1

1. Introduction:

Improved cooking stove has brought a revolution in Bangladesh which reduced time and money

consumption, produces minimum Carbon dioxide and saves from health disorder. Dependency on fuel

consumption has significantly reduced. Many organizations, specifically GIZ, big NGO’s and even the root

level NGO’s have come forward working together. Many initiatives have been taken by the Government of

Bangladesh. Cow dung, jute sticks, other agricultural waste, wood – 90% of all Bangladeshis still employ

these traditional fuels for cooking, and most use inefficient and poorly ventilated clay stoves that produce

smoke, carbon monoxide, and carcinogens; the particulate pollution levels may be 30-35 times higher than

accepted guidelines.

The women, who cook over these stoves and their small children, are exposed to these high levels of toxins

for between three and seven hours a day. The World Health Organization has estimated that 46,000

women and children die each year in Bangladesh as a direct result of exposure to indoor air pollution, while

millions more suffer from respiratory diseases, tuberculosis, asthma, cardiovascular disease, eye problems,

and lung cancer. 70% of the victims of indoor air pollution are children under five. The best immediate way

of addressing this urgent problem is the rapid and widespread introduction of improved cooking stoves:

stoves that burn biomass much more efficiently and – even more importantly – are designed to draw off

the smoke and toxins, thus creating a safe environment for women and children.

General Energy Situation in Bangladesh:

Power: Installed capacity: 10000 MW (Operating: 8000 MW)

Natural Gas: 11 tcf, Consumption: 500 bcf/a

Coal reserve: 2 billion ton

50% of total energy supply is provided by biomass

40% of HHs: connected to grid electricity (rural area, 20%)

6% of the HHs: natural gas, primarily in urban areas

For cooking: >90% depend on biomass, e.g. rice husks, jute sticks, cow dung, wood.

The way is traditional, inefficient

2. Improved Cooking Stove (ICS):

A stove is the combination of heat generation and heat transfer to a cooking pot. Cook stoves are

commonly called “improved” if they are more “efficient” than the traditional cook stoves. “Efficient” mean

Energy efficiency. The core question concerning the efficiency of two alternative stoves is: “With which of

the two stoves do I use less fuel to prepare my meal?”

Traditional Cooking Stove:

These stoves may be built under ground or over ground. Heat transfer to the cooking pot is very low,

resulting into low efficiency. Mud-built cylinder with three raised points. Because of the large size of the

2

flue gas exits lowering conventional heat transfer, emits smoke, which affects the health of the users,

incomplete combustion of biomass fuel.

Traditional Cook stove Scenario in Bangladesh:

About 90 % of all families in Bangladesh use traditional stoves for cooking and other heating purposes. A traditional

stove is usually a mud-built cylinder with three raised points on which the cooking utensil rests. One opening

between these raised points is used as the fuel-feeding port and the other two for flue gas exit. The stove may be

built under- or over ground. In some cases two potholes are joined together and a single fuel-feeding port is made for

common use.

The traditional stove allows excessive loss of heat for the following reasons:

1. The large distance between the pot and fuel bed (depth ranging from 30 to 60 cm) causes heat transfer to the

cooking pot to be considerably reduced.

2. Because of the large size of flue gas exits between the cooking pot and stove much of the hot flue gas exits the

stove without coming into contact with the cooking pot, thus reducing the convective heat transfer.

3. Since air cannot reach the bottom of the stove, a considerable amount of cooking fuel accumulates at the bottom

as charcoal.

The efficiencies of these stoves vary between 5 and 15 %, depending on the depth of the stove and size of the flue

gas exits.

Improved Cooking Stove (ICS): Improved cooking stove having an optimum geometry to facilitate good combustion of

fuel, and a grate to hold biomass in optimum distance from the pot including a chimney to take smoke out of kitchen.

