Thermo-chemical characteristics of peat as a potential gasifier fuel in the Lake Victoria Basin
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Date
2016-11
Authors
Odhiambo, Markus Okoth
Journal Title
Journal ISSN
Volume Title
Publisher
Kenyatta University
Abstract
The Lake Victoria Basin (LVB) in East Africa is endowed with substantial deposits of peat, a
form of biomass, but has failed to gasify peat due to technical, financial and organizational
aspects. While hydroelectric power is sensitive to climate change, gasification technology has a
high potential for reducing biomass/peat energy consumption and increasing access to electricity
and cooking facilities hence improving livelihoods and income. The key aspect for failure is the
insufficient adaptation of gasification equipment to fuel characteristics, fuel specification and
inadequate material choice of system components. This study investigated thermo-chemical
characteristics of peat sampled from Yala swamp in Kenya, Kabale in Uganda, Rulindo in
Northern Rwanda and Butare, Southern Rwanda. The proximate analysis involving moisture
content, ash content and volatile matter, were conducted in an oven and muffle furnace. The
moisture mean percentage ranged between 36.20±0.23 and 38.10±0.22, ash content between
0.116±0.02 and 0.256±0.014, volatile matter between 65.30±0.38 and 68.10±0.61, and fixed
carbon between 20.84±0.27 and 23.05±0.42. Heating values were determined using the
Gallenkamp Auto bomb calorimeter. Peat sampled from Yala had the highest mean percentage
moisture of36.55±0.24, while Rulindo had the highest ash mean percentage ofO.256±0.014. The
heating values mean percentages ranged between 19.69±0.05 and 20.96±0.13 MJ/Kg. The
ultimate analysis was determined using 2400 CHN elemental analyzer to characterize existence
of individual elements in the sample. The mean percentage levels obtained indicated that all peat
samples had a mean range for Carbon between 54.26±0.26 and 57.32±0.25, Nitrogen, between
O.019±0.001 and 0.58±0.21, Oxygen, between 36.17±0.14 and 39.21±0.27 and Hydrogen,
between 5.8±O.l2 and 6.4±0.22. Rulindo had the highest mean percentage of 55.84±0.15% C
while Kabale had the highest mean percentage of 0.58±0.01 % N. The energy content of peat
from Yala had the highest mean percentage of 20.96±0.13 MJ/Kg The theoretical syngas
composition as calculated from thermo-dynamic equilibrium model ranged C02, between
6.87±0.10 and 8.33±0.25, H2, between 12.50±0.12 and 14.20±0.12 and CO, between 24.45±0.38
and 27.20±0.87 mean percentages. Considering that updraft gasifier requires feedstock of mean
percentage moisture content of up to 20-50%, 30-40% oxygen, 50-60% carbon and calorific.
value of 20-30 MJ/kg. Therefore all the sampled peat from the Lake Victoria basin are potential
fuels for gasification. From the determined thermochemical characteristics, gasification of peat
would be carried out using updraft and downdraft gasifiers.
Description
A thesis submitted in partial fulfillment of the requirements for the award of the degree of Master of Science in the School of Pure and Applied Sciences, Kenyatta University
November, 2016