Presentation on theme: "Future and energy BIOENERGY"— Presentation transcript:
1 Future and energy BIOENERGY BUDAPEST UNIVERSITY OF TECHNOLOGY AND ECONOMICSFACULTY OF CHEMICAL AND BIOCHEMICAL ENGINEERINGDEPARTMENT OF CHEMICAL ANDENVIRONMENTAL PROCESS ENGINEERINGFuture and energy BIOENERGYWhat about me 40 years later ?Dr. Bajnóczy GáborTonkó Csilla1
2 The pictures and drawings of this presentation are used and can be used only for education ! Any commercial use is prohibited !
7 Energy from bio-energy plant Adequate technology is applied to convert the biomass to- energy (direct conversion)● combustion- fuel (indirect conversion)● thermal gasification● bio-oil by pyrolysis● gasification by biomethods● bioethanol production● biodiesel production
8 The most important questions are the - ENERGY CONTENT OF THE BIOMASS - Availability of Biomass - Costs
9 ENERGY CONTENT OF BIOMASS Unit:solid, liquid fuels kJ/kg, MJ/kggas fuels: kJ/Ndm3, MJ/ Nm3N refers to normal state (0°C ≈ 273,15 K and 1 atm = MPa)Low heat value (LHV) and high heat value (HHV)completecombustionPRODUCTSCO2, SO2, H2OT= 298 KP= 1 bar+ HEAT (LHV)REACTANTSfuel + oxygenT=298 KP= 1 barPRODUCTSCO2, SO2,H2OT= 298 KP= 1 bar+ HEAT (HHV)liquidcompletecombustion
10 LHV and HHV of fuels Measuring by calorimeter Calculation by not typical in biomassavailable hydrogen33829 C% (H% - 1/8 O2%) S%HHV = [kJ/kg]1002500 (9H% + water%)LHV = HHV [kJ/kg]100
11 LHV values of fuelsNatural gas CH MJ/kg the highest hydrogen contentLiquid gas CH3-CH2-CH2-CH MJ/kg less hydrogen contentOil CH3-CH2-….-CH2-CH MJ/kg even less hydrogen contentBiodiesel CH3-(CH2)n-C-OH MJ/kg even less hydrogen contentOIICoal MJ/kg oxygen, water is presentCoke mainly carbon MJ/kg lack of hydrogen !Biogas CH4 : CO2 ≈50-50% ≈24 MJ/kg CO2 does not burnBioethanol CH3-CH2-OH MJ/kg increased oxygen contentWood, straw MJ/kg high oxygen content and water
12 Direct Thermal Conversion of Biomass Combustion
13 Some row materials for biomass combustion Forestry productAgriculture productAgriculture residuewoodwheatStrawbranchmaizeoilcakebarkrape seed
14 Wood for biomass combustion firewoodwood chipsWood pelletsThe prime cost is significantEnergy input:- decreased water content- grinding to powder- high pressure must be applied
15 BIOMASS CONVERSION TO ENERGY COMBUSTION ON MOVING GRATES
16 BIOMASS CONVERSION TO ENERGY Combustion in Fluidized Bed Combustion (FBC) boilerThe air stream through the grate is strong enough to keep fluid or bubbling state the wood particlesSecondary air (over fire air)Primary air (under fire air)The fuel must be uniform in size !
17 BIOMASS CONVERSION TO ENERGY COMBUSTION III.GILLES pellet heaterHousehold: 10 – 160 kWIndustrial: 140 kW – 5 MWThe pellet heating is getting more and more popular in western countries
18 What can we do at home ? (η = efficiency) Tile stove only for wood η = 60 – 70 %Open fire place η= 10 – 15 %Tile stove for wood and coal η = 60 – 70 %Central heating by pellet η ≈ 90 %Closed fire place η = %
19 Biomass transformation to fuel Thermal gasification
20 THERMAL GASIFICATION OF BIOMASS Conversion of biomass into carbon- and hydrogen-rich fuel gases(carbon monoxide, hydrogen, methane)Fuel gasbetter utilizationefficiency of energy conversion ≈ 90 %less environmental polluting materialsperfect combustion due toperfect mixing of fuel gasand airdue to perfect mixing of fuel gasand air less carbon monoxide,hydrocarbons and shoot particleswill be formed.