Difference between Improved Cooking Stove with Traditional Cooking:

Issues ICS Smart ICS

Heat Trapping No Yes through sealed body with glass wool and black coated outer side of inner body

3

Self-Heat Consumption

Yes, made of cement, sand and crushed brick, these material consumes heat faster and release faster

Negligible amount as SS sheet is used

Corrosion Problem Yes, cause dimension change of body, air inlet/ Outlet and feed holes

No

Installation Type Fixed, site selection is important

Portable

Ready to go After installation required certain time for ensuring dry stove is thoroughly rubbed

Ready to use immediately

Body fracture/crack Required smoothen the ICS body with mud or cow dung at least twice a week

No such problem

Chimney Clogging Problem Yes, required cleaning once in a week

No cleaning required

Dimension Change Problem of Air inlet/Feed hole

Yes, Due to the corrosion of cement or mud the air inlet or feed hole dimension may change, result of improper combustion

No

Importance of ICS:

Over recent years, a variety of projects aiming to spread the use of improved cook stoves have been

realized. The first NGOs introduced the improved cook stoves on a local level in order to reduce the dangers

that come with traditional stoves: to prevent children from burn injuries and reduce respiratory problems

caused by inhaling smoke from indoor cooking. These projects have progressively been expanded to a

greater scale, with the aim of reducing the impact of domestic cooking on the local and global environment.

Looking back on several decades of activity on this topic, it is interesting to take stock of the issue of

improved cook stoves and the role they can play in a sustainable supply of cooking energy for local

communities.

To make a project aiming to spread the use of improved cook stoves successful, it is necessary to first

understand the rationale of the different actors; if the project does not respect the rationale of the people

involved, it is not likely to succeed or for its effects to outlast the life of the project. Who are the actors

interested by such projects and what are their motivations and constraints: National and international

institutions that finance projects on improved cook stoves, families with the power of decision (will they or

won't they replace their traditional stove with an improved cook stove?), and craftsmen with their power of

decision (will they or won't they produce and commercialize improved cook stoves instead of traditional

stoves?).

4

Importance of ICS in short:

No smoke in the kitchen

Efficiency: 26%-29% (traditional stove: 5% - 15%)

Fuel saving: 50% - 60%

Household, which buys fuel, saves 250 – 400 Taka/month (payback period: 2-3 month)

Restaurant saves 200-400 Taka/day ( payback period: 1-2 month)

Significant reduction of indoor air pollution in kitchens

Reduction of cooking fuel by about 50% - biomass saving

Saving of money

Reduced burden on forest resources

Improvement of soil by increased use of bio-fertilizer

Time saving

Clean kitchen & pots

Income generation for builders and trainers

Why are improved cook stove projects important in the developing world?

The need to improve cook stove efficiency has increased in the developing world as approximately 3 billion

people worldwide rely on coal or biomass as their primary energy source for cooking and heating,

accounting for 13% of global energy consumption (HEDON). The use of open fires and traditional stoves

leads to incomplete combustion of fossil fuel, causing high Black Carbon (BC) emissions. Furthermore, open

fires and traditional stoves have low combustion efficiency, leading to higher cooking times and inefficient

use of fuel wood.

Despite these facts, a large number of people still use open fires and traditional stoves in household

cooking and heating. Various attempts at disseminating improved cook stoves have been made since the

1980s. Although a majority of the attempts have been unsuccessful, there have been successful in

disseminating improved cook stoves. Views on adopting cook stoves seem to vary at the user level and at

the national or project level. This webpage will examine past successes and failures along with current

initiatives in improved cook stove distribution efforts. Through these we will define keys to success in

future cook stove distribution initiatives. Finally, we will examine future initiatives, for improved cook stove

dissemination.

5

Black Carbon:

Black Carbon (BC) is a product of incomplete combustion of fossil fuel the major causes of global BC include

the burning of agricultural residue, residential cooking and heating, transportation, and industrial fossil fuel

use. Black Carbon mitigation strategies have been implemented for all of the mentioned sources, however

the distribution of improved cook stoves is among the most cost effective means of mitigating global BC

emissions. Also, since BC is a short-term warming agent and is only in the atmosphere between 1 and 2

weeks, any permanent reductions in BC will reap immediate benefits.

BC's negative effects include:

1. Contribution to global and regional climate change.

2. BC contribution likely 2nd greatest after CO2.

3. Indoor air pollution major cause of illness and mortality for women and children inhaling BC

4. 1.6 million premature deaths annually worldwide (400,000 annually in India alone)

5. Childhood pneumonia, lung cancer, bronchitis, cardiovascular disease are among effects.

6. Decreased surface albedo from BC particles settling on Tibetan Glaciers and Arctic Ice Caps causing

accelerated melt.

