Bioenergy Potential of Turkey's Forest Sources, Biomass Energy Conversion Methods, Products, and Applications

*Selçuk Sarıkoç*

## **Abstract**

Forests have been an important bioenergy source for mankind through the long ages, and they will continue as biomass feedstock sources in the future. This study aims to investigate Turkey's forest source, biomass resource, fuel wood, and forest residue potential to discover the bioenergy potential of Turkey. How to convert this potential to energy was evaluated in terms of applications and products. Thus, the most common biomass conversion methods such as thermal processes, pyrolysis, gasification, and combustion, and biological processes, fermentation, anaerobic digestion, and biophotolysis processes, have been explained as biomass energy conversion methods. Besides, the products of biomass are explained by its energy application fields. Overall, the bioenergy potential of Turkey's forest sources and biomass energy conversion methods will be overviewed by this study. Thus, this study will be attracted attention to forests' biomass source the effects on economic, ecological, and socio-economic respects.

**Keywords:** Turkey's forest, biomass, bioenergy potential, biomass energy conversion methods, alternative biofuels

## **1. Introduction**

Rapidly growing population and industrialization have increased the energy request. It is very important that this increased energy requirement is from sustainable and environmentally friendly resources. At this point, biomass energy stands out with it being sustainable, environmentally friendly, and an inexhaustible resource that can be obtained anywhere. Especially in rural areas, it is becoming the most promising energy source due to its positive effects on socioeconomic developments [1]. In addition to this, woody biomass is estimated to meet approximately 2–18% of primary energy consumption in 2050 [2].

Biomass is vegetative organisms that plants produce and store from organic matter using photosynthesis using solar energy. Bioenergy is used to define energy and energy-related products produced from biomass. Biomass is formed as a result of the combination of sunlight and carbon dioxide and water in the atmosphere with photosynthesis reaction [1, 3].

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$$

where |CH2O| refers to biomass as carbohydrate [3].

Biomass has been the most common and crucial energy source that is used in heating and cooking for thousands of years. Thus, wood is still the most widely used and richest biomass energy source. Today, plants, agriculture and forest residues, organic household waste, industrial waste, and algae are used as biomass sources. The biomass sources can be used in wide areas such as producing heat, electricity, fuel, and some chemicals [4].

When technical, economic, environmental, and social effects of alternative energy sources such as biomass, wind, hydroelectric, solar, and geothermal energy are evaluated, it is concluded that the most suitable alternative energy is biomass energy. The most important reason for this is that its social benefit is the highest among others [5]. In addition to this, the use of bioenergy has considerably the potential to reduce emissions of greenhouse gases. Bioenergy produces approximately the same amount of carbon dioxide as fossil energy sources, but net carbon emission is zero since the plant uses carbon dioxide by photosynthesis during the day [4].

Three sides of Turkey are surrounded by seas so that it has different climates. Besides, it is located in the center of the triangle connecting the continents of Asia, Europe, and Africa [6]. In 2015 the amount of carbon absorbed by forests in Turkey is 1.9 billion tons. In addition to this, oxygen production was annually calculated as 42 million tons [7]. Turkey has a very rich fauna and plant species source due to moderate climatic conditions. For this reason, it is among the countries rich in biodiversity. Turkey's territory is covered with 27.6% of forests, 31.1% of agricultural land, 18.6% of pasture, 21.3% of other areas, and 1.4% of water. The distribution ratios of the land situation in Turkey are shown in **Figure 1** [8].

The objective of this study is not only to address the current situation of Turkey's forest sources and their bioenergy potential but also to present the recent methods of biomass utilization in the applications. This book section exhibits forest bioenergy potential of Turkey and discusses the biomass conversion methods, products, and applications in terms of the production process and usage of the products in the field. This section aims to attract attention to the forests' bioenergy source and help to seek proper investments for the government and investors regarding forest biomass energy potential.

**135**

**Figure 2.**

*Map of Turkey's forest assets [8].*

*Bioenergy Potential of Turkey's Forest Sources, Biomass Energy Conversion Methods, Products…*

Turkey is a transit point that connects the Asian and European continents. It is at the center of the triangle formed by the continents of Asia, Europe, and Africa. Besides, Turkey is surrounded by seas on three sides so it has a different climate. As a result, this situation makes it a rich country in terms of animal and plant diversity. Turkey's forests cover about 30% of the land area and have an equivalent of 11,000 plant species to plant diversity. Furthermore, 3708 of these plant species consist of endemic plant species. When we evaluate the forests of our country as tree species and the area they cover, the first three ranks are 18 species and 6,476,277 ha of oak (*Quercus* spp.), 5,420,524 ha of red pine (*Pinus brutia*), and 4,202,298 ha of larch (*Pinus nigra*) takes the forests. These are followed by beech (*Fagus orientalis* and *Fagus sylvatica*), scots pine (*Pinus sylvestris*), and fir (*Abies nordmanniana* and *Abies cilicica*) forests. The classification of Turkey's forests is as follows: the Black Sea Region, the North Anatolia Forests which constitute 25% of the forests in Turkey, is the most forested area in Turkey, followed by Thrace, West and Middle Black Sea Forests, Eastern Black Sea Forests, Mediterranean Forests, and Central, East, and South East Anatolia Forests [6]. Turkey's forest asset map and the distribution of the

Turkey has an ecologically rich diversity due to its geographical location and climatic diversity. The effects of forests on this ecological diversity and wealth are very important. Turkey has 78 million hectares of surface area. In addition to this, forest areas cover by 28.6% percentage except for treeless forest areas [7]. The ratio

Forest areas can be divided into two classes as grove and coppice according to their operation types. Turkey's forests are composed of 88% of grove forest areas (19.6 million hectares) and 12% of coppice forest areas (2.7 million hectares) [7]. The rates of the forest areas according to the operation types are given in **Figure 4**.

of land area and the amount of woodland in Turkey is given in **Figure 3**.

*DOI: http://dx.doi.org/10.5772/intechopen.92974*

forests are given in **Figure 2**.

**2.1 Distribution of forest land in Turkey**

**2. Turkey's forest biomass resources and distribution**

**Figure 1.** *The distribution ratios of the land situation in Turkey [8].*

*Bioenergy Potential of Turkey's Forest Sources, Biomass Energy Conversion Methods, Products… DOI: http://dx.doi.org/10.5772/intechopen.92974*

## **2. Turkey's forest biomass resources and distribution**

*Renewable Energy - Technologies and Applications*

fuel, and some chemicals [4].

day [4].

**Figure 1** [8].

biomass energy potential.

*The distribution ratios of the land situation in Turkey [8].*

where |CH2O| refers to biomass as carbohydrate [3].

CO2 <sup>+</sup> 2 H2O ⎯⟶ light+heat(|CH2O| + H2O) + O2 (1)

Biomass has been the most common and crucial energy source that is used in heating and cooking for thousands of years. Thus, wood is still the most widely used and richest biomass energy source. Today, plants, agriculture and forest residues, organic household waste, industrial waste, and algae are used as biomass sources. The biomass sources can be used in wide areas such as producing heat, electricity,

When technical, economic, environmental, and social effects of alternative energy sources such as biomass, wind, hydroelectric, solar, and geothermal energy are evaluated, it is concluded that the most suitable alternative energy is biomass energy. The most important reason for this is that its social benefit is the highest among others [5]. In addition to this, the use of bioenergy has considerably the potential to reduce emissions of greenhouse gases. Bioenergy produces approximately the same amount of carbon dioxide as fossil energy sources, but net carbon emission is zero since the plant uses carbon dioxide by photosynthesis during the

Three sides of Turkey are surrounded by seas so that it has different climates. Besides, it is located in the center of the triangle connecting the continents of Asia, Europe, and Africa [6]. In 2015 the amount of carbon absorbed by forests in Turkey is 1.9 billion tons. In addition to this, oxygen production was annually calculated as 42 million tons [7]. Turkey has a very rich fauna and plant species source due to moderate climatic conditions. For this reason, it is among the countries rich in biodiversity. Turkey's territory is covered with 27.6% of forests, 31.1% of agricultural land, 18.6% of pasture, 21.3% of other areas, and 1.4% of water. The distribution ratios of the land situation in Turkey are shown in

The objective of this study is not only to address the current situation of Turkey's forest sources and their bioenergy potential but also to present the recent methods of biomass utilization in the applications. This book section exhibits forest bioenergy potential of Turkey and discusses the biomass conversion methods, products, and applications in terms of the production process and usage of the products in the field. This section aims to attract attention to the forests' bioenergy source and help to seek proper investments for the government and investors regarding forest

**134**

**Figure 1.**

Turkey is a transit point that connects the Asian and European continents. It is at the center of the triangle formed by the continents of Asia, Europe, and Africa. Besides, Turkey is surrounded by seas on three sides so it has a different climate. As a result, this situation makes it a rich country in terms of animal and plant diversity. Turkey's forests cover about 30% of the land area and have an equivalent of 11,000 plant species to plant diversity. Furthermore, 3708 of these plant species consist of endemic plant species. When we evaluate the forests of our country as tree species and the area they cover, the first three ranks are 18 species and 6,476,277 ha of oak (*Quercus* spp.), 5,420,524 ha of red pine (*Pinus brutia*), and 4,202,298 ha of larch (*Pinus nigra*) takes the forests. These are followed by beech (*Fagus orientalis* and *Fagus sylvatica*), scots pine (*Pinus sylvestris*), and fir (*Abies nordmanniana* and *Abies cilicica*) forests. The classification of Turkey's forests is as follows: the Black Sea Region, the North Anatolia Forests which constitute 25% of the forests in Turkey, is the most forested area in Turkey, followed by Thrace, West and Middle Black Sea Forests, Eastern Black Sea Forests, Mediterranean Forests, and Central, East, and South East Anatolia Forests [6]. Turkey's forest asset map and the distribution of the forests are given in **Figure 2**.

