oil 0 .0 % 1970-1990- 20101990 2010 2030 Includes biofuets Figure 4: Shares of world primary energy |1] BP predicted that world primary energy consumption grew by 45% over the past 20 years, and is likely to grow by 39% over the next 20 years. Global energy consumption growth averages 1.7% p.a. from 2010 to 2030, with growth decelerating gently beyond 2020. Non-OECD energy consumption is 68% higher by 2030, averaging 2.6% p.a. growth from 2010, and accounts for 93% o f global energy growth. OECD energy consumption in 2030 is just 6% higher than today, with growth averaging 0.3% p.a. to 2030. From 2020, OECD energy consumption per capita is on a declining trend (-0 .2 % p.a.). The fuel mix changes relatively slowly, due to long asset lifetimes, but gas and non-fossil fuels gain share at the expense o f coal and oil. The fastest growing fuels are renewables (including biofuels) which are expected to grow at 8.2% p.a. 2010-30; among fossil fuels, gas grows the fastest (2.1% p.a.). [1] One o f renewables source o f energy is waste. Waste to energy is a hot topic in many countries. It not only provides a non-fossil energy source but also solves 12 M a ster Thesis 1. Theoretical background the problem o f waste management. Recovered energy from waste is used to generate electricity and heat for household or industrial use. However, generating quality fuel from waste and controlling environment impact during producing process is still challenges for developing country such as Vietnam. 1.1.3. Energy consumption in Vietnam Vietnam is one o f the best performing economies in the world over the last decade. Real GDP has on average grown by 7.3 percent per year during 19952005 and per capita income by 6.2 percent per year. In US dollar terms, income per capita rose from $260 in 1995 to a 2007 level of $835 [2]. Electricity consumption per capita increased rapidly since Vietnam changed to market economy in 1990s. In only 18 years since 1990 to 2008, electricity consumption per capita in Vietnam increased from 98 kWh to 810 kWh, nearly ten times greater (see Figure 5). "S iB Vietnam (http://data.worldbank.orp/indicator/EG. USE.ELEC.KH.PC/countries/VN?displav=graph) Figure 5: Electricity consumption in Vietnam (kWh per capita) Moreover, Vietnam population is continuously increasing in the last decade despite o f many government efforts. High population and improvement o f standard living push more pressure on energy supply. Furthermore, the country’s industrialization and integration into the global economy are others reason for energy consumption growing in Vietnam. Primary energy consumption, excluding biomass, grew at an annual rate o f 10.6% in the 2000-2005 periods. Despite the fast growth, a large part of the rural population still relies heavily on 13 M aster Thesis 1. Theoretical background non-commercial biomass energy sources, which still accounts for almost half of total energy consumption (see Figure 6). Vietnam's per capita consumption o f commercial energy thus remains among the lowest in Southeast Asia. Energy is being used inefficiently, and energy production and distribution are poorly managed. Comb, renew & waste 42.0% _ Coal/peat 19.9% Hydro 3.8% Gas 10.5% Oil 23.8% 59,415 ktoe (http://www.iea. org/'stats/pdf graphs/ VNTPESP I. pdf) Figure 6: Share of total primary energy supply in Vietnam in 2008 Even though renewable and waste energy accounts for 42% in total primary energy supply in Vietnam; waste used to generate energy is mainly agriculture waste and its product is only used for domestic purpose. In industrial sector, main energy source is still fossil fuel. There are several laboratory and pilot researches about generating energy from waste for industrial purpose but it has not been implemented in Vietnam. [6, 14] 1.2. 