ΤΗEOFANIS .A. GEMTOS, SPYROS FOUNTAS, CHRISTOS ΚAVALARIS

LABORATORY OF FARM MECHANISATION, DEPARTMENT OF AGRICULTURE, CROP PRODUCTION

AND RURAL ENVIRONMENT, UNIVERSITY OF THESSALY, GREECE

Agricultural crops and wastes for Bioenergy

Introduction

Greece as well as EU are short of energy resources.

Therefore we need to use RES to reduce dependence on energy imports and the relevant spending .

Biomass is a RES that can be produced locally offering several advantages like:

It already exists in some amounts at the moment not used

It can be produced by energy crops offering opportunities to introduce new plants in crop rotations

It can produce transportation fuels

(vegetable oils, alcohols, methane)It can offer employment and income in areas

of the country that at least before the crisis presented a lot of economic problems

It can be considered friendly to the environment

What is Biomass?

Any type of residues of biological processes like:

Crop and forestry residues, wastes of animal feeding and human living

Residues of the industry of agricultural product processing

Energy crops

Crop, forestry and industry residues

Any crop (except hay producing) offers a useful product and a residue that usually remains in the field and requires management by the farmer

Most of the residues are not used at the moment and are left in the field or burnt.

Forest residues are also left on the soil producing a mulch with problems for fires control.

Many industries are producing residues (or wastes) that are in many cases not used.

Animal feeding is producing huge amounts of manure that at least in Greece are not used or are not used properly causing environmental problems

Similar problem exists with human living wastes, Most of the products of biological treatments or garbage offer biological material that is usually buried.

Crop residues yield in Thessaly

S[ecies Part of the plant Moisture content after harvesting

Dry matter yield Heating value

% (kg/ha.) MJ/kg DM

Maize Total 14,7 10100 18,0

Cobs 16,5 1100 18,5

Cotton Aerial part 39,9 2540 18,0

Root 55,7 580 18,5

Sunflower Total 20,3 3320 17,3

Wheat straw Aerial part 5 2170 18,5

Barley straw Aerial part 5 1200 18,2

Processing tomatoes Aerial part 65 469 17,3

Tobacco

American type Aerial part 45 375 16,2

Domestic type Aerial part 45 1436 18,2

Sugar beet Aerial part 70 3400 17,1

Pruning yield

Plant Yield dry matter

Heating value

Energy production

Oil equivalent

kg/ha MJ/kg MJ/ha kg oe/ha Olive trees 4542 19 86260 1917 Apples and pears 4925 18.7 92100 2047 Apricots 5505 17.8 97900 2176 Almond, peaches, cherries etc

4620 18.8 86856 1930

Vines 5130 18.7 95931 2132

Crop residues production, Thessaly(2003)

