Biomethanation - Environment Notes

Biomethanation is the microbiologic conversion of organic substance to biogas under anaerobic circumstances. Fermenting bacteria, organic acid oxidising bacteria, and methanogenic archaea are the three major physiological categories of microorganisms involved. Biomethanation has a high capacity for producing energy from organic wastes and leftovers. It will aid in reducing the use of natural fuels and thus CO(2) emissions. This article explains about Biomethanation, which is important for UPSC IAS exam preparation.

Biomethanation

• Biomethanation is the microbiologic conversion of organic substance to biogas under anaerobic circumstances.
• Fermenting bacteria, organic acid oxidising bacteria, and methanogenic archaea are the three major physiological categories of microorganisms involved.
• In this process, the organic portion of refuse is separated and put into a confined receptacle (Biogas digester) where it experiences bio-degradation in the presence of methanogenic bacteria and under anaerobic circumstances, creating methane-rich biogas and effluent.
• Biogas is primarily composed of methane and carbon dioxide.
• Biogas can be used for cooking and warmth, or it can be used to generate motive power or energy via dual-fuel, gas engines, low pressure gas turbines or steam turbines.
• After stabilisation, anaerobic digestion sludge can be used as a soil conditioner or as manure, based on its makeup, which is primarily decided by the structure of the incoming refuse.

• Industrial organic waste-to-energy bio-methanation projects are typically capital demanding and monetarily susceptible to both running expenses and income, including refuse supply.
• Such projects' innovations aim to improve total energy production while lowering energy generation costs.
• In collaboration with the United Nations Industrial Development Organization (UNIDO) and the Global Environment Facility (GEF), the Ministry of New and Renewable Energy (MNRE) has introduced a loan interest subvention plan to provide financial help for creative waste-to-energy biomethanation projects.

Biomethanation - Process

• Organic matter is degraded by microorganisms through a series of metabolic transformations to methane and carbon dioxide.
• The process is dependent on syntrophic interactions between hydrogen makers (acetogens) and hydrogen scavengers (homoacetogens, hydrogenotrophic methanogens, etc.).
• A broad range of biomethanation process applications for wastewaters, slurries, and solid waste have been created.
• They use various reactor types and process circumstances (retention periods, loading rates, temperatures, and so on) to maximise waste energy production while also reducing retention time and improving process stability.

Biomethanation - Advantages

• Production of gaseous fuel.
• It is feasible on a modest basis.
• Unlike aerobic therapy, there is no need for external electricity.
• The enclosed system allows all of the gas generated to be gathered and used. Greenhouse gas emissions.
• No emissions are released into the environment.
• Free of foul odours, rodent and fly infestations, obvious waste, and societal opposition.
• Plant modularization and confined treatment require less ground area; and
• Biogas and high-quality soil conditioner production.

Biomethanation - Disadvantages

• Pathogenic organisms may be destroyed less effectively in digesters operating at mesophilic temps than in aerobic composting.
• There are, however, several digester devices that work at high thermophilic temps.
• It requires more money than recycling and landfill.
• Not appropriate for materials with a low Biodegradability.

Issues of Biomethanation

• In the nation, waste-to-energy is still a relatively new idea.
• Most established and profitable urban garbage technologies must be imported.
• The costs of projects, particularly those based on biomethanation technology, are expensive because essential tools for a project must be imported.
• Due to Municipal Corporations/Urban Local Bodies' poor level of conformance with MSW Rules 2000, separated municipal solid refuse is usually not accessible at the plant location, which may result in the non-availability of waste-to-energy plants.
• Municipal Corporations/Urban Local Bodies lack cash means.
• Lack of favourable policy guidelines from state governments in terms of land allocation, garbage supply, and electricity buy / evacuation facilities.

Way Forward

• The underdeveloped condition of waste handling in India motivates the study of environmentally favourable processes such as biomethanation and bioremediation.
• The installation of biogas plants at various research institutes in India, such as the Sardar Patel Renewable Energy Research Institute (SPRERI) in Gujarat, the Biogas Plant at Trombay, the Appropriate Rural Technology Institute (ARTI) in Pune, and the Bhabha Atomic Research Centre (BARC) in Mumbai, practise full-fledged biomethanation and yield a high rate of biogas fuel from waste materials.
• The methane generated is safe, cost-effective, and can be used commercially.
• However, the government should spend more on this technology so that it spreads to municipal governments.

Conclusion

Biomethanation is the anaerobic microbiologic change of organic substances to methane. The three main physiological groups of microorganisms involved are fermenting bacteria, organic acid oxidising bacteria, and methanogenic archaea. It has the ability to generate approximately 1700 MW of electricity from urban and local refuse, as well as approximately 1000 MW from industrial waste in the nation. With economic growth, the potential is expected to grow even more.

FAQs

MCQs

Question: In the context of solving pollution problems, what is/are the advantages/disadvantages of bioremediation techniques? (UPSC 2017)

1. It is a technique for cleaning up pollution by enhancing the same biodegradation process that occurs in nature.
2. Any contaminant with heavy metals such as cadmium and lead can be readily and completely treated by bioremediation using microorganisms.
3. Genetic engineering can be used to create microorganisms specifically designed for bioremediation.

Select the correct answer using the code given below:

(a) 1 only

(b) 2 and 3 only

(c) 1 and 3 only

(d) 1, 2 and 3

Question: With reference to 'Global Environment Facility", which of the following statements is/are correct? (UPSC 2014)

(a) It serves as financial mechanism for 'Convention on Biological Diversity' and 'United Nations Framework Convention on Climate Change'

(b) It undertakes scientific research on environmental issues at global level.

(c) It is an agency under OECD to facilitate the transfer of technology and funds to underdeveloped countries with specific aims to protect their environment.

(d) Both (a) and (b)