August 1996 Gasification Archive

From 73002.1213 at CompuServe.COM Thu Aug 1 09:20:43 1996
From: 73002.1213 at CompuServe.COM (Thomas Reed)
Date: Tue Aug 31 21:07:12 2004
Subject: GAS-L: praktical carbon conversion figures
Message-ID: <960801132239_73002.1213_FHM66-3@CompuServe.COM>

Robert van der Plum and Gasification:

Robert asked: Can someone help me to find praktical figures about carbon
conversion in a downdraft gasifier and circulating fluid bed gasifier. Also
praktical
coldgas efficiencies would be a help.

Here's one answer, I hope others will weigh in. This is not a simple question,
for downdraft gasifiers and is of course dependent on fuel type, operation
conditions, grate shaking grate hole size etc.

I have worked with downdraft gasifiers for many years. The char-ash residue is
typically from 3% (low) to 6% (high). Wood typically contains about 1% ash. If
100% of the mineral remains in the char-ash, a 3% residue would contain 33%
ash, 66% carbon; a 6% residue would contain 17% ash. If one wishes to "shake
the grate" often or auger out the char-ash, conversion rates soar, the energy
value of the gas goes up, but tar/oil also goes up rapidly.

There are physical and thermodynamic reasons for incomplete carbon conversion.

As the hot rich-combustion gases from flaming pyrolysis (1300C?) meet the fresh
charcoal (15% yield?) they are reduced, increasing CO and H2 content in the gas.
The reducing reactions are very endothermic, so in a few partricle diameters the
temperature drops to 800C, then continues down to about 700C in an infinitely
long char bed. There is not enough energy in the got gases to consume all the
carbon.

As the carbon reacts, the cellular walls get thinner and thinner until only the
intersection nodes (micron size remain. These will be carried away by the gas
stream through the grate and into the cyclone or filters. I believe the 3%
residue represents the thermodynamic limit, while the 6% is due to physical drop
out and carry through.

Incidentally, I have long believed that the incomplete carbon conversion is a
hidden benefit in fixed bed gasifiers in that much of the mineral remains with
this carbon. Incidenally there seems to be good evidence that it is a good soil
conditioner.

Without specifying the equipment and conditions, I don't think it is possible to
give any answer for fluidized beds. Carbon re-circulates within the bed or can
be recirculated from the cyclones. I hope the FB gasifier members can give us
some guidance here.

Good question, keep asking.

Yours truly, TOM REED
Professor Chemical Eng.
303 278 0558; 0560 FAX The Colorado School of Mines,
E-Mail 73002.1213@compuserve.com Golden,
CO. 80401

From 73002.1213 at CompuServe.COM Fri Aug 9 10:02:15 1996
From: 73002.1213 at CompuServe.COM (Thomas Reed)
Date: Tue Aug 31 21:07:12 2004
Subject: GAS-L: Bourbaki again
Message-ID: <960809140142_73002.1213_FHM106-3@CompuServe.COM>

Good morning Colleagues:

Some of the greatest - and smallest - gifts I have received in my life have been
recommendations of books to read - books which have sometimes improved my life
incalculably. Assuming that most of you have some time left over from E-mail to
read books, I hereby present such a present to all of you.

A few months ago in the STOVES network I brought up the question of multiple
creators of ideas and how to apportion credit amongst those responsible. I
mentioned the name BOURBAKI, a group of creative mathematicians who worked and
published together and didn't worry about who go the credit. At that time that
was the total extent of my knowledge about BOURBAKI. I have now come across an
interesting and exciting novel that has increased my knowledge and interest in
the question 100 fold, ie

THE BOURBAKI GAMBIT - CARL DJERASSI
(The Univ. of Georgia Press, Athens, London, 1994)

This novel explores: Scientific creation and ego; outpasturing of creative
scientists by the establishment; gender in science; sex in advanced age; the
world of DNA; the world of Science prizes, .... in 230 well written pages.

(Carl Djerassi is a professor of chemistry at Stanford U., winner of the 1992
Priestley medal, etc. etc. He follows some of the roads of C.P. Snow, but with
more humanity.)

*****
The Internet has enhanced the "collective consciousness" of science and
scientists by permitting worldwide the free talk of colleagues usually only
possible at meetings. It is hard to know what the consequences will be, but
this book certainly raises some of the issues that will need to be addressed to
reach our full potential.

I'll be interested in any reactions you-all have.

Yours truly, TOM REED

From houmoller at dk-teknik.dk Mon Aug 12 08:07:10 1996
From: houmoller at dk-teknik.dk (S?ren Houm?ller)
Date: Tue Aug 31 21:07:12 2004
Subject: GAS-L: Fluid bed gasification
Message-ID: <320F9CFE@mail.dk-TEKNIK.dk>

Hi bio-netters.

I had some good responses on my mail "Why not small scale fluid bed
gasification" and although I now know more about small scale fluid beds I am
still not convinced that there are unsolved problems involved.

I promised to add some information about the process on my homepage, which
has now been done. You can check it out at

http://www.sh.dk/~cbt/sh/fluidbed.htm

You can also see a compilation of Danish gasification projects on

http://www.sh.dk/~cbt/sh/opencore.htm

I posted this message to the bioenergy list as well as the gasification
list. This is because the bioenergy list members should be able to follow
the rest of the fluid bed gasification discussion which started on the
bioenergy list.

S|ren
______________________________________________________
Soren Houmoller, http://www.sh.dk/~cbt/sh
CENTRE FOR BIOMASS TECHNOLOGY homepage:
http://www.sh.dk/~cbt/
Email: houmoller@dk-teknik.dk

From 73002.1213 at CompuServe.COM Thu Aug 15 09:11:42 1996
From: 73002.1213 at CompuServe.COM (Thomas Reed)
Date: Tue Aug 31 21:07:12 2004
Subject: GAS-L: Re: Fluid bed gasification
Message-ID: <960815131049_73002.1213_FHM74-2@CompuServe.COM>

Soren:

I'll try to collect the beginnings of the Fluid bed gasification thread from the
BIOENERGY group and insert into the GASIFICATION group files.