## **2.1 Distribution of forest land in Turkey**

Turkey has an ecologically rich diversity due to its geographical location and climatic diversity. The effects of forests on this ecological diversity and wealth are very important. Turkey has 78 million hectares of surface area. In addition to this, forest areas cover by 28.6% percentage except for treeless forest areas [7]. The ratio of land area and the amount of woodland in Turkey is given in **Figure 3**.

Forest areas can be divided into two classes as grove and coppice according to their operation types. Turkey's forests are composed of 88% of grove forest areas (19.6 million hectares) and 12% of coppice forest areas (2.7 million hectares) [7]. The rates of the forest areas according to the operation types are given in **Figure 4**.

**Figure 2.** *Map of Turkey's forest assets [8].*

#### **Figure 3.**

*The ratio of land area and the amount of woodland in Turkey [7].*

#### **Figure 4.**

Turkey's forest lands' main function distribution is composed of 50% economic, 42% ecological, and 8% sociocultural [7]. Distribution rates according to the main functions of forest areas are given in **Figure 5**.

According to Turkey's forest lands taken into consideration for 42 years, the field of forest area size and change of forest wealth have increased through the years. Forest areas increased by 2.1 million hectares in 42 years. Activities such as protection, development, afforestation, and precautions for forests have been effective on this increase [7]. The amount of the forest area of Turkey through the years and the rate of the country land are given in **Table 1**.

#### **2.2 Distribution of forest wealth**

Turkey's forest assets are 20.2 million hectares in 1972 and reached 22.3 million hectares in 2015. In parallel with this, the wood wealth in forests increased from 0.9 billion m3 in 1972 to 1.2 billion m3 in 2003, to 1.6 billion m3 in 2015. In respect to this, between 1973 and 2015, there has been an increase of 700 million m3 in the tree wealth of the country's forests. In this increase, afforestation studies, migration of citizens living around the forest, and improvement of forest areas have been very effective [7]. The amount of coniferous, broad-leaved, mixed grove, and coppice forest areas of the forest asset in 2012 is given in **Table 2**.

**137**

**Table 2.**

lion m3

**Table 1.**

*Forest area change by years [7].*

**Figure 5.**

*Bioenergy Potential of Turkey's Forest Sources, Biomass Energy Conversion Methods, Products…*

According to the forest renovation plan in 2013–2015 in Turkey, the amount of forest area in 2015 was estimated to be 22.3 million hectares. The amount and rates of the distribution of the forest areas according to the operation types, the forest area, tree wealth, and annual current increase status are given in **Table 3**. Turkey's average annual amount of revenue derived from forests planted in 2015 is calculated as the volume-shelled body. This value was calculated as approximately 15.94 mil-

**Years Field (ha) Rate (%)** 20.199.296 26.1 20.763.248 26.7 21.188.747 27.2 21.678.134 27.7 22.342.935 28.6

 of total forest area [7]. Turkey's 13.9 million hectares of forest area (62%) is pure forest. In this amount,

the rate of tree species entering the mixture is less than 10%. Besides, approximately 8.4 million hectares of forest (38%) is mixed forest [7]. The distribution of

> **Mixed grove (ha)**

Productive 6.792.336 2.156.746 1.332.464 10.281.728 1.276.940 11.558.668 Degraded 4.983.059 950.319 1.045.486 6.978.864 3.140.602 10.119.466 Total 11.775.395 3.107.066 2.378.131 17.260.592 4.417.542 21.678.135

from coppice forests. As a result, it

**forest (ha)**

**Total forest (ha)**

**Total grove (ha) Coppice** 

from grove forests and 2.37 million m3

*Distribution rates according to the main functions of forest areas [7].*

forest ratio of species to general forest area is given in **Figure 6**.

**Broadleaved tree (ha)**

was calculated as 18.31 million m3

**tree (ha)**

*Turkey's amount of forest assets in 2012 [8].*

**Qualification Coniferous** 

*DOI: http://dx.doi.org/10.5772/intechopen.92974*

*The rates of the forest areas according to the operation types [7].*

*Bioenergy Potential of Turkey's Forest Sources, Biomass Energy Conversion Methods, Products… DOI: http://dx.doi.org/10.5772/intechopen.92974*

#### **Figure 5.**

*Renewable Energy - Technologies and Applications*

Turkey's forest lands' main function distribution is composed of 50% economic, 42% ecological, and 8% sociocultural [7]. Distribution rates according to the main

According to Turkey's forest lands taken into consideration for 42 years, the field

Turkey's forest assets are 20.2 million hectares in 1972 and reached 22.3 million hectares in 2015. In parallel with this, the wood wealth in forests increased from

wealth of the country's forests. In this increase, afforestation studies, migration of citizens living around the forest, and improvement of forest areas have been very effective [7]. The amount of coniferous, broad-leaved, mixed grove, and coppice

this, between 1973 and 2015, there has been an increase of 700 million m3

in 2003, to 1.6 billion m3

in 2015. In respect to

in the tree

of forest area size and change of forest wealth have increased through the years. Forest areas increased by 2.1 million hectares in 42 years. Activities such as protection, development, afforestation, and precautions for forests have been effective on this increase [7]. The amount of the forest area of Turkey through the years and the

functions of forest areas are given in **Figure 5**.

*The rates of the forest areas according to the operation types [7].*

*The ratio of land area and the amount of woodland in Turkey [7].*

rate of the country land are given in **Table 1**.

in 1972 to 1.2 billion m3

forest areas of the forest asset in 2012 is given in **Table 2**.

**2.2 Distribution of forest wealth**

**136**

0.9 billion m3

**Figure 3.**

**Figure 4.**

*Distribution rates according to the main functions of forest areas [7].*


#### **Table 1.**

*Forest area change by years [7].*

According to the forest renovation plan in 2013–2015 in Turkey, the amount of forest area in 2015 was estimated to be 22.3 million hectares. The amount and rates of the distribution of the forest areas according to the operation types, the forest area, tree wealth, and annual current increase status are given in **Table 3**. Turkey's average annual amount of revenue derived from forests planted in 2015 is calculated as the volume-shelled body. This value was calculated as approximately 15.94 million m3 from grove forests and 2.37 million m3 from coppice forests. As a result, it was calculated as 18.31 million m3 of total forest area [7].

Turkey's 13.9 million hectares of forest area (62%) is pure forest. In this amount, the rate of tree species entering the mixture is less than 10%. Besides, approximately 8.4 million hectares of forest (38%) is mixed forest [7]. The distribution of forest ratio of species to general forest area is given in **Figure 6**.


#### **Table 2.**

*Turkey's amount of forest assets in 2012 [8].*


#### **Table 3.**

*The situation of forest areas according to their operation types [7].*

#### **Figure 6.**

*Proportion of forest areas by tree type [7].*

Turkey's forest areas consist of 33% broad-leaved forests (oak, beech, alder, chestnut tree species such as beech), 48% coniferous forests (tree species such as Turkish pine, crimean pine, scots pine, fir, spruce, cedar), 19% coniferous + broadleaved mixed forests. Oak occupies the largest area in the forests (5.9 million ha), followed by Turkish pine, crimean pine, beech, scots pine, juniper, fir, cedar, spruce, stone pine, alder, chestnut, hornbeam, poplar, lime tree, ash tree, and eucalyptus [7]. Distribution values of forest areas by tree species are given for 2018 in **Table 4**.

