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Future and energy BIOENERGY. What about me 40 years later ?. BUDAPEST UNIVERSITY OF TECHNOLOGY AND ECONOMICS. DEPARTMENT OF CHEMICAL AND ENVIRONMENTAL PROCESS ENGINEERING. FACULTY OF CHEMICAL AND BIOCHEMICAL ENGINEERING. Dr. Bajnóczy Gábor Tonkó Csilla.
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Future and energyBIOENERGY What about me 40 years later ? BUDAPEST UNIVERSITY OF TECHNOLOGY AND ECONOMICS DEPARTMENT OF CHEMICAL AND ENVIRONMENTAL PROCESS ENGINEERING FACULTY OF CHEMICAL AND BIOCHEMICAL ENGINEERING Dr. Bajnóczy Gábor Tonkó Csilla
The pictures and drawings of this presentation are used and can be used only for education !Any commercial use is prohibited !
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
The most important questions are the-ENERGY CONTENT OF THE BIOMASS- Availability of Biomass- Costs
ENERGY CONTENT OF BIOMASS • Unit: • solid, liquid fuels kJ/kg, MJ/kg • gas fuels: kJ/Ndm3, MJ/ Nm3 • N refers to normal state (0°C ≈ 273,15 K and 1 atm = 101325 MPa) Low heat value (LHV) and high heat value (HHV) complete combustion PRODUCTS CO2, SO2, H2O T= 298 K P= 1 bar + HEAT (LHV) REACTANTS fuel + oxygen T=298 K P= 1 bar PRODUCTS CO2, SO2,H2O T= 298 K P= 1 bar + HEAT (HHV) liquid complete combustion
LHV and HHV of fuels • Measuring by calorimeter • Calculation by not typical in biomass available hydrogen 33829 C% + 144277 (H% - 1/8 O2%) + 10467 S% HHV = ------------------------------------------------------------------ [kJ/kg] 100 2500 (9H% + water%) LHV = HHV - ---------------------------- [kJ/kg] 100
LHV values of fuels Natural gas CH4 48 MJ/kg the highest hydrogen content Liquid gas CH3-CH2-CH2-CH346 MJ/kg less hydrogen content Oil CH3-CH2-….-CH2-CH342 MJ/kg even less hydrogen content Biodiesel CH3-(CH2)n-C-OH 38 MJ/kg even less hydrogen content O II Coal 32 - 22 MJ/kg oxygen, water is present Coke mainly carbon28 MJ/kg lack of hydrogen ! BiogasCH4 : CO2≈50-50%≈24 MJ/kg CO2 does not burn BioethanolCH3-CH2-OH 27 MJ/kg increased oxygen content Wood, straw14 - 16 MJ/kg high oxygen content and water
Some row materials for biomass combustion Forestry product Agriculture product Agriculture residue wood wheat Straw branch maize oilcake bark rape seed
Wood for biomass combustion firewood wood chips Wood pellets The prime cost is significant Energy input: - decreased water content - grinding to powder - high pressure must be applied
BIOMASS CONVERSION TO ENERGY COMBUSTION ON MOVING GRATES
BIOMASS CONVERSION TO ENERGY Combustion in Fluidized Bed Combustion (FBC) boiler The air stream through the grate is strong enough to keep fluid or bubbling state the wood particles Secondary air (over fire air) Primary air (under fire air) The fuel must be uniform in size !
BIOMASS CONVERSION TO ENERGY COMBUSTION III. GILLES pellet heater Household: 10 – 160 kW Industrial: 140 kW – 5 MW The pellet heating is getting more and more popular in western countries
What can we do at home ? (η = efficiency) Tile stove only for woodη = 60 – 70 % Open fire placeη= 10 – 15 % Tile stove for wood and coalη = 60 – 70 % Central heating by pelletη ≈ 90 % Closed fire placeη = 20 - 30 %
THERMAL GASIFICATION OF BIOMASS Conversion of biomass into carbon- and hydrogen-rich fuel gases (carbon monoxide, hydrogen, methane) Fuel gas better utilization efficiency of energy conversion ≈ 90 % less environmental polluting materials perfect combustion due to perfect mixing of fuel gas and air due to perfect mixing of fuel gas and air less carbon monoxide, hydrocarbons and shoot particles will be formed.
