Development of an Improved Stove for Small Scale Parboiling

Audrey YankMichael Ngadi

Robert Kok

McGill University, Québec, Canada

Introduction - Energy• Rice parboiling is an energy intensive process

• 80% of the energy in developing countries comes from biomass (UNEP, 2001)

• Low stove efficiency leads to high fuel demand and wood use

Introduction - Health

• Smoke exposure affects the respiratory health

• 1.6 million people, mainly women and children, die every year as a result of the wood smoke (WHO, 2006)

Source: practicalaction.org/smoke-and-its-impact

ObjectivesDevelop and test improved stoves for small

scale rice parboiling:

Reduce emission of air pollutant Increase thermal efficiency and reduce wood

requirements Increase user safety during rice parboiling

3-Stone Stove Stove 1

Stove 2 (with grate) Stove 3 (with chimney)

Water Boiling Test - Protocol

Low Power: Simmering

High Power: Warm Start

High Power: Cold Start

Preliminary Results

Stove Type Cold Start Hot Start3-Stone Stove 42 51

Stove 1 28 23Stove 2

(with grate) 33 31

Stove 3 26 30

Table 1: Time to boil* 15L of water (min)

* Starting with 15◦C water temperature up to 98.7 ◦C

Thermal Efficiency (%)

3-Stones Stove 1 Stove 2 Stove 30

5

10

15

20

25

30

Cold Start Hot Start Simmering

Specific Fuel Consumption (g/L)

3-Stones Improved 1 Improved 2 Improved 30

100

200

300

400

500

Cold Start Hot Start Simmering

Gas Emissions – Concentration (ppm)

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 400

10

20

30

40 HydrocarbonsCarbon Monoxide

Time (min)

0

10

20

30

40

3-Stone Stove

Improved Stove

Conclusion

• Improved wood stoves have the potential to significantly reduce the wood requirement for rice parboiling.

• The design of the wood stoves still needs to be optimized to reduce the emissions.

Questions?

Thank You!Merci!