As a citizen of this country and this world, I increasingly get concerned about many issues we as a society face. Of all our issues/problems, one of the larger onesis the waste we as a race generate. And there is no real solution in sight to this problem, particularly for small town and cities.
The numbers are telling:
Human beings as they ‘develop’ produce more and more waste. Urban Indian’s average waste generation per capita is today 400 grams per day. For The USA, it is at a staggering 2,500 grams per capita per day, and we seem to be slowly but surely moving in that direction – a frightening prospect indeed! The world today generates close to 2 Billion tonnes of waste per annum. This is up from about 1.3 Billion tonnes in 2010 (as per World Bank numbers). This number will probably grow to more than 2.2 Billion in 2020. India today collects close to 100,000 tonnes per day of waste (the generation is higher and so we see the waste everywhere). And as we urbanize, this problem will only dramatically increase.
We all know the reasons for this problem.
Increasing urbanization, coupled with economic development and modern living styles have created this monumental problem in the form of solid waste for urban India. Past frugal habits, almost no use of packaging, no knowledge of plastics, a limited population that was largely rural have given way to a scenario where municipal solid waste generation occurs at each step, without much thought going into the aggregated Municipal Solid waste (MSW) heaps that are becoming an integral part of our urban (and partially, even rural) landscape.
So what do we do?
The first and most obvious and desirable step that has been talked about for some time is: Reduce, Recycle, and Reuse. But at this stage in our country’s development, this is easier said than done. As we urbanize, some of our past practices are dying and being replaced with new, more “convenient” practices. I remember, when I was younger, my mother would never go to the market without a bag (typically cloth) of her own. Then, along came plastic bags at each hawkers’ end and out went the earlier re-usable cloth bags. Thus now all the vegetables come home in their own plastic bags. If we also look at most products we buy today, the packing has gone up dramatically. Similarly, the new urban economy has given a boost to the attitude of “convenience” and thus changed our age-old ways of recycling and reusing. Thus while the 3 Rs as they are called should be the aim of each one of us, we should understand that these generally go against current human behavior, find limited acceptance and even if successful, will still leave large quantities requiring treatment and safe disposal/ utilization.
MSW collection and management has thus become one of the most difficult and expensive tasks for most municipalities and Municipal Corporations across the world and in India. Most municipal bodies either spend a substantial part of their budget on this or just see this as a problem with no solution. Even where the waste is being collected, there are limited technical solutions available to handle the waste effectively.
Available solutions and their limitations / current status
The only real solutions that exist today are listed below:
♦ Landfilling Most waste collected in the country today is sent to an identified landfill. The landfills are not really scientifically designed and this leads to issues of groundwater contamination (the leachate generated in landfills should be trapped and treated but this is seldom done), air emissions, etc. As the quantum of waste grows, the landfills start choking and become a physical hazard as well. Recently there have been news reports of people dying due to part of the kachra in the landfills collapsing and falling on people (Delhi). In Deonar, Mumbai, parts of the landfill caught fire leading to all of Mumbai suffering smog. These are just a couple of examples but we read and hear such depressing stories each day! Similar stories come from other parts of the world as well – Colombo, Kenya etc. Thus the landfill can only be an interim solution and that too is becoming an increasingly difficult solution to implement as no one, including villagers, want these landfills in their backyards and for very obvious reasons!
♦ Composting As per the National Green Tribunal Guidelines, the wet waste (food waste, dung, vegetable and fruit waste, etc.) should be composted and the compost so generated should be used as fertilizer. A few sites are doing this but this finally treats less than 10% of the incoming waste. Thus there has to be a solution to handle the balance.
♦ Waste to Energy This seems to be the only real solution that can get rid of the waste in an economical and sustainable manner. But at this point of time, the technology available is complex, has emissions issues and is not available for villages, towns and smaller cities (typical combustion plants need at least 500 tonnes of waste per day). Many of the plants installed earlier have been shut down due to emission issues.
Parameters of an Ideal solution
The ideal solution should thus be a waste to energy technology that does below:
♦ It will need to substantially reduce the volume of the waste – ideally it should lead to all waste being processed and should send nothing to landfills.
♦ The process should generate wealth – fertilizer, gas/power etc, ensuring that the bane of MSW could become a boon.
♦ The solution should be usable in small towns as well as large cities.
♦ Even for large cities, the solution should allow decentralized processing to minimize transportation and related costs/ issues.
♦ Its emissions should be in keeping with all norms as defined worldwide.
♦ The solution should be financially viable.
An innovative solution
Under this very gloomy scenario, there seems to be a glimmer of hope as a new and promising technology has come to convert most kinds of waste to Energy. The technology uses the process of gasification to break down the solid waste into a combustible gas called Syngas. This gas is then used to generate heat or power.
♦ The technology uses all fractions of MSW without extensive segregation and coupled with composting / biogas plants, ensures that nothing goes to landfills. Part of the in-feed is given out as totally benign ash/ char that can be used for roads/buildings etc. while the balance material is converted to gas.
♦ The way the systems are designed ensures that all emission norms are
met.
♦ The systems are designed for distributed use. Thus, the smallest system is a 2.5 tonnes per day plant and the largest can handle up to 200 tonnes per day. This allows the use of the technology in small towns as well as large cities.
♦ The systems ensure that at current Waste to Energy power tariffs, the projects can be financially viable, particularly if small support/viability gap funding is made available.
♦ The systems have been designed, developed and made in India. A typical configuration uses about 100 tonnes of waste to generate about 1.8 MWe of power. It is envisaged that apart from using these systems in towns and villages, the systems can also be used to distribute waste processing in larger cities. This will ensure that the transport costs for the waste are much reduced.