BE Magazine

the influence of humidity, and other factors.
The characteristics of waste are important when
selecting a specific Waste to Electricity (WtE)
technology. An optimized plant that treats
preselected waste can recover two or three times
more electricity and heat than a more traditional
plant that treats raw waste.
There is a wide range of WtE technologies.
Successful implementation of WtE conversion
technology depends considerably on the efficiency
of the process, which, in turn, depends on the
quality of the considered waste.
Recovery of energy and materials from MSW
through the production of a Refuse Derived Fuel
(RDF) is one of the feasible alternatives. RDF is
the product of processing MSW to separate the
waste to energy technologies such as Incineration,
Plasma Pyrolysis or Gasification.
A proposed new generation solution for
Bangladesh is to generate biogas, electricity, and
compost from the MSW. The process begins with
the recovery of recyclable material by passing
MSW through screen and sorter conveyer belt.
Then bypassing through Organic Liquifying press,
organic and inorganic components are separated.
The bio-degradable organic wet portion is sent to
anaerobic digestion. The biogas thus generated
can be then used to generate electricity by using
gas generators. The solid residue generated from
the biogas operation is used as organic fertilizer
(compost) after dehydration. The liquid portion
can be collected as liquid fertilizer.
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Pollution Control
noncombustible from the combustible portion,
enabling better reuse of materials and recycling
of MSW with the possibility of achieving higher
efficiencies in energy recovery treatments. RDF has
several advantages compared to raw MSW. RDF
is an efficient fuel due to its high calorific value,
more homogeneous chemical composition, more
convenient storage, and handling characteristics,
and fewer carbon emissions.
The composition of MSW in Bangladesh has very
low heat content (3-6 MJ/kg) due to the high
percentage of moisture. Because of high moisture
and organic content, a great amount of additional
energy is required to preprocess the MSW to
prepare as feedstock for a conventional type of
The inorganic or non-biodegradable portion
obtained from the pressing process is further
processed by screening, manual, optical and
magnetic separator. The residue is then shredded
and dried to obtain RDF. The RDF is used to
generate electricity by Grate Incineration or
Gasification based gas turbine. This process has a
substantial amount of by-products as ash (3%-5%),
which can have secondary demand in the cement
manufacturing plant.
Converting MSW to energy has numerous
economic, health and environmental benefits,
including, serving energy demand; several useful
by-products; minimum end residue produced and
little to no waste products; clean & healthy city;
and besides all that, sustainable pollution control.
December, 2019
Monthly business magazine