[Biology Class Notes] on Biomass Energy Pdf

Although biomass is a term that is closely associated with ecology, it can also be defined and described in terms of energy. The biomass energy is one of the primary sources of energy for many activities. It is considered as the source of renewable energy since the primary source of this energy is plenty in this world. Most biomass comprises carbon, hydrogen, oxygen, nitrogen, and other alkali metals, which provide a large amount of energy when burnt. Organic materials like agricultural wastes, wood, and municipal wastes can be recycled for the production of biofuels.

Definition of Biomass in terms of energy

Definition of Biomass could be, the energy that is generated from biomass is called biomass energy. All organic matter that can produce energy when reactions are done with it can produce biomass energy. These can be wood, leaves, pellets, fecal wastes, and other organic matters. Technically speaking, biomass energy was discovered back during the ages when humans used to live in caves. Marco Polo, in the 13th century, described the use of biomass for the production of fuel after taking inspiration from the Chinese who used to cover sewage tanks to generate biogas.

Biomass energy can be both renewable and non-renewable. The first source of energy in the production of biomass is the sun. The plants convert solar energy by photosynthesis into chemical energy as food and subsequently uses it in their growth, which is later converted to fuel. The energy derived from biomass can be processed directly by burning to produce heat, or converted directly into electricity, or can also be processed to produce biofuels in an indirect manner.

Plants that are a rich source of Biomass energy and hence considered for Biofuel production

There are several plants that can be considered as a rich source of biomass energy and hence are often considered for the production of biofuels. Some of them include wheat, switchgrass, sunflower, cottonseed, mustard oil, corn, canola, sugarcane, soy plants, jatropha, palm oil, and many more. These plants are often cultivated in large fields for the production of biofuels.

Ways to produce Biomass energy- Thermal conversion

One of the primitive ways of producing biomass energy is to burn the organic material and utilize the heat energy produced from it. The thermal conversion of biomass involves heating the feedstock so that energy is released, the feedstock is dehydrated, or the biomass is stabilized. The common source of biomass feedstock is the municipal solid wastes and also waste from lumber mills and paper factories.

The different processes of thermal conversion are direct firing, pyrolysis, co-firing, gasification, as well as anaerobic decomposition. Before the biomass is burnt, they are needed to be dried. The chemical process of drying biomasses is called torrefaction. In this process, the biomass is heated to a temperature of 200 to 320ᴼC. The biomass not only loses all its moisture, and also loses the ability to absorb it. After torrefaction, the biomass is converted into a black dry material, which is then compressed to form briquettes. Briquettes are highly hydrophobic, thus enabling them to be kept in moist places. Also, the briquettes have high energy density and can easily be burnt by direct firing or co-firing.

Ways to produce Biomass energy- Biofuel

Biomass is considered a renewable source of biofuels like biodiesel and ethanol. Such biofuels are used to power vehicles and machines in several countries like Austria, Sweden, and the United States of America. Ethanol is produced by the fermentation process of biomasses that are rich in carbohydrates, such as corn, wheat, and sugarcane. Biodiesel can be made by combining this ethanol with animal fat, vegetable oil, and recycled cooking fat. 

Biofuels do not produce as much energy and, therefore, not as effective as gasoline. However, they can be mixed with gasoline, and this mixture can be used to power automobiles and pieces of machinery used in several industries. By using such mixture, the emission of harmful gases, as observed in the case of fossil fuels, is greatly minimized.

Ways to produce Biomass energy- Biochar

Biochar is a byproduct of the pyrolysis process of biomasses. It is considered to be a valuable source of energy for agriculture and other environmental uses. 

When biomass rots or burns, it releases large amounts of carbon dioxide and methane into the atmosphere. However, such emissions are prevented, and the process of charring these biomasses can retain the carbon content. When these biochars are added back to the soil, they can still absorb carbon from the surroundings. They can act as sequestered carbon sinks, which is beneficial for maintaining the quality of the soil it has been found that addition of biochars to the soil helps in increasing the quality and quantity of agricultural production.

Ways to produce Biomass energy- Black liquor

Black liquor is a toxic byproduct in the production of paper from wood. Till the 1930s, this black liquor is considered as an industrial waste product and was dumped into the nearby water bodies. However, later it was found that the black liquor can retain almost 50% of the carbon content of the source material. Later it was used as a power source in several mills with the help of the recovery boiler. It was also tried to be gasified so that it can be used to generate electricity.

Ways to produce Biomass energy- Hydrogen fuel cells

Hydrogen fuel cells are produced from biomass that is rich in hydrogen. These hydrogen atoms are chemically extracted from the biomasses and are used in batteries for generating powers and fuel machines and vehicles. These cells are mainly used for automobiles driven in remote locations, like wilderness areas or in spacecraft. Hydrogen fuel cells can be considered as an alternative source of energy for vehicles. In current times, these cells are used as a source of power for boats, buses, submarines, and forklifts. Testings are going on for their usage in airplanes as well.

Conclusion

All living organisms can be considered as a rich source of energy. Most of our energy sources are carbon, hydrogen, and oxygen, and all these atoms make up the carbohydrate, which is an integral part of all living organisms. Biomass can be converted to different forms of energy, which can then be used in different ways like as fuel for automobiles, as a source of power for different industries, and to generate electricity.