Future and energyFuture and energyBIOENERGYBIOENERGY

What about me 40 years later ?

Dr. Bajnóczy GáborTonkó Csilla

BUDAPEST UNIVERSITY OF TECHNOLOGY AND ECONOMICS

DEPARTMENT OF CHEMICAL AND ENVIRONMENTAL PROCESS ENGINEERING

FACULTY OF CHEMICAL AND BIOCHEMICAL ENGINEERING

The pictures and drawings of The pictures and drawings of this presentation are used this presentation are used and can be used only for and can be used only for

education !education !

Any commercial use is Any commercial use is prohibited !prohibited !

Perhaps this will be my car ?Perhaps this will be my car ?

Or these vehicles ?Or these vehicles ?

Fuel shortage !Fuel shortage !Is it me at home in winter ?Is it me at home in winter ?

Or she is my wife waiting for me at Or she is my wife waiting for me at homehome

Energy from bio-energy plantEnergy 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 theThe most important questions are the

-- ENERGY CONTENT OF THE BIOMASSENERGY CONTENT OF THE BIOMASS

- Availability of Biomass- Availability of Biomass

- Costs- Costs

REACTANTS

fuel + oxygen

T=298 K

P= 1 bar

PRODUCTSCO2, SO2, H2O

T= 298 KP= 1 bar

+ HEAT (LHV)

PRODUCTSCO2, SO2,H2O

T= 298 KP= 1 bar

+ HEAT (HHV)liquidcomplete

combustion

completecombustion

ENERGY CONTENT OF BIOMASSENERGY 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)

LHV and HHV of fuelsLHV and HHV of fuels Measuring by calorimeter Calculation by

33829 C% + 144277 (H% - 1/8 O2%) + 10467 S%HHV = ------------------------------------------------------------------ [kJ/kg] 100

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

available hydrogen

not typical in biomass

LHV values of fuelsNatural gas CH4 48 MJ/kg the highest hydrogen content

Liquid gas CH3-CH2-CH2-CH3 46 MJ/kg less hydrogen content

Oil CH3-CH2-….-CH2-CH3 42 MJ/kg even less hydrogen content

Coal 32 - 22 MJ/kg oxygen, water is present

Coke mainly carbon 28 MJ/kg lack of hydrogen !

Wood, straw 14 - 16 MJ/kg high oxygen content and water

Biodiesel CH3-(CH2)n-C-OH 38 MJ/kg even less hydrogen content

OII

Bioethanol CH3-CH2-OH 27 MJ/kg increased oxygen content

Biogas CH4 : CO2 ≈50-50% ≈24 MJ/kg CO2 does not burn

Direct Thermal Conversion of BiomassDirect Thermal Conversion of Biomass

CombustionCombustion

Some rSome row materials for biomass combustionow materials for biomass combustion

Forestry product Agriculture product Agriculture residue

wood

Straw

branch

barkoilcake

wheat

maize

rape seed

Wood for biomass combustionWood 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

Primary air (under fire air)

Secondary air (over 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)

Open fire place η= 10 – 15 %

Closed fire place η = 20 - 30

%

Tile stove only for wood

η = 60 – 70 %

Tile stove for wood and coal η = 60 – 70 %

Central heating by pellet

η ≈ 90 %

Biomass transformation to fuelBiomass transformation to fuel

Thermal gasificationThermal gasification

THERMAL GASIFICATION OF BIOMASS

Conversion of biomass into carbon- and hydrogen-rich fuel gases(carbon monoxide, hydrogen, methane)

better utilization

efficiency of energy conversion ≈ 90 % less environmental polluting materials

Fuel gas

perfect combustion due toperfect mixing of fuel gas

and air

due to perfect mixing of fuel gasand air less carbon monoxide,

hydrocarbons and shoot particleswill be formed.

THERMAL GASIFICATION OF BIOMASS

CH1.4O0,6 + O2 → CO2 + H2O

C + CO2 → CO

CH1.4O0,6 → CO + C + (CH)x + H2O

C + H2O → CO + H2

CO + H2O → CO2 + H2

Downdraft gasifier

1450 °C

800 - 1000 °C

300 - 700 °C

> 200 °C

300 - 400 °C

Wood (12-20w% moisture) CO 17-22 v%

H2 16-20 v%CO2 10-15 v%CH4 2-3 v%N2 55-60 v%

LHV : 5-5,86 MJ/Nm3

GASIFIER

atmospheric

CO + 3 H2 CH4 + H2O

2 C + 2 H2 CH4

Syngas or producer gas

The methan concentration can be increasedby pressure increase

THERMAL GASIFICATION OF BIOMASSin circulating fluidized (CFB) boiler

Environtherm.de

THERMAL GASIFICATION OF BIOMASS

Direct heat system Synthesis gas for methanol, ethanol production

Synthesis gas for Fischer-Troops

plant

petroldiesel oil

lubricating oil

Condensation ▼ Bio-oil

Direct heat system

GASIFICATION BY BIOMETHODSBIOGAS

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

Technology of biogas production

row material

Biogas yield

[Nm3/t]

Energy* content

[kJ]

Wood eq.**

[kg]

Oil eq.***

[kg]

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 500 9000 643 225

brewer grains 180 3240 231 81

grain 560 10080 720 252

* Methane content 50 v% ** 16 MJ/kg *** 40 MJ/kg

ENERGY FROM BIOGAS

LANDFILL GAS

flaring

heating

Jenbacher gasmotor

Electric energyGreenhouse effect: CH4 >> CO2

The landfill gas is a very polluted gas !!

Mercury, chlorinated hydrocarbons, non methane organic compounds

15-30 Nm3 / ton. year from the second year

Energy from biomassEnergy from biomass

Maize corn

bioethanol → motor fuel

BIOPLANTS FOR LIQUID BIOFUELSBIOETHANOL

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 BIOFUELSBIOETHANOL

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 BIOFUELSBIOETHANOL

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 BIOFUELSBIOETHANOL

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

Sugar cane

cassava

Maize corn

wheat1 hectare = 10 000 m2

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 BIOFUELSBIOETHANOL

ADVANTAGES

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)

BIOPLANTS FOR LIQUID BIOFUELSBIOETHANOL

DRAWBACKS

Energy from biomassEnergy from biomass

rape rape from rape seed

Biodiesel from rape → motor fuel

Rape-straw, rape-cake: burning → by-products: energy sources

BIOPLANTS FOR LIQUID BIOFUELSBIODIESEL

BIOPLANTS FOR LIQUID BIOFUELSBIODIESEL

Row material:

- plant product containing any vegetable oil

- animal fat (ONLY IN WASTE FORM !)

- waste vegetable oil

TECHNOLOGY

1. 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 BIOFUELSBIODIESEL

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

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 BIOFUELSBIODIESEL

ADVANTAGES

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.

BIOPLANTS FOR LIQUID BIOFUELSBIODIESEL

DRAWBACKS

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

Maize 2,8 ton alcohol/hectare/year

Alcohol claim : 1 600 000 * 43.5/26.8 ≈ 2 600 000 ton/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.

Wheat

bioethanol

Maize

bioethanol

Sunflower

biodiesel

Rape

biodiesel

Energy grass

only combustion

Energy rate 1,19 1,42 2,35 2,13 4,95

The rate of energy output and energy inputBy Monica Gottfried 2006 thesis

Energy distribution in Energy distribution in the futurethe future

ConclusionsConclusions

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.