Biogas

    Waste is any unwanted or unusable material which is discarded after its primary use. There are many issues that surrounds focusing on the wastes. It is reported in 2001 that nearly 338 million tons of waste was generated. This volume of waste exponentially increases with time and so is the problem of its dumping.

    The waste is most commonly bifurcated into organic waste and inorganic wastes. Inappropriate management of waste attract rodents, insects, flies which are responsible for many fatal diseases viz. gastrointestinal diseases, yellow fever, worms and many other dangerous fatal diseases. These wastes are subjected to incineration which causes generation of toxic and carcinogenic gases which contaminate the environment. The waste which is dumped in dumping grounds cause seepage of wastewater underground causing underground water pollution. The waste disposal/dumping causes degradation (composting) of the organic material in absence of oxygen due to the huge dumps. The anaerobic condition during the degradation process generates methane which is a Green House Gas (GHG). These GHG’s are having a far greater global warming potential(GWP). The Intergovernmental Panel on Climate Change (IPCC) has decided the values of GHP gases. These GWP values were changed in 2007.  The values in the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) in 2007 where refined from the IPCC Second Assessment Report (SAR) values used previously and still in much of the literature.

    To reduce the impact of the wastes on the environment, waste management is very important and should be taken very seriously by us or we should be ready to face the consequences developed.

There are many different conventional ways to treat the wastes which include Composting, Incineration, Landfills & Recycling. These process are conventional and have many drawbacks of themselves, viz. the process generate GHG’s which is let in the environment proving it hazardous. Many new technologies are developed which are very effective and also it generates revenue of it. Most appreciated and well known method is Biomethanation of organic wastes. This process of biomethanation occurs in absence of oxygen. This is a biological process where the microorganisms are involved, which degrade the organic material from the waste to generate biogas. This biogas is comprised of methane 55%, carbon dioxide 35-40%, and other gas in traces. The methane in this gas is a combustible gas which can be used for many different purposes like, energy generation using generators, using it in kitchen burners instead of LPG, using it in the commercial/industrial burners for different applications.

Anaerobic digestion process –

    This process is a  group of process where microorganisms are involved to breakdown the complex organic molecules into simpler molecules in absence of oxygen. The digestion process begins with hydrolysis of the raw material such as carbohydrates  which are broken down to simpler derivatives by the microorganisms. The acidogenic bacteria converts the sugars and amino acids into Carbon dioxides, ammonia, hydrogen and organic acids. In the next step, the bacteria convert these organic acids into acetic acids and finally the Methanogenic archaea population convert the products into methane and carbon dioxides. The graphical presentation of the process is given in the Figure below.