Solid Waste to Wealth Tech Designed by CSIR

Researchers developed sustainable processing of municipal solid waste.

The CSIR-CMERI developed a municipal solid waste processing facility plant.
The plant helps in achieving the decentralized decimation of solid wastes and also creates value-added end products.
The new technology disposes of solid waste in a scientific way following the Solid Waste Management Rules (SWM), 2016, notified by the Ministry of Environment, Forests and Climate Change.
The primary focus is on the advanced segregation techniques.
The segregation system segregates solid waste into metallic waste- metal body; metal container inert-glass, stones, etc.; biodegradable waste- food, vegetables, fruits, grass; non-biodegradable-plastics, packaging material, pouches, bottles etc.
In an anaerobic environment, the bio-degradable waste is decomposed and is popularly known as bio-gasification.
The biogas is used as a fuel for cooking and in the gas engine for the generation of electricity.
The residual slurry is converted to compost known as vermicomposting and utilized in organic farming.

Due to rapid urbanization and increasing population, India is facing a waste managementchallenge.
The estimation of the volume of waste may rise from 62 million tonnes currently to 150 million tonnes by 2030.
There will be a huge requirement of landfill area for the dumping such huge volumes of garbage.
So there is an urgent need for scientific solid waste management.

Solid waste management and disposing of utilizing plasma arc gasification is the best option for solid waste management.
This process is eco-friendlywhere a large volume reduction of waste of up to 90% is possible.
This process utilizes electricity to generate high-temperature plasma – 3000 degrees centigrade – inside the plasma reactor.
In the plasma reactor, the waste is converted into syngas.
The syngas passes through a series of gas purification systems.
The gas purification system consists of catalyst compressors like convertor, redox reactor, cyclone separator, scrubber and condenser.
The condenser is ready for use in gas engines for electricity generation.
The ash obtained can be mixed with cement for the preparation of recycled bricks.
But this technology is not economically viable as the energy requirement for waste treatment is very high approximately 1.5kWh/kg of waste for small plants for <100 MT capacity and for greater than 100MT is approximately 1.2 kWh/kg.
The recurring expenses make the process expensive as the rate of electrode consumption is very high approximately 500mg/kg of waste processed.
In India, the solid waste generated majorly consists of organic wastes (>50%).
The disposal of organic waste produces greenhouse gases.
The ineffective processing of Municipal Solid Wastes causes many diseases as the landfills to transform into contamination hubs for pathogens, viruses and bacteria.

The dry leaves, dead branches, dry grass are biomass waste and these are disposed of by first shredding them into a suitable size, then mixing them with the slurry of the biogas digester.
This mixture forms the feedstock for briquette which is subsequently used as a fuel for cooking.
Also, the briquette is utilized for the production of syngas for the generation of electricity.
The ash produced by burning the briquettes can be used in cement bricks production by mixing an appropriate quantity of ash with cement and water.

The polymer waste is disposed of through two main processes.
In the pyrolysis process, the waste is heated to a temperature of 400-600°C in an anaerobic environment.
The volatile matter comes out from the waste and on condensation gives pyrolysis oil.
The non-condensed syngas and pyrolysis oil are reused for heating purposes.
The char which is a solid material is mixed with the biogas slurry for making briquette.

The sanitary napkins, masks and diapers are disposed of by using high-temperature plasma.
The CSIR MSW facility is equipped with disinfection capabilities.
The Decentralized Solid Waste Management plant has the potential to scientifically manage the waste including COVID-19 and other viruses.
This helps to break the COVID-19 chain through UV-C Lights and Hot-Air Convection methods.
The pilot plant is self-sufficient in terms of energy requirements.By installing roof-topped solar panels on the facility, surplus energy can be provided to a mini-grid to operate the facility.