Importance of Increased Fuel and Combustion Efficiencies through Improved Cook stoves:

1. Compared to traditional cooking practices improved stoves can save up to 20-67% fuel.

2. Health benefits to women and children.

3. Poverty alleviation and women’s empowerment as women will spend less time gathering wood and

cooking.

4. This will enable them to focus on other activities such as earning extra income.

5. Biodiversity conservation and reduced forest degradation through reduced pressure on forests.

6

Improved cook stoves for better lives

The traditional cooking practice in Bangladesh uses a “three-stone” cooking stove. Only 5%-10% of the

households in Bangladesh use fossil fuels such as kerosene or liquefied petroleum gas for cooking. The

majority uses a mix of agricultural residues, twigs, leaves, cow dung and fuel wood. The combustion of

some of this biomass in the traditional cooking stoves generates a variety of gases including carbon dioxide

(CO2), carbon monoxide and other particulate matter. The replacement of traditional stoves by improved

cooking stoves (ICS) improves heat transfer, which reduces the total amount of fuel required for cooking

and the amount of emissions. Altogether, the improved cook stoves have the following benefits.

Environmental benefits:

• Air quality: Air pollution from cooking with solid fuel is a key risk factor for childhood pneumonia as well

as many other respiratory diseases and cancer. By using ICS units children and mothers are exposed to

fewer air pollutants through reduced emission of not only CO2 but also carbon monoxide and particulate

matter.

• Biodiversity: ICS reduce the demand for wood and the impact on remaining forest reserves in Bangladesh.

Social and Economic benefits:

• Employment: The program gives rise to employment opportunities for new ICS technicians, assistants,

office staff and other related jobs in Bangladesh.

• Livelihood of the poor: The circumstances of poor families are improved since the stoves reduce fuel cost,

providing financial savings. The reduced wood consumption also means less time spent collecting fuel,

which is a relief from drudgery and provides more opportunity for other productive activity.

• Access to energy services: The ICS require less fuel, which in many areas can be a scarce, expensive

resource Users also have found ICS more convenient, as it shortens the cooking time.

• Human and institutional capacity: The project has a positive effect on local skills and institutional capacity.

By initiating large-scale promotion and advertising campaigns, quality control and branding initiatives,

together with the introduction of improved production and accounting systems, the local population is

developing various business skills.

• Technological self-reliance: The introduction of a locally manufactured technology with optimized energy

efficiency helps to build technological self-reliance.

Reasons for Promoting Improved Cooking Stoves

1. Health

For people who cook indoors with wood in unventilated or partially ventilated kitchens, the introduction of

improved cooking stoves with chimneys or other means to reduce exposure to the health-threatening

pollutants found in biomass smoke is of significant benefit. As described before in this section numerous

studies in recent years have associated a number of health problems with smoke expo-sure. The World

7

Development Report has classified indoor air pollution as one of the four most critical global environmental

problems. Use of ICS will contribute in reducing the severity of the adverse effects of indoor burning of

biomass fuel in the kitchen. A healthier and safer environment, particularly for women and children, may be

one of the most important potential contributions of improved cooking stoves to ameliorating the cramped

living conditions of many poor people.

2. Economics

Efficient burning of fuel will reduce the amount of fuel needed per family which will in turn reduce the time

for collection of fuel. Further efficient burning will generate more heat during the time for cooking thus

shortens the time for cooking. These will enable the women to be engaged in other income generating

activities. ICS will also reduce the expenditure of families who have to buy biomass fuel for cooking because

of the reduction of amount of fuel. Improved biomass stoves, with their higher fuel efficiency and better

design, can potentially diminish the drudgery of collecting fuels and expenditure on cooking energy for

millions of rural families who cannot afford modern fuels.

3. Demand side management

Demand-side approach refers to introduction of improved cooking stove technology as a new step in the

energy ladder between traditional biomass stoves, and the modern fuels and appliances. This approach is

appropriate in the many parts of the developing world where modern fuels are not affordable or will not be

affordable in the near future.