Glad to learn of the two WWW addresses. I am currently waiting for my server,
Compuserve, to become fully NETSCAPE compatible. However, I am to generally
more satisfied with the E-mail and group E-mail than I am with the WEB pages.
The WEB pages have more "hype" than these letters.

Incidentally, you should check out my company page at http://www.SeaSweep.com.
We make a superior oil absorbent from wood residues.

Best Regards, TOM REED

PS: S?ren Houn?iler: If one leaves out the diacritical marks in Danish can
Danes still read and understand?

From 73002.1213 at CompuServe.COM Sat Aug 24 10:56:25 1996
From: 73002.1213 at CompuServe.COM (Thomas Reed)
Date: Tue Aug 31 21:07:12 2004
Subject: GAS-L: Gasification in India
Message-ID: <960824145828_73002.1213_FHM20-2@CompuServe.COM>

Tom: In case you missed it, here are some (edited) gasification items for INDIA
from Mukunda. Those East Indians sure work hard.

To All the Members,

This is regarding BUN-INDIA's NewsLetter that is made available
at Web site http://144.16.73.100/~mukunda/home.html. As we got the
information that some people are not able to access this site, we are
sending the same below and welcome your comments and suggestions:
----------------------------------------------------------------------------
----------------------------------------------------------------------------
August 1996 Volume 1.1
BUN-INDIA
Biomass Users Network India

Chairman

WOODY BIOMASS FOR ENERGY IN INDIA
N. H. Ravindranath, ASTRA, Indian Institute of Science,
Bangalore 560 012, India

There have been significant developments in bioenergy
technologies in the last decade. Bioenergy technologies have
been shown to be desirable and feasible for meeting rural energy
requirements in developing countries on social, economic and
environmental considerations. Studies (Ravindranath and Hall
1995) have shown that, it is possible to meet all the
electricity requirements of all the 557, 000 villages in India
through kilowatt scale systems. The crucial question here is
the land availability for woody biomass production. India is a
large populous developing country with a population of 900
million and a population density of 275/km2.

A detailed analysis of land availability for energy in India has
shown that in India 66 to 130 Mha of degraded land is available
for woody biomass production (Ravindranath and Hall 95). Out of
this only 15 Mha is adequate to produce about 122 Mt. of wood
required at a productivity of 8 t/ha/year to meet all the rural
electricity requirements in India. This vast degraded or
wastelands are subjected to over grazing, soil compaction, soil
erosion and degradation. At the current annual rates of
afforestation of about 1.5 Mha, it is going to take at least 50
years to revegetate the wastelands.

The assured demand for wood production and the commercial nature
of sustainable wood production and bioelectricity generation
system would provide the necessary financial incentive to
reclaim a part of vast wastelands in India. Thus land is not a
constraint in India for producing woody biomass for energy.

Reference
Ravindranath N. H. and Hall D. O. (1995). Biomass Energy and
environment - A developing country perspective from India.
Oxford University press, Oxford.

DEVELOPMENT OF BIOMASS GASIFIER SYSTEMS FOR FINE/LOW DENSITY
BIOMASS A.D.S. Chauhan, Sr. Advisor, Ankur Scientific Energy
Technologies Pvt. Ltd., Ankur, Near Old Sama Jakat Naka,
Baroda 390 008

While the initial focus of the biomass gasification programme in
the country was generally on use of firewood/wood waste/wood
chips (i.e. woody biomass), increasing emphasis has
subsequently been laid on use of various agricultural and
agro-industrial residues like rice husk, bagasse, saw dust
etc,. Many of these feedstocks are characterised by relatively
small particle size (fines), low bulk density and/or high ash
content. A major effort was launched at Ankur Scientific to
develop a range of gasifier systems capable of accepting many of
these feedstocks without substantial pre-processing or fuel
preparation (in terms of pulverising, briquetting etc.,). The
FBG series of gasifiers, commercialised as a result of this
effort, have shown very satisfactory performance on both rice
husk and saw dust. Initial trials on other similar feedstocks
have given promising results. Field installations on commercial
basis have been undertaken in Andhra Pradesh and Madhya Pradesh
with high customer satisfaction reported so far.

The gasifier systems use novel control strategies and mechanisms
for feed movement, char removal and also for responding to
variable load conditions. Another unique achievement has been
almost total elimination of large amounts of tar that are
typical of rice husk gasifiers. The experience so far indicates
that the FBG series gasifiers could accept a very wide variety
of fine/low density/high ash feedstocks and a prototype has been
set up at Ankur Scientific for regular trials with new
feedstocks that may be of interest to likely customers/users of
gasifier systems.

BIOMASS GASIFIER FOR DRYING OF CHEMICALS
Dr. B C Jain, Ankur Scientific Energy Technologies Pvt. Ltd.,
Ankur, Near Old Sama Jakat Naka, Baroda 390 008

ACE manufacturing & Marketing at village: Gothda Taluka: Savli
Dist.: Baroda - 391 770, is using a 20 kW, Ankur wood based
gasifier for the dehydration of chemical grade aluminium
hydroxide, to manufacture end product activated alumina. The
system consists of a gasifier, contact chamber, recovery
cyclones and a suction blower. The producer gas from the
gasifier is burnt in a suitably designed burner to give maximum
heat output of 5000 kcal/hr.

The hot flue comes in contact with free flowing alumina powder,
in the contact chamber, whereas the dehydrated product after the
removal of 30-32 % combined moisture is collected in the
recovery cyclones.

With the process using gasifier, the drying costs has been
reduced to 40% and 70% of the cost using similar system with
other fuels, such as kerosene, diesel or LPG and an electric
furnace, respectively. This drying system using biomass
gasifier has run for more than 5000 hrs so far, without any
serious operational or maintenance problems.

The experiments with drying of other solids with varying
consistence and also adopting gasifier to attain temperatures of
up to 2500 C, in a tray drier in the indirect mode, have been
successful and are being implemented in the actual production.