Turkey's forest wealth distribution, the current value increment distribution, and distribution of forest areas by the year 2005–2018 are given as follows. **Figure 7** shows forest wealth distribution in 2018. The forest was composed of 95%

**139**

**Figure 7.**

*Forest wealth distribution in 2018 [9].*

**Table 4.**

*Distribution of forest areas by tree species 2018 [9].*

*Bioenergy Potential of Turkey's Forest Sources, Biomass Energy Conversion Methods, Products…*

**Tree type groups Total (ha) Productive (ha) Degraded (ha)** Oak (*Quercus* spp.) 5,938,527 2,435,265 3,503,262 Turkish pine (*Pinus brutia*) 5,686,009 3,527,063 2,158,946 Crimean pine (*Pinus nigra*) 4,304,821 2,787,424 1,517,397 Beech (*Fagus orientalis*) 1,935,730 1,665,997 269,733 Scots pine (*Pinus sylvestris*) 1,538,304 901,606 636,698 Juniper (*Juniperus*) 963,217 223,097 740,120 Fir (*Abies* spp.) 593,201 391,842 201,359 Turkish cedar (*Cedrus libani*) 487,819 252,590 235,229 Oriental spruce (*Picea orientalis*) 327,890 234,224 93,666 Stone pine (*Pinus pinea*) 164,798 131,548 33,250 Alder (*Alnus* spp.) 149,215 115,646 33,569 Chestnut (*Castanea sativa*) 89,941 69,727 20,214 Hornbeam (*Carpinus* spp.) 35,609 28,872 6737 Poplar (*Populus* spp.) 16,430 6587 9843 Lime tree (*Tilia* spp.) 12,803 10,637 2166 Ash tree (*Populus* spp.) 7359 6854 505 Eucalyptus (*Eucalyptus* spp.) 1434 1383 51 Other species 368,826 192,784 176,042 Total 22,621,935 12,983,148 9,638,787

**Total forest area by tree species (2018) Forest form**

*DOI: http://dx.doi.org/10.5772/intechopen.92974*

*Bioenergy Potential of Turkey's Forest Sources, Biomass Energy Conversion Methods, Products… DOI: http://dx.doi.org/10.5772/intechopen.92974*


#### **Table 4.**

*Renewable Energy - Technologies and Applications*

**Normal forest Degraded forest Total ha % ha % ha %**

**Normal forest Degraded forest Total m3 % m3 % m3 %**

Grove 11.919.061 54 7.700.657 34 19.619.718 88 Coppice 785.087 3 1.938.130 9 2.723.217 12 Total 12.704.148 57 9.638.787 43 22.342.935 100

Grove 1.506.131.410 93 59.996.731 4 1.566.128.141 97 Coppice 33.692.118 2 11.953.934 1 45.646.052 3 Total 1.539.823.528 95 71.950.665 5 1.611.774.193 100

Grove 42.322.876 92 1.484.455 3 43.807.331 95 Coppice 1.511.561 3 585.191 2 2.096.752 5 Total 43.834.437 95 2.069.646 5 45.904.083 100

**Operation types**

**Operation types**

**Table 3.**

**Forest area distribution**

**Distribution of tree wealth**

**Distribution of annual current increase**

*The situation of forest areas according to their operation types [7].*

Turkey's forest areas consist of 33% broad-leaved forests (oak, beech, alder, chestnut tree species such as beech), 48% coniferous forests (tree species such as Turkish pine, crimean pine, scots pine, fir, spruce, cedar), 19% coniferous + broadleaved mixed forests. Oak occupies the largest area in the forests (5.9 million ha), followed by Turkish pine, crimean pine, beech, scots pine, juniper, fir, cedar, spruce, stone pine, alder, chestnut, hornbeam, poplar, lime tree, ash tree, and eucalyptus [7]. Distribution values of forest areas by tree species are given for 2018 in **Table 4**. Turkey's forest wealth distribution, the current value increment distribution, and distribution of forest areas by the year 2005–2018 are given as follows. **Figure 7** shows forest wealth distribution in 2018. The forest was composed of 95%

**138**

**Figure 6.**

*Proportion of forest areas by tree type [7].*

*Distribution of forest areas by tree species 2018 [9].*

**Figure 7.** *Forest wealth distribution in 2018 [9].*

**Figure 8.**

*Distribution of forest wealth between 2005 and 2018 [9].*

**Figure 9.** *Distribution of increment in 2018 [9].*

**Figure 10.**

*Distribution of increment between 2005 and 2018 [9].*

**141**

million m3

**Figure 12.**

2.372.162 m3

*Bioenergy Potential of Turkey's Forest Sources, Biomass Energy Conversion Methods, Products…*

productive high forest. **Figure 8** shows distribution of forest wealth between 2005 and 2018. The productive high forest percentage increased by 88–95% in 13 years. **Figure 9** indicates distribution of increment in 2018. **Figure 10** indicates distribution of increment between 2005 and 2018. **Figure 11** shows distribution of forest areas in

In the last 30 years, an increase of approximately 990.000 ha has been achieved in forest areas with afforestation studies and increasing environmental awareness. Thus, not only superficial increase but also quality increase in forest areas was observed [6].

Annual increment in volume of forests can be explained by the increase in total

hectare in 1973. In addition to this, the annual current increment was calculated as 45.9

The total amount of trees and annual revenue growth of forest areas can be considered as the biomass potential of forests. Thus, the amount of production and unprocessed wood production according to the tree species shows the potential of the production of firewood. **Tables 5** and **6** show the amount of wood that can be

It is estimated that available biomass energy potential from waste is about 8.6 million tons of oil equivalent (toe) in Turkey. Furthermore, it is anticipated that

the increment in tree wealth and forest areas with the maintenance to forests [7]. In **Figure 13**, the wood biomass source that can be obtained from forests is given as a model. Revenue in forestry is the annual revenue amount and is calculated in m3

from coppice forests, with a total of 18.314.621 m3

) during the growth period of the

in hectare in 2015. The reason for this increase is due to

in total and 1.4 m3

in grove forests and

[7]. The change in

in a

. The

2018. **Figure 12** shows change of forest areas by years 2005–2018 [9].

**3. Turkey's forest bioenergy potential**

*Change of forest areas by years 2005–2018 [9].*

in total and 2.1 m3

**3.1 Production amounts of fuel wood**

**3.2 Forest waste bioenergy potential**

height and diameter of the tree in a cubic meter (m3

trees. Thus, the annual current increment was 28.1 million m3

amount of revenue in 2015 was determined as 15.942.459 m3

produced as fuel according to the forest area and tree types.

these waste biomass have a biogas potential of 1.5–2 Mtoe [10].

forest revenue amounts by years is given in **Figure 14**.

*DOI: http://dx.doi.org/10.5772/intechopen.92974*

**Figure 11.** *Distribution of forest areas in 2018 [9].*

*Bioenergy Potential of Turkey's Forest Sources, Biomass Energy Conversion Methods, Products… DOI: http://dx.doi.org/10.5772/intechopen.92974*

*Change of forest areas by years 2005–2018 [9].*

*Renewable Energy - Technologies and Applications*

*Distribution of forest wealth between 2005 and 2018 [9].*

**Figure 8.**

**Figure 9.**

**Figure 10.**

*Distribution of increment in 2018 [9].*

*Distribution of increment between 2005 and 2018 [9].*

**140**

**Figure 11.**

*Distribution of forest areas in 2018 [9].*

productive high forest. **Figure 8** shows distribution of forest wealth between 2005 and 2018. The productive high forest percentage increased by 88–95% in 13 years. **Figure 9** indicates distribution of increment in 2018. **Figure 10** indicates distribution of increment between 2005 and 2018. **Figure 11** shows distribution of forest areas in 2018. **Figure 12** shows change of forest areas by years 2005–2018 [9].

In the last 30 years, an increase of approximately 990.000 ha has been achieved in forest areas with afforestation studies and increasing environmental awareness. Thus, not only superficial increase but also quality increase in forest areas was observed [6].

## **3. Turkey's forest bioenergy potential**

Annual increment in volume of forests can be explained by the increase in total height and diameter of the tree in a cubic meter (m3 ) during the growth period of the trees. Thus, the annual current increment was 28.1 million m3 in total and 1.4 m3 in a hectare in 1973. In addition to this, the annual current increment was calculated as 45.9 million m3 in total and 2.1 m3 in hectare in 2015. The reason for this increase is due to the increment in tree wealth and forest areas with the maintenance to forests [7]. In **Figure 13**, the wood biomass source that can be obtained from forests is given as a model.

Revenue in forestry is the annual revenue amount and is calculated in m3 . The amount of revenue in 2015 was determined as 15.942.459 m3 in grove forests and 2.372.162 m3 from coppice forests, with a total of 18.314.621 m3 [7]. The change in forest revenue amounts by years is given in **Figure 14**.

#### **3.1 Production amounts of fuel wood**

The total amount of trees and annual revenue growth of forest areas can be considered as the biomass potential of forests. Thus, the amount of production and unprocessed wood production according to the tree species shows the potential of the production of firewood. **Tables 5** and **6** show the amount of wood that can be produced as fuel according to the forest area and tree types.

