**1. Introduction**

The European Union must reduce its overall greenhouse gas emissions by 8% from 1990 levels between 2008 and 2012 [1]. This can be made possible by substituting common fossil fuels with low-carbon fuels for energy generation. Wastes of various origins, such as industrial or agricultural wastes, are usually disposed *via* incineration. This act can be replaced by utilizing them as sources of energy. The cost of landfill, environmental pollution/degradation, and the diminishing space available for landfilling trash, particularly in densely populated places, has become a source of concern lately. This in turn has become major driver for waste-to-energy and it is receiving more and more attention. Due to emerging issues from lack of

land for landfills, CO2 and CH4 emissions, potential groundwater pollution, and the need for more recycling and reuse of trash, policy and regulation of waste disposal have been a front-burner issue in many nations. As stated in the EU legislation that is now being prepared, landfilling of garbage that can serve as a source of renewable energy will be prohibited. Organic materials derived from plants are commonly referred to biomass. The chemical energy in biomass can be extracted when it undergoes combustion and it is transformed into heat or electricity. Green biomass refers to biomass resources that are sustainably managed as they have become renewable energy sources and do not contribute to global warming. Sustainable management of plants has helped in reabsorbing carbon dioxide released during the combustion of other biomass thus leaving no net carbon dioxide emissions in the atmosphere. Both valuable compounds and energy (biofuel) can be obtained from biomass [2]. Fossil fuels, in addition to increasing the amount of carbon, sulfur, nitrogen, and other air pollutants by thousands of tons, also cause environmental hazards. These adverse effects serve as a pointer to the need to find creative and affordable alternative fuels. A reliable alternative consists of renewable energy sources. Many researchers across the globe have been conducting extensive studies on these sources to examine their uses [3, 4].

Renewable fuels are processed from biomass, which consists of organic waste products obtained from sources such as industry, forestry, and agriculture. Agrobased biomass is mostly biomass obtained from considerable organic wastes that are left in fields after crops have been harvested. Although some of these wastes are used as animal feed, the majority lie on the fields and are usually burnt or left as a nuisance in the environment. Crop wastes, such as wheat and paddy straw, have been utilized as raw materials in biomass-based power plants for the production of electricity. Biomass such as melon seed husk, mango endocarp, and moringa pod are just a few of the abundant agricultural by-products obtainable in an agrarian nation like Nigeria. Worthy of note is that Nigeria ranks as Number 10 among the world's top producers of mangoes [5]. About 35 to 60% of the mango fruit are being wasted after processing [6]. Also, more than a million tons of mango seeds are produced yearly as waste and are currently not adding value to the nation's economy [7]. A typical moringa tree (15–20 feet tall) can produce thousands of seed pods, yielding an incalculable number of moringa seeds [8]. The majority of agricultural wastes lack commercially viable conversion technology as they are in most cases set ablaze on the field. A significance of agricultural wastes is that they serve as one of the alternatives to grains for the generation of ethanol or gasoline without compromising the security of the food supply. Owing to their quantity and renewability, agricultural wastes are a major raw material in the commercial manufacture of bioethanol [9]. The lignocellulose content of agricultural wastes has been acknowledged as a significant and promising source of biofuels and other products of immense value [10]. The effect of global warming can be significantly alleviated by reducing greenhouse gas emissions through the manufacture of biofuels using lignocellulosic materials [11]. The majority of the global biomass supply comes from lignocelluloses. Lignocellulose can be obtained in significant quantities from municipal solid wastes, crop leftovers, forest residues, and specific energy crops [12, 13]. The components of plants known as extractives are those found outside of the cell wall; they are made up of low or medium molecular weight materials and may be readily extracted using particular solvents such as acetone, toluene, alcohol, and water [14–16]. Studies have shown that lignocelluloses are converted to biofuel at a greater rate when cellulose's crystallinity is reduced significantly [17]. Four main steps are involved in the synthesis of biofuel (e.g., ethanol)

*Analysis and Characterization of Lignocellulosic Biomass Extracted from Selected Agricultural… DOI: http://dx.doi.org/10.5772/intechopen.112954*

from lignocellulose biomass: These are pretreatment, hydrolysis, fermentation, and product purification. Monomeric sugars are produced when carbohydrate polymers undergo hydrolysis, and they (monomeric sugars) are then fermented to produce ethanol. To make it simpler for the enzyme to convert carbohydrate polymers into fermentable sugars, the pretreatment step lyses the lignin seal and disrupts the crystalline portion of the cellulose [12]. The amount of ethanol output (L/mg) depends on the precise assessment of the lignocellulose content in the biomass [18]. A major factor that determines how effectively the processes can convert lignocellulosic biomass into ethanol is the composition of the lignocellulose. To the best of the authors' knowledge, little has been done to determine the lignocellulose biomass content of mango endocarp, moringa pods, and melon husks. This study is therefore aimed at characterizing and analyzing the lignocellulose biomass of these selected agricultural wastes in order to determine their morphological, chemical, and compositional characteristics.
