Use of waste as a source of energy WASTE TO ENERGY

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1 HIGHBIO INTERREG POHJOINEN Korkeasti jalostettuja bioenergiatuotteita kaasutuksen kautta EUROPEAN UNION European Regional Development Fund Use of waste as a source of energy WASTE TO ENERGY Ulla Lassi Professor, Applied chemistry and process chemistry University of Oulu

2 Content of lecture Introduction ( Waste to Energy ) Technologies to Waste to Energy Pyrolysis and thermal gasification of (municipal) solid waste Co gasification of organic waste and biomass (eg. wood chips) Gasification process an overview Utilisation of producer gas (syngas) Conclusions Ulla Lassi

3 Introduction What is meant by Waste to energy or Energyfrom waste concept? It is the process of creating energy in the form of electricity or heat from the incineration of waste source. It is a question of energy e recovery. e Most processes produce electricity directly through combustion, or produce a combustible fuel, such as methane, methanol, ethanol or other synthetic fuels. Ulla Lassi

4 Waste hierarchy Wasteonline.org.uk Ulla Lassi

5 Legislation IE directive (Directive of Industrial Emissions) will combine seven earlier directives incl. IPPC IE directive was implemented in EU (Finland has two years to national level activities) Requirement of BAT (best available technology) Waste directive which includes end of waste concept ( waste tax for waste disposal at landfills ) Ulla Lassi IPPC =Integrated Pollution Prevention and Control

6 Possibilities for energy recovery in waste treatment Direct combustion of waste, i.e. incineration Other thermal treatment of waste (e.g. pyrolysis and thermal gasification) Biochemical i treatment of organic waste (pretreatment of biomass followed by fermentation, biogasification) Ulla Lassi Wasteonline.org.uk

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8 Thermal technologies for waste treatment Gasification (produces combustible gas, hydrogen, synthetic fuels can be prepared from purified syngas) Thermal depolymerization (produces synthetic crude oil, which can be further refined) Pyrolysis (produces combustible bio oil and chars) Plasmaarc arc gasification or plasma gasification process (produces rich syngas including hydrogen and CO for fuel cells) Incineration (direct combustion) Ulla Lassi

9 Incineration (direct combustion) Incineration, i.e. thermal combustion of organic material such as waste with energy recovery is the most commonly used waste to energy to energy implementation. All waste incinerationplantsmust meet strict emission standards. Incinerators typicallyreducethe the volume of the original waste by %, depending upon composition and degree of recovery of materials, such as metals from the ash (bottom and fly ash) for recycling. Ulla Lassi

10 Incineration Emissions i of incinerators i include fine particulates, heavy metals, traces of dioxin and acidic gas emissions These emissions are relatively low in modern plants, andthey haveto bestrictly followed Other emissions include toxic fly ash and incinerator bottom ash Incinerators have electric efficiencies appr %. The rest of the energy can be utilized for e.g. district heating (otherwise lost as waste heat). Ulla Lassi

11 Incineration Incineration to convert municipal solid waste to energy is a relatively old method Principle: Burning of waste (carbage) to boil water which powers steam generators to produce power (electricity) Problems are e.g. acidic emissions (acid rains) Ulla Lassi

12 Incineration plants District waste to energy plant (incineration) in Vienna Waste to energy plant (incineration) in Oulu (2012), capacity of tonnes of domestic waste annually Ulla Lassi

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14 Waste to energy technologies (other than incineration) Thermal: Non thermal: Gasification Plasma arc technology Thermal depolymerization Pyrolysis Anaerobic digestion Fermentation Mechanical biological treatment Ulla Lassi

15 Gasification The production of gaseous hydrogen (H 2 ) or syngas a mixture of H 2 and carbon monoxide (CO) is known technology since World War II THERMOCHEMICAL PROCESSING of biomass GASIFICATION PRODUCT GAS Ulla Lassi

16 Pyrolysis and Thermal Gasification of (Municipal) Solid Waste Gasification and pyrolysis are similar processes; both decompose organic waste by exposing itt to high h temperatures. Bothprocesses limitthe the amount of oxygen present during decomposition; gasification allows a small amount of oxygen, pyrolysis allows none. Ulla Lassi

17 Pyrolysis a rapidly increasing technology Ulla Lassi

18 Plasma (arc) gasification Plasma arc gasification uses electrically generated plasma torches to converting waste material into gas and a slag byproduct. Syngas is produced exclusively from organic materialswitha a conversion rate of greater than 99% using plasma gasification Ulla Lassi

