Around the world, pollution of the air and water from municipal, industrial and agricultural operations continues to grow .The concept of the ‘four R's’, which stands for Reduce, Reuse, Recycle, and Renewable energy, has generally been accepted as a useful principle for waste handling. The emission of carbon dioxide (CO2) and other greenhouse gases (GHG) has become an important issue, Governments and industries are therefore increasingly on the lookout for technologies and alternatives source of energy that will allow for more efficient and cost-effective waste treatment while minimizing GHG. Country’s dependence on fossil fuel (gasoline) imports should further encourage the energy market and politicians to invest in a renewable alternative source of energy and create market incentives for biogas. Biogas is the versatile, sustainable energy carrier developing countries are looking for. Energy diversity brings stability. The use of manure and other organic waste should be a priority for biogas production. A large share of energy crops could be converted into biogas, but also used in different technologies, depending on needs in the particular country/region. “Such a diverse and wide ranging approach to power will bring greater economic security and stability to our environmental and energy future than our current one-size-fits-all approach” (Logan, 2006).
2.0 WHAT IS BIOGAS?
Various bacteria stains break down organic matter and generate a burnable gas.
Biogas is a fuel which is produced from the breakdown of organic matter. The term “biogas” includes all gas produced by anaerobic digestion of organic matter. In the absence of oxygen various types of bacteria break down the feedstock to form a secondary energy carrier, a burnable gas which mainly consists of methane (50% - 75%) and carbon dioxide (25% - 45%). Biogas as a secondary energy carrier can be produced out of many different kinds of organic materials and its options for utilization can be equally versatile. Biogas can be used to generate electricity, heat and biofuels. Also the fermentation residues, called digestate, can be used, for example as a fertilizer. Historically, a simple gas collector installed over a pile of cattle or pig manure can be seen as the simplest and earliest version of a biogas plant. This principle was already known to the ancient Persians. Today many different feedstocks are used in production of biogas. A general distinction can be made between biomass from agriculture like by-products (manure) or dedicated crops for biogas and various waste streams (see table below). Biogas Feedstocks
Energy Crops, catch crops| Sewage|
Landscape Management| Municipal Solid Waste|
Grass| Food Waste|
Other by-products| Other waste|
3.0 BIOGAS AS AN ALTERNATIVE SOURCE OF ENERGY
The quest for alternate sources of energy is propelled by numerous factors. One is shortage of conventional fossil fuels. These non-renewable resources like Hydrocarbon, Coal, etc. are constantly shrinking while their demand is ever-increasing. In effect, it pushes the cost of generating power upwards. Apart from scarcity and cost, another problem facing most countries is the ever-growing pile of waste dumps. What could be more appealing than being able to generate cheaper, cleaner power from waste? One excellent source of energy is Biogas. This is produced when bacteria decompose organic material such as garbage and sewage, especially in the absence of oxygen. Biogas is a mixture of about 60 percent methane and 40 percent Carbon dioxide. Methane is the main component of natural gas. It is relatively clean burning, colorless, and odorless. This gas can be captured and burned for cooking and heating. This is already being done on a large scale in some countries of the world. Farms that produce a lot of manure, such as hog and dairy farms, can use biogas generators to produce methane....