So, the people will have to continue to rely on traditional fuels. If improved biomass stoves were adopted

on a large enough scale in such settings, they would reduce the pressure on biomass re-sources. In

addition, a deliberate slowing of the transition to modern fuels may sometimes be warranted. In China, for

example, many rural households had been moving up the energy ladder to coal, which, because opening up

of the rural economy, was widely available in many areas that do not have official supplies. This in turn

contributed to severe problems in coal supply, so the Chinese government wanted to slow or even reverse

the movement of households to coal. The government included improved biomass stoves as a part of the

strategy.

4. Prevent deforestation

Traditional forests are under constant threats of extinction due to diversified use of forest resources

including demand for fuel wood by the ever -increasing population particularly in developing countries.

Some of the adverse effects of deforestation are climatic change, ecological imbalance and soil erosion etc.

Improved cooking stoves, by enhancing thermal efficiency and consequent reduction in volume of fuel, may

contribute in preserving the forest and save many species of flora and fauna from extinction; and prevent

environmental degradation.

5. GHG reduction tool

Improved cooking stoves can contribute positively in reduction of greenhouse gas (GHG) emissions. The

Asian Institute of Technology (AIT) conducted a study on GHG reduction by different stoves in seven

countries. The total emission reduction potentials of substitution of all traditional stoves by each of the

8

selected cooking options are given in the Table 3.4. GHG emission amounting to about 38, 58, and 60

million tons of CO2 equivalents can be reduced annually in the selected countries by substitution of

traditional stoves by improved cooking stoves, biogas stoves and producer gas stoves, respectively. These

values are equivalent to about 1.1%, 1.7%, and 1.8% of the total CO2 emitted from fossil fuel use in the

selected countries, respectively. It is also estimated that GHG emission will be increased by 50, 70 and 173

million tons of CO2 equivalent per year if all traditional stoves are re-placed by natural gas, LPG and

kerosene fired stoves respectively.

Evolution of ICS and collaboration with various organizations in Bangladesh:

The Institute of Fuel Research and Development (IFRD) of the Bangladesh Council of Scientific and Industrial

Research (BCSIR) has been pursuing R&D activities on stove technology since 1978 [Eusuf, et al., 1990;

Eusuf et al., 1993] and has developed a series of models of improved stoves and their accessories [Hossain,

1995] to suit the needs of the user in respect of biomass fuel, shape of the cooking pot and cooking habits.

These models may be grouped into 3 categories: (1) improved stoves without chimneys; (2) improved

stoves with chimneys; (3) improved stoves with waste heat utilization. These improved stoves save 50-65 %

fuel and cooking time compared with traditional stoves. In the chimney stove, fuel is burnt in the first

combustion chamber over a grate where cooking is done by direct heat, and cooking in the other pothole is

done by the hot fuel gases coming from the front chamber. The stoves are so designed as to maximize heat

transfer to cooking utensils. This model decreases the time of cooking and also makes the kitchen free of

smoke and hot air. It can be easily made from mud.

R&D activities are being carried out by IFRD and so far 31 updraft and 9 downdraft models of improved

stoves have been developed [BCSIR, 2000]. To popularize the improved stoves in the country, the IFRD has

chosen five different models of updraft improved stoves: improved single-mouth cooking stove (portable);

improved single mouth cooking stove (half-underground); improved double-mouth cooking stove coupled

with chimney (on the ground); improved double-mouth cooking stove coupled with chimney (half-

underground); and improved double mouth cooking stove coupled with chimney suitable for large-scale

cooking and other heating purposes. The following strategies were adopted for the programme.

1. Advertisements in mass media.

2. Seminars

3. Training courses

4. Demonstrations

The Ministry of Science and Information & Communication Technology since its inception has being putting

its best efforts into popularizing the renewable energy technologies developed by BCSIR in the country. The

ministry has been regularly arranging seminars on ‘‘Application and dissemination of appropriate

technologies developed in the country’’ since 1986 at the district/upazila (sub-district) administrative levels

of the country. During these seminars, along with other technologies improved stove technology is being

exhibited to the common people.

9

To popularize the improved stoves, IFRD has developed two training course manuals on ‘‘Improved stoves’’.

One course is of 1-week duration and the other of 4-day duration. Scientists of IFRD have till now

conducted over 215 training courses on improved stove technology and trained about 10,000 men and

women from different government, semi-government and non-governmental organizations of the country.

Most of the trained personnel are now engaged in dissemination of improved stoves in different parts of

the country.