NARI GASIFIERS FOR THERMAL APPLICATIONS
Anil K. Rajvanshi and Rajeev M. Jorapur,
Nimbkar Agricultural Research Institute, P.O. Box 44, Phaltan -
415 523, Maharastra, India

NARI has developed low density and leafy biomass gasifiers upto
800 kW capacity for thermal applications under a grant from
Rockefeller Foundation. This multifuel gasifier produces
producer gas which burns with an intense bluish-white flame with
flame temperature about 10000 C. The system was tested in an
actual user-industry (makers of speciality refractories) in
India by retrofitting it to an existing LDO-fired furnace in the
industry. Other possible thermal applications are in bakeries;
brick kilns; metallurgical furnaces; for making jaggery (gud);
for drying seeds and other agricultural produce; or for other
industrial drying applications where sufficient biomass is
available. The gasification system can therefore prove to be a
boon for rural and agro-based industries.

SALIENT FEATURES OF NARI SYSTEM

Capacity : Two sizes of 400 and 800 kW are available. Higher
capacity gasifiers can be custom designed.

Multi-fuel gasifier : Can handle different biomass fuels like
sugarcane leaves/bagasse, sweet sorghum stalks/bagasse etc.
Systems to operate on other fuels like coconut coir, wheat husk,
different types of grasses and safflower residues etc. are being
developed.

Value added by-product : About 24% of the fuel is converted to
char, which is a value-added product. It can be briquetted to
form excellent fuel for chulhas (wood stoves) or can be used as
a soil conditioner.

Zero waste water system : No process water is required for the
operation, and so no waste water is generated

Minimal maintenance and downtime : Hot gas cleaning, so on
condensation and accumulation of toxic tars and other
condensables occur in pipe-lines and equipments

Quick start-up and shut-down : Cold start within ten minutes and
hot start-up within three minutes

Judicious mix of auto and manual controls : A PLC-based control
system controls the entire gasifier operation. Only two
operators per shift are required for fuel and ash handling
operations.

TECHNICAL SPECIFICATIONS
(A) Fuel : Biomass fuels like sugarcane leaves, bagasse, bajra
residues, wheat straw etc. with the following specifications
have been gasified in the NARI gasifier

Bulk density : 25-100 kg/m3
Particle size : 1-10 cm long
Ash content : < 10%
Moisture content: <20% w/w (wet basis)

(B) NARI gasification system

Thermal output : 100-800 kW (thermal) or 360-3280 MJ/h
Gas calorific value : 3.36 -4.62 MJ/Nm3
Flame temperature : ~ 10000 C

ECONOMICS

The fixed cost of the system varies from Rs. 1,500/kW to Rs.
2,000/kW depending on the capacity, the materials used, the
degree of mechanisation of the fuel and ash handling systems and
the extent of automation of the system. The operating costs are
extremely site- specific and depend primarily on the landed cost
of biomass at site and the capacity utilisation of the gasifier
system. The cost of energy delivered therefore varies from Rs.
480/MWh to Rs. 720/MWh and compares very favourably with that
from light diesel oil (LDO) fired units whose cost is 1000
Rs./MWhr.

GASIFIER DEMONSTRATION

MNES has been implementing a nation-wide demonstration
programme for gasifiers and provides a partial capital cost
of gasifier, 30 per cent in case of thermal, 60 per cent in
case of mechanical and electrical applications with
upper limit prescribed for different ratings. Capital
subsidy ranging from 30 to 75 per cent is being provided for
use of gasifier for cooking application in hostels,
mess rooms of military, para-military forces and police.
The programme is being implemented in a market oriented
manner, manufacturers develop the proposals by selecting users
and government subsidy is routed through state nodal
departments/ agencies in a phased manner to ensure the
quality and performance of the systems installed by the
manufacturers. Under gasifier demonstration programme,
village electrification is also supported by providing 75
per cent of cost of gasifier and gasifier engine set, balance 25
percent panchayat. Operation and maintenance cost is met by
the Panchayat through collection of payments from the
beneficiaries.

So far, about 1600 gasifiers with an aggregate installed
capacity of about 18 MW equivalent have been installed in
the various parts of the country for irrigation, industrial
and village electrification. About 15 villages have been
electrified under the programme. A state- wise list of
gasifiers is given at Table I.

FISCAL AND FINANCIAL INCENTIVES

Several promotional incentives for renewable systems have been
provided by the government in order to overcome the inherent
bias and distortions in the energy sector policies which
favoursfossil fuels. These incentives include tax concessions,
customs and excise duty reliefs. Indian Renewable Energy
Development Agency (IREDA), a financing public sector unit
under MNES, provides soft loan for manufacturing and utilization
of renewable energy devices and systems including biomass
briquetting and gasification.

Table-I

STATEWISE LIST OF GASIFIER SYSTEMS INSTALLED UP TO March 31, 1996.

Upto March 1993 1993-94 1994-95 1995-96
--------------- -------------- ----------------- -------------------- -------
STATE No.of Capacity No.of Capacity No.of Capacity No.of Capacity
systems (kW) systems (kW) systems (kW) systems (kW)
installed installed installed installed
-------------------------------------------------------------------------------------
Andhra
Pradesh 40 194 18 390 24 2400 17 1700
-------------------------------------------------------------------------------------
Arunachal
Pradesh - - 3 120 - - - -
-------------------------------------------------------------------------------------
Assam - - - - 5 23 - -
-------------------------------------------------------------------------------------
Bihar 2 20 - - - - - -
-------------------------------------------------------------------------------------
Goa 3 30 - - - - - -
-------------------------------------------------------------------------------------
Gujarat - 164 1260 14 1030 12 1104 5
-------------------------------------------------------------------------------------
Haryana 16 274 1 100 8 590 - -
-------------------------------------------------------------------------------------
Himachal
Pradesh 2 8 - - - - - -
-------------------------------------------------------------------------------------
Jammu &
Kashmir 4 120 - - - - - -
-------------------------------------------------------------------------------------
Karnataka 468 2329 - - - - - -
------------------------------------------------------------------------------------
Kerala 5 115 1 100 4 400 - -
-------------------------------------------------------------------------------------
Madhya
Pradesh 105 649 10 100 14 1740 10

From 73002.1213 at CompuServe.COM Sat Aug 24 10:56:24 1996
From: 73002.1213 at CompuServe.COM (Thomas Reed)
Date: Tue Aug 31 21:07:12 2004
Subject: GAS-L: Gasification in India
Message-ID: <960824145809_73002.1213_FHM20-1@CompuServe.COM>

To - Gasification Group:

H.S. Mukunda recently posted the following message from his WWW site. I have
collected only the articles dealing with gasification below. The full text that
has a lot of other useful information can be found in his posting.

