Abstract:
Conventional fuel sources, such as fossil fuels, have become unafordable for the low end of the economy and thus the need for
sustainable alternatives. Gasifcation of coal and biomass is considered as an alternative source for small-sized engines, such as
tricycles in Kenya. Mui basin coal is a low-quality coal, available in Kenya, and blending with selected biomass (rice husks, Prosopis
julifora, and Hyphaene compressa) presents a new source of alternative transport fuel through cogasifcation and upgrading. Te
selected biomass samples were collected, air-dried, and crushed to 60μm and subjected to calorifc determination, proximate, and
ultimate analysis. Blending was done at various ratios weight by weight, while thermochemical determinations were conducted
using the American Society for Testing and Materials (ASTM). Te fxed carbon content was reported as 29.3±5.51% for Mui
basin coal, 21.1±1.55% for rice husk, and 31.0±1.00% for H. compressa. Blending was found to improve the hydrogen:carbon
ratio with an averagerate of 0.12 and decreasedthesulphurandnitrogencontent, leadingtolowemissions.Testudyrevealedthat
calorifc values of the fuel sources were as follows: Mui basin coal, 20.41±0.15MJ/kg; P. julifora, 18.68±0.17MJ/kg; and
H. compressa, 18.69±0.00MJ/kg, while rice husks had 12.95±0.1MJ/kg. Blending was also found to improve calorifc values by
average values of 0.4MJ/kg for P. julifora, 1.3MJ/kg for H. compressa, and 2.28MJ/kg for rice husk. Te moisture content was
reduced by 1–2% for all fuel sources; ash content was reduced by 33%, while the volatile matter was increased by 11% for
P. julifora, 7% for H compressa, and 0.2% for rice husks. Te optimal blend of ratio 1:1 when cogasifed produced syngas, which
was upgraded through cleaning and cooling. Te upgraded syngas had a moderate ratio of hydrogen to carbon monoxide with the
right modifcation and retroftting; it can be applied in internal combustion engines of tricycles-“tuk tuks.” Te study reveals that
the optimal blending ratio of 1:1 for coal:biomass reduces the pollution ash content, increases calorifc values, and enhances
syngas fuel properties to moderate ratio.