#### **3.2 Forest waste bioenergy potential**

It is estimated that available biomass energy potential from waste is about 8.6 million tons of oil equivalent (toe) in Turkey. Furthermore, it is anticipated that these waste biomass have a biogas potential of 1.5–2 Mtoe [10].

#### **Figure 13.**

*Model of wood biomass source that can be obtained from forests [2].*

#### **Figure 14.**

*Forest revenue by years [7].*


**143**

**Range of products**

Sewn shell body volume (m3

Fuel wood

) High forest (from allowable

cut)

Coppice (from allowable cut)

Site clearance, wreck, etc.

Total

**Range of products**

Sewn shell body volume(m3

Fuel wood

High forest (from allowable

cut)

Site clearance, wreck, etc.

Total

> **Table 6.**

*Production amounts of the tree species for volume of wood per species in 2018 [9].*

209,091 1,323,625

69,497

793,986

12,373

9805

238,473

2,447,759

4,890,455

5334

332,170

7432

1605

38,958

594,590

1,728,371

)

2,286,005

506,016

57,851

358,467

4559

8200

139,551

1,074,608

2,354,439

301,162

4,032,484

138,236

49,932

324,418

7,132,237

24,437,797

5491 43,881 *Quercus*

*Carpinus*

*Fagus*

*Populus*

*Alnus*

**Other** 

**Total**

**Final total**

**non-coniferous**

13,164

1,018,659

1,072,410

100,067 **Non-coniferous**

123,057

71,458

2,442,696

754

292,649

662,736

43,024

90,171

38,959

1,133,781

4651

318

8893

8926

5155

1141

29,084

177,316

33,739

12,092

717,120

400,748

57,043

27,731

31,358

1,279,831

29,959

6,541,644

7,443,431

636,806

2,067,953

408,451

17,305,560

*Cedrus*

*Juniperus*

*Pinus brutia*

**Other pinus**

*Picea*

*Abies*

**Other coniferous**

**Total**

*Bioenergy Potential of Turkey's Forest Sources, Biomass Energy Conversion Methods, Products…*

*DOI: http://dx.doi.org/10.5772/intechopen.92974*

**Coniferous**

#### **Table 5.**

*Volume of wood between 2014–2018 [9].*


*Bioenergy Potential of Turkey's Forest Sources, Biomass Energy Conversion Methods, Products… DOI: http://dx.doi.org/10.5772/intechopen.92974*

> **Table 6.**

*Production amounts of the tree species for volume of wood per species in 2018 [9].*

*Renewable Energy - Technologies and Applications*

*Model of wood biomass source that can be obtained from forests [2].*

**Description Unit 2014 2015 2016 2017 2018**

m3 14,923,209 16,637,598 17,009,998 15,521,622 19,080,137

m3 5,257,994 5,022,986 4,877,067 4,359,646 4,890,455

m3 2,120,632 2,176,826 2,203,385 1,926,629 2,442,696

m3 3,137,362 2,846,160 2,673,682 2,433,017 2,447,759

**142**

**Table 5.**

**Figure 13.**

**Figure 14.**

Turkey (industrial wood)

Turkey (fuel wood)

Fuel wood (coniferous)

Fuel wood (non-coniferous)

*Volume of wood between 2014–2018 [9].*

*Forest revenue by years [7].*

**Figure 15.** *Distribution of Turkey's forest waste amount [11].*

The total amount of waste originating from forests was calculated as 4.8 million tons (1.5 Mtoe) in Turkey. The gasification plant capacity that can be installed is estimated to be 600 MW [11]. The energy value of forest waste is estimated to be 859.899 toe/year in Turkey. The number of biomass electricity generation plant in Turkey is 128 units [12]. Wood biomass potential in forests depends on factors such as forest biomass increase, forest area, and forest growth [2]. Therefore, the bioenergy potential is also highly dependent on factors such as forest biomass increase, obtained from forest wastes, forest area, and growth of the forest. **Figure 15** shows the distribution of the amount of Turkey's forest wastes based on the amount of biomass.

### **4. Biomass energy conversion methods, products, and applications**

The majority of biomass energy is used for cooking and heating in households. Approximately 6.5 million houses use wood as the main fuel for heating purposes in Turkey. Moreover, in the paper industry, approximately 60% of the factories' energy needs are obtained from waste wood [5].

There are main processes such as direct combustion, gasification, alcoholic fermentation, pyrolysis, liquefaction, anaerobic digestion, hydrogasification, and transesterification where energy is obtained from biomass. These processes have their own advantages according to the biomass source and the type of energy obtained. If biomass is converted using modern technologies and energy conversion efficiency is ensured, biomass energy could be a primary energy source in the future [4].

Demirbaş [13] classified wood as a second-generation biofuel in the study. Besides, examples of these biofuels are bio-alcohols, bio-oil, bio hydrogen, and bio Fischer-Tropsch diesel. In addition to these, using alternative fuels from biomass as fuel additives can improve fuel properties such as cetane and octane number, viscosity, and density in diesel and gasoline engines. Thus, fuels produced from biomass can be used as alternative fuels in internal combustion engines [14].

Biomass conversion techniques can be applied on biomass materials to obtain solid, liquid, and gaseous fuels. After the conversion process, fuels can be produced with the main products such as biodiesel, biogas, bioethanol, and pyrolytic gas. Besides, by-products such as fertilizer and hydrogen can be also obtained [15].

**145**

**4.1 Thermal process**

gasification, and pyrolysis (**Figure 17**).

*Biomass processing method and products [16].*

*Bioenergy Potential of Turkey's Forest Sources, Biomass Energy Conversion Methods, Products…*

**Biomass Conversion method Fuels Application fields**

Energy crops Direct combustion Hydrogen Heating

Garbage (organic) Gasification Methanol Jet engines

Algae Hydrolysis Synthetic oil, rockets

gas oil

Esterification reaction Diesel fuel Transport vehicles, heating,

anaerobic digestion

Energy forests Biophotolysis Automotive

*Biomass, biomass conversion methods, fuels, and application areas [15].*

Forest wastes Anaerobic digestion Biogas Electric power production,

Pyrolysis Ethanol Heating, transport vehicles

heating

Methane Transport vehicles, heating

Drying

greenhouse cultivation

Alternative biofuels such as biogas and bioethanol fuels can be obtained by the biomass conversion process. Bioethanol can be used instead of oil, and biogas can be used instead of natural gas [16]. Conversion techniques using biomass sources, fuels obtained using these techniques, and application areas are given in **Table 7**. The biomass processing process can be divided into two classes: thermal and biochemical. It can be divided into three subtitles as direct combustion, gasification, and pyrolysis in the thermal process. The biochemical process can be classified under two subtitles as fermentation and anaerobic digestion. **Figure 16** shows the methods and products obtained in the processing processes of biomass [16].

The majority of modern bioenergy plants are use biomass for obtaining heat and power. Developing gasification and pyrolysis bio-oil technology offers much more efficient energy conversion with turbine and combined cycle technologies [3]. Thermal process can be examined under three main headings: burning,

*DOI: http://dx.doi.org/10.5772/intechopen.92974*

Animal waste Fermentation and

Agricultural wastes

Vegetable and animal oils

**Table 7.**

**Figure 16.**

*Bioenergy Potential of Turkey's Forest Sources, Biomass Energy Conversion Methods, Products… DOI: http://dx.doi.org/10.5772/intechopen.92974*


#### **Table 7.**

*Renewable Energy - Technologies and Applications*

*Distribution of Turkey's forest waste amount [11].*

The total amount of waste originating from forests was calculated as 4.8 million tons (1.5 Mtoe) in Turkey. The gasification plant capacity that can be installed is estimated to be 600 MW [11]. The energy value of forest waste is estimated to be 859.899 toe/year in Turkey. The number of biomass electricity generation plant in Turkey is 128 units [12]. Wood biomass potential in forests depends on factors such as forest biomass increase, forest area, and forest growth [2]. Therefore, the bioenergy potential is also highly dependent on factors such as forest biomass increase, obtained from forest wastes, forest area, and growth of the forest. **Figure 15** shows the distribution

of the amount of Turkey's forest wastes based on the amount of biomass.

energy needs are obtained from waste wood [5].

