Composting is a managed process which utilizes microorganisms naturally present in organic matter and soil to decompose organic material. These microorganisms require basic nutrients, oxygen, and water in order for decomposition to occur at an accelerated pace. The end-product, compost, is a dark brown, humus-like material which can be easily and safely handled, stored, and used as a valuable soil conditioner. The composting process is dependent upon several factors, including: the population of microorganisms, carbon to nitrogen ratio, oxygen level, temperature, moisture, surface area, pH, and time.The composting process involves microorganisms feeding on organic material and consuming oxygen.The process generates heat, drives off moisture, and reduces bulky organic waste into a beneficial soil-like material containing nutrients, humus and microorganisms in just a few months. Material in an UN-managed pile of organic debris will eventually break down but the process will take a long time and may result in odor or other nuisance problems due to poor aeration.
9. Incineration-
incineration of waste is the most prevalent form of
converting MSW to energy. The waste is combusted ,
and the heat or biogas created is harnessed and either
distributed as heat or converted into a form of useful
energy -steam or electricity
10. Incineration System is a technology
which is used to destroy organic waste
by thermal oxidation of all hazardous
and harmful constituents in the waste.
The incineration system installed at
MWML is designed by M/S ALSTOM
power Inc. U.S.A and having thermal
Capacity of 5.5 MKcal/hr. It is a ROTARY
KILN type incinerator suitable for all
types of waste like solid, liquid and
gaseous waste. It is operated
automatically with PLC system and
connected with continuous emission
monitoring system.
11.
12. Pyrolysis
* Pyrolysis is an advanced form of gasification that chemically
decomposes organic materials by heat in the absence of oxygen.
*The process typically occurs under pressure and at very high operating
temperatures – around 500 degrees Celsius
*—Bio-oil, a gas, and char are the products of the
pyrolysis process
Bio-oil is a purified, liquid renewable energy source which can be used to
produce power and heat for industrial boilers
—Pyrolysis as WTE technology has been piloted and is beginning to be
tested in the markets
—Pyrolysis is also reaching commercialization in the production of cellulosic
ethanol
13. ANAEROBIC DIGESTION
/BIOMETHANATION
What is Anaerobic Digestion?
Anaerobic digestion is the process by which organic matter
such as animal or food waste is broken down to produce
biogas and biofertiliser. This process happens in the
absence of oxygen in a sealed, oxygen-free tank called an
anaerobic digester.
14.
15.
16. What materials do you put into an anaerobic digester?
Ideal materials – also known as feedstocks – for
digesters include:
food waste
municipal wastewater solids
fats, oils and grease (FOG)
livestock manures
High-caloric feedstocks with lots of fat, sugar and starch typically
yield more biogas than other materials.
17.
18.
19. What products do you get
from anaerobic digestion?
Typically, three things come
out of an anaerobic digester
for beneficial reuse:
Biogas (which can be turned into
electricity and heat, or fuel)
Solid fertilizer (from the digestate,
the materials after they have been
digested)
Liquid Fertilizer (from the centrate,
the liquids after they have been
digested)
22. Anaerobic digestion consists of four stages
that happen on the microscopic level:
Hydrolysis – Longer chain carbohydrates, fats and proteins are broken into
shorter chain molecules
Acidogenesis – Shorter chain molecules produce carbon dioxide, hydrogen
sulfide and more volatile fatty acids
Acetogenesis – Simple molecules created through the first two steps are
digested by specific bacteria to produce acetic acids as well as hydrogen
and carbon dioxide
Methanogenesis – A certain class of bacteria known as methanogens
utilizes the products developed in stages 1-3 and converts them into
methane, carbon dioxide and trace amounts of other gases
25. A typical treatment cycle will begin with the
loading of unsorted waste material and end in
the offload of a dry powder (product), which
now possesses new characteristics and that
the input material did not. The garbage is
loaded into a chamber, also the conversion
cell, by hand or through the use of a loading
elevator or conveyor belt, depending on the
application and toxicity/danger level
associated with handling the waste. The
previous batch of post-treatment product is
removed and a new cycle is started through an
electronic control panel. Modern converters
are fully automatic and will finish the
computer controlled cycle autonomously,
unless a failure occurs.
26. The conversion cycle consists of several sequential steps or phases. The waste is first ground
and pulverized to an unrecognizable mixture by a combination of fixed and actuated hardened
steel blades. The mixture is then heated through the injection of steam and also by the heat
generated by frictional forces of the grinding phase. The exact temperature required to
pasteurize, and in the subsequent phase to sterilize the waste, is maintained for a time that
allows for an 18 log 10 reduction in microorganisms. In order to eliminate the required amount
of microorganisms required by government regulations, a complete saturation of waste matter
with superheated steam is required for a minimum amount of time, also regulated by
environmental agencies. The modern converter achieves saturation within 10–15 minutes due
to the high degree of pulverization preceding the sterilization phase, whereas older models
required up to several hours to saturate and sterilize the same load.
The cycle ends in a cooling phase, during which product continues to be dehydrated. Upon
reaching temperature at which product is safe to handle, near ambient temperature, the cycle
automatically shuts down. The end product is expelled into a tray that can then be hauled off
for storage. The entire process and statistics are recorded and stored in computer memory for
record keeping.