WASTE FUELS COMBUSTION AND FUELS

Transcription

1 WASTE FUELS

2 CHARACTERISTICS OF WASTE FUELS 1. Waste fuels belong to the group of prepared fuels. Usually they are formed of separated and converted fraction of municipal wastes or of a similar type of wastes. 2. Reasons for manufacturing of fuels from waste: recycling (fuels aren t waste) to make burning wastes to in power and heat and cement plants more convenient to decrease hazard caused by some waste (like used oils, sewage sludge, animal wastes, pesticides...). 3. Waste fuels vs. fossil fuel: economically they cannot afford the competition.

3 REASONS TO MANUFACTURE WASTE FUELS 1. Unfavourable energetic characteristic of wastes (municipal): moisture un-combustible parts different sizes. 2. Problems with burning wastes in power and heat plants. 3. Hazard of dangerous pollutant emissions due to the presence of some species in wastes.

4 TYPE OF WASTES USED TO MANUFACTURE FUELS The greatest potential for manufacturing waste fuels lies in: Municipal wastes Other types of wastes: plastics sewage sludge used wood tires agriculture wastes.

5 NAMES OF WASTE FUELS PAKOM (Polish) paliwo komunalne RDF (English) Refuse Derived Fuel BRAM (German) Brennstaus Müll

6 SORTS OF WASTE FUELS Sorts of waste fuels produced: A. Solid waste fuels made of : municipal wastes dried sewage sludge used wood B. Liquid waste fuels made of: used oils liquified plastics C. Gaseous waste fuels made due to: fermentation of municipal wastes or agricultural wastes fermentation of sewage sludge gasification of wastes

7 SELECTED FEATURES OF WASTE FUELS 1. With respect to chemical composition, reactivity and caloric value RDF are close to biofuels. 2. The main difference is low water content and higher mineral matter content. 3. Usually RDF have more chlorine and heavy metals. 4. They are characterised by higher reactivity 5. Cost of RDF manufacture excesses its value.

8 COMPARISON OF IGNITION TEMPERATURES OF WASTES AND FOSSSIL FUELS Fuel Municipal wastes RDF RDF (from paper) Wood Lignite Bituminous coal Heating oil LPG Temperature of ignition, C approx

9 WASTE FUELS FROM MUNICIPAL WASTE

10 TECHNOLOGY OF MANUFACTURING FUELS FROM MUNICIPAL WASTES 1. Segregation from wastes: noncombustible parts (glass, stones, metals) big elements: TV sets, refrigerators, washing machines, furniture, ) 2. Densification of the combustible fraction briquiette pelletization 3. Stabilization (with calcium hydroxide) and adding more caloric fuels (coal)

11 SEGREGATION OF MUNICIPAL WASTES Methods of segregation of waste: 1. hand segregation of: noncombustible parts: glass, stones, metals large elements: TV-sets, refrigerators, washing-machines, furniture Mechanical classifiers: cylindrical, blown, magnetic (metals). Effectiveness of mechanical separation is in the range of 80-98%.

12 SCHEME OF INSTALLATION OF SEGREGATION AND DISPERSION OF SOLID WASTES Shreder Magnetic separator Drum separator Air separator N S Municipal waste Waste derived fuel

13 THICKENING OF WASTES (making dense) Methods of thickening of wastes: 1. Pelletisation 2. Briquette

14 IMPROVEMENT OF PROPERTIES OF WASTE FUELS 1. Stabilization and reduction of biological hazard by adding calcium hydrate. 2. Increase of caloric value of waste fuels by adding coal.

15 COMPARISON OF PAKOM AND COAL Parameter Hard coal NPW * PAKOM Used part of waste, % mass. Extracted part of energy of waste, % Components, % mass. C H O N S Cl Moisture, % Ash, % Higher heating value (HHV), MJ/kg

16 WASTE FUELS OF PLASTICS OF PVC TYPE

17 Problems arose during conversion of wastes due to the presence of plastics 1. Plastics of PVC type contain a significant part of chlorine which could be a source of dioxins and furans. 2. To avoid this problem the segregated form wastes plastics PVC type undergo the process of thermolysis ( C), where chlorine is recovered in the form of HCl.