**4. Biomass energy conversion methods, products, and applications**

The majority of biomass energy is used for cooking and heating in households. Approximately 6.5 million houses use wood as the main fuel for heating purposes in Turkey. Moreover, in the paper industry, approximately 60% of the factories'

There are main processes such as direct combustion, gasification, alcoholic fermentation, pyrolysis, liquefaction, anaerobic digestion, hydrogasification, and transesterification where energy is obtained from biomass. These processes have their own advantages according to the biomass source and the type of energy obtained. If biomass is converted using modern technologies and energy conversion efficiency is

Biomass conversion techniques can be applied on biomass materials to obtain solid, liquid, and gaseous fuels. After the conversion process, fuels can be produced with the main products such as biodiesel, biogas, bioethanol, and pyrolytic gas. Besides, by-products such as fertilizer and hydrogen can be also obtained [15].

ensured, biomass energy could be a primary energy source in the future [4]. Demirbaş [13] classified wood as a second-generation biofuel in the study. Besides, examples of these biofuels are bio-alcohols, bio-oil, bio hydrogen, and bio Fischer-Tropsch diesel. In addition to these, using alternative fuels from biomass as fuel additives can improve fuel properties such as cetane and octane number, viscosity, and density in diesel and gasoline engines. Thus, fuels produced from biomass can be used as alternative fuels in internal combustion engines [14].

**144**

**Figure 15.**

*Biomass, biomass conversion methods, fuels, and application areas [15].*

#### **Figure 16.**

*Biomass processing method and products [16].*

Alternative biofuels such as biogas and bioethanol fuels can be obtained by the biomass conversion process. Bioethanol can be used instead of oil, and biogas can be used instead of natural gas [16]. Conversion techniques using biomass sources, fuels obtained using these techniques, and application areas are given in **Table 7**.

The biomass processing process can be divided into two classes: thermal and biochemical. It can be divided into three subtitles as direct combustion, gasification, and pyrolysis in the thermal process. The biochemical process can be classified under two subtitles as fermentation and anaerobic digestion. **Figure 16** shows the methods and products obtained in the processing processes of biomass [16].

#### **4.1 Thermal process**

The majority of modern bioenergy plants are use biomass for obtaining heat and power. Developing gasification and pyrolysis bio-oil technology offers much more efficient energy conversion with turbine and combined cycle technologies [3]. Thermal process can be examined under three main headings: burning, gasification, and pyrolysis (**Figure 17**).

**Figure 17.** *Transformation of biomass in thermal process [17].*

#### *4.1.1 Pyrolysis*

Pyrolysis process is the simplest and oldest method for biomass to gas from. Pyrolysis process is a physical and chemical situation that occurs by heating organic substances up to 500–600°C without oxygen. In this process, gas components, volatile condensates, charcoal, and ash are released. When it rises to high temperature, wood gas and components gas are released by heating the wood up to 900°C in an oxygen-free environment. As a result of pyrolysis, substances such as gases, water, organic compounds, tar, and charcoal are obtained [15, 18].

Pyrolysis is the method of obtaining solid, liquid, and gas products by breaking down the biomass with heat. Slow pyrolysis is a well-known method widely used in the production of charcoal. Fast pyrolysis is the method in which biomass converts more than 75% of liquid bio-oil at high temperatures. This bio-oil chemical composition obtained is very similar to biomass. This bio-oil can be used as renewable fuel in gas turbines, diesel engines, or boilers. Bio-oil has about 60% calorific value of conventional fuel oils by volume [3].

Bio-oil is a liquid fuel obtained by the thermochemical process of biomass. Bio-oil obtained from wood is liquid and dark brown-colored. Its density is 1200 kg/m3 and it is more than the density of biomass and fuel oil. Bio-oil water content is 14–33 wt% by mass and cannot be removed by traditional methods such as distillation. Higher heating value (HHV) is 27 MJ/kg, and it is lower than traditional fuel oil (43–46 MJ/kg) [13]. The conversion of biomass into product by pyrolysis and the process steps of the products obtained are given in **Figure 18**.

#### *4.1.2 Gasification*

Gasification technology is one of the oldest conversion processes, and it has been used for more than 200 years [19]. The gasification process is the method for achieved combustible gas by dissolving solids like carbon-containing biomass at high temperatures. The process up to approximately 500°C in the gasification of organic substances is the pyrolysis phase. Here, carbon, gases (calorific value can be up to 20 MJ/m3 ), and tar are obtained. When heating up to 1000°C, carbon reacts with water vapor to produce CO and H2. Depending on the variable oxygen rate in the raw material, additional oxygen input may not be required for the gasification process. Gasification takes place in a reducing atmosphere with low air oxygen or steam injection. During this process, biomass is burned with the air supplied to the fuel cell under control, and the resulting products include combustible gases such as hydrogen, methane, as well as carbon monoxide, carbon dioxide, and nitrogen. Thus, combustible gases such as carbon monoxide, hydrogen, methane, and low

**147**

**Figure 18.**

**Figure 19.**

*Conversion of biomass to products by pyrolysis [13].*

*Bioenergy Potential of Turkey's Forest Sources, Biomass Energy Conversion Methods, Products…*

amounts of other gases with low or medium calorific value are obtained. After cleaning the gas, it can be used as fuel in gas turbines, gasoline engines, dual fuel

Biomass gasification technology provides the opportunity to convert renewable biomass resources into clean gaseous fuels or synthesis gases. Heat or electricity is produced from these produced gases. In addition to these, there is the potential to produce liquid transportable fuel, hydrogen, or chemicals from them. Gasification

diesel engines, or in fuel cells after purification [3, 15, 18] (**Figure 19**).

*Transformation processes of biomass into products by gasification [19].*

*DOI: http://dx.doi.org/10.5772/intechopen.92974*

*Bioenergy Potential of Turkey's Forest Sources, Biomass Energy Conversion Methods, Products… DOI: http://dx.doi.org/10.5772/intechopen.92974*

#### **Figure 18.**

*Renewable Energy - Technologies and Applications*

*Transformation of biomass in thermal process [17].*

Pyrolysis process is the simplest and oldest method for biomass to gas from. Pyrolysis process is a physical and chemical situation that occurs by heating organic substances up to 500–600°C without oxygen. In this process, gas components, volatile condensates, charcoal, and ash are released. When it rises to high temperature, wood gas and components gas are released by heating the wood up to 900°C in an oxygen-free environment. As a result of pyrolysis, substances such as gases, water,

Pyrolysis is the method of obtaining solid, liquid, and gas products by breaking down the biomass with heat. Slow pyrolysis is a well-known method widely used in the production of charcoal. Fast pyrolysis is the method in which biomass converts more than 75% of liquid bio-oil at high temperatures. This bio-oil chemical composition obtained is very similar to biomass. This bio-oil can be used as renewable fuel in gas turbines, diesel engines, or boilers. Bio-oil has about 60% calorific value of

Bio-oil is a liquid fuel obtained by the thermochemical process of biomass. Bio-oil obtained from wood is liquid and dark brown-colored. Its density is

content is 14–33 wt% by mass and cannot be removed by traditional methods such as distillation. Higher heating value (HHV) is 27 MJ/kg, and it is lower than traditional fuel oil (43–46 MJ/kg) [13]. The conversion of biomass into product by pyrolysis and the process steps of the products obtained are given in **Figure 18**.

Gasification technology is one of the oldest conversion processes, and it has been used for more than 200 years [19]. The gasification process is the method for achieved combustible gas by dissolving solids like carbon-containing biomass at high temperatures. The process up to approximately 500°C in the gasification of organic substances is the pyrolysis phase. Here, carbon, gases (calorific value can be

with water vapor to produce CO and H2. Depending on the variable oxygen rate in the raw material, additional oxygen input may not be required for the gasification process. Gasification takes place in a reducing atmosphere with low air oxygen or steam injection. During this process, biomass is burned with the air supplied to the fuel cell under control, and the resulting products include combustible gases such as hydrogen, methane, as well as carbon monoxide, carbon dioxide, and nitrogen. Thus, combustible gases such as carbon monoxide, hydrogen, methane, and low

and it is more than the density of biomass and fuel oil. Bio-oil water

), and tar are obtained. When heating up to 1000°C, carbon reacts

organic compounds, tar, and charcoal are obtained [15, 18].

conventional fuel oils by volume [3].

*4.1.1 Pyrolysis*

**Figure 17.**

1200 kg/m3

*4.1.2 Gasification*

up to 20 MJ/m3

**146**

*Conversion of biomass to products by pyrolysis [13].*

#### **Figure 19.**

*Transformation processes of biomass into products by gasification [19].*

amounts of other gases with low or medium calorific value are obtained. After cleaning the gas, it can be used as fuel in gas turbines, gasoline engines, dual fuel diesel engines, or in fuel cells after purification [3, 15, 18] (**Figure 19**).

Biomass gasification technology provides the opportunity to convert renewable biomass resources into clean gaseous fuels or synthesis gases. Heat or electricity is produced from these produced gases. In addition to these, there is the potential to produce liquid transportable fuel, hydrogen, or chemicals from them. Gasification

**Figure 20.** *Products obtained from biomass by Fischer-Tropsch synthesis [20].*

is a promising energy conversion technology with its flexible, efficient, and environmentally adaptable features [17]. Besides, the most important feature of gasification is its high electrical efficiency. In the future, it is expected to be used instead of natural gas or diesel fuel in gas turbines or fuel cells, industrial boilers, and furnaces, to replace gasoline or diesel in internal combustion engines [19] (**Figure 20**).

