Keywords : Bio mass, Bioenergy , Bio fuels
Most societies today are experiencing a high level of dependence on fossil fuels which is increasingly problematic. Also, almost 10GT of carbon di oxide is released onto the atmosphere every year across the globe. In order to achieve the changes required to address the impact of global warming and other threats to the atmosphere the use of renewable energy sources is very much necessary.
Biomass is the most common form of renewable energy, widely used across the world until recently less so in the western world. Biomass is a term for all organic material that stems from plants including trees, algae and crops. Biomass is produced by green plants converting sunlight into plant material through photosynthesis and also includes all the land and water-based vegetation, as well as all the organic wastes. The biomass resource can be considered as an organic matter, in which the energy of sunlight is stored in the form of chemical bonds. When the bonds between the adjacent carbon, oxygen and hydrogen molecules are broken by digestion, combustion, or even decomposition, these substances release their stored, chemical energy. Biomass has always been a major source of energy for mankind and is presently estimated to contribute of the order 10-14 percent of world’s energy supply. This paper mainly focuses on the methodology involved to set up a biomass energy plant, the challenges it faces both technically and financially and also, we foresee how biomass would play a major role in the future in United States of America.
Fire, unquestionably the most important discovery in the history of mankind, was discovered thanks to the accidental combustion of wood. Fire has illuminated, heated, protected and fed mankind for thousands of years. Briefly, fired fostered the birth of civilisation. Wood, on the other hand, remained the most widely used raw material for many centuries, not only to burn fires, but also as building material. The invention of the steam engine allowed mankind to obtain mechanic energy from the combustion of wood, whereas up to the 18th century wind and water where the only mechanic energy sources available, thanks to wind and water mills. During the Industrial Revolution wood started to become scarce owing to the massive deforestation carried out to produce energy. Mankind had to look for alternative energy sources and found them in coal and oil, which at the time were abundant albeit not renewable. Only recently, energy need and the possible disappearance of fossil fuels and the pollution produced by the combustion led man to “re-discover” the usefulness of wood and biomass as energy sources.1
Biomass is the plant material derived from the reaction between carbon di oxide in the air, water and sunlight through photosynthesis, to produce carbohydrates that form the building blocks of biomass. Photosynthesis typically converts less than 1 percent of the available sunlight to stored chemical energy. Photosynthesis which is driven from the solar energy is stored in the chemical bonds of the structural components of biomass.
The various types of biomass in different ways are, namely;
• Woody plants,
• Herbs/ grasses,
• Aquatic plants,
Within this category, herb plants can be further subdivided into those with high and low moisture contents. Apart from specific applications or needs, the commercial activity mostly has been directed towards low moisture content types, woody plants and herbs species.
Biomass contains various amounts of cellulose, hemicellulose, lignin and a small number of other extractives. Woody plant species are typically characterized by slow growth and are composed of tightly bound fibres, giving a hard-external surface, while herb plants are usually perennial, with more loosely bound fibres, indicating a lower proportion of lignin, which binds together the cellulose fibres: both materials are examples of polysaccharides; long chain natural polymers.
Cellulose is a glucose polymer, consisting of linear chains of (1, 4)-D-glucopyranose units, in which the units are linked 1-4 in the beta- configuration, with an average molecular weight of around 100,000.
Hemicellulose is a mixture of polysaccharides, composed almost entirely of sugars such as arabinose, glucose, mannose and xylose and even methyl glucuronic and galacturonic acids, with an average molecular weight of