Bioenergy
Bioenergy is essentially the use of organic material to produce different forms of energy.
Biomass (organic matter) can be used to provide heat, make fuels, and generate electricity.
Wood, the largest source of bioenergy, has been used to provide heat for thousands of years.
There are many types of biomass, wood, plants, residue from agriculture or forestry, and the organic component of municipal and industrial wastes. These can all be used as renewable energy sources.
Today, many bioenergy resources are replenished through the cultivation of energy crops, such as fast-growing trees and grasses..
Biomass can be burned directly to produce steam for electricity production or manufacturing processes.
Unlike other renewable energy sources, biomass can be converted directly into liquid fuels for our transportation needs.
The decay of biomass in landfills produces a gas-methane that can be burned in a boiler to produce steam for electricity generation or industrial processes.
In places where lots of animals are raised, the animals - like cattle, cows and even chickens - produce manure.
When manure decomposes, it also gives off methane gas similar to organic waste. This gas can be burned right at the farm to supply heat and electricity supplies to for the farm. .
Using biomass does not add to global warming.
Plants use and store carbon dioxide (CO2) when they grow. The CO2 is released when the plant material is burned and other plants in turn consume the released CO2. Using biomass closes this cycle of storing carbon dioxide.
Carbon dioxide is a gas that contributes to the "greenhouse effect" and global warming. The use of biomass is environmentally friendly because the biomass is reduced, recycled and then reused.
Biopower
Biopower , or biomass power, refers to the use of biomass to generate electricity.
There are six major types of biopower systems :
Direct fired
Cofiring
Gasification
Anaerobic digestion
Pyrolysis
Small modular
Direct fired
Most of the biopower plants in the world use direct-fired systems.
They burn bioenergy feedstocks directly to produce steam.
The steam is usually captured by a turbine, and turns a generator converting the energy into electricity.
In some industries, the steam from the power plant is also used directly in manufacturing processes or to heat buildings. These are known as combined heat and power facilities.
Cofiring
Many coal-fired power plants can use cofiring systems to significantly reduce emissions, especially sulfur dioxide. Cofiring involves using bioenergy feedstocks as a supplementary energy source.
Gasification
Gasification systems use high temperatures and an oxygen-starved environment to convert biomass into a gas (a mixture of hydrogen, carbon monoxide, and methane).
The gas fuels a gas turbine, which powers an electric generator.
Biogas can also be used directly in a furnace, or further refined for use in fuel cells for transport or heating.
Anaerobic digestion
The decay of biomass produces a gas (methane) that can be used as an energy source.
In landfills, wells can be drilled to release the methane from the decaying organic matter. Pipes from each well carry the gas to a central point where it is filtered and cleaned before burning.
Methane also can be produced from biomass through a process called anaerobic digestion.
Anaerobic digestion involves using bacteria to decompose organic matter in the absence of oxygen.
Over a period of between 10 and 25 days, an Anaerobic Digestion process can convert 40 to 60% of the dry mass of a liquid biomass feedstock (such as animal slurry and/or vegetable waste) into biogas.
The gas may be used like fossil fuel gas for heat and power generation and to power vehicles.
The balance of the feedstock used in this process is recovered as a stable residue. It can be separated into liquid fertiliser and a solid soil conditioner.
Pyrolysis
Liquid fuels can be produced from biomass through a process called pyrolysis.
Pyrolysis occurs when biomass is heated in the absence of oxygen.
The biomass then turns into a liquid called pyrolysis oil, which can be burned like petroleum to generate electricity.
Pyrolysis oil can be used to fuel a furnace, a modified medium speed diesel engine, or a gas turbine.
Small modular
Several biopower technologies can be used in small, modular systems.
A small, modular system generates electricity at a capacity of 5 megawatts or less.
These systems are designed for use at the small town level or even at the consumer level.
As an example, farmers could use the waste from their livestock to provide their farms with electricity.
These systems provide renewable energy and by consuming waste, help farmers meet environmental regulations.
Biofuels
Unlike other renewable energy sources, biomass can be converted directly into liquid fuels -
biofuels - for our transportation needs (cars, trucks, buses, airplanes, and trains).
The two most common types of biofuels are ethanol and biodiesel.
Ethanol
Ethanol is an alcohol, the same found in beer and wine. It is made by fermenting any biomass high in carbohydrates (starches, sugars, or cellulose) through a process similar to brewing beer.
Ethanol is used as a fuel additive to cut down a vehicle's carbon monoxide and other smog-causing emissions.
Flexible-fuel vehicles, which run on mixtures of gasoline and up to 85% ethanol, are now available.
Biodiesel
Biodiesel is made by combining alcohol (usually methanol) with vegetable oil, animal fat, or recycled cooking greases.
It can be used as an additive to reduce vehicle emissions (typically 20%) or in its pure form as a renewable alternative fuel for diesel engines.
Methanol
Methanol, commonly called wood alcohol, is currently produced from natural gas, but can also be produced from biomass.
There are a number of ways to convert biomass to methanol, but the most likely approach is gasification.
Gasification involves vaporizing the biomass at high temperatures, removing impurities from the hot gas and passing it through a catalyst thereby converting it into methanol.
Bio-products
Whatever products we manufacture from fossil fuels, we can also make using biomass.
Bio-products, or bio-based products, are not only made from renewable sources, they often require less energy to produce than petroleum-based products.
The process for making biofuels involves releasing the sugars that make up starch and cellulose in plants.
These products can be used to make antifreeze, plastics, glues, artificial sweeteners, and gel for toothpaste.
Other important building blocks for bio-products include carbon monoxide and hydrogen.
When biomass is heated with a small amount of oxygen present, these two gases are produced in abundance.
This mixture is called biosynthesis gas (carbon monoxide and hydrogen).
Biosynthesis gas can be used to make plastics and acids needed in the manufacture of photographic films, textiles, and synthetic fabrics.
When biomass is heated in the absence of oxygen, it forms pyrolysis oil (an alternate energy fuel).
A chemical called phenol can be extracted from pyrolysis oil.
Phenol is used to make wood adhesives, molded plastic, and foam insulation.
Source: http://www.kerryenergy.ie
