From Waste to Impact: Converting Organic Solid Waste into Green Energy
India is facing a serious issue in effectively dealing with its municipal solid waste (MSW). More sustainable solutions to landfilling must be found and implemented, to secure a healthy future for all citizens, and ensure that we are staying on course with global climate targets. Waste management solutions, such as waste to energy, make for an excellent opportunity to move from a linear, waste-producing economy, to a circular economy, wherein goods are used beyond their intended lifespan. Extending the lifespan of goods, however, must occur in tandem with the reduction of consumption. Any kind of waste-to-energy technology should complement and not compete with waste reduction and reuse (GIZ, 2017).
There are several technologies available that offer solutions to landfilling, one of them being Biomethanation. Biomethanation is the process by which the methane emitted from organic waste is captured, and converted under anaerobic conditions into biogas. Biogas is a renewable energy source that can be used for functions such as fuelling vehicles, cooking, heating homes, and generating electricity. In India, the largest proportion of municipal solid waste is wet waste, representing about 55% of all waste produced (MOHUA, gov.in). This means that of the 62 million tonnes of waste generated every year, about 34.1 million tonnes is organic waste. Anaerobic digesters can yield anywhere from 20m3 to 800m3 per tonne of waste. These numbers indicate that, at the very least, widespread adoption of biomethanation technology could mean that India generates 682,000,000m3 of biogas per year. This is a huge amount of energy that could contribute to India’s rising energy demands whilst simultaneously displacing the use of fossil fuels. The lack of implementation of this technology, as well as low compliance to legislation around waste management, such as segregation at source, makes our enormous production of organic waste, untapped potential. The country is sitting on what is essentially an energy gold mine and we ought to take advantage of it, especially in the present time, where decarbonisation is fundamental to securing a safe and habitable future on Earth.
Sustainable Impacts: Organic Waste to Bio-CNG & Organic Fertilizer Plant
Despite having several barriers to its implementation biomethanation offers an undeniably profitable return on investment. It is a highly viable option to solve waste disposal issues. Inspired by our visit to a biomethanation plant in Bangalore, set up by Sustainable Impacts Pvt ltd, a 50:50 joint venture between Hasiru Dala Innovations and Carbon Masters, we learned about the untapped potential of organic waste through biomethanation. In this post, we will discuss how biomethanation works, and why the end product, purified, compressed biogas, is a resource worth producing.
What is Biomethanation?
Biomethanation is a process by which organic material is microbiologically converted under anaerobic (in the absence of oxygen) conditions into biogas (Angelidaki, 2011). Microorganisms degrade organic matter through cascades of biochemical conversion, to methane and carbon dioxide (ibid.). The chemical processes that take place to convert raw organic waste into biogas are complex and can be difficult for a layman to understand. The infographic below is a short, practical summary of what occurs in a biomethanation plant.
To produce the highest quality, and purest form of biogas, the waste being fed into the plant must be 100% organic. Therefore, segregation at source is key. The bi-product of biogas production, post-digested slurry or ‘digestate’, can be used as liquid fertiliser which meets the guidelines set by the government. On its own, it serves as a nutrition-rich supplement to regenerate soil on barren land.
A Sustainable and Affordable Fuel
What makes biogas an attractive alternative to other fuel sources, is largely how sustainable and affordable it is. Biogas is produced using renewable resources, thus displacing fossil fuels. Further, as there is no combustion required in the process of production, there is no anthropogenic emission of greenhouse gases. Finally, methane which would otherwise be escaping into the air and contributing to the effect of global warming is being captured and put to productive use. Biogas is also less wasteful than its fossil-fuel-based counterpart LPG, as is 100% gas while LPG cylinders contain liquefied butane and/or propane, where some liquid is always left behind, unused.
Barriers to Implementation
Although there are several advantages and positive externalities associated with this energy source, there are reasons that biomethanation has not yet been widely adopted.
Firstly, setting up a biomethanation plant requires suitable land, ideally to be given by the government, a high capital investment, for upfront costs such as construction, skilled labour, and equipment. Further, bio-CNG can only be harnessed from pure organic matter. This means that compliance with segregation at source must be high, and an adequate infrastructure for the collection of waste must already be in place.
Additionally, other fuel substitutes available on the market make for fierce competition. A lack of awareness about the technology also contributes as a barrier. An adequate supply of water is also required, and many places suffer shortages, making this difficult to guarantee. Inconsistencies in temperature also make for a barrier, as places that experience cold winters may experience a significant decrease in biogas production, as low temperatures inhibit methanogenesis.
At present, there are many individual actors and agencies involved with developing biogas programmes. As they are not coordinated or working in collaboration with one another, there is competition for incentives and there is low dissemination of biogas technology across India, especially in rural areas.
The potential to create two climate-friendly products, Bio-CNG, and organic manure, out of what is currently a menacing issue for not only India but the world over, is immense. By using biomethanation as a waste-to-energy technology, organic waste which would otherwise be landfilled is being turned into a carbon-neutral source of energy. Whilst the combustion of biogas does produce carbon dioxide, the carbon present in biogas comes from plant matter, which in turn absorbs carbon from atmospheric carbon dioxide. Thus, it does not add to greenhouse gas emissions, making it carbon neutral (Wilkie, 2019).
Biogas has a vast range of uses and can be a revolutionary step in the direction of decarbonising India’s power sector and displacing fossil fuels. All this being said, it is very important to emphasise that although waste has the potential to be managed sustainably, by no means should this management encourage consumption. As technologies continue to be developed to address the issue of waste, people are allowed to over-consume and therefore overproduce waste with a clean conscience. The ‘productivist, capitalist model of overconsumption and overproduction’ which dominates the global economy and culture today, is fundamentally incompatible with the ecological well-being of the Earth, as the French Green MEP so eloquently put it. Within a system wherein profit-seeking, growth, and competition are institutionally protected (Pirgaimer, 2020), overconsumption is but a natural outcome. Perhaps the only way to reduce consumption to a permissible amount is to change the very nature of the way we consume. However, such a civilisational shift, despite being very urgent, would indeed require a long time to take place. Nonetheless, moving towards a circular economy and adequately managing the waste that is already on its way through the supply chain is certainly a step in the right direction.
We believe that widespread adoption of biomethanation technology can be made possible through investment from international climate funds and India’s private sector, and can help keep us on track with our contribution to the world's goal of keeping warming under 1.5 degrees.
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