STEPS has developed a Comprehensive Municipal Solid Waste Management and Disposal system that processes non segregated MSW and converts it into commercial products such hydrocarbon fuels. Moreover, the unprocessed residues such as glass, metals etc. are segregated automatically for efficient disposal.
In conventional MSW management systems, handling of wet garbage during monsoons and disposal of plastics poses severe problems. Today, plastics are segregated and buried into land fills. But the technology developed by STEPS handles these critical aspects effectively. The MSW system converts organic matter into combustible gas and carbon; the gas is used to provide energy to the process making this a zero energy system, whereas the carbon is compacted into pellets for use as solid fuel by industry. On the other hand, the MSW system converts plastics to liquid hydrogen fuel for industrial use. In contrary to conventional systems which convert waste to bio-compost in a long process, STEPS’ system converts the garbage on the same day leaving no backlog for the next day.
Technology for segregation and treatment of waste
MSW can be classified into four categories:
- Organic material
- Other waste
A brief description of the process for municipal solid waste treatment is set out below:
The system consists of optic sensors which identify plastics by the colour, size etc and at the end of a star screen on the conveyor, these plastics get sucked and delivered into an exclusive plastic collection area.
Process for biomass gasification and bio coke manufacture
The MSW is taken into the biocoke processing system after the pre-segregation is done and the plastics are removed. The gasification and coke formation takes place in the reactor between 70oC and 350oC in the reactor. The gas formed during the process is passed through a catalytic converter where the cracking of the gas takes place and the hydrocarbon gas is formed. This gas is then passed through a condenser to form liquid petroleum fuels. The residue which remains are in the reactor is then collected. The residue is in the form of biocoke.
Segregation / Sorting of metals
Ferrous Metals Segregation
The metals are distinguished as ferrous and non-ferrous. Ferrous metals are attracted to a magnetic belt, which collects all the metal debris such as nails, screws, clips, needles etc.
Non- Ferrous metals segregation system
The non-ferrous metals such as aluminum cans etc., are repulsed by eddy currents. Using this principle, an eddy current roller identifies and throws the aluminum cans and the non-ferrous metal articles into a separate collection bin for non-ferrous metals.
The construction debris, paper etc are separated by star screens using the particle size as the criterion and the paper and stones etc. are deposited in their designated areas. Similarly glass is crushed into pieces and collected into a separate area using gravity as the separator.
The bio-coke which remains is then forced through a pelletizer where it gets compressed into small pellets; alternatively it can be made into brickets. These pellets or brickets can be used as a substitute for coal.
Conversion of plastics to fuel
STEPS has developed a technique wherein plastics of all kinds including thermo set, industrial plastics, thin film bags, PVC etc. can be converted into petroleum products such as gasoline. The method is called “STEPS POLYCRACK” system.
The segregated plastics from the MSW are converted into a feed stock for the STEPS P2P conversion system. In this system, the plastics are heated to app 350 deg C in the presence of a specially formulated catalyst. The molten plastics in the presence of the catalyst, convert into gaseous matter and the molecules of gas are re-arranged by the action of the catalyst and the final product coming out of a condenser in the system is light diesel oil.
Advantages of the system
- No pre-segregation of material since segregation completed during processing
- Wet garbage and dry garbage can be handled with same ease
- Organic material converted to valuable biocoke
- Plastics converted to valuable petroleum products
- Plant generates own energy and needs minimal external power
- Segregated metals are saleable
- Segregated grit and sands can be re-used for road construction
- High capacity plant within a limited area can release the burden of land requirement
- Old landfills can be revived releasing valuable land for re-use
- Environmentally friendly process
- Minimum requirement of water
- Modular system that can be upgraded based on garbage generation
- Modular system can be designed for fertilizer or cellulose generation instead of bio-coke
- Entire unit is enclosed, no dust or smoke pollution
- Automated system requires minimum man power
- Highly experienced manufacturer with a strong international standing
- Highly economic cost of operation