21 The methan concentration can be increased THERMAL GASIFICATION OF BIOMASSGASIFIERDowndraft gasifieratmosphericSyngas or producer gasWood (12-20w% moisture)CH1.4O0,6 → CO + C + (CH)x + H2OCO v%H v%CO v%CH4 2-3 v%N v%°CC + CO2 → COC + H2O → CO + H2LHV : 5-5,86 MJ/Nm3> 200 °CCO + H2O → CO2 + H2°C°CCH1.4O0,6 + O2 → CO2 + H2O1450 °CThe methan concentration can be increasedby pressure increaseCO + 3 H2 CH4 + H2O2 C + 2 H2 CH4
22 THERMAL GASIFICATION OF BIOMASS in circulating fluidized (CFB) boiler Environtherm.de
23 Synthesis gas for Fischer-Troops plant THERMAL GASIFICATION OF BIOMASSDirect heat systemSynthesis gas for methanol, ethanol productionCondensation▼Bio-oilDirect heat systemSynthesis gas for Fischer-Troops plantpetroldiesel oillubricating oil
24 GASIFICATION BY BIOMETHODS BIOGASProduced by biological breakdown of wet organic matters- biomass- manure- sewage- municipal waste- green waste- energy cropsin the absence of oxygen (anaerobic digestion)PRODUCT COMBUSTIBLE BIOGAS ~ MJ/Nm3Natural gas MJ/Nm3
27 Mercury, chlorinated hydrocarbons, non methane organic compounds LANDFILL GAS15-30 Nm3 / ton. year from the second yearflaringheatingElectric energyGreenhouse effect: CH4 >> CO2The landfill gas is a very polluted gas !!Mercury, chlorinated hydrocarbons, non methane organic compoundsJenbacher gasmotor
28 bioethanol → motor fuel Energy from biomassbioethanol → motor fuelMaize corn28
29 BIOPLANTS FOR LIQUID BIOFUELS BIOETHANOLPhotosynthesis of glucose:6 CO2 + 6 H2O + light = C6H12O6 + 6 O2Fermentation by yeast:C6H12O6 = 2 C2H6O + 2 CO2 + heatCombustion of ethanol:2 C2H6O + 6 O2 = 4 CO2 + 6 H2O + heatThe carbon dioxide balance is zero → No greenhouse effect
30 BIOPLANTS FOR LIQUID BIOFUELS BIOETHANOLRow materials:- sugar containing biomass (sugarcane, sugar beet)● direct fermentation- starch containing biomass (maize, wheat, potato)● hydrolysis● fermentation- cellulose containing biomass (wood)☻long chain cellulose (40-60%) is resistant to hydrolysis☻ hemi cellulose (20-40%): easy to hydrolyze but the five ring sugars can not be fermented☻lignin: it is not sugar (10-24%)
31 BIOPLANTS FOR LIQUID BIOFUELS BIOETHANOLTECHNOLOGY1. Hydrolysis in case of starch containing row materials2. Fermentation of glucose- significant water claim, strict pH and temperature control,- additives for the yeast wellness3. Ethanol separation by distillation- significant energy claim4. Dewatering of ethanol, by molecular sieves5. Biofuel mixing- E100 pure ethanol- E v% ethanol 10 v% petrol
32 BIOPLANTS FOR LIQUID BIOFUELS Which is the best row material ? BIOETHANOLWhich is the best row material ?1. Sugar beet 7140 dm3/ hectare2. Sugar-cane 6620 dm3/ hectare3. Cassava dm3 / hectare4. Maize corn dm3/ hectare5. Wheat dm3/ hectareSugar beetMaize cornSugar cane1 hectare = m2wheatcassava
33 BIOPLANTS FOR LIQUID BIOFUELS BIOETHANOLADVANTAGESNo contribution to the greenhouse effect. The carbon dioxide balance is neutral.No sulfur dioxide emissionDecrease in carbon monoxide CO, hydrocarbon (CH)x, soot emission due to the oxygen content of bioethanol.No need to change the distribution system.Octane numbers: RON: MON: 97real RON :Well known technology can be appliedMiscibility with petrol