19 HIGHBIO INTERREG POHJOINEN Korkeasti jalostettuja bioenergiatuotteita kaasutuksen kautta EUROPEAN UNION European Regional Development Fund Biomass (waste) gasification Ref: Handbook Biomass Gasification, Ulla Lassi

20 HIGHBIO INTERREG POHJOINEN Gasifier Gasifier types Korkeasti jalostettuja bioenergiatuotteita kaasutuksen kautta EUROPEAN UNION European Regional Development Fund Down draft gasifier < 1MW th Ulla Lassi

21 HIGHBIO INTERREG POHJOINEN Korkeasti jalostettuja bioenergiatuotteita kaasutuksen kautta EUROPEAN UNION European Regional Development Fund Gasifier types Circulating fluidized bed Fluidized bed gasifier MWth gasifier MW th

22 Current status gasification of municipal solid waste Gasification of municipal solid waste, household garbage and commercial waste products was used in the United States in the 1970s, but those plants were closed because of operating and financial problems. Today there are only a handful of pyrolysis units burning municipal ii solid waste, located din Japan, Taiwan, Great Britain and Canada. Ulla Lassi

23 Biomass gasification plants

24 HIGHBIO - INTERREG NORD Refining of new products and raw materials by gasification of biomass Ulla Lassi

25 HIGHBIO - INTERREG NORD Refining of new products and raw materials by gasification of biomass Ulla Lassi

26 HIGHBIO - INTERREG NORD Refining of new products and raw materials by gasification of biomass Possibilities Example of energy and material integration in the greenhouse Ulla Lassi

27 Comparison Incineration In the presence of air, heat causes organic materials to burn The burning of waste in incinerators causes well known negative environmental and public health effects. Incinerators emit nitrogen oxides, sulfur dioxide, particulate matter, carbon monoxide, carbon dioxide, acid gases, lead, cadmium and mercury, and organic compounds, such as dioxins and furans, into the atmosphere. Ulla Lassi Gasification Gasification facilities produce gas primarily carbon monoxide and hydrogen (85%) plus hydrocarbon oils, char and ash. Gasification plants air emissions also include nitrogen oxides, sulfur dioxide, particulate matter, carbon monoxide, carbon dioxide, methane, hydrogen chloride, hdrogenfl hydrogen fluoride, ammonia, heavy metals mercury and cadmium, dioxins and furans.

28 Some recent activities in Finland UPM s waste to energy plant in Lappeenranta (published in 2012): a crude tall oil (a by product from pulp mill) is used as a raw materialin in biodiesel production Lahti Energia Oy is building in Lahti a power plant, which uses recycled fuel made from energy waste. This plant is based on waste gasification (250,000 tonnes of energy waste into electricity and heat per year), completed in 2012 Gasification power plant will produce 50 MW of electricity and 90 MW of district heat. Ulla Lassi

29 Some recent activities in Finland Severalconcepts for waste to energy (biodiesel plants) based on the gasification (use of wood chips and residuals frompulping process); NSE Fuels (Stora Enso and Neste Oil), pilot plant in Varkaus UPM (Rauma or Strasbourg) Vapo (Kemi area) NER decision i was given at the end of 2012 NSE Fuels is not active on that anymore BTL Plant produces tons of biodiesel annually (estimation of UPM BTL plant) Ulla Lassi

30 HIGHBIO INTERREG POHJOINEN Korkeasti jalostettuja bioenergiatuotteita kaasutuksen kautta EUROPEAN UNION European Regional Development Fund Ctlti Catalyticconversioni of product gas from gasification Technologies to be considered: Fischer Tropsch synthesis Mixed (higher) alcohol synthesis (MAS/HAS) Syngas fermentation (enzyme catalysed) Methanol synthesis Ulla Lassi

31 HIGHBIO INTERREG POHJOINEN Korkeasti jalostettuja bioenergiatuotteita kaasutuksen kautta EUROPEAN UNION European Regional Development Fund Chemical reactions during the gasification

32 Syngas cleaning and processing Source: Carbona Oy

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35 HIGHBIO INTERREG NORD Högförädlade bioenergiprodukter via förgasning Korkeasti jalostettuja bioenergiatuotteita kaasutuksen kautta EUROPEAN UNION European Regional Development Fund