Cheers, TOM REED
****
This is regarding BUN-INDIA's NewsLetter that is made available
at Web site http://144.16.73.100/~mukunda/home.html. As we got the
information that some people are not able to access this site, we are
sending the same below and welcome your comments and suggestions:
----------------------------------------------------------------------------
----------------------------------------------------------------------------
August 1996
Volume 1.1
BUN-INDIA
Biomass Users Network India

Chairman

Prof. H S Mukunda
Combustion, Gasification & Propulsion Lab.
Dept. of Aerospace Engineering
Indian Institute of Science
Bangalore 560 012, India
Tel +90-80-3348536
Fax +90-80-3341683
E-mail mukunda@aero.iisc.ernet.in
Internet http://144.16.73.100/~mukunda/home.html

Contents

* Foreword
* What is BUN-INDIA?
* Agro-residue potential of India
* Wood Biomass for energy in India
* Development of Biomass Gasifier Systems for Fine/low density biomass
* Biomass Gasifiers for drying of Chemicals
* Case study of family size biogas plants Dhanwas
* NARI Gasifiers for thermal Applications
* Efficient use of biomass in Karnataka
* Species choice and space geometry to enhance biomass production
* Biomass programme in India
* Editorial

Foreword

We are pleased to place before you the inaugural issue of the
newsletter of Biomass Users Network India). We would like to
largely concern ourselves with the use of bioresidues for energy
generation purposes. In the process, if value addition takes
place, it is also considered a part of the activities of BUN.
The basic idea of this newsletter is to provide a forum for
exchange of ideas, presentation of newer developments in Biomass
utilisation. We hope to bring together technologists,
manufacturers, users, and anybody interested in the efficient
utilisation of biomass. While this issue has explanatory
articles which are from those who have spent time in the
development of the technologies and those who have used them in
the service of the society, a section on letters from readers
and responses to them from appropriate people will be provided
from the second issue. We need to recognise that there are
other newsletters and networks in the area of thermochemical
conversion of biomass - Pyne Network, Wood fuel now!, Biomass
Focus, Warmer Bulletin, The Solar Letter and the like. Yet, the
activities in Biomass Utilisation currently active in India
because of Governmental and Industrial support are perhaps most
unique and need to be brought out for the benefit of the
progress in our country and elsewhere. This Newsletter will be
put out on WWW electronically at the address
http://144.16.73.100/~mukunda/ home.html and is being sent to
about four hundred and fifty people all over the world. It is
also being sent to all the active Newsletter offices. We hope
that this will generate more discussion and lead to more and
better utilisation of the natures most bountiful and least
expensive renewable source of energy in a sustainable way.

DEVELOPMENT OF BIOMASS GASIFIER SYSTEMS FOR FINE/LOW DENSITY
BIOMASS A.D.S. Chauhan, Sr. Advisor, Ankur Scientific Energy
Technologies Pvt. Ltd., Ankur, Near Old Sama Jakat Naka,
Baroda 390 008

BIOMASS GASIFIER FOR DRYING OF CHEMICALS
Dr. B C Jain, Ankur Scientific Energy Technologies Pvt. Ltd.,
Ankur, Near Old Sama Jakat Naka, Baroda 390 008

CASE STUDY OF FAMILY SIZE BIOGAS PLANTS IN DHANAWAS
S N Srinivas, Tata Energy Research Institute Darbari Seth
Block, Habitat Place, Lodi Road , New Delhi - 110 003, India

Dhanawas village is about 50 km Southwest of Delhi. The village
situated in the Farrukhnagar block, is about 15 km from the
district headquarters Gurgaon, in the State of Haryana. There
are about 181 households with a total population of 1056. Tata
Energy Research Institute (TERI) has been working in the village
since 1984 and a number of technology interventions including
biogas, improved chulhas, solar lanterns, solar street lights,
biomass gasifier, biomass briquettes, etc. have been attempted.
Among all the interventions made in the village, biogas plant
has emerged as a most successful and infact, a competing
technology to LPG (growth of biogas plant was twice than that of
LPG during the last decade).

The end uses of cooking and water heating together constitute to
more than 80% of the total energy use in the village, most of
which is met by the non-commercial fuels. None for the
households depend only on one fuel to meet all their cooking
energy requirements. The surveys showed that use of
non-commercial fuels included, 40% dung cake; 40%crop residue
and the rest fuel wood from various sources. The biogas
generation potential in the village was estimated to be 237 cum
of gas per day (including 25.1 cum per day biogas generated from
poultry). The total gas requirement for cooking at 340 litres
per person per day, would be about 340 cum per day. The
villagers were not keen on community biogas plant for two
reasons; (i) scattered houses - most houses are in Dhanis
(fields) and (ii) villagers preferred to have systems with
independent operation. A survey to assess the potential for
family size biogas plants revealed that 40% of the households in
the village have enough cattle for individual biogas plants.
Thus TERI decided to take up the development (improvement over
the existing biogas plants) and demonstration of biogas plants.

Initially a modified Janata model was introduced, and
subsequently various improvements were carried out for
enhancement in performance and reduction in the cost. After
several design changes and construction of about 10 biogas
plants in the village, the spherical type of biogas plant was
developed. Now there are 20 biogas plants of which 19 are
functional. One is not in use because of the conflict about
land among the family members.