THERMAL GASIFICATION OF BIOMASS GASIFIER Downdraft gasifier atmospheric Syngas or producer gas Wood (12-20w% moisture) CH1.4O0,6 → CO + C + (CH)x + H2O CO 17-22 v% H2 16-20 v% CO2 10-15 v% CH4 2-3 v% N2 55-60 v% 300 - 400 °C C + CO2 → CO C + H2O → CO + H2 LHV : 5-5,86 MJ/Nm3 > 200 °C CO + H2O → CO2 + H2 300 - 700 °C 800 - 1000 °C CH1.4O0,6 + O2 → CO2 + H2O 1450 °C The methan concentration can be increased by pressure increase CO + 3 H2CH4 + H2O 2 C + 2 H2 CH4
THERMAL GASIFICATION OF BIOMASS in circulating fluidized (CFB) boiler Environtherm.de
THERMAL GASIFICATION OF BIOMASS Direct heat system Synthesis gas for methanol, ethanol production Condensation ▼ Bio-oil Direct heat system Synthesis gas for Fischer-Troops plant petrol diesel oil lubricating oil
GASIFICATION BY BIOMETHODS BIOGAS Produced by biological breakdown of wet organic matters - biomass - manure - sewage - municipal waste - green waste - energy crops in the absence of oxygen (anaerobic digestion) PRODUCT COMBUSTIBLE BIOGAS ~ 25 - 10 MJ/Nm3 Natural gas 32 MJ/Nm3
ENERGY FROM BIOGAS * Methane content 50 v% ** 16 MJ/kg *** 40 MJ/kg
LANDFILL GAS 15-30 Nm3 / ton. year from the second year flaring heating Electric energy Greenhouse effect: CH4 >> CO2 The landfill gas is a very polluted gas !! Mercury, chlorinated hydrocarbons, non methane organic compounds Jenbacher gasmotor
Energy from biomass bioethanol → motor fuel Maize corn
BIOPLANTS FOR LIQUID BIOFUELS BIOETHANOL Photosynthesis of glucose: 6 CO2 + 6 H2O + light = C6H12O6 + 6 O2 Fermentation by yeast: C6H12O6 = 2 C2H6O + 2 CO2 + heat Combustion of ethanol: 2 C2H6O + 6 O2 = 4 CO2 + 6 H2O + heat The carbon dioxide balance is zero → No greenhouse effect
BIOPLANTS FOR LIQUID BIOFUELS BIOETHANOL Rowmaterials: - 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%)
BIOPLANTS FOR LIQUID BIOFUELS BIOETHANOL TECHNOLOGY 1. Hydrolysis in case of starch containing row materials 2. Fermentation of glucose - significant water claim, strict pH and temperature control, - additives for the yeast wellness 3. Ethanol separation by distillation - significant energy claim 4. Dewatering of ethanol, by molecular sieves 5. Biofuel mixing - E100 pure ethanol - E90 90v% ethanol 10 v% petrol
BIOPLANTS FOR LIQUID BIOFUELS BIOETHANOL Which is the best row material ? 1. Sugar beet 7140 dm3/ hectare 2. Sugar-cane 6620 dm3/ hectare 3. Cassava 4100 dm3 / hectare 4. Maize corn 3540 dm3/ hectare 5. Wheat 2770 dm3/ hectare Sugar beet Maize corn Sugar cane 1 hectare = 10 000 m2 wheat cassava
BIOPLANTS FOR LIQUID BIOFUELS BIOETHANOL ADVANTAGES • No contribution to the greenhouse effect. The carbon dioxide balance is neutral. • No sulfur dioxide emission • Decrease 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: 121 MON: 97 real RON : 106 - 108 • Well known technology can be applied • Miscibility with petrol
BIOPLANTS FOR LIQUID BIOFUELS BIOETHANOL DRAWBACKS • Lower energy content petrol: 43,5 MJ/kg ethanol: 26,8 MJ/kg • Starting problems in winter (max: E75) • Danger of corrosion • Week electrolyte itself • Water 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)
Energy from biomass rape rape from rape seed Biodiesel from rape → motor fuel Rape-straw, rape-cake: burning → by-products: energy sources
BIOPLANTS FOR LIQUID BIOFUELS BIODIESEL
BIOPLANTS FOR LIQUID BIOFUELS BIODIESEL Row material: - plant product containing any vegetable oil - animal fat (ONLY IN WASTE FORM !) - waste vegetable oil TECHNOLOGY • Pretreatment of oil seeds • 2. Oil gain by pressing → oil and oilcake • 3. Rest oil extraction by organic solvents • 4. Transesterification • 5. Separation of methylester • 6. Purification
BIOPLANTS FOR LIQUID BIOFUELS BIODIESEL Which is the best row material ? • palm oil tree : 5000 - 7000 dm3/hectare • coco palm: 2300 dm3/hectare • yathropa : 1900 dm3/hectare • soya : 760-1610 dm3/hectare • rape seed: 1000 dm3/hectare • hazelnut: 900 dm3/hectare • sunflower: 820 dm3/hectare • algae: 2700 dm3/hectare
Row materials for biodiesel Oil palm Oil palm yathropha algae farm
BIOPLANTS FOR LIQUID BIOFUELS BIODIESEL ADVANTAGES • No 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% • Biodegradable • Miscibility with diesel oil • Excellent lubricating effect. • Smaller power loss on roads at higher altitudes from see level (the fuel contains oxygen)
BIOPLANTS FOR LIQUID BIOFUELS BIODIESEL DRAWBACKS • The 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.
IS THE BIOMASS A REAL ENERGY SOURCE ? Let see Hungary ! 93 000 km2
Let’s substitute the petrol consumption by bioethanol ! Petrol consumption = 1 600 000 ton/year petrol: 43,5 MJ/kg ethanol: 26,8 MJ/kg Alcohol claim : 1 600 000 * 43.5/26.8 ≈ 2 600 000 ton/year Maize 2,8 ton alcohol/hectare/year Area claim: 2 600 000/2,8 ≈ 930 000 hectare = 9 300 km2 The growing can not be repeated on the same site : Area claim ≈ 3 * 9 300 = 27 900 km2
Let’s substitute the diesel oil consumption by biodiesel ! Diesel oil consumption = 2 500 000 ton/year Biodiesel claim : 2 500 000 * 1,1 = 2 750 000 ton/year Rape: 1000 dm3 biodiesel /hectare/year ≈ 880 kg/hectare/year = 0,88 ton/hectare/year Area claim : 2750000/0,88 = 3 125 000 hectare = 31 250 km2 The growing can not be repeated on the same site : Area claim ≈ 3 * 31 250 = 93 750 km2
Bioethanol vs. Biodiesel II. The rate of energy output and energy input By Monica Gottfried 2006 thesis
Conclusions • The 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.