## *4.1.3 Combustion*

The process of biomass giving a fast chemical reaction with oxygen is called burning. As a result of combustion, heat, carbon dioxide, water vapor and some metal oxides are given to the environment [15]. The biomass and full combustion components are given in **Figure 21**.

Industrial and commercial combustion plants can burn a wide variety of fuels, from tree biomass to urban solid waste. Furnaces are the simplest combustion technology, and biomass burns in a combustion chamber. Combustion technology can be divided into two main categories as grate burner and fluid bed burner. In biomass combustion plants, a high-temperature and high-pressure steam is obtained as a result of combustion. This steam is passed through the turbine and converted into electrical energy with efficiency in the range of 17–25%. It can be increased up to 85% with efficient cogeneration systems [3, 19].

Pellets are generally solid wood particles with a cylindrical diameter of 10 mm and a length of less than 35 mm. Pellets produced from wood or waste wood are used to generate electricity in cogeneration systems, for heating in residences and industry. Wood pellets are the fuel with the highest thermal value after coal [22]. A comparison of the higher heat values of biomass and coal are given in **Table 8**.

**149**

**4.2 Biological process**

*4.2.1 Fermentation*

**Figure 21.**

**Table 8.**

*The components of the biomass [21].*

*4.2.2 Digestion*

*Bioenergy Potential of Turkey's Forest Sources, Biomass Energy Conversion Methods, Products…*

It contains hemicellulose and lignin in different amounts in the biomass. Glucose

can be obtained from cellulose using enzymes with chemical hydrolysis or after enzymatic hydrolysis with chemical processes. This process must be done with extreme care, as glucose can sometimes degrade during chemical hydrolysis. By fermentation of glucose, many chemical products can be obtained such as ethanol,

Anaerobic digestion is a biological process and can take place in a completely oxygen-free environment. It is done by microorganisms that can live in an oxygen-

Biomass can be separated by microorganisms through fermentation in an oxygen-free environment. End of the fermentation process, a valuable fertilizer, and gases such as methane and carbon dioxide products can be obtained [15].

heat→ methane + carbon dioxide + hydrogen, sulfur + stable,fertilizer + bacteria (2)

acetone, and butanol which are equivalent to products from crude oil [15].

**Fuel form HHV (MJ/kg)** Wood 10–20 Vineyard pruning 14–18 Rice husk 12–14 Sawdust 12 Wood pellets 20 Coal 28

free environment. The process is given in Eq. (2): Organic matter <sup>+</sup> bacteria <sup>+</sup> water ⎯

*A comparison of the higher heat values of biomass and coal [22].*

*DOI: http://dx.doi.org/10.5772/intechopen.92974*

*Bioenergy Potential of Turkey's Forest Sources, Biomass Energy Conversion Methods, Products… DOI: http://dx.doi.org/10.5772/intechopen.92974*

#### **Figure 21.**

*Renewable Energy - Technologies and Applications*

is a promising energy conversion technology with its flexible, efficient, and environmentally adaptable features [17]. Besides, the most important feature of gasification is its high electrical efficiency. In the future, it is expected to be used instead of natural gas or diesel fuel in gas turbines or fuel cells, industrial boilers, and furnaces,

The process of biomass giving a fast chemical reaction with oxygen is called burning. As a result of combustion, heat, carbon dioxide, water vapor and some metal oxides are given to the environment [15]. The biomass and full combustion

Industrial and commercial combustion plants can burn a wide variety of fuels, from tree biomass to urban solid waste. Furnaces are the simplest combustion technology, and biomass burns in a combustion chamber. Combustion technology can be divided into two main categories as grate burner and fluid bed burner. In biomass combustion plants, a high-temperature and high-pressure steam is obtained as a result of combustion. This steam is passed through the turbine and converted into electrical energy with efficiency in the range of 17–25%. It can be increased up to

Pellets are generally solid wood particles with a cylindrical diameter of 10 mm and a length of less than 35 mm. Pellets produced from wood or waste wood are used to generate electricity in cogeneration systems, for heating in residences and industry. Wood pellets are the fuel with the highest thermal value after coal [22]. A comparison of the higher heat values of biomass and coal are given in **Table 8**.

to replace gasoline or diesel in internal combustion engines [19] (**Figure 20**).

**148**

*4.1.3 Combustion*

**Figure 20.**

components are given in **Figure 21**.

85% with efficient cogeneration systems [3, 19].

*Products obtained from biomass by Fischer-Tropsch synthesis [20].*

*The components of the biomass [21].*


#### **Table 8.**

*A comparison of the higher heat values of biomass and coal [22].*

## **4.2 Biological process**

#### *4.2.1 Fermentation*

It contains hemicellulose and lignin in different amounts in the biomass. Glucose can be obtained from cellulose using enzymes with chemical hydrolysis or after enzymatic hydrolysis with chemical processes. This process must be done with extreme care, as glucose can sometimes degrade during chemical hydrolysis. By fermentation of glucose, many chemical products can be obtained such as ethanol, acetone, and butanol which are equivalent to products from crude oil [15].

#### *4.2.2 Digestion*

Anaerobic digestion is a biological process and can take place in a completely oxygen-free environment. It is done by microorganisms that can live in an oxygenfree environment. The process is given in Eq. (2):

Organic matter <sup>+</sup> bacteria <sup>+</sup> water ⎯ heat→ methane + carbon dioxide + hydrogen, sulfur + stable,fertilizer + bacteria (2)

Biomass can be separated by microorganisms through fermentation in an oxygen-free environment. End of the fermentation process, a valuable fertilizer, and gases such as methane and carbon dioxide products can be obtained [15].

Anaerobic digestion (AD) is a process of producing flammable gas, consisting of methane and carbon dioxide at a rate of 60:40 using microbes in an oxygen-free environment. Therefore, the biogas production process is a complex and sensitive process that contains many microorganism groups. Biogas is a flammable gas formed by decomposing biological wastes in an oxygen-free environment. Biogas approximately contains 50–60% methane gas. Biogas is a colorless, flammable gas. In addition to this, biogas consists of its main components such as methane and carbon dioxide. Besides, it contains a small amount of hydrogen sulfide, nitrogen, oxygen, and carbon monoxide. Generally, 40–60% of organic matter is converted to biogas. The general composition of biogas consists of 60% CH4 and 40% CO2, and its thermal value is 17–25 MJ/m3 . The remaining waste is an odorless solid or liquid waste suitable for use as fertilizer. After producing methane gas, methane gas can be used instead of LPG with very small changes. This gas can be used in spark ignition engines, gas turbines, and fuel cells [3, 16, 23, 24]. The components of biogas are given in **Table 9**.


## **Table 9.**

*Composition of biogas [24].*

Biogas is a gaseous fuel as an alternative to natural gas. Thus, it can be used in the following fields: direct heating, motor fuel, turbine fuel power generation, fuel cells, additives for natural gas, and in the production of chemicals [23]. Flow diagrams of biogas production facilities are given in **Figures 22** and **23**.

## *4.2.3 Biophotolysis*

Hydrogen and oxygen can be obtained by the biophotolysis process using some microscopic algae. These algae use solar energy in seawater, so they can work as a kind of solar cell. Thus, the microscopic algae can separate seawater photosynthetically to hydrogen and oxygen [15].

**151**

*Bioenergy Potential of Turkey's Forest Sources, Biomass Energy Conversion Methods, Products…*

The study concludes that biomass energy in Turkey is seen as one of the most sustainable and promising renewable energy sources. Forest bioenergy potential can be converted to alternative biofuels. This process consists of the most common biomass conversion methods such as thermal processes, biological processes, and biophotolysis processes. The thermal processes consist of pyrolysis, gasification, and combustion, while the biological processes are fermentation and anaerobic digestion. Thus, forest bioenergy potential can be used for producing energy. In this regard, forest wastes or forest biomass can be turned into pellets and used in electricity generation in power plants. In addition to this, pyrolysis, gasification, fermentation and anaerobic digestion methods, alcohol, and biogas can be produced from forest wastes and used in the residential industry and transportation. Especially, bio-oils and bio-alcohols can be used in internal combustion engines, furnaces, or boilers as fuel. Besides, biogas also is used as a fuel in households or industry. Thus, Turkey can be reduced to its dependence on foreign energy demand due to the advantage of the rich forest resources. Besides, it is obvious that rich forest resources will contribute to both the ecological and socioeconomic structures of countries. Overall, the rich forest biomass potential is not only contributed to

countries' economic field but also the ecological and socio-economic.

