Chennai has recently outshined the other smart cities of India and emerged as a role model for sustainability. It is one of the most populous cities in India harboring over 8.5 million inhabitants and subsequently generating approx. 5,200 tons of Municipal sewage wastes (MSW) per day.
It is one of India’s first 20 Smart Cities to nurture an innovation in managing its waste effectively and undertake and extensive wastewater treatment, as a pioneer for entire gamut of Indian metropolitan cities.
The Integrated Solar Dryer and Pyrolysis pilot has been inaugurated by Dr. K J Sreeram, Director, CSIR- Central Leather Research Institute (CLRI), Chennai, that strives to offer an innovative approach for smart cities to transform their urban untreated organic waste into biochar and clean form of Energy.
Therefore, Pyrasol stands for Pyrolysis and Solar systems integrated in a single package.
Lessons from a wasteful market:
A prior analysis made at the local fruits-vegetables market, known to generate about 3.5% of wastes out of entire city’s, found that there were left-off nutrients and fibers in the wastes those could be utilized to trigger energy.
The banana peduncles comprise with 32.5 % lignin and 24.5 % hemicellulose (based on dry matter) a high share of slowly degrading fibers. Vegetable and fruit wastes contain 17.5 % and 17.2 % lignin respectively.
Indo-German classic collaboration: Involved Parties
With greater emphasis on Industrial participation, applied research and technology advancement, the project was rendered to CSIR-CLRI(Council of Scientific and Industrial Research) by the Indo-German Science & Technology Centre (IGSTC).
IGSTC has been established by the Department of Science & Technology (DST), Govt. of India & Federal Ministry of Education and Research (BMBF), Govt. of Germany in collaboration.
Targets to the Mission:
The mission focuses on managing and streamlining the collection, segregation, treatment, and disposal systems of urban wastes in Indian Smart Cities as well as other urban centres on their path to Sustainability.
It aims to develop Technology needed for the joint processing of Fibrous Organic Waste (FOW) and Sewage Sludge (SS) of Indian smart cities into highly valuable biochar associated with energy recovery, carbon sequestration and environmental conservation.
Through the Pyrasol project, simple and robust processing techniques for abandoned organic waste will be further developed to improve sanitation and welfare, supply regenerative energy, convert waste into products and reduce the carbon footprint of smart cities.
It does so by an innovative organic waste drying system using the solar natural chimney effect followed by a highly efficient single-chamber pyrolysis.
In upcoming 10 years, it is estimated that Chennai would possibly generate approx. 1.7 million m³ of sewage per day. It is to note that entire city of Chennai is connected to a sewer system.
In the Indian Urban areas, approx. only 30% liquid waste is treated on an average, before its discharge in the larger waters.
On the other hand, any suspended solids and BOD of 300 mg/L and 150 mg/L in the inlet of sewage, about 250 tons per day of dewatered sludge from STP is generated and disposed in dumping sites.
This called for an urgent need of injecting modern and scientific methods for FOW and sewage sludge treatment for Indian urban areas like Chennai, which also corresponds to the main objectives of the Government of India’s Swachh Bharat Mission.
And hence Co-pyrolysis of both forms of wastes, a nutrient-rich, slowly releasing biochar and the sludge commonly high in Nitrogen and other valuable nutrients like phosphorous, is undertaken.
The PYRASOL project addresses synergies of both materials to reduce the individual treatment costs and to create a high value product and a zero-waste approach.
Indirectly, this project addresses highly-required sanitation and sustainability standards of Smart Cities in a novel, economic and innovative fashion.
Biochar and its services to Ecosystem:
Biochar and clean energy (heat and power) produced by pyrolysis (super-heating biomass in closed system-ovens) provides an alternative form of energy, reducing greenhouse gases by offsetting fossil fuel use and working along the Climate Action.
Upon addition to soil, biochar captures and sequesters the carbon that otherwise would oxidize and return to the atmosphere as CO2 and cause Global Warming.
Biochar-amended soils are known to provide a 50-80% reduction in nitrous oxide emissions.
This can help us incessantly to further provide an impetus to Green planet dream that Humans nowadays nurture, without much change in efforts. Little and innate changes can therefore be integrated into our bigger charms of decelerating a bigger evil called Climate change.