improved biomass cooking stove for household use - (PDF, 101 mb ...

Lack of Understanding of Fuel Preparation
Wet fuel burns less effectively than dry fuel because part of the heat
of combustion is consumed to evaporate the water. Fresh wood generally
contains about 50% moisture; therefore, wood should be ideally dried down to
a moistura content of approximately 15%-12% before use. This can be done
easily by placing it under the grate during cooking, or by letting it air dry
for several days after splitting. It was found that many househola cooks do
not practice fuelwood preparation and drying. Another factor that
contributes to the inefficient consumption of fuel is the lack of understanding
of fuel use. For example, some household cooks insert a large piece of log
into the stove. This kind of practice not only prolongs cooking time but also
requires more firewood. In addition, the heavy wood piece can damage the
stove structure easily. Smaller sized wood burns more effectively than fuel
of a larger size, since a smaller size has a larger surface area of combustion
with air. Therefore, large pieces of wood should be split or chopped into
smaller ones for more efficient use of fuel.
High Cost, Limited Production and Distribution of Good Stoves
Since the main energy sources for cooking in Thailand are wood and
charcoal, the degradation of natural forest has become evident in many areas
of the country. The rate of deforestation has increased tremendously during
the last decade. For example, the forest areas of the country have been
reduced from 273,628 sq.km. in 1961 to 156,600 sq.km. in 1982 (Forestry
Statistics 1982). Even though the depletion of the forest is not only caused
by the consumption of fuelwood for cooking but also by slash and burn
agriculture, road construction, etc., 40 million cu.m./yr of wood fuel is
used for cooking alone. This will contribute significantly to the wood
scarcity problem in the near future.
Fortunately, commercial, fast-growing tree plantations that produce fuel
(such as the mangrove, Eucalyptus, and Casuarina) can somewhat reduce the
depletion of wood. However, if the commercial wood plantations are not
expanded on a large scale, or are developed without the attempt to reduce
heavy woodfuel consumption by initiation of efficient stoves, or by encouraging
the people to grow more wood for their own use, Thailand's natural forests
can become exhaused within a very short time.
D. OBJECTIVES OF THE STUDY
The following are the five major objectives of the study:
1. Tu established a model stove testing and evaluation center to
accommodate the national need for present and future research and
development of biomass cooking stoves.
2. To conduct a systematic investigation on present performance of existing
stoves being used in Thailand.
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