The author would like to thank Amasya University.

*DOI: http://dx.doi.org/10.5772/intechopen.92974*

**5. Conclusions**

*Flow diagram of dry fermentation [24].*

**Figure 23.**

**Acknowledgements**

CH2O carbohydrate CH4 methane

MW megawatt

HHV higher heating value (MJ/kg) LPG liquefied petroleum gas Mtoe million tons of oil equivalent

**Abbreviations**

**Figure 22.** *Flow diagram of the biogas production facility [24].*

*Bioenergy Potential of Turkey's Forest Sources, Biomass Energy Conversion Methods, Products… DOI: http://dx.doi.org/10.5772/intechopen.92974*

**Figure 23.** *Flow diagram of dry fermentation [24].*

## **5. Conclusions**

*Renewable Energy - Technologies and Applications*

Anaerobic digestion (AD) is a process of producing flammable gas, consisting of methane and carbon dioxide at a rate of 60:40 using microbes in an oxygen-free environment. Therefore, the biogas production process is a complex and sensitive process that contains many microorganism groups. Biogas is a flammable gas formed by decomposing biological wastes in an oxygen-free environment. Biogas approximately contains 50–60% methane gas. Biogas is a colorless, flammable gas. In addition to this, biogas consists of its main components such as methane and carbon dioxide. Besides, it contains a small amount of hydrogen sulfide, nitrogen, oxygen, and carbon monoxide. Generally, 40–60% of organic matter is converted to biogas. The general composition of biogas consists of 60% CH4 and 40% CO2, and its thermal

for use as fertilizer. After producing methane gas, methane gas can be used instead of LPG with very small changes. This gas can be used in spark ignition engines, gas turbines, and fuel cells [3, 16, 23, 24]. The components of biogas are given in **Table 9**.

Biogas is a gaseous fuel as an alternative to natural gas. Thus, it can be used in the following fields: direct heating, motor fuel, turbine fuel power generation, fuel cells, additives for natural gas, and in the production of chemicals [23]. Flow

Hydrogen and oxygen can be obtained by the biophotolysis process using some microscopic algae. These algae use solar energy in seawater, so they can work as a kind of solar cell. Thus, the microscopic algae can separate seawater photosyntheti-

diagrams of biogas production facilities are given in **Figures 22** and **23**.

. The remaining waste is an odorless solid or liquid waste suitable

Methane, CH4 55–75% Carbon dioxide, CO2 25–45% Carbon monoxide, CO 0–0.3% Nitrogen, N2 1–5% Hydrogen, H2 0–3% Hydrogen sulfide, H2S 0.1–0.5% Oxygen, O2 Traces %

**150**

**Figure 22.**

**Table 9.**

*Composition of biogas [24].*

*4.2.3 Biophotolysis*

cally to hydrogen and oxygen [15].

*Flow diagram of the biogas production facility [24].*

value is 17–25 MJ/m3

The study concludes that biomass energy in Turkey is seen as one of the most sustainable and promising renewable energy sources. Forest bioenergy potential can be converted to alternative biofuels. This process consists of the most common biomass conversion methods such as thermal processes, biological processes, and biophotolysis processes. The thermal processes consist of pyrolysis, gasification, and combustion, while the biological processes are fermentation and anaerobic digestion. Thus, forest bioenergy potential can be used for producing energy. In this regard, forest wastes or forest biomass can be turned into pellets and used in electricity generation in power plants. In addition to this, pyrolysis, gasification, fermentation and anaerobic digestion methods, alcohol, and biogas can be produced from forest wastes and used in the residential industry and transportation. Especially, bio-oils and bio-alcohols can be used in internal combustion engines, furnaces, or boilers as fuel. Besides, biogas also is used as a fuel in households or industry. Thus, Turkey can be reduced to its dependence on foreign energy demand due to the advantage of the rich forest resources. Besides, it is obvious that rich forest resources will contribute to both the ecological and socioeconomic structures of countries. Overall, the rich forest biomass potential is not only contributed to countries' economic field but also the ecological and socio-economic.

## **Acknowledgements**

The author would like to thank Amasya University.

### **Abbreviations**


*Renewable Energy - Technologies and Applications*

## **Author details**

Selçuk Sarıkoç Taşova Vocational School, Amasya University, Amasya, Turkey

\*Address all correspondence to: sarikocselcuk@gmail.com

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

**153**

*Bioenergy Potential of Turkey's Forest Sources, Biomass Energy Conversion Methods, Products…*

2019]

26 December 2019]

30 December 2019]

30 December 2019]

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[10] Republic of Turkey Ministry of Energy and Natural Resources. Info Bank, Energy, Biomass, 2019. Available from: https://www.enerji.gov.tr/ tr-TR/Sayfalar/Biyokutle [Accessed:

[11] Republic of Turkey Energy and Natural Resources Ministry and General Directorate of Energy Affairs. Home\Renewable Energy\Biomass\ Turkey Forest Biomass Potential Source, 2019. Available from: http:// www.yegm.gov.tr/yenilenebilir/ tur\_or\_kay\_biyo\_pot.aspx [Accessed:

[12] Republic of Turkey Energy and Natural Resources Ministry and General Directorate of Renewable Energy. Biomass Energy Potential Atlas of Turkey. 2019. Available from: http://bepa.yegm.gov.tr/ [Accessed:

*DOI: http://dx.doi.org/10.5772/intechopen.92974*

[1] Republic of Turkey Energy and Natural Resources Ministry and General Directorate of Energy Affairs. Home\ Renewable Energy\Biomass\What Is the Biomass Energy?, 2020. Available from: http://www.yegm.gov.tr/yenilenebilir/ biyokutle\_enerjisi.aspx [Accessed:

[2] Lauri P et al. Woody biomass energy potential in 2050. Energy Policy.

[3] Schuck S. Bioenergy as a sustainable energy source. Australian Journal of Multi-Disciplinary Engineering.

[4] Chang J et al. A review on the energy production, consumption, and prospect of renewable energy in China. Renewable and Sustainable Energy

[5] Baris K, Kucukali S. Availability of renewable energy sources in Turkey: Current situation, potential, government policies and the EU perspective. Energy Policy.

[6] Republic of Turkey General Directorate of Forestry, Republic of Turkey Ministry of Forestry and Water Affairs. General Directorate of Forestry—E-Library Publications, Forest of Turkey, 2019. Available from: https://www.ogm.gov.tr/ekutuphane/ Yayinlar/Forests%20of%20TURKEY. pdf [Accessed: 27 December 2019]

[7] Republic of Turkey General Directorate of Forestry, Republic of Turkey Ministry of Forestry and Water Affairs. General Directorate of Forestry—E-Library Publications, Turkey Forest Wealth-2015, 2019. Available from: https://www. ogm.gov.tr/ekutuphane/Yayinlar/ T%C3%BCrkiye%20Orman%20Varl%C 4%B1%C4%9F%C4%B1-2016-2017.pdf

[Accessed: 27 December 2019]

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2014;**66**:19-31

2015;**5**(1):69-74

2012;**42**:377-391

*Bioenergy Potential of Turkey's Forest Sources, Biomass Energy Conversion Methods, Products… DOI: http://dx.doi.org/10.5772/intechopen.92974*

## **References**

*Renewable Energy - Technologies and Applications*

**152**

**Author details**

Selçuk Sarıkoç

Taşova Vocational School, Amasya University, Amasya, Turkey

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

\*Address all correspondence to: sarikocselcuk@gmail.com

provided the original work is properly cited.

