**3. Production processes of biochar and biochar efficiency**

Biochars could be made either by burying organic waste particles in the soil or from pyrolysis of selected types of waste and fuel under different temperature conditions ranging from 260°C to about 600°C [4, 14]. When wastes are buried under the soil, for example wooden debris, sewage, sawdust and other similar wastes, they are placed in a shallow garden bed of 1–2 feet, smoked and covered with soil of up to 1 inch [12]. The waste material is thereafter left to char before the fire is put out. This leftover material referred to as biochar, is used in the improvement of soil composition. Likewise, the pyrolysis process involves the anaerobic digestion of biomass, usually between 260°C to about 600°C [4, 13–16]. These wastes could be regarded as raw materials for the pyrolytic process of making biochar. Thus, these waste materials are major constituents in the chemical and structural properties of biochars. Example of the raw materials for the pyrolytic process is categorized into three groups which include the following:


The composition of the raw materials determines the structural and chemical properties of the biochar. The processes involved in the biochar production through gasification procedures should be reviewed occasionally to avoid difficulty in the production of biofuel. The type of bioreactor and range of products should also be simplified enough to allow for the efficiency of the production process and technological reliability.

The high temperature enhances the production of hemicelluloses and depolymerization of celluloses in the biofuel production. The collisions alongside the high

**147**

*Enhancement of Soil Health Using Biochar DOI: http://dx.doi.org/10.5772/intechopen.92711*

grade biochar production.

well as sequestering carbon.

regarded as waste. These conditions are:

heat transfer and the distribution of products.

**4. Soil fertility and biochar soil amendment**

level of temperature are effective enough to prevent dehydration reactions; unlike the low temperature rates where the collisions always produce dehydration reactions [18]. Similarly, the fast and slow heating rate affects the product efficiency and volatility of the carbonated material. A slow heating rate has been shown to reduce the rate at which volatile substances from the production materials escape into the atmosphere causing more secondary reactions take place; while the fast heating rate increases volatility of volatile compounds thereby less secondary reactions take place [19]. Thus, more secondary reactions definitely result into high

However, the most important properties are the chemical and physical properties. The raw materials with high lignin content have a very high tendency of producing efficient biochar but at relatively moderate temperatures. Furthermore, biomass materials that are relatively volatile produce efficient and large amount of pyrolitic gas and biofuel [20]. Furthermore, the amount of moisture in the raw materials for biochar determines the speed of the process of

Soil fertility is a condition whereby a particular soil is physically, chemically and biologically stable with the required ecosystem intact without disrupting it. The state of complete functioning of the ecosystem is still intact in a soil termed to have the soil quality. There must be favorable interactions between the abiotic and biotic elements of the soil's ecosystem and still serve the purpose of crop production for sustainability [21]. A soil may have a complete ecosystem, yet not serving the purpose of crop production. Thus, soil fertility depends on the holistic process of managing the soil and at the same time keeping a robust biodiversity. Part of this process is through the application of natural carbonrich materials like biochar as soil amendments [22]. The natural organic material added to the soil should fulfill the conditions of sustaining life, increasing biodiversity, keeping good water and air quality, beneficial to human health, as

**5. Application of biochar and environmental safety standards**

• If the specified waste is commonly used for certain purposes

• If the product is being traded in the market or has market value

Legal standards, ab initio have been set on environmental matters, part of which includes biochar. Biochar in many countries is regarded as waste or fertilizers which have been guided by regulations and legal statements. Although, biochar may not appear in the legislation of many countries, even in the European Union (EU), but the law and regulations about waste control is in the offing of the constitutions of many nations across the world; though a few have gone beyond implementation. In reality, biochar is considered as waste, but in several literatures, it is usually considered as a by-product of carbonization. Waste, according to the EU, is defined as any product that is supposed to be discarded or any substance the holder proposes to discard. The Waste Act of the EU therefore specifies that any waste that undergoes a recycling process and meet the following conditions may not be

### *Enhancement of Soil Health Using Biochar DOI: http://dx.doi.org/10.5772/intechopen.92711*

*Applications of Biochar for Environmental Safety*

*The porous nature of biochar (Burrell et al. [14]).*

**Figure 1.**

three groups which include the following:

fuel material for the pyrolytic process.

• Sewage sludge: examples of these are tyres.

loose in structure [4, 7].

**3. Production processes of biochar and biochar efficiency**

Biochars could be made either by burying organic waste particles in the soil or from pyrolysis of selected types of waste and fuel under different temperature conditions ranging from 260°C to about 600°C [4, 14]. When wastes are buried under the soil, for example wooden debris, sewage, sawdust and other similar wastes, they are placed in a shallow garden bed of 1–2 feet, smoked and covered with soil of up to 1 inch [12]. The waste material is thereafter left to char before the fire is put out. This leftover material referred to as biochar, is used in the improvement of soil composition. Likewise, the pyrolysis process involves the anaerobic digestion of biomass, usually between 260°C to about 600°C [4, 13–16]. These wastes could be regarded as raw materials for the pyrolytic process of making biochar. Thus, these waste materials are major constituents in the chemical and structural properties of biochars. Example of the raw materials for the pyrolytic process is categorized into

• Coal: charcoal can be made from coal to produce biochar. Apart from coal, charcoal can be made from peat, wood and petroleum. One of the common raw materials for charcoal is coal. The presence of solid coal increases the efficiency of the production of good biochar [17]. However, coal could also be used as a

• Biomass: example of biomass is wood, plant debris and organic matter. Biomass is one of the most important raw materials for pyrolytic production of biochar. It could be homogenous or heterogeneous in composition, and could either have a high or low humidity. The biomass could either be strongly bonded or

The composition of the raw materials determines the structural and chemical properties of the biochar. The processes involved in the biochar production through gasification procedures should be reviewed occasionally to avoid difficulty in the production of biofuel. The type of bioreactor and range of products should also be simplified enough to allow for the efficiency of the production process and techno-

The high temperature enhances the production of hemicelluloses and depolymerization of celluloses in the biofuel production. The collisions alongside the high

**146**

logical reliability.

level of temperature are effective enough to prevent dehydration reactions; unlike the low temperature rates where the collisions always produce dehydration reactions [18]. Similarly, the fast and slow heating rate affects the product efficiency and volatility of the carbonated material. A slow heating rate has been shown to reduce the rate at which volatile substances from the production materials escape into the atmosphere causing more secondary reactions take place; while the fast heating rate increases volatility of volatile compounds thereby less secondary reactions take place [19]. Thus, more secondary reactions definitely result into high grade biochar production.

However, the most important properties are the chemical and physical properties. The raw materials with high lignin content have a very high tendency of producing efficient biochar but at relatively moderate temperatures. Furthermore, biomass materials that are relatively volatile produce efficient and large amount of pyrolitic gas and biofuel [20]. Furthermore, the amount of moisture in the raw materials for biochar determines the speed of the process of heat transfer and the distribution of products.