Crop Yield Dry Matter

Heating Value

Energy yeild Oil equivallent Cultivated area Total energy production

kg/ha MJ/kg DM

MJ/ha ha GJ

Wheatι 2180 19,1 41638 925,3 131156 5461073,528

Barley 1200 18,5 22200 493,3 27524 611032,8

Sunflower 3320 17,3 57436 1276,4 6524 374712,464

Maize 10000 18 180000 4000 13420 2415600

Cotton 144700 0

Aerial and root 3140 18 56520 1256 144700 8178444

Aerial part only 2540 18 45720 1016 144700 6615684

Tomatoes 470 17,3 8131 180,7 5827 47379,337

Tobaco 1000 17,2 5826 0

Domestic type 380 16,2 6156 136,8 0

American type 1440 18,2 26208 582,4 0

Olive trees 4540 19 86260 1916,9 30563,7 2636424,762

Apples, peaaches etc 4930 18,7 92191 2048,7 42108 3881978,628

Legumes 1500 17 25500 566,7 3263 83206,5

Sugar Beet 5360 17 91120 2024,9 5000 455600

Total only aerial part cotton

22582692,02

Total with cotton roots 24145452,02

Biomass from forestry residues and energy content

Wood Residues

Energy

Total Christmas treee

Pine Οακ Beech Different

Residues

Charcoal

t t t t t t GJ Thesaly 72386 50995 11771 66 6621 2933 132 1,324,664

Karditsa 10875 10658 7 _ 210 _ 864 _ 199012.5

Larisssa 9566 1003 6592 66 1090 815 12399 _ 175057.8

Magnesia 320 298 _ _ 15 7 366 132 5856

Trikala 51625 39036 5172 _ 5306 2111 8045 _ 944737.5

Biomass and energy content from stable wastes

Geographic region Horses, asses Beef, Cows Pigs Chicken Total

Thessalia animal number 18637 69618 121686 1068159 live weight 200 250 80 2 total live wheight kg/d 3727400 17404500 9734880 2136318 fresh manure kg DM/d 55911 147938.25 107083.68 40590.04 351523.0 mean energy value/d 17.5 17.5 17.5 17.5 17.5 total energy MJ/d 978443 2588919 1873964 710326 6151652.0 total energy GJ/y 357132 944956 683997 259269 2245353.0 TEP/d 22 58 42 16 136.7 TEP/y 7936 20999 15200 5762 49896.7

Industrial residues

Residues Coefficient of residue estimation (%)

Water Content %

Heating value (MJ/kg)

Almonds 60 15 19,4 Residue after olive oil extraction

40% 45 17

Residues after olive oil extraction by chemicals

3 % 15 15,6

Peaches 5 15-20 20,8 Cotton gins 6 8-15 17.5

Wood processing units

20-30 10 19

Total biomass produced by processing units in Prefecture of Larissa

Processing units Amount processed t/y

Available for use t/y

1 Olive oil extraction 24.620 9.554 2 Textile industry 235.000 15.950 3 Fruit canning 100.000 5.190 4 Wood [rpvessing 25.000 t 6.500 5 Almond processing 5.000 to 3.000 Total

40.194

Total biomass energy production

Source Energy in GJ Energy in TOE Crop residues 22.582.692 501.837 Animal Waste 2.245.353 49.896 Forestry Residues 1.324.664 29.436 Processing residues 1.183.500 26.300 Total 28.458.934 607.379 Energy consumptionThessaly 2.049.060 % cover 29,6

Energy crops

There are annual and perennialPerennial have the advantage of low

establishment costAnnual are more flexible and can be used in

rotation with food crops

Perennial

There are several crops tested in the country like cardoon, switch grass as rain fed and Miscunthus and Arunda as irrigated

Yield is estimated at about 10t DM/ha for rain fed and about tree times as much for irrigated

It should be stressed the difference between theoretical yield and harvested one.

Annual energy crops

They offer products for different uses like oil seeds produced by sunflower, rape seed or soy bean offering oil for biodiesel and residue for burning or second generation biofuels. Other seeds can be raw material for alcohol production (first or second generation) like maize, sweet or seed sorghum and others producing high yields of biomass with or without sugars.

Sweet sorghum or sugar beet can offer sugars for alcohol production and lignocellulosic material for second generation biofuels.

Fibre sorghum, kenaf, maize for biomass production (irrigated) tritical, lolium, oats in mixtures with legumes (rain fed) can be used for biomass production for burning or second generation biofuels.

How much are yielding?

Sunflower (irrigated) yielded 2.5 to 6 t/ha and up to 6 t DM/ha crop residue.

Rape seed (rain fed) yielded up to 2 t/ha of seed.

Sweet sorghum (irrigated) yielded up to 33 t DM/ha

This year soy bean yielded 42 t/of seed /ha under conventional or strip tillage

Harvesting of biomass

Initially hay making equipment was used.This was convenient as it did not require new

investment and increase machinery use.But these equipment proved unable to

harvest long stems biomass. Chopping at different level of the stems was required.

Cardoon harvesting in Thessaly, Greece

Impact to the environment

Removing whole cropΗ απόληψη όλης της βιομάζας from the fields can cause problems to soil fertility from:

Soil erosion by leaving the soil bareReduction of organic matterSoil compactionReduced biodiversityA research project under THALIS is going to

study the effects and the possible ways to alleviate the problems

What is the future of biomass use?

To my opinion there is a major problem to be solved to help in the promotion of biomass use. We need to close the cycle. No one farmer is prepared to introduce energy crops when no transformation unit exists and no one investor will invest in the unit when the crops are not there.

Several pellet making plant that are growing can help to that direction

Second generation biofuels can be the basis of a wider biomass use.

Conclusions

Biomass use will improve the energy balance of the country as well its environmental obligations while it will create employment and income to the rural areas.

There is a potential in the form of residues and wastes that is not used at the moment and requires appropriate technologies to be used profitably.

We require research to develop energy crops and to oppimise biomass harvesting and logistics.

We need to study carefully the impact to the environment and develop methods to reduce them

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