# Future and energy BIOENERGY

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Future and energy BIOENERGY
BUDAPEST UNIVERSITY OF TECHNOLOGY AND ECONOMICS FACULTY OF CHEMICAL AND BIOCHEMICAL ENGINEERING DEPARTMENT OF CHEMICAL AND ENVIRONMENTAL PROCESS ENGINEERING Future and energy BIOENERGY What about me 40 years later ? Dr. Bajnóczy Gábor Tonkó Csilla 1

The pictures and drawings of this presentation are used and can be used only for education ! Any commercial use is prohibited !

Perhaps this will be my car ?

Or these vehicles ?

Fuel shortage ! Is it me at home in winter ?

Or she is my wife waiting for me at home

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 = 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% (H% - 1/8 O2%) S% HHV = [kJ/kg] 100 2500 (9H% + water%) LHV = HHV [kJ/kg] 100

LHV values of fuels Natural gas CH MJ/kg the highest hydrogen content Liquid gas CH3-CH2-CH2-CH MJ/kg less hydrogen content Oil CH3-CH2-….-CH2-CH MJ/kg even less hydrogen content Biodiesel CH3-(CH2)n-C-OH MJ/kg even less hydrogen content O II Coal MJ/kg oxygen, water is present Coke mainly carbon MJ/kg lack of hydrogen ! Biogas CH4 : CO2 ≈50-50% ≈24 MJ/kg CO2 does not burn Bioethanol CH3-CH2-OH MJ/kg increased oxygen content Wood, straw MJ/kg high oxygen content and water

Direct Thermal Conversion of Biomass Combustion

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 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 = %

Biomass transformation to fuel Thermal gasification

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.

The methan concentration can be increased
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 v% H v% CO v% CH4 2-3 v% N v% °C C + CO2 → CO C + H2O → CO + H2 LHV : 5-5,86 MJ/Nm3 > 200 °C CO + H2O → CO2 + H2 °C °C CH1.4O0,6 + O2 → CO2 + H2O 1450 °C The methan concentration can be increased by pressure increase CO + 3 H2  CH4 + H2O 2 C + 2 H2  CH4

THERMAL GASIFICATION OF BIOMASS in circulating fluidized (CFB) boiler
Environtherm.de

Synthesis gas for Fischer-Troops plant
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 ~ MJ/Nm3 Natural gas MJ/Nm3

Technology of biogas production

ENERGY FROM BIOGAS * Methane content 50 v% ** 16 MJ/kg *** 40 MJ/kg
row material Biogas yield [Nm3/t] Energy* content [kJ] Wood eq.** [kg] Oil eq.*** cattle, pig manure 60 1080 77 27 fresh grass 500 9000 643 225 fat 1300 23400 1671 585 fat grease trap 250 4500 321 113 slaughterhouse waste 300 5400 386 135 techn. glycerin brewer grains 180 3240 231 81 grain 560 10080 720 252 ENERGY FROM BIOGAS * Methane content 50 v% ** 16 MJ/kg *** 40 MJ/kg

Mercury, chlorinated hydrocarbons, non methane organic compounds
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

bioethanol → motor fuel
Energy from biomass bioethanol → motor fuel Maize corn 28

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 Row 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%)

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 - E v% ethanol 10 v% petrol

BIOPLANTS FOR LIQUID BIOFUELS Which is the best row material ?
BIOETHANOL Which is the best row material ? 1. Sugar beet 7140 dm3/ hectare 2. Sugar-cane 6620 dm3/ hectare 3. Cassava dm3 / hectare 4. Maize corn dm3/ hectare 5. Wheat dm3/ hectare Sugar beet Maize corn Sugar cane 1 hectare = 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: MON: 97 real RON : 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)

Rape-straw, rape-cake: burning → by-products: energy sources
Energy from biomass rape rape from rape seed Biodiesel from rape → motor fuel Rape-straw, rape-cake: burning → by-products: energy sources 35

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 Which is the best row material ?
BIODIESEL Which is the best row material ? palm oil tree : dm3/hectare coco palm: 2300 dm3/hectare yathropa : 1900 dm3/hectare soya : 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 ! km2

Let’s substitute the petrol consumption by bioethanol !
Petrol consumption = ton/year petrol: 43,5 MJ/kg ethanol: 26,8 MJ/kg Alcohol claim : * 43.5/26.8 ≈ ton/year Maize 2,8 ton alcohol/hectare/year Area claim: /2,8 ≈ hectare = km2 The growing can not be repeated on the same site : Area claim ≈ 3 * = km2

Let’s substitute the diesel oil consumption by biodiesel !
Diesel oil consumption = ton/year Biodiesel claim : * 1,1 = ton/year Rape: dm3 biodiesel /hectare/year ≈ 880 kg/hectare/year = 0,88 ton/hectare/year Area claim : /0,88 = hectare = km2 The growing can not be repeated on the same site : Area claim ≈ 3 * = km2

By Monica Gottfried 2006 thesis
Bioethanol vs. Biodiesel II. The rate of energy output and energy input By Monica Gottfried 2006 thesis Wheat bioethanol Maize Sunflower biodiesel Rape Energy grass only combustion Energy rate 1,19 1,42 2,35 2,13 4,95

Energy distribution in the future

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.