IFRD has successfully completed two Annual Development Programme (ADP) projects on dissemination of

improved cook stoves in the country. Both the projects were implemented jointly by BCSIR, Ansar-VDP (VDP

means Village Defense Party) and Bangladesh Rural Development Board (BRDB), as detailed in Table 1.

Some of the main objectives of the projects are given below:

1. To save traditional fuels by popularizing the improved stoves and eliminate air pollution in rural areas of

Bangladesh.

2. To develop skilled manpower for dissemination of improved stoves through training courses.

3. To create awareness about the effectiveness and usefulness of improved stoves through massive

advertisement campaigns using various media.

4. To reduce deforestation and maintain the ecological balance of the country through the massive use of

improved stoves.

5. To involve various governments, semi-government and non-governmental organizations in dissemination

programmes of improved stoves.

6. To improve hygienic conditions in the kitchen. At present, the dissemination of improved cook stoves is

being carried out by IFRD, along with its R&D activities. Some government, semi-government and non-

governmental organizations are also carrying out dissemination in a limited way throughout the country.

The Program Sustainable Energy for Development (SED), supported by the Bangladesh Ministry of Power,

Energy, and Mineral Resources and the German Federal Ministry for Economic Cooperation and

Development, through the Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH, is doing

that too. Various models of improved cooking stoves have been developed in different countries. In

Bangladesh, it was a group of scientists at the Institute of Fuel Research and Development (IFRD) of the

Bangladesh Council of Scientific and Industrial Research, led by Dr. A. M. Hasan Rashid Khan, who worked

with rural women in the early 1980s to adjust the clay, water, and cow dung stoves they routinely build and

use: The simple addition of a grate at the correct depth, which focuses the fire on the bottom of the

utensils and small air holes in the wall of the stove just below the grate reduces the biomass required to

cook a meal by 50%. The addition of a chimney eliminates the smoke and particles which so threaten the

health of women and children near the stove. The cost: around 800 takas (8 euros).

10

Existing Design & Testing of ICS:

Improved Single Mouth Cooking Stove (Portable)

This model, also called Model 1, was developed by BCSIR in 1982. The model and the actual stove in use are

shown in the Figure 6.1. This is suitable for wood, branches, cow dung cake, briquettes etc; and can be used

for cooking throughout the year. Main parts of this model are a structure, grate and lid for covering the ash

outlet.

Figure: Dimension of Single Mouth ICS (Portable)

Improved Single Mouth Cooking Stove (Half underground):

This model, designed by BCSIR in 1983, is the fixed version of the Model 1. If installed inside the kitchen it

can be used round the year. If installed outside it is suitable for use in the dry season only. Main parts of

this model are: structure, grate and two perforated lids for covering the ash outlets.

11

Figure: Dimensions of Single Mouth ICS (Half underground)

Common Problems of Existing ICS: Fixed type so site selection is an important issue and required a space of at least 2-3 foot to set up. Required installation, hence additional cost of installation, labour charge are concerned issues After installation required certain time for ensuring stove is thoroughly rubbed else wet and partially

damp stove consume large amount of fuel and flexibility Chimney blockage by deposition of soot on the inner wall and cause flame and hot flue gas coming out

through feed hole during cooking instead of releasing through chimney

Body fracture/crack due to heat pressure after continuous use of stove for a week Required smoothen the ICS body with mud or cow dung after 5-7 days of use for preventing body

corrosion. Advance preparation of cooking stuff is required, so after cooking one item immediately another item

has to place in stove to save energy of the stove. (Heat trapping system absent) For double mouth ICS both mouth should be in use cooking at same time whereas it is tough to manage

cooking simultaneously in two mouths. If the combustion chamber, which is, first mouth of ICS is overstuffed with fuel then there is no

sufficient space available for air to get in.

12

After using for long time, the diameter of hole of grate becomes larger, as a result some piece of firewood will fall down through the grate without burning, which ultimately increase the fuel use

Due to the corrosion of cement or mud the air inlet or feed hole dimension may change which may result improper combustion, excess firewood use, smoke exit through these holes and in case longer time for cooking.

Factors beyond the design Concern

Heat transfer into the pot & Heat Trapping

Handling of the fuel

Handling of the stove

Management of the cooking process

Cooking environment

Ten Design Principles of ICS

Principle-1: Whenever possible, insulate around the fire using lightweight, heat-resistant materials.