An evaluation of the biogas programme in twenty-seven villages
in Farrukh Nagar block of Gurgaon district implemented by the
State Agriculture Department was conducted by TERI which
revealed that only 16% of the installations were functional.
The major reasons identified for the failure were, incomplete
commissioning of biogas plants, faulty construction leading to
major repair requirements which were not attended to, minor
problems such as broken pipelines/valves, lack of simple
maintenance & servicing due to the absence of awareness and
training to the users, and non-rectification of dysfunctional
biogas plants, etc. Further, various administrative procedures
involved with the implementing agency created problems in
disseminating the programme in fact lead to a strong negative
impact about the technology among the villagers.

However, in Dhanawas, the functionality rate of biogas plants
has been high (nineteen out of twenty plants functional). A
study was conducted to identify the factors for the success of
biogas plants in the village and prioritize them as per the
users. About ten factors were identified; the factors and their
rankings have been discussed in the following paragraphs.

Time saving is the factor which scored highest and from the
feedback it was found that, the time saved by the use of biogas
for cooking, was spent in attending to other domestic chores or
in relaxation. The second ranking of institutional issues
reflected the confidence the people had with the implementing
agency. This confidence may be due to their observation of the
implementing agency on other activities or functionality of
installed biogas plants. Smoke removal was perceived as one
important benefit ranked third which besides resulting in
improved health, reduced the cleaning of walls and whitewashing
them. Since, the biogas meet some large parts of the cooking in
the households, use of biomass fuels including dung cake has
reduced, though, not eliminated completely. Thus, it has become
possible to divert a large proportion of dung as fertilizer in
the fields. This alternate use of dung as fertilizer ranked
fourth among the factors. The fifth ranking factor was a group
of other reasons where convenience of operation of biogas plants
over types of stoves and less or no maintenance problem along
with its relatively safer operation was acknowledged by the
users.

Fuel saving that the researchers, policy makers, and
implementing agencies have paid maximum attention, did not score
well and ranked sixth according to the users. The biogas light
generally used as a standby in case of power failure is another
perceived benefit by the villagers and as ranked seventh. The
subsidy involved, by the government (33%) and an additional
subsidy by TERI (another 33%) was identified as eighth important
factor, showing that it was not a limiting criterion. Less
effort in cleaning the vessels and kitchen and the plant as a
status symbol scored last in the ranking of factors.

The study shows that, they have perceived time saving as a major
benefit by the users and confidence in the implementing agency
has played a major role in the success of the programme in the
village. Though fuel saving has been used for the publicity of
biogas, it does not appear very high on the list of perceived
benefits by the users. The ranking of these factors in
different areas may be different and a simple exercise can be
carried out to decide the factors of priority in different
areas. Thus, if the family size biogas clearly plant if
disseminated properly, could even be a substitute to modern
fuels such as LPG in the rural areas.

EFFICIENT USE OF BIOMASS IN KARNATAKA
M. S. Rama Prasad
Joint Executive Secretary, Karnataka State Council for Science
and Technology, Bangalore 560 012, India

Realising the importance of biomass resources in the energy
scenario of the country, Karnataka State Council for Science and
Technology (KSCST) has been actively involved in this vital area
for the last 20 years. Over the years KSCST has sponsored a
number of R&D projects in effective utilisation of biomass in
Karnataka. KSCST is also very actively involved in the
dissemination of various technologies in the state. The paper
discusses in detail the various programmes and its possible
impact on the energy scenario of the state and future course of
action to be pursued by the Council.

As already mentioned, the main source of energy in rural areas
of the state is firewood. Indiscriminate use of firewood has
already caused irreparable damage to the environment in the form
of deforestation, floods, soil erosion etc. In the absence of
a viable alternative (particularly for cooking) it is almost
impossible to prevent use of firewood in rural area. Therefore,
it is imperative that efforts must be made to conserve as much
of firewood as possible. In this direction KSCST alongwith
ASTRA undertook a project of developing an improved high
efficiency firewood burning stove a few years back. After
sustained R&D work, the scientists from ASTRA successfully
developed a high disseminated in large numbers in the state
under the popular name ASTRA OLE. Under National programme on
Improved Chullah (NPIC) the executive agency in the state i.e.,
Rural Development Department has so far constructed nearly 10
lakh oles in the performance evaluation of these stoves. KSCST
is helping the department in training of masons and performance
evaluation of these stoves. A survey conducted by an independent
agency has shown that 60% of these stoves are being effectively
used in the field. This has resulted in annual savings of near
1.5 million tonnes of firewood.

In addition to Astra ole, KSCST has also disseminated a portable
metallic stove namely Swosthee. During the last 3 years
nearly 3000 stoves have been distributed in the state.

In addition to villages, firewood is also used in towns and
cities for both domestic and commercial use. A detailed survey
conducted by Astra group in 1985 has indicated that nearly 1500
tonnes of firewood is consumed in Bangalore city alone. In
addition to domestic use, firewood is used in large quantities
in commercial establishments like hotels, hospitals, hostels
etc., and in industries like brick and tile, printing and
dyeing, jaggery making etc. Another important factor to be
considered is that, this firewood is transported from far off
places, amounting to an average distance of nearly 200 km
through commercial mode of transportation. In order to reduce
firewood consumption in town and cities, KSCST sponsored two
projects namely design and development of Efficient brick and
tile kiln and large size Astra ole. Both these projects have
been successfully completed by Astra achieving a savings of
nearly 40 to 50% of firewood. KSCST is now in the process of
diffusing these technologies in the state. In the past two
years, KSCST has constructed nearly 300 large size Astra Ole,
which has resulted in substantial savings of firewood. Another
major programme launched alongwith education department of the
state is to introduce large size Astra Ole in all the kitchen
centres (numbering 4000) under mid-day meal programme. It is
estimated that, when this project is completed, the net savings
in firewood will be 80,000 tonnes every year. Another important
factor in all these programmes is environmental protection (less
firewood consumption) and improvement in the health of rural
women folk due to smokeless characteristic of stoves.

In addition to these stoves, a large number of driers have been
disseminated for procuring of areca, cardamom, cashew etc.
These driers can also reduce fuel wood consumption by 50% as
compared to conventional driers in the field.