34 BIOPLANTS FOR LIQUID BIOFUELS BIOETHANOLDRAWBACKSLower energy content petrol: 43,5 MJ/kg ethanol: 26,8 MJ/kgStarting problems in winter (max: E75)Danger of corrosionWeek electrolyte itselfWater and acetic acid formation during storage (electrochemical corrosion)Peroxy acetic acid formation inside the chamber (chemical corrosion of metal alloy)Immiscibility with lubricating oil.New environmental pollutants (aldehyde and acetic acid)The row material might be food. (rival in food supply)The energy balance is not outspokenly positive (debates)
35 Rape-straw, rape-cake: burning → by-products: energy sources Energy from biomassraperape from rape seedBiodiesel from rape → motor fuelRape-straw, rape-cake: burning → by-products: energy sources35
37 BIOPLANTS FOR LIQUID BIOFUELS BIODIESELRow material:- plant product containing any vegetable oil- animal fat (ONLY IN WASTE FORM !)- waste vegetable oilTECHNOLOGYPretreatment of oil seeds2. Oil gain by pressing → oil and oilcake3. Rest oil extraction by organic solvents4. Transesterification5. Separation of methylester6. Purification
38 BIOPLANTS FOR LIQUID BIOFUELS Which is the best row material ? BIODIESELWhich is the best row material ?palm oil tree : dm3/hectarecoco palm: 2300 dm3/hectareyathropa : 1900 dm3/hectaresoya : dm3/hectarerape seed: 1000 dm3/hectarehazelnut: 900 dm3/hectaresunflower: 820 dm3/hectarealgae: 2700 dm3/hectare
39 Row materials for biodiesel Oil palmOil palmyathrophaalgae farm
40 BIOPLANTS FOR LIQUID BIOFUELS BIODIESELADVANTAGESNo contribution to the greenhouse effect. The carbon dioxide balance is neutral.The energy content is 9 % less than that of biodiesel.Higher cetane number.Due to the oxygen content less CO and (CH)x. Debates on soot emission.Sulfur content is low. biodiesel : < 0,01mass% diesel : 0,2 mass%BiodegradableMiscibility with diesel oilExcellent lubricating effect.Smaller power loss on roads at higher altitudes from see level (the fuel contains oxygen)
41 BIOPLANTS FOR LIQUID BIOFUELS BIODIESELDRAWBACKSThe row material might be food. (rival in food supply)The energy balance is not outspokenly positive (debates)The exhaust gas has a definite oily smell.Bacterial attack.
42 IS THE BIOMASS A REAL ENERGY SOURCE ? Let see Hungary !km2
43 Let’s substitute the petrol consumption by bioethanol ! Petrol consumption = ton/yearpetrol: 43,5 MJ/kg ethanol: 26,8 MJ/kgAlcohol claim : * 43.5/26.8 ≈ ton/yearMaize 2,8 ton alcohol/hectare/yearArea claim: /2,8 ≈ hectare = km2The growing can not be repeated on the same site :Area claim ≈ 3 * = km2
44 Let’s substitute the diesel oil consumption by biodiesel ! Diesel oil consumption = ton/yearBiodiesel claim : * 1,1 = ton/yearRape: dm3 biodiesel /hectare/year ≈ 880 kg/hectare/year = 0,88 ton/hectare/yearArea claim : /0,88 = hectare = km2The growing can not be repeated on the same site :Area claim ≈ 3 * = km2
45 By Monica Gottfried 2006 thesis Bioethanol vs. Biodiesel II.The rate of energy output and energy inputBy Monica Gottfried 2006 thesisWheatbioethanolMaizeSunflowerbiodieselRapeEnergy grassonly combustionEnergy rate1,191,422,352,134,95
47 ConclusionsThe biomass is only one possibility to reduce the consumption of fossil fuels and decrease the greenhouse effect carbon dioxide emission.From the point of ‘sustainable development’, the total substitution is impossible.From the point of ‘sustainable survival’, it has an outstanding significance.