18 KARBOTERM TECHNOLOGY bitumen municipal wastes production wastes selective collection grinding thermal preparation KARBOTERM production plant electricity and heat generation hard coal

19 PRODUCT OF KARBOTERM TECHNOLOGY Properties 1. Granules 2. Structure similar to coal 3. Safety fuel Contribution of plastics to manufacture this fuel is approx 20%)

20 COMPARISON OF KARBOTERM AND COAL Parameter Plastic C, % 74.9 Karboterm 83.1 Hard coal 84.0 H, % O, % N, % S, % Cl, % Apparent density, kg/m 3 Ok. 300 Ok. 900 Ok. 850 LHV, MJ/kg Ok. 41 Ok Milling ability no yes yes

21 WASTE FUELS FROM USED WOOD

22 CHARACTERISTICS OF WASTE WOOD 1. Waste-wood fuels are with different elements of used wood, like: wrapping, woodwork, furniture, construction elements, About 3 mln Mg of waste wood is produced yearly in Poland. 3. Environmental standards require utilization of waste wood before being stored. 4. There are two ways of waste wood utilization: Its secondary used in manufacture process (after some preparation), energetic utilization (recovery of energy).

23 CLASSIFICATION OF WASTE WOOD (GERMANY) Group I Group II Group II Group IV clean wastes of natural wood, without additives, waste wood different than natural, without PVC and impregnants, waste wood different than natural with PVC, without impregnants, waste wood with impregnants. Only waste wood form the group I can be burned without limits.

24 LOWER HEATING VALUE OF WASTE WOOD Type of waste wood Clean wood Elements of garden woodwork Railway sleepers Construction woodwork Old windows Doors Furniture LHV, MJ/kg

25 FUELS FROM WASTE WOOD Typical fuels obtained from waste wood are silvers, pellets, briquettes.

26 FUELS FROM ANIMAL WASTES

27 CHARACTERISTICS OF ANIMAL WASTES 1. Directive 90/667/EEC classifies animal waste into two categories: High risk waste HRM - carcasses, Low risk waste LRM - slaughter waste intended for feeding animals (with the exception of ruminants*) 2. Directive 99/534/EC specifies the types of high risk slaughter wastes: skull, brain, eyes, tonsils, spinal cord and intestine. Method of disposal: processing into meals and fats, and then burning. *przeżuwacze

28 EXAMPLE OF ANIMAL WASTE

29 TYPES OF PROCESSING OF ANIMAL WASTES dispersion, drying, sterilization, removal of fat.

30 MANUFACTURE OF MEAT-BONES FLOUR animal wastes grinder destructor press mill bone&meat flour fat tank flour silo

31 CHARACTERISTICS OF MEAT-BONES FLOUR Parameter Meat flour Bone flour Animal fat C, % H, % O, % N, % S, % Cl, % < 0.09 Ash, % Moisture, % Fat, % P 2 O 5, % LHV, MJ/kg

32 PLANTS WHERE MEAT-BONE FLOURS CAN BE BURNT waste incineration plants, coal-fired power plants, sewage sludge incineration plants, cement plants.

33 FUELS MADE FROM COAL MUD AND SEWAGE SLUDGE

34 GRANULATES MADE FROM SEWAGE SLUDGE AND COAL MUD 1. Sewage sludge is a product of cleaning municipal sewage. sewage sludge production in Poland: 0.5 mln Mg dry/y moisture content: 65-70%. 2. Coal mud is an by-product of cleaning of hard coal in coal mines. it is estimated that approximately 50 mln Mg of coal mud is stored in Poland.

35 ADVANTAGES OF GRANULATION OF COAL MUD AND SEWAGE SLUDGE 1. Stabilisation of coal mud and sewage sludge. 2. Lack of dusting. 3. Prevention of wash away heavy metals to the soil from sewage sludge. 4. Recovery of energy from wastes.