Although almost all the villages in Karnataka has been
electrified under Rural Electrification Programme, still there
are a number of remote villages and tribal hamlets not
electrified. Even in electrified villages, the supply of
electricity is far from satisfactory. Hence, most of the
farmers depend upon diesel based water pumping systems to meet
their irrigation requirements, thus, consuming huge amount of
this non- renewable source of energy. To overcome this problem,
KSCST sponsored a project for the development of wood gasifiers
in 1982. The project team at Indian Institute of Science,
successfully developed a 5 HP biomass gasifier system which can
be used either for water pumping or for decentralised
electrification of rural areas. During the last 10 years nearly
500 systems have been installed in the state.

A unique experiment under this programme is electrification of
an unelectrified village viz, Hosahalli 100 km. away from
Bangalore. This backward village in a dryland area has 50
households. Now all these houses have been electrified by
installing a biomass gasifier generator system. In addition to
this 10 street lights have also been provided. The system is
being operated for 4 hours in the night by local boys, trained
by KSCST/ASTRA. It has been possible to achieve nearly 80%
diesel replacement and the biomass requirement is met by the
energy forest on the outskirts of the village.

MNES has sponsored a project at Indian Institute of Science
(initially supported by KSCST) for the development of Powdery
Biomass Gasifiers capable of accepting any agro waste in powder
form. The project team has successfully developed a 100 kW
system which can be used for both thermal and electrical
application. Attempts are now being made to install a few
systems in the state to meet power requirements in remote rural
area.

To conclude, KSCST is actively working in the area of effective
biomass utilisation in Karnataka for the last 15 to 20 years,
keeping in mind, the possible impact on environment. It has
sponsored a number of R&D projects, which has resulted in a
number of products/systems/processes capable of achieving
substantial savings in firewood and also solving energy problems
in rural area. It is also actively involved in disseminating
various technologies in this area and already significant number
of products/systems have been installed in the state.

NARI GASIFIERS FOR THERMAL APPLICATIONS
Anil K. Rajvanshi and Rajeev M. Jorapur,
Nimbkar Agricultural Research Institute, P.O. Box 44, Phaltan -
415 523, Maharastra, India

SALIENT FEATURES OF NARI SYSTEM

Capacity : Two sizes of 400 and 800 kW are available. Higher
capacity gasifiers can be custom designed.

Zero waste water system : No process water is required for the
operation, and so no waste water is generated

Minimal maintenance and downtime : Hot gas cleaning, so on
condensation and accumulation of toxic tars and other
condensables occur in pipe-lines and equipments

Quick start-up and shut-down : Cold start within ten minutes and
hot start-up within three minutes

Judicious mix of auto and manual controls : A PLC-based control
system controls the entire gasifier operation. Only two
operators per shift are required for fuel and ash handling
operations.

TECHNICAL SPECIFICATIONS
(A) Fuel : Biomass fuels like sugarcane leaves, bagasse, bajra
residues, wheat straw etc. with the following specifications
have been gasified in the NARI gasifier

Bulk density : 25-100 kg/m3
Particle size : 1-10 cm long
Ash content : < 10%
Moisture content: <20% w/w (wet basis)

(B) NARI gasification system

Thermal output : 100-800 kW (thermal) or 360-3280 MJ/h
Gas calorific value : 3.36 -4.62 MJ/Nm3
Flame temperature : ~ 10000 C

ECONOMICS

SPECIES CHOICE AND SPACE GEOMETRY TO ENHANCE BIOMASS PRODUCTION
M.S. NAGARAJA & P. CHANDRASHEKAR, Soil Science & Agricultural
Chemistry, GUAS, GKVK, Bangalore 560 065, India

The present worlds energy crisis and its related environmental
issues has put the scientific community in confusion. Long term
sustainable development particularly in developing world,
requires a gradual shift towards renewable energy sources, viz.
Wind, solar and biomass energy. Bio-energy is one such
sustainable and self reliant option, more so for countries like
India with large geographical area. The biomass production, a
must for bio-energy, depends on the efficiency with which the
solar energy is harnessed. Increasing the canopy area by
altering the spacing geometry and proper choice of species in
canopy and non-canopy areas can enhance biomass production.

The study conducted at the southern dry zone of Karnataka under
various systems indicate that about 5-10 tonnes ha-1 of biomass
can be generated through mango, sapota and some fodder trees.
However, this can be further enhanced by 10-20 per cent without
altering the spacing and only by altering its geometry, i.e.
hexagonal planting instead of square planting. The non-canopy
area, space between canopies, can also be utilized for biomass
production. The Stylosanthus and horse gram can produce 3-5
tonnes ha-1 of biomass in the non- canopy area. These plants
would also help in building up of soil fertility. Thus, there
is a great potentiality for producing biomass (to the tune of
8-14 tonnes ha-1) through proper selection of species and
spacing geometry.

BIOMASS PROGRAMME IN INDIA-TECHNOLOGY DEVELOPMENT,
DEMONSTRATION AND COMMERCIALISATION
Dr. N.P Singh, Director, MNES, Delhi, India

BIOMASS PRODUCTION AND IMPROVEMENT PRACTICES

About 93 million hectares of non-forest land is classified into
14 different agro-climatic zones and about 60 million hectares
of forest land has been estimated as degraded wasteland in
India. With a view to develop package of practices for fast
growing, short rotation, high coppicing fuelwood species on
different wastelands, MNES has been supporting research and
development and demonstration projects at 9 Biomass Research
Centres (BRCs) in different agro-climatic zones.

A package of practices have been developed including
standardization of nursery requirements, application of
biofertilizers, pest and diseases management for 36 fast growing
and short rotation fuelwood species for getting an average
of a minimum of about 20-26 tonnes of the biomass per
hectare per year. BRCs have been organising training
programmes to various target groups viz. officers of State Govt.
NGOs and local people in their respective zones on nursery
development and other aspects of energy plantations. These
centres are also providing quality seedlings and consultancy to
tree growers.