1.2.1. M u n icip al solid w aste m a n a g e m en t in H anoi Waste gen eration Hanoi is the capital o f Vietnam and the country’s second largest city. Its population in 2009 was estimated at 2.6 million for urban districts, 6.5 million for the metropolitan jurisdiction [23]. Rapid economic growth coupled with fast urbanization in the last decade has pushed solid waste management to the forefront of environmental challenges. According to National Environmental Report (2010), waste generation in Vietnam’s cities in 2008 was 1.45 kg/capita/day - 45% higher than in 2004 [21]. Hanoi and Ho Chi Minh city 14 1. Theoretical background M aster Thesis (HCMC) are the main waste generators with 8,000 ton/day (2.92 million ton/a), accounted for 45.24% o f total urban Municipal Solid Waste (MSW); whereby HCMC produces 5,500 tons/d and the left is generated by Hanoi (2006-2007) [24]. ■ Organic ■ Paper and textiles B Plastic, rubber, leather, w ood, hair, feathers ■ Metal ■ Glass ■ Inert matter Figure 7: Waste composition o f Flanoi [20] In most cities in Vietnam, MSW account for 60-70% o f total generated waste. In some cities, the share o f MSW can reach 90%. In Hanoi, organic fraction is the main part o f waste - 49%. The other half o f generated waste are plastic, paper, textile, metal, glass, and inert matter (see Figure 7). [6] Table 1: Waste composition in Hanoi in 1995 and 2003 [20] Percent o f total Waste component 1995 2003 51.9 49.1 Paper and textiles 4.2 1.9 Plastic, rubber, leather, wood, hair, feathers 4.2 Metal 0.9 6.0 Glass 0.5 7.2 38.0 18.4 0.2 0.9 Organic 16.5 (Plastics 15.6) Inert matter Others 15 1. Theoretical background M aster Thesis Waste composition in Hanoi has changed during the last decade. Organic waste percentage is reducing and plastic waste percentage is increasing. This is due to the more affluent lifestyles, larger quantity o f commercial activities, and more intense industrialization. These activities increase the proportion o f nondegradable waste (such as plastic, metal, and glass) found in urban waste. Plastics, metal, glass increased from 4.3%, 0.9% and 0.5% in 1995 to 15.6%. 6.0% and 7.2% respectively in 2003. It is estimated that, the generation rate of plastic increased about 18.3% p.a. Plastic which has high heating value is expected to contribute to the potential o f producing RDF from MSW in Vietnam. [20 ] 1.2.2. Collection and treatment MSW collection rates and efficiency vary from one area to the next depending on the size o f the city, the distance to the urban center and the type o f collection service. Hanoi, capital o f Vietnam, has the highest MSW collection rate - 98%. MSW there is mainly collected by State-owner Public Urban Environment Companies (URENCO) then transported to Nam Son landfill. Table 2 shows waste generation and waste collection in some big cities o f Vietnam. [9] Table 2: MSW generation and collection rate in cities/towns in Vietnam No Name o f city/town Generated amount m Collected amount m Collection rate [%] Reference 1 Hanoi 2,500 2,450 98.0% URENCO Hanoi (2006) 2 Hai Phong 690 552 80.0% Master plan on Hai Phong (2005) 3 Hue 178 160 89.9% local URENCO 4 Da Nang 647 541 83.6% 5 HCMC 5,128 4,102 80.0% local URENCO As for waste treatment, landfill is a dominant form o f solid waste disposal in Vietnam currently. A survey with 90 URENCOs in Vietnam was taken by Kawai et al. in November 2009 by questionnaire; 83 feedbacks o f environmental 16 1. Theoretical background M a ster Thesis companies which serve o f 21.9% population. The result showed that around 4% o f collected MSW is composted: the rest is disposed at landfill-sites. [13] In Hanoi, Cau Dien composting plant was established in 1992 under the management o f Hanoi URENCOs dealing with municipal solid wastes, designed capacity is 60 tons/d. In 2002. the plant was expanded and upgraded in capacity to 140-150 tons/d. The compost products o f Cau Dien is trading on market and the trading amount is increasing yearly, 2.114 tons in 2004: 2,735 tons in 2005; 2.799 tons in 2006 and 4,485 tons in 2007 [9]. Since 1997, waste incinerators were built in Vietnam; however this method is only applied for healthcare waste due to its high expense. [9] Reuse and recycling