Renewable Energy-Biomass

What is biomass?

Biomass refers to non-fossil, carbon-based, renewable materials from which energy can be produced. Examples of biomass include agricultural and municipal wastes, agricultural crops and wood.

Biomass can be used to substitute fossil fuels. It may be burnt or 'digested' to produce heat or electricity or used as a transport fuel. While the burning of biomass does release carbon dioxide, it also absorbs carbon dioxide during its life cycle and the net dioxide emissions are zero.

How is biomass converted to energy?

Biomass can be converted to different forms of energy including heat, power, combined heat and power (CHP) or liquid biofuels by a number of different methods.

• Combustion: Fuel + oxygen = carbon dioxide + water + energy. The heat, often in form of steam, can be converted to electricity or it can be used for heating houses and buildings.
• Burning wood in an open fireplace: Wood is an eco-friendly fuel (when sourced from local woodlands and forests), taking just a few years to grow. Wood is still one of the most inexpensive fuels in Ireland and is readily available from farmers and local suppliers.
• Wood stoves: A modern stove can convert over 80% of the energy content of the wood into heat, compared to a standard Irish fireplace which is only about 20% efficient. A fireplace insert can give you all the benefits of the traditional fireplace look, as well as the advantages of a highly efficient wood stove.
• Gasification: It is a method of power generation with higher effiiciencies than combustion-based steam cycles. It is a process in which biomass is converted at high temperatures to a higher grade fuel (gas) prior to combustion.
• Pyrolysis: This is a means of converting solid organic material into a liquid biofuel by heating at high temperatures in absence of oxygen.
• Anaerobic Digestion (AD): This is the breakdown of organic waste by bacteria in an oxygen-free environment. It can take place in a specially designed AD plant or naturally at landfill sites.
• Landfill Gas: Methane in landfill gas has 21 times the global warming potential of carbon dioxide. Wells are inserted into the waste to collect the gas through a series of perforated pipes. A suction pump collects the gas, which is then cleaned and ready to be used as a source of energy. This method is used at the Kinsale Road Landfill Site.
• Liquid Biofuels: Certain types of biomass may be processed in order to be used as petrol or diesel substitutes. Biomethanol which is produced from crop or forest residues, grasses or short rotation forestry may be used as a petrol substitute while biodiesel which is produced from vegetable oils (e.g. oilseed rape, sunflower oil, palm oil, soybean oil and waste vegetable oil) may be used as a diesel substitute. Oilseed rape is used as a diesel substitute in 17 of Cork City Council's vehicles.

Benefits from using Biomass:

• Reduction in CO2 emissions
• Biomass is available locally, so it can reduce our need for imported fuel
• The biomass industry can provide more employment, especially in rural areas
• Biomass is sustainable and does not use up fossil fuels
• Biomass crops have a greater diversity of wildlife & flora
• Biomass may be one of the solutions to our surplus waste problem.