Biomass A Strong Source Of Renewable Energy
Since it is an organic material containing stored energy from the sun, biomass could provide a transition from fossil-fuel.
A Bio-grass plantation: Burning of elephant grass leads to emission of less carbon than it is consumed meaning that it is a reliable, green and renewable.
Photovoltaic panels and wind turbines are the first things to cross your mind whenever renewable energy is mentioned. Renewable energy is a wide field, and biomass is also another green form of energy that could be a replacement to the environmental polluting sources such as oil and coal. However, the question to ask yourself is what is biomass and how can it have a positive impact on energy in the future?
Biomass comprises the biodegradable materials from living organisms, which contain energy from the sun. Radiant energy from the sun is absorbed from sunlight and converted into chemical energy in the form of glucose and sugar. Consuming plant materials by people is fundamental for energy intake. Moreover, when burnt, the chemical energy from biomass is released in the form of heat.
Biomass can be harnessed from waste products or plants that are grown for energy, for example, hemp, willow, corn, poplar, sorghum, sugarcane and switch grass.
Data from the U.S. Energy Information Administration indicate that almost 4% of the total energy consumed in 2010 resulted from biomass. Approximately, 46% of that amount was obtained from wood or wood products, for example, wood chips and saw dust while 43% was obtained from ethanol and 11 % from municipal waste products.
Biomass boiler in Seattle
Mechanism of working of biomass
Before it is converted into an environmental friendly and efficient energy source, biomass undergoes some processes, which include direct burning, co-firing, re-powering, combined heat and power, gas pumping and anaerobic breakdown.
Since long, direct combustion has been the easiest and the most common means of obtaining energy. It has helped humanity to gain civilization. For instance, our forefathers have been generated energy from fire from wood. In the coal driven power plants, co-firing entails mixing of biomass with coal but until proper mechanisms for renewable energy are put in place, it may be an efficient means of obtaining green energy that is environmental friendly. Re-powering refers to the conversion of coal plants to run on biomass alone.
“Combined heat and power” refer to the situation where direct burning is used to generate heat to a building besides producing energy. Gasification entails the pressurized heating of biomass under limited amounts of oxygen then converting it to “syngas.” Syngas is a mixture of hydrogen and carbon monoxide, and it can be used to generate electricity when it is run through a gas or steam turbine.
In anaerobic digestion, breakdown of the biomass is initiated by microorganisms in a controlled environment resulting in production of methane and CO2. The greenhouse gases generated are used in the processing of sewage, animal manure and landfill waste. Moreover, the resulting methane is not lost to the atmosphere since it is used for power and heat production.
Advantages and disadvantages of biomass
However clean it may be; biomass has some environmental dangers. The Union of Concerned Scientists explains that biomass for energy production can be overexploited resulting to environmental damage and pollution of the air in addition to using enormous amounts of water thereby producing greenhouse-gas emissions. Proper handling of the biomass may avert the aforementioned damages. Crops for energy production should never compete with food crop for land and recycling of the emitted gases is the key to growth of plants.
An assumption by most scientists is that the overall emission of carbon will be reduced by the numerous biomass resources. Cultivation of beneficial biomass crops can lead to an increase or maintained carbon quantities; especially those in the soil and plants. Native energy crops can also be grown on marginal land, and some of them include switch grass (which grow very fast and is now commonly used for biomass).
Various byproducts such as manure, methane gas from landfills, wood pulp from sawmills and paper mills and waste from urban areas, for example, tree products and other organic household waste can be used to generate electricity. This results in value creation besides cleaning the environment.
Source: MNN – Earth Matters