in Vietnam reach a high rate. Many households have a habit o f separation recyclable waste then giving or selling it away. This is the reason that metal, textile only account for 6% and 1.9% respectively in waste stream. However, people are losing the custom due to economy develops and standard living increases. Recyclable waste is then recycled mainly in small craft village around city. As for waste composition o f Hanoi, there is high percentage o f plastic and it is still increasing. This kind o f waste contains high energy - heating value. Therefore dumping plastic in landfill is not only the problem of non-degradable, it also a waste o f resources. However, recovery energy from waste is still new subject in Vietnam. There are several researches and pilot studies on this topic, but it is still not implemented in reality. More detail o f recent researches and studies will be given in the next part of this thesis. 1.3. 1.3.1. R efuse-d erived fuel (R D F ) History RDF or refuse derived fuel was developed due to high demand o f MSW treatment. Date back to XIX century, many household in USA and Europe burned their waste in open-burning. The first systematic cremation o f waste at municipal level was built in Nottingham, England in 1874. However heat from incinerator is first used to generate power in 1876 in Leeds, England. Then, in 1885, a garbage furnace was established in United 17 M aster Thesis 1. Theoretical background waste plant was built in Hamburg with 35 cells o f multitubular boilers and forced draft fans. [4] By 1917. there was the first method which converting waste into combustible bricks, it is likely to be the first day o f processing activities to produce RDF which has had many improvement in the next decades. However, the term '"refuse derived fuel” (RDF) had not been given until 1973 (Dr. Jerome Collins) [4]. In fact. RDF is a category o f the generic class of Waste-Derived Fuel (WDF) which include wood waste, hogged waste paper, and or so. From residues, there are some other types o f "'Derived Fuels” such as Recovered Fuel (REF), Packaging Derived Fuel (PDF). Paper and Plastic Fraction (PPF) and Processed Engineered Fuel (PEF) which are taken from source-separated waste [8J. Although having a long history. RDF has not been given the universe definition. In fact, it depends on the technologies, methods o f each sectors, each countries. European Commission Directorate General Environment defines: “RefuseDerived Fuel covers a wide range o f waste materials which have been processed to fu lfill guideline, regulatory or industry specifications m ainly to achieve a high calorific value. Waste derived fu els include residues fro m M SW recycling, industrial/trade waste, sewage sludge, industrial hazardous waste, biomass waste, etc.” [8]The American Society for Testing and Materials (ASTM) has defined several forms o f RDF, as shown in Table 3. [4] Table 3: Type of refuse derived fuel ASTM Description Designation RDF-1 Waste used as fuel in as-discarded form RDF-2 Wastes processed to coarse particle size with or without magnetic metals RDF-3 Shredded fuel derived from MSW has been processed to removed metal, glass, and other inorganic materials (this material has a particle size such that 95 wt.% passes through a 50 mm square mesh) RDF-4 Combustible waste processed into powder form: 95 wt.% passing 10 mesh screen (2 mm) RDF-5 Combustible waste densified (compressed) cubettes, or briquettes (this is d-RDF) 18 into pellets, slugs, M aster Thesis 1. Theoretical background RDF-6 Combustible waste processed into liquid fuel RDF-7 Combustible waste processed into gas fuel RDF-1 in Table 3 refers to MSW as fuel in the as-received or as-discarded condition. Worldwide. RDF-1 is the major form o f RDF used. Another term for RDF-5 is densified refuse derived fuel (d-RDF). This was chosen as a generic class to include pellets, briquettes, cubettes and the like by Alter in 1975 in a proposal to the U.S. Environmental Protection Agency. [4] One important term in RDF's definitions is "high calorific value". This is to be one of the important parameters considered during RDF production, which is given more detail in the follow ing sections. 