ENERGY PLANTATION

Plantation of fast growing tree species on degraded lands have
been supported by MNES under its demonstration programme till
March 1992. A total area of about 17,000 hectares in
various parts of country have been covered under
energy plantation under this programme. The outcome of R&D in
BRCs have been tested on large areas through many such
demonstration projects under energy plantation programme.

In India, about 70 biomass briquette machines using die and
punch, ram and die and screw technologies are in use. These
machines have the capacity of 250 kg-1.5 ton/hr and using
agricultural and agro-industrial residues. The
briquettes produced are finding market in tea drying, hotels
etc. Indian Renewable Energy Development Agency (IREDA), a
financing agency under MNES is providing soft loan to
briquetting industry. There are about seven biomass
briquetting machine manufacturers in India which are mainly
manufacturing piston ram type press type. Some prototypes of
screw press type of briquetting machines.

RESEARCH AND DEVELOPMENT

R&D projects were supported for development of a 3.7 KW
gasifier mainly based on wood or woody biomass for water
pumping for irrigation in 1986 at Sardar Patel Renewable Energy
Research Institute (SPRERI), Vallabh Vidyanagar, Gujarat
and Punjab Agricultural University, Ludhiana, Punjab and
Indian Institute of Technology (IIT), New Delhi under
International Collaborative projects. Later, other groups at
IIT Bombay; Indian Institute of Sciences (IISc.), Bangalore;
Nimbkar Agriculture Research Institute (NARI), Phaltan;
Madurai Kamaraj University (MKU), Madurai have also been
supported for R&D projects.

Under the above mentioned R&D projects and ARCs, gasifiers of
different ratings from 3.7 KW to 500 KW have been developed
for various applications viz. Mechanical, thermal and
electrical. A number of training programmes and business
meets with potential industries have been organised,
specifications have been developed and 300 samples of
different biomass have been characterized for their suitability
for gasification and briquetting.

TECHNOLOGY COMMERCIALISATION

Gasification technology has been commercialised with
indigenous R&D efforts. There are about 8 manufacturers
viz. M/s.Ankur, Vadodara; M/s.AEW, Tanuku; M/s.Cosmo,
Raipur; M/s.Grain Processing, Calcutta; M/s.Netpro, Bangalore
etc. The product range is from 3.7 KW to 500 KW for woody and
non-woody biomass. Technology packages for various
industries such as plywood, rice mills, soap making, bakeries
and tea processing are being offered by the manufacturer.

GASIFIER DEMONSTRATION

FISCAL AND FINANCIAL INCENTIVES

Table-I

STATEWISE LIST OF GASIFIER SYSTEMS INSTALLED UP TO March 31, 1996.

Upto March 1993 1993-94 1994-95 1995-96
--------------- -------------- -----------------
-------------------- -------
STATE No.of Capacity No.of Capacity No.of Capacity No.of
Capacity
systems (kW) systems (kW) systems (kW) systems (kW)
installed installed installed installed
---------------------------------------------------------------------------------
----
Andhra
Pradesh 40 194 18 390 24 2400 17 1700
---------------------------------------------------------------------------------
----
Arunachal
Pradesh - - 3 120 - - -
-
---------------------------------------------------------------------------------
----
Assam - - - - 5 23 - -
---------------------------------------------------------------------------------
----
Bihar 2 20 - - - - - -
---------------------------------------------------------------------------------
----
Goa 3 30 - - - - - -
---------------------------------------------------------------------------------
----
Gujarat - 164 1260 14 1030 12 1104 5
---------------------------------------------------------------------------------
----
Haryana 16 274 1 100 8 590 - -
---------------------------------------------------------------------------------
----
Himachal
Pradesh 2 8 - - - - -
-
---------------------------------------------------------------------------------
----
Jammu &
Kashmir 4 120 - - - - - -
---------------------------------------------------------------------------------
----
Karnataka 468 2329 - - - - - -
---------------------------------------------------------------------------------
---
Kerala 5 115 1 100 4 400 - -
---------------------------------------------------------------------------------
----
Madhya
Pradesh 105 649 10 100 14 1740 10

From 73002.1213 at CompuServe.COM Fri Aug 30 08:23:54 1996
From: 73002.1213 at CompuServe.COM (Thomas Reed)
Date: Tue Aug 31 21:07:12 2004
Subject: GAS-L: STRAW GASIFICATION
Message-ID: <960830122559_73002.1213_FHM22-6@CompuServe.COM>

Gasification Group:

Nils Peter Astrupgaard suggested that I post a part of his comment on straw in
gasification, so here they are:

"Now to Tom R.
You stated in item 4 that straw is difficult to gasify and burn. I agree.
That is why we at dk-TEKNIK among other developments run a two stage
combustion R&D programme aiming at burning straw and municipal solid waste
sponsored by The Danish Energy Agency. Actually the first stage is a grate
gasifier and it is in developping this first stage that we spend most of our
effort. A grate gasifier offers a lot of opportunities that you don't have
in other gasifiers. You might find this type of plant worth mentioning in
your gasifier up-date."

I am sure Nils knows 10X as much as I do about straw gasification and I am
looking forward to meeting him
in Denmark next month.

Here's a related comment: "Close-coupled gasifier-combustor" to me means that
you have a discrete gasifier and combustor in the same shell with combustion air
added in the second phase. I would like to propose the phrase
"coupled-gasifier-combustor" for a dedicated gasifier feeding a boiler or burner
that is at some minor distance, as in the Producers RIce MIlls system (about 30
feet of insulated pipe to the boiler). Sometimes the issue of whether a unit is
a close coupled gasifier or just another form of combustor can have considerable
legal and tax implications.

Does anyone have any objections to this usage or a better differentiation to
propose?

Talk to you later, TOM REED

From 73002.1213 at CompuServe.COM Fri Aug 30 08:23:55 1996
From: 73002.1213 at CompuServe.COM (Thomas Reed)
Date: Tue Aug 31 21:07:12 2004
Subject: GAS-L: Re: gasification
Message-ID: <960830122543_73002.1213_FHM22-3@CompuServe.COM>

Dear Robin Smit:

The National renewable energy Lab, NREL, in Golden, CO has commisioned a major
study of gasification for waste by Dorr Oliver Co. It is rumored to come out in
Fall. Tom Milne at NREL can tell you who to see to get a copy when it is
issued.