Principle-2: Place an insulated short chimney right above the fire.

13

Principle-3: Heat and burn the tips of the sticks as they enter the fire.

Principle-4: High and low heat are created by how many sticks are pushed into the fire.

Principle- 5: Maintain a good fast draft through the burning fuel.

14

Principle-6: Too little draft being pulled into the fire will result in smoke and excess charcoal.

Principle-7: The opening into the fire, the size of the spaces within the stove through which hot air flows,

and the chimney should all be about the same size.

Principle-8: Use a grate under the fire.

15

Principle-9: Insulate the heat flow path.

Principle-10: Maximize heat transfer to the pot with properly sized gaps.

Different steps in making a portable improved stove

Target arenas where we did the development ;

1. Efficiency Improvement

2. Economic feasibility

3. Hygiene Concern

4. Environmental Issues

5. User friendliness

16

Efficiency improvement

For improving the efficiency we can consider the following table:

Proposed ICS Design

Materials for Making ICS

1. Steel Sheet

2. Glass wool

Challenges solutions

1. Minimize heat loss through combustion

chamber and chimney.

1. Use porous materials.

2. Maintain an optimum draft. 2. Longer chimney.

3. Assure maximum contact of flue gas to the

pot.

3. Using skirt.

4. Adequate air flow to combustion chamber. 4. Maintain air hole equal to chimney diameter.

5.Assuring lighter(less mass)

Combustion chamber and chimney.

5. Ceramic, mud clay with saw dust or coal powder

(must withstand 200-225 degree Celsius temp).

6. Separation of fuel residues. 6. Using grate to separate residues and air flow.

7. Smaller fuel particle assure clean burning. 7. Wood chips, pellets, briquettes.

8. Minimizing water particle from fuel. 8. 12% moisture.

9. Hot air feed to combustion chamber. 9.

10. Using metallic pot. 10. Pressure cooker is better

17

Design Structure

Inner body

18

Outer Body

Door (For Feed Hole & Ash Outlet)

Air Blower

19

Air Blower Connector

Blower Stand

Chimney

20

Annex Part:

Water Tank (Inner body)

Water Tank (Outer Body)

21

Salient Design Features

Robust design with dual body layer to constrain heat inside the burning chamber for long time.

Efficient insulating material: glass wool (Thermal conductivity: 0.04W/m.K) is used in the middle of

the dual bodies to isolate outer body from adjacent chamber body. Hence heat transfer through

stove body is baulked.

Inner body containing burning chamber is coated black in outer surface to keep maximum amount

of heat inside the chamber.

22

Intelligent smoke outlet system engineered to prolong smoke exertion from the burning chamber

and forged to maximize the existence of heat into the stove.

Separate feed hole and air inlet with insulated door make efficient heat collapsed stove.

Perforated fuel carrier, which stands at the middle of air inlet. Therefore, easy access of air to fuel

wood for ensuring optimal combustion of fuel wood hence maximizes the stove’s efficiency.

Additional water boiling system is adjusted with the system, where smoke exerting from burning

chamber is maneuvering to heat the water for using extend purpose.

This tank is also constructed with dual part where inner body is coated black outside for storing heat

inside. Moreover, this additional part can be used for ordinary heating, boiling of food preparation.

23

After heating tank body smoke is proceed to flow through long chimney (78 inch) to ensure

releasing clean smoke to the environment.

Thermal Modeling of the ICS Insulation Material

Combustion Modeling

Heat Transfer Modeling of the ICS

Development Testing Facility of ICS:

24

25

26

ICS Performance Testing

Testing Procedure

Water boiling test (WBT)

Controlled cooking test (CCT)

Kitchen Performance Test (KPT)

Conclusion/New Beginning:

Let’s tie hand together endeavoring green cooking technology

Reference:

http://www.giz.de/en/downloads/giz2012-en-cooking-stoves-bangladesh.pdf

https://energypedia.info/images/8/83/GTZ_Bangladesh_Khaleq_Promotion_of_improved_cook_stove_2008.pdf

http://www.dailyjanakantha.com/news_view.php?nc=29&dd=2013-01-09&ni=121714