1.3.2. Characteristics As for A STM 's types o f RDF, waste can be processed to make fuel in solid, liquid or gas phase. In the content o f this thesis, only solid RDF will be concentrated and it will be mentioned as RDF from here. RDF can be produced under the fluff or densified forms. As regards Huff RDF, it is not biologically stable and difficult to store, therefore, it must be used within 2 or 3 days. This kind o f RDF has low bulk density, resulting in the limited market and in demanding the proper design o f combustion systems. In terms o f densified or pelletized RDF (Figure 8), it has advantages over fluff type. It is transportable and easier to handle and store. If kept under right condition, densified RDF can be stored indefinitely. This kind is also suitable for burning on wider range o f combustion systems. However, due to the well preparation, it is also cost more than fluff RDF. Therefore, one factor should be care about when choosing between fluff RDF and pelletized RDF is the distance between RDF producing facility and combustion place.[5] 19 M aster Thesis 1. Theoretical background Figure 8: Densified RDF (Saitama Prefectural Environmental Management Center, Japan) One characteristic o f MSW is heterogeneous; therefore RDFs produced from MSW has different composition. Normally, RDF contains plastic (exclude recyclable plastic), paper, cardboard and textile; however proportion o f them changes depending on time, location and management system. Table 4 shows RDF composition from various sources. This difference can result in RDF quality especially heating value characteristic. In table 4, it can be seen that the main composition in western and eastern countries is different. The distinction in paper and cardboard can be a good example. In Italy and UK, the percentage of paper and cardboard is respectively 5 times and 10 times higher than it in Taiwan. Table 4: Typical RDF composition in some regions |8] Waste fraction Plastic Flemish Region[4] ltaly(4) UK(4) Taiwan(10) Sorting process (%) MBT (%) (%) (%) 25-100 mm (%) >100 mm (%) 31 9 23 11 29.15 57.81 20 1. Theoretical background M aster Thesis Paper/cardboard 13 64 44 84 8.08 5.7 Textile 14 27(a) 12 5(0 7.43 18.23 Others (undesirable materials, wood. Le ath er...) 42 55.34(d) 18.26(d) Notes: a) Including rubber, 21 20 MJ/kg) and similar with heating value o f wood and coal (15-37 MJ/kg). Another important characteristic o f RDF is Chlorine content. High Chlorine content will lead to damaging o f combustion system. More 21 M aster Thesis 1. Theoretical background seriously, high concentrate of Chlorine increase the risk of Dioxins and Furans formation. Heavy metal concentration is also considered when burning RDF. fable 6 lists RDF standard which is required by law in some European country. Table 6: Quality of RDF in some Europe Countries (17| Parameters Switzerland mg/MJ Finland mg/MJ Italy mg/MJ Germany mg/MJ As 0.6 n.a 0.5 0.7 Be 0.2 n.a n.a 0.1 Cd 0.1 0.3 0.4 0.5 Co 0.8 n.a n.a 0.7 Cr 4.0 n.a 6 14 Cu 4 n.a 17 56 Hg 0.02 0.03 n.a 0.07 Ni 4 n.a 2 8.9 Pb 8 n.a 11 n.a Sb 0.2 n.a n.a 3.3 Se 0.2 n.a n.a 0.3 Sn 0.4 n.a n.a 3.9 Te n.a n.a n.a 0.3 Tl 0.12 n.a n.a 0.11 V 4 n.a n.a 1.4 Zn 16 n.a 28 n.a Chlorine n.a 1.5% by weight 0.9% by weight Only declaration 1.3.3. Producing methods RDF can be produced from different types o f waste: MSW. industrial waste, and commercial waste. In this thesis, RDF which produced from MSW will be concentrated. In general. RDF producing is a process in which high-caloric material will be taken out from waste stream to produce fuel in type o f gas, liquid or solid. RDF producing methods can be divided to two main groups: • Mechanical Biological Treatment (MBT) which can be divided to aerobic or anaerobic-MBT. 22
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