Experimental Analysis on the Characteristics of Pulverized Coal - Palm kernel Shell Fuel Blend

Abstract

This study investigates the potentials of supplementing coal with kernel shell for
use in high efficiency boilers aimed at reducing greenhouse emissions and
adding value to palm kernel waste. Sub-bituminous coal was obtained from
Ankpa coal field in Kogi State, Nigeria while Palm Kernel Shell was obtained
from an oil processing mill in Benin City, Edo State. Both biomass fuel samples
were prepared separately for pelleting and further analysis. Afterwards, seven
different fuel pellets lettered A to G of differing blending ratios were produced
using a piston-type pelleting machine: The ratios used for this study includes
100% palm kernel shell, 100% coal and coal combined with palm kernel shell at
varying masses having mix ratios of : 10 %, 20 %, 30 %, 40 % and 50 %
respectively. The produced fuel pellets were characterized according to:
moisture content, calorific value, proximate and ultimate analyses in order to
define its property (characteristics). The calorific values fuel blends were
21714.74 kJ/kg, 28430.26 kJ/kg, 26449.16 kJ/kg, 25508.01 kJ/kg, 25017.95
kJ/kg, 22046.31 kJ/kg and 20811.92 kJ/kg for samples A to G respectively. It
was seen that the calorific values of the coal-palm kernel shell blends decrease
with increased co-firing rate compared with that of pure bituminous-coal which
was 28430.26 KJ/Kg. The ash content obtained were 13.61 %, 14.89 %, 11.89
%, 11.15 %, 11.51 %, 11.88 % and 16.77 % for samples A to G respectively.
Also, Sulphur content results showed 0.84 %, 0.76 %, 0.67 %, 0.70 %, 0.73 %,
0.82 % and 0.88 % for samples A to G respectively. The percentage ash and
Sulphur contents obtained in this study were in the recommended range of: 5 -
40% for ash and 0.5 - 0.8% for Sulphur. Fuel sample D with a mix ratio 80-20
having a Sulphur content of 0.70 and the least Carbon content of 51.52
amongst the fuel samples was considered the most environment friendly.
These properties were significantly lower than that of pure coal.