I believe that when gasification is understood as well as combustion, we will
see many new gasifiers arise. In the last decade we have seen the stratified
downdraft (also called open top, core, topless, ...) and the inverted downdraft
(charcoal, top burning, ...) developed. Whether they have anything special to
offer to waste, it is too early to tell. Unfortunately, there are millions of
dollars available to build big, conventional gasisfier that may or may not work,
but no thousands available for understanding what REALLY goes on. While at NREL
I developed a well insulated transparent gasifier that let you "see inside".
Fascinating.

I hope to be visiting Eindhoven and Twente the week ending October 3. Maybe I
will see you there.

Yours truly, TOM REED

From 73002.1213 at CompuServe.COM Fri Aug 30 08:24:27 1996
From: 73002.1213 at CompuServe.COM (Thomas Reed)
Date: Tue Aug 31 21:07:12 2004
Subject: GAS-L: Re: Dioxin ... tolerance??
Message-ID: <960830122537_73002.1213_FHM22-2@CompuServe.COM>

Dear Doug:

I appreciated your "understanding dioxin" letter. It raises some more questions
to one peripheral to the issue.

1) Is dioxin uniquely toxic amongst combustion products, or is it only one of
many that we happen to focus on because of the Italian well-studied incident?

2) Is asbestos uniquely toxic amongst mineral and synthetic insulation or is it
singled out because it is so cheap and therefore so widely used?

3) Same for mercury, benzene, ... and other instances of useful chemicals, too
late discovered to be toxic.

If the answer to 1-3 is no, we should have some fraction of the EPA and related
organizations "casting a wider net" to understand the general nature of toxicity
so that we can catch other toxins without needing epidemiology which in turn
requires thousands of toxic incidents.

Is it possible that the body develops a toleration, an inorganic immunity to
some of these materials if the exposure isn't too abrupt? Do smokers have a
higher tolerance for CO than the rest of us because they continually are exposed
to 100-500 ppm CO? Maybe we can fall back on "everything in moderation" as an
operating principle to ensure that we all get our "peck of dirt" before we die.

Go with it!

Yours truly, TOM REED

From sturn at hawaii.edu Fri Aug 30 14:36:03 1996
From: sturn at hawaii.edu (Scott Turn)
Date: Tue Aug 31 21:07:12 2004
Subject: GAS-L: Re: Dioxin ... tolerance??
In-Reply-To: <960830122537_73002.1213_FHM22-2@CompuServe.COM>
Message-ID: <Pine.GSO.3.93.960830082719.21234D-100000@uhunix5>

If you are looking for information regarding the health risks and
regulatory strategies concerning dioxin, I refer you to Environmental
Science and Technology, Vol 29, No 1, 1995, special report entitiled
"Dioxin Risk: Are We Sure Yet" which details EPA's dioxin assessment.

------------------------------------------------------------------------------
Scott Q. Turn
Hawaii Natural Energy Institute Phone: (808) 956-2346
University of Hawaii Fax: (808) 956-2335
2540 Dole St., Holmes Hall 246 email: sturn@hawaii.edu
Honolulu, Hawaii, 96822
------------------------------------------------------------------------------

From tmiles at teleport.com Fri Aug 30 14:42:54 1996
From: tmiles at teleport.com (Tom Miles)
Date: Tue Aug 31 21:07:12 2004
Subject: GAS-L: STRAW GASIFICATION
Message-ID: <2.2.32.19960830184506.00981e84@mail.teleport.com>

At 08:25 AM 8/30/96 EDT, Thomas Reed wrote:
> I would like to propose the phrase
>"coupled-gasifier-combustor" for a dedicated gasifier feeding a boiler or
burner
>that is at some minor distance, as in the Producers RIce MIlls system (about 30
>feet of insulated pipe to the boiler).

"close coupled" would be gasification and combustion in separate vessels.

"staged combustor" has been used for modular incinerators where a mostly
reducing chamber is followed by an afterburner or oxidizing chamber.

If you look at the CO2 in the gas of most of the small scale
gasifier-combustors installed in the early 1980s they often look like staged
combustors.

Tom
----------------------------------------------------------------------------
-------
Tom Miles, Jr. Thomas R. Miles
tmiles@teleport.com, tmiles@ortel.org Consulting Design Engineer
http://www.teleport.com/~tmiles/ 5475 SW Arrowwood Lane
Tel (503) 591-1947 Fax (503) 292-2919 Portland, Oregon, USA 97225-1353

From 73002.1213 at CompuServe.COM Sat Aug 31 11:33:40 1996
From: 73002.1213 at CompuServe.COM (Thomas Reed)
Date: Tue Aug 31 21:07:12 2004
Subject: GAS-L: BIOENERGY DREAM
Message-ID: <960831153439_73002.1213_FHM49-2@CompuServe.COM>

Dear Carol:

I second Peter's observation on your biomass power plant. The use of biomass
for energy is a beautiful dream that I have been dreaming for 20 years. During
that period I have changed my career from Material Scientist at MIT to Renewable
Energy Specialist at the Colorado School of Mines (after 8 years at the Solar
Energy Research Institute). I have changed my title from Physical Chemist to
Chemical Engineer.

Lately I have refined the dream to using more agricultural residues (high ash,
easy availability) and less wood (see previous comments on straw). And
probably more gasification/pyrolysis and less combustion.

It is not an impossible dream, but it requires time - and money - and
dedication. Hang in there.

Your co-dreamer, TOM REED

PS: Yes, I would like to subscribe to your -E-mail letter - would you be
interested in my "letters home" from my gasifier trip around the world? You'll
see them in gasification@crest.org. Print what you like.

Subscribe WESHEMOL.

BioEnergy Lists: Gasifiers & Gasification

August 1996 Gasification Archive