TERI develops and disseminates biomass-based
gasifier systems that serve as a source of heat for a various uses.
Customised gasifer systems have been developed for large-scale cooking;
cremation; sericulture; dyeing; extraction of chemicals; metal smelting;
and drying tobacco, rubber, and large cardamom. During the past
two decades, more than 300 gasifier systems have been installed
throughout India with a cumulative capacity of
12 MWthermal.
These gasifiers burn locally available low-grade biomass
fuels such as twigs, husk, shells of coconut and cashew, mustard
stalks, and other crop residues in briquetted form, but offer the
convenience associated with high-grade fuels such as gas and electricity.
The technology has been licensed to six manufacturers for commercialization.
It has also crossed international borders; TERI gasifiers are found
in neighbouring countries like Myanmar, Nepal, and Bhutan.
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| Improvement in system design and associated
benefits with product development approach followed |
The salient features of TERI gasifier design
are:
 Throat less design
Low specific gasification
rate
Use of castable
insulation of firebox
Use of water-seal
ash-pit and gasifier top cover (fuel charging door) for quick and
easy ash removal without disturbing operation and quick fuel charging
respectively
The various gasifier designs developed by TERI
so far along with its advantages and limitations are as follows:
Down-draft
gasifier
Relatively
clean gas
Can handle relatively
smaller wood pieces with low moisture content (upto 15%)
Up-draft
gasifier
Relatively
dirty gas (more tar content)
Can handle relatively
larger wood pieces and high moisture content (upto 20-25%)
Needs relatively
smaller capacity air blower
Up-draft
gasifier operating under natural draft mode
Can
be operated in remote areas where electricity is not available
for using blower
Relatively dirty
gas (more tar content)
Can handle relatively
larger wood pieces
Operates under
narrow range of designed gas production rates
Recently, TERI also developed a small sized wood
gas stove operating on IDG (inverted downdraft gasifier) principle.
This can be operated for given (design) output power under natural
draft mode or can be used for varying output power using tiny sized
blower (turbo stove), which can be operated using small battery.
These batteries can be charged using small solar cell in remote
areas. These turbo stoves or updraft gasifier can even be used as
efficient charcoal making devices utilizing volatiles
for some useful thermal applications. Turbo stoves can be operated
with efficiency levels of about 30-35% with charcoal yield of about
20-22%.
As mentioned earlier, TERI has been working on
developing tailor-made packages for thermal applications of gasifiers—both
updraft and downdraft type—over two decades. Gasifier development
work was initiated in TERI much before TERI-SDC (Swiss
Agency for Development and Cooperation) partnership came
into being. The partnership boosted the work
being pursued in the field in SMiEs (Small and Micro Enterprises),
which accelerated the pace of intervention. It also gave an opportunity
to work systematically in collaborative manner involving users,
sector experts, and product developers. It further provided an insight
on development of complete package of gasifier system for utilizing
producer gas efficiently. This helped in achieving higher overall
efficiency levels since in most of the cases this resulted in development
of better processes, making it faster, cleaner, and of better quality.
Various gasifier thermal application packages developed
by TERI under TERI-SDC partnership projects include:
Down-draft
gasifer along with improved SERI 2 000 oven for silk reeling
units
Down-draft gasifier
system for silk yarn dyeing along with improved oven
Up-draft gasifier
system as retrofit option for Italian cottage basin oven in Siddlaghatta
cluster along with options for silk yarn drying using either waste
heat of flue gases or by obtaining the required charcoal
as byproduct using gasifier
Improved charka
oven (about 25% fuel saving) using HRU (heat recovery unit) concept
for producing hot water and for silk yarn drying
Down-draft gasifier
application for namkeen making and sweet (sohan halwa)
making
Down-draft
and updraft gasifier systems for puffed rice making along
with improved bhatti, HRU and simple retrofitting devices
for reducing particulate emissions from the chimney
Up-draft gasifier
for bamboo-mat factory boiler
Up-draft gasifier
(either using blower or under natural draft operation) for community
cooking in residential hostels
Refining turbo
stove design
In addition to these, other gasifier thermal
applications developed so far under various other projects include:
Up-draft
gasifier for magnesium chloride manufacturing
Down-draft gasifier
for carbon dioxide production
Down-draft gasifier
for large scale community cooking
Up-draft and down
draft gasifiers for crum rubber drying
Down-draft gasifier
based crematorium
Down-draft gasifier
for tobacco curing
Down-draft gasifier
for plaster of paris making
Down-draft gasifier
for copper smelting
Down-draft gasifier
for lead melting
Down-draft gasifier
for bakeries
Up-draft gasifier
operating under natural draft mode for green brick drying
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