**2. Biomass**

Biomass waste stream can be categorized into proteineous (animal-based), lignocellulosic (plant-based), municipal solid (biogenic and non biogenic),

*Pyrolysis: A Convenient Route for Production of Eco-Friendly Fuels and Precursors for Chemical… DOI: http://dx.doi.org/10.5772/intechopen.101068*

industrial (sewage sludge) and other wastes. They are referred to as feedstock in bio-refinery. Biomass based on animal and plant residues (briefly described in subsections 2.1–2.2) is an area where researchers are currently exploiting for possibility of obtaining sustainable and environmental friendly alternative to fossil fuels/ precursors for chemical and allied industries. The use of biomass for these aforementioned purposes reduces demand for fossil fuels, their derivatives and makes our environment greener [1].

## **2.1 Animal-based biomass**

Animal wastes, such as blood, bones, crab shells, hairs, horns, dung, etc. are by-products of livestock rearing. Often seen livestock that generate these wastes are cattle, sheep, chickens, goats, crabs and pigs (**Table 1**). They have been used in raw or pyrolyzed form as source of energy and raw materials for industrial productions by several researchers. Adetuyi and Jabar [9] are among the researchers that have used carbonized animal bone for treatment of wastewater. **Table 1** shows list and applications of some animal-based biomass.

### **2.2 Lignocellulose-based biomass**

Lignocellulosic biomass is carbonaceous plant materials containing lignin and cellulose as major constituents, other are hemicellulose, pectin and other extractives as stated earlier [2, 12].

These compositions of biomass vary from plant species to another. Variation equally exists between/among different parts from the same plant. Factors responsible for this variation are in introduction section [4]. List of some biomasses with their compositions are presented at **Table 2**.

Lignocellulose can be categorized as woody, herbaceous and aquatic biomass [17]. These biomasses have been modified by many researchers for production of biofuels and starting materials for chemical industry.

### *2.2.1 Woody biomass*

These are plant-based resources obtainable from forest; they include trees, leaves, limbs, needles, tops and their residues [17]. Less than two-third of the woody biomasses is converted to timber, others end up as wastes in the forest. The occurrence of huge wastes might be as a result of inappropriate harvesting technique or equipment. Utilization of these wastes called residues as bioenergy for fuel and for generation of raw materials for furniture, pulp and paper industries will be a good


### **Table 1.** *Animal-based biomass and applications.*


### **Table 2.**

*Chemical composition of some selected lignocellulose.*

waste management approach in the forest. Consequently, this conversion of wastes to wealth will reduce rate of deforestation for fuels and industrial precursors [18].

### *2.2.2 Herbaceous biomass*

Herbaceous is non-woody biomass called annual crops. They include rice, wheat, sorghum, maize, millet, groundnut, soyabean etc. After harvesting, their residues do not constitute much treat to the environment, as they are grown and their residues decay within a year. Alternatively, their residues can be utilized for production of bio-gas, bio-oil and bio-chair as bio-fuels and bio-chemical raw materials for chemical and allied industries [19].

### *2.2.3 Aquatic biomass*

Approximately, one-third of the world is water body. Weeds grow exceptionally on water bodies when compared to terrestrial, whereby enhancing aquatic pollution index. The aquatic biomass includes algae (micro and macro), water hyacinth, kelp, water lily, seaweed etc. These so called aquatic weeds are underutilized; they can be made to serve as raw materials for bio-fuels and bio-chemicals for industrial productions through pyrolysis [20].