[1] Republic of Turkey Energy and Natural Resources Ministry and General Directorate of Energy Affairs. Home\ Renewable Energy\Biomass\What Is the Biomass Energy?, 2020. Available from: http://www.yegm.gov.tr/yenilenebilir/ biyokutle\_enerjisi.aspx [Accessed: 14 March 2020]

[2] Lauri P et al. Woody biomass energy potential in 2050. Energy Policy. 2014;**66**:19-31

[3] Schuck S. Bioenergy as a sustainable energy source. Australian Journal of Multi-Disciplinary Engineering. 2015;**5**(1):69-74

[4] Chang J et al. A review on the energy production, consumption, and prospect of renewable energy in China. Renewable and Sustainable Energy Reviews. 2003;**7**(5):453-468

[5] Baris K, Kucukali S. Availability of renewable energy sources in Turkey: Current situation, potential, government policies and the EU perspective. Energy Policy. 2012;**42**:377-391

[6] Republic of Turkey General Directorate of Forestry, Republic of Turkey Ministry of Forestry and Water Affairs. General Directorate of Forestry—E-Library Publications, Forest of Turkey, 2019. Available from: https://www.ogm.gov.tr/ekutuphane/ Yayinlar/Forests%20of%20TURKEY. pdf [Accessed: 27 December 2019]

[7] Republic of Turkey General Directorate of Forestry, Republic of Turkey Ministry of Forestry and Water Affairs. General Directorate of Forestry—E-Library Publications, Turkey Forest Wealth-2015, 2019. Available from: https://www. ogm.gov.tr/ekutuphane/Yayinlar/ T%C3%BCrkiye%20Orman%20Varl%C 4%B1%C4%9F%C4%B1-2016-2017.pdf [Accessed: 27 December 2019]

[8] Republic of Turkey General Directorate of Forestry, Republic of Turkey Ministry of Forestry and Water Affairs. General Directorate of Forestry—E-Library Publications, Forest Atlas, 2019. Available from: https://www.ogm.gov.tr/ekutuphane/ Yayinlar/Orman%20Atlasi.pdf [Accessed: 27 December 2019]

[9] Republic of Turkey Ministry of Agriculture and Forestry General Directorate for Forest Management. General Directorate of Forestry—E-Library Publications, Statistics-Forestry Statistics 2018, 2019. Available from: https://www.ogm.gov.tr/ekutuphane/ Sayfalar/Istatistikler.aspx?RootFolder= %2Fekutuphane%2FIstatistikler%2FOr manc%C4%B1l%C4%B1k%20%C4%B 0statistikleri&FolderCTID=0x0120003 01D182F8CB9FC49963274E712A2DC00 &View={4B3B693B-B532-4C7F-A2D0- 732F715C89CC [Accessed: 30 December 2019]

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[12] Republic of Turkey Energy and Natural Resources Ministry and General Directorate of Renewable Energy. Biomass Energy Potential Atlas of Turkey. 2019. Available from: http://bepa.yegm.gov.tr/ [Accessed: 30 December 2019]

[13] Demirbas A. Competitive liquid biofuels from biomass. Applied Energy. 2011;**88**(1):17-28

[14] Sarıkoç S. Chapter 2: Fuels of the diesel-gasoline engines and their properties. In: Viskup R, editor. Diesel and Gasoline Engines. London: IntechOpen; 2020. pp. 1-17

[15] Republic of Turkey Energy and Natural Resources Ministry and General Directorate of Energy Affairs. Home\ Renewable Energy\Biomass\Biomass Cycle Technologies, 2019. Available from: http://www.yegm.gov.tr/ yenilenebilir/biyokutle\_cevrim\_tekno. aspx [Accessed: 30 December 2019]

[16] Hamawand I et al. Bioenergy from cotton industry wastes: A review and potential. Renewable and Sustainable Energy Reviews. 2016;**66**:435-448

[17] Demirbas A. Biofuels securing the planet's future energy needs. Energy Conversion and Management. 2009;**50**(9):2239-2249

[18] Republic of Turkey Energy and Natural Resources Ministry and General Directorate of Energy Affairs. Home\Renewable Energy\Biomass\ Gasification, 2020. Available from: http://www.yegm.gov.tr/yenilenebilir/ biyo\_gazlastirme.aspx [Accessed: 14 March 2020]

[19] Bilgen S et al. A perspective for potential and technology of bioenergy in Turkey: Present case and future view. Renewable and Sustainable Energy Reviews. 2015;**48**:228-239

[20] Demirbas A. Biofuels sources, biofuel policy, biofuel economy and global biofuel projections. Energy Conversion and Management. 2008;**49**(8):2106-2116

[21] Dahlquist E. Biomass as Energy Source—Resources, Systems and Applications. Boca Raton, FL: Taylor & Francis; 2012. p. 287

[22] Nulocnes LJR, Matias JCO, Catalão JPS. Mixed biomass pellets for thermal energy production: A review of combustion models. Applied Energy. 2014;**127**:135-140

[23] Küçükçalı R. Yenilenebilir Enerjiler Alternatif Sistemler Isısan Çalışmaları No: 375. İstanbul, Türkiye: Isısan Akademi; 2008. p. 704

[24] Karellas S, Boukis I, Kontopoulos G. Development of an investment decision tool for biogas production from agricultural waste. Renewable and Sustainable Energy Reviews. 2010;**14**(4):1273-1282

**155**

**Chapter 10**

**Abstract**

*and Awani Bhushan*

renewable energy, bio-energy

**1. Introduction**

Combustion Characteristics

Biomass: A Short Review

and Behaviour of Agricultural

*Swapan Suman, Anand Mohan Yadav, Nomendra Tomar* 

Biomass energy is one of the alternative sources of energy, which is particularly accessible in huge quantity worldwide in rural areas. Globally, solid biomass waste is the fourth as an energy resource after coil, oil and gas, which was providing approximately 14% of the world's energy needs. The potential of biomass materials depends on feedstock quantities and their composition. The use of biomass materials as energy source provides extensive benefits as far as the environment is concerned. The agricultural biomass materials absorb carbon dioxide (CO2) during growth and emit it during combustion. Utilization of these types of wastes in various applications is in the form of a renewable and CO2-neutral fuel. The physicochemical and structural analyses of agricultural biomass differ significantly with the feedstock types. This review study provides an alternative approach and better understanding to utilize huge amount of energy stored in biomass as the substitute of fossil fuels and also it should play an important role in sustainable energy systems as a component of a renewable energy mix.

**Keywords:** biomass, combustion characteristics, physicochemical properties,

Energy is most imperative need of human life. Energy consumption pattern indicates the social and economic development of any country [1]. Primary energy sources (natural gas, oil, coal) are considered as the main energy sources in the world [2]. **Table 1** shows the world's primary energy demand that is projected until 2035. As clearly can be seen, as the total worldwide demands for energy keep increasing year-by-year, biomass and other renewables are expected to gain significant contributions in meeting these demands. The world's depleting fossil fuels and increasing Green House Gas (GHG) emissions have given rise to much research into renewable and cleaner energy. In 2010, 76% of total GHG emissions, CO2 remain the major anthropogenic GHG with the increasing fossil CO2 emissions more than trebling from 420 GtCO2 in 1970–1300 GtCO2 in 2010 [3]. Since 2000, emissions of anthropogenic CO2 have risen by more than 3% per year with the net addition likely

The concern over global warming and climate changes has stimulated a search for alternatives of energy that are renewable and environment friendly. There

to rise to 8–12 GtC by 2020 and as much as 6–23 GtC by 2050 [4, 5].

## **Chapter 10**

*Renewable Energy - Technologies and Applications*

[22] Nulocnes LJR, Matias JCO, Catalão JPS. Mixed biomass pellets for thermal energy production: A review of combustion models. Applied Energy.

[23] Küçükçalı R. Yenilenebilir Enerjiler Alternatif Sistemler Isısan Çalışmaları No: 375. İstanbul, Türkiye: Isısan

[24] Karellas S, Boukis I, Kontopoulos G. Development of an investment decision

tool for biogas production from agricultural waste. Renewable and Sustainable Energy Reviews.

2014;**127**:135-140

Akademi; 2008. p. 704

2010;**14**(4):1273-1282

[13] Demirbas A. Competitive liquid biofuels from biomass. Applied Energy.

[14] Sarıkoç S. Chapter 2: Fuels of the diesel-gasoline engines and their properties. In: Viskup R, editor. Diesel and Gasoline Engines. London:

[15] Republic of Turkey Energy and Natural Resources Ministry and General Directorate of Energy Affairs. Home\ Renewable Energy\Biomass\Biomass Cycle Technologies, 2019. Available from: http://www.yegm.gov.tr/

yenilenebilir/biyokutle\_cevrim\_tekno. aspx [Accessed: 30 December 2019]

[16] Hamawand I et al. Bioenergy from cotton industry wastes: A review and potential. Renewable and Sustainable Energy Reviews. 2016;**66**:435-448

[17] Demirbas A. Biofuels securing the planet's future energy needs. Energy Conversion and Management.

[18] Republic of Turkey Energy and Natural Resources Ministry and General Directorate of Energy Affairs. Home\Renewable Energy\Biomass\ Gasification, 2020. Available from: http://www.yegm.gov.tr/yenilenebilir/ biyo\_gazlastirme.aspx [Accessed:

[19] Bilgen S et al. A perspective for potential and technology of bioenergy in Turkey: Present case and future view. Renewable and Sustainable Energy

[20] Demirbas A. Biofuels sources, biofuel policy, biofuel economy and global biofuel projections. Energy Conversion and Management.

[21] Dahlquist E. Biomass as Energy Source—Resources, Systems and Applications. Boca Raton, FL: Taylor &

Reviews. 2015;**48**:228-239

2008;**49**(8):2106-2116

Francis; 2012. p. 287

2009;**50**(9):2239-2249

14 March 2020]

IntechOpen; 2020. pp. 1-17

2011;**88**(1):17-28

**154**