36 TECHNOLOGY OF MANUFACTURE OF GRANULATES FROM COAL MUD AND SEWAGE SLUDGE 1. Sewage sludge after fermentation: 65-70% H 2 O 2. Coal mud: 5-6% H 2 O 3. Mixture: 50% of coal mud 50% sewage sludge 4. Homogenisation 5. Seasoning 6. Granulation

37 GRANULATES FROM COAL MUD AND SEWAGE SLUDGE

38 CHARACTERISTICS OF SEWAGE SLUDGE, COAL MUD AND HARD COAL Parameter Sewage sludge Coal mud Hard coal LHV, MJ/kg Ash, % C, % H, % S, %

39 CHARACTERISTICS OF GRANULATES FROM SEWAGE SLUDGE AND COAL MUD Parameter LHV, MJ/kg S, % Moisture, %, Ash, % Granulates

40 DISTILLATES FROM USED ENGINE OIL Liquid fuel obtained form used engine oils. Technology of manufacture: distillation.

41 COMPARISON of DISTILLATE AND OIL PROPERTIES Parameter Density, g/cm 3 Char, % Lead, mg/kg PAH, % PCB, mg/kg Acid number, mgkoh/g Basic number, mgkoh/g Oil Distillate , >

42 GASEOUS FUELS FROM WASTES

43 GASEOS FUELS FROM WASTES 1. Fermentation gas from sewage sludge 2. Landfill gas

44 LANDFILL GAS 1. Organic components of landfill municipal wastes undergo fermentation during long-term storage. 2. The main component of the resulted fermentation gas is methane. 3. Methane is a very efficient greenhouse gas, therefore it shouldn t be evacuated to atmosphere. 4. Landfill gas makes hazard of explosion. 5. Standards allow two ways of secure landfill gas against emission to atmosphere burning in flares, burning to heat recovery.

45 GENERATION OF LANDFILL GAS 1. Landfill gas is formed in the landfill municipal wastes due to methane fermentation of organic substances which undergo biodegradation. 2. The characteristic time of biodegradation of components of municipal wastes: food up to 1 year, garden wastes approx. 5 ys, paper, wood, fabrics s approx. 15 ys. 3. Period of landfill gas production: years % of methane is formed of cellulose, 8,4% of organic nitric compounds, 0,5% of sugar. 5. The temperature of landfill gas production is in the range of i C.

46 DEGASIFICATION OF LANDFILL

47 DEGASIFICATION OF LANDFILL

48 COLLECTORING OF LANDFILL GAS

49 LANDFILL WITH GAS COLLECTOR leachate odciek liner - wykładzina

50 FACTORS INFLUENCING LANDFILL GAS PROPERTIES Theoretically THE efficiency of landfill gas production is on the level: m 3 /Mg. In fact, it is lesser, depending on : 1. Morphology of landfill wastes. 2. Moisture in wastes. 3. Degree of density of wastes. 4. Temperature in bed. 5. Age of landfill. Food 31,7% Small fract. 21,4% Paper 18,6% Glass 7,5% Plastics 3,7% Metals 3,5% Other 13,6 %

51 CHARACTERISTIC OF LANDFILL GAS Component Methane (CH 4 ) Carbon dioxide (CO 2 ) Nitrogen (N 2 ) Oxygen (O 2) approx. 1 Rest LCV Content, % approx MJ/m 3

52 BIOGAS OF SEWAGE SLUDGE Technology description: Subtract: sewage sludge, Process of gas manufacture: methane fermentation, Gas product: fermentation gas (biogas) State of technology: commercial

53 CHARACTERISTIC OF BIOGAS OF SEWAGE WASTE Parameter LHV Components Limits of explosibility Efficiency Unit MJ/m 3 % % l/md Value CH 4 : CO 2 : N 2 : 1-10 O 2 : H 2 : 0-1 H 2 S:

54 FERMENTATION REACTORS

55 TANK OF BIOGAS AND DESULFURIZATION PLANT