36 Utilisation of syngas by catalytic conversion

37 HIGHBIO INTERREG NORD Fischer Tropsch synthesis Högförädlade bioenergiprodukter via förgasning Korkeasti jalostettuja bioenergiatuotteita kaasutuksen kautta A chemical catalytic process, which has been used since 1920s to produce liquid fuels from coal derived syngas and naturalgas Ulla Lassi

38 HIGHBIO INTERREG NORD Högförädlade bioenergiprodukter via förgasning Korkeasti jalostettuja bioenergiatuotteita kaasutuksen kautta Reaction steps in the catalytic reaction Fischer Tropsch synthesis (Co and Fe catalyst): Adsorption of CO on the catalyst surface Breakage of a C O bond Dissociative adsorptionoftwohof two 2 molecules onthe catalyst surface Bonding of two hydrogen atoms with an oxygen atom resulting in the formation of a water molecule, l H 2 O Desorption of water Bonding of two hydrogen atoms with a carbon atom resulting in the formation of CH 2 Formation of a new C C C bond

39 Parameters affecting Correct ratio between hd hydrogen and CO Temperature, pressure Ctl Catalystt and itsproperties ti (eg. particle size) Presence of inert gases Poisonous gases Impurities in the gas Tar compounds Particulates

40 Effect of H2/CO ratio on the chain lengths Ref. Vessia, Øyvind, Biofuels from lignocellustic material, project report, Norwegian University of Science technology, 2005,

41 Particle size of the carrier affects catalytic activity and selectivity Deugd et al., Trends in Fischer Tropsch reactor tegnology opportunities for structured reactors, Topics in Catalysis, vol.26, 2003, p.29 39

42 HIGHBIO INTERREG NORD Högförädlade bioenergiprodukter via förgasning Korkeasti jalostettuja bioenergiatuotteita kaasutuksen kautta FT Reactor for the Conversion of Syngas Pressure 5 60 bar Pressure 5 60 bar Temperature ~ C

43 Catalysts used in FT reactions Metals wt% Co; 0,1wt% Ru or Re wt% Fe; 0,1 wt% Ru Carriers Al 2 O 3 pellets Al 2 O µm, SiO 2 Sasol Puralox SCCa 5/200 Precursor salts Co(NO3)2 * 6H2O Fe(NO3)2 Ru(NO)(NO3)3 Co(Ac)2

44 Reactions 1. CO (ad) C (ad) + O (ad) 2. H 2 (ad) 2 H (ad) Adsorption and bond cleavage 2 (ad) (ad) 3. C (ad) + 2 H (ad) CH 2 (ad) ( CH 2 )) n 4. O (ad) + 2 H (ad) H 2 O (ad) H 2 O Synthesis reactions H r = 165 kj/mol exothermic

45 Characterisation of paraffin products Commercial diesel FTS diesel

46 Methanolsynthesis from syngas

47 Methanol synthesis A chemical catalytic process currently used to produce methanol from syngas derived from steam reformed natural gas or syngas from coal

48 HIGHBIO INTERREG NORD Högförädlade bioenergiprodukter via förgasning Korkeasti jalostettuja bioenergiatuotteita kaasutuksen kautta Reaction steps in the catalytic reaction Methanol synthesis s (Cu catalyst) Methane synthesis (Ni catalyst)

49 Parameters affecting Ratio between hydrogen and CO has no effect!!! Temperature, pressure, form of contact (liquid orgas) Catalyst and its properties (eg. particle size) Cu/Zn/alumina for gas contact and Cu/ZnO for liquid contact Inert gases Poisonous gases Impurities Tars Particulates

50 Methanol synthesis

51 Deactivation of catalysts

52 Mixed alcohol synthesis Very similar to FT and methanol synthesis Catalysts e.g. Alkali/Cu/ZnO(or li/c /Z alumina) Alkali/CuO/CoO Catalystsmodifiedfrom from those processeswith the addition ofalkali metals Hydrogen to CO ratio must be which reduces the demand for WGS (water gas shift) reaction

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54 Syngas to liquid efficiencies (from biomass)

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56 Conclusions Waste to energy concept will strongly increase in Finland during the next years (eg. due to the increased demand of material efficiency and legislation) Waste gasification and incineration will be the main potentials, and often associated with the industrial activities, e.g. pulp mill integrates Main products of waste to energy are heat and power (electricity), further some valuables can be considered i.e. fuels and chemicals Overall system efficiency of waste utilisation is critical Estimations of costs vary substantially short and long term

57 Thank You! More information: kemia Ulla Lassi Professori, soveltava kemia Oulun yliopisto Kemian laitos