Abstract:
Biodiesel is widely accepted as comparable fuel to diesel in compression ignition
engines and Diesel fired boiler. It offers many advantages including; higher cetane
number, reduced emissions of particulates, CO, NOX, and hydrocarbons, reduced
toxicity, improved safety and lower lifecycle CO2 emissions. A characteristic of
bio-diesel limiting its application is its relatively poor low-temperature flow
properties. Improvement of its low-temperature flow characteristic still remains
one of the major challenges when using biodiesel as an alternative fuel for Diesel
fire boiler. The bio-diesel fuels derived from fats or oils compounds display
higher cloud points and pour points thus limiting their application. The objective
of this research was to determine the relationship between Diesel fired boiler
performance and emissions using diesel, volumetric blends of palm oil biodiesel
and diesel as a fuel in a diesel fired vertical coil type, water tube, and non IBR
boiler. Boiler efficiency with B25, B50, B75 and B100 fuels are 62.73%, 62.45%,
62.36% and 62.32% respectively, which are higher compared to 62.39% of diesel.
Maximum brake thermal efficiency with B100 fuel is found 64.98%, which are
lower compared to 65.30% with diesel. The higher kinematic viscosity of B100
results in larger droplet diameter and hence in lower brake thermal efficiency.
Maximum EGT measure for diesel, B25, B50, B75 and B100 fuels are 300°C,
295 °C, 308°C 328°C and 340 °C respectively at 11 bar fuel pressure. Except
B20, other blends shows higher EGT compared to diesel fuel. Minimum emission
of CO with diesel, B25, B50, B75 and B100 fuels are 0.037 %/Vol., 0.0336
%/Vol., 0.0326 %/Vol., 0.033%/Vol. and 0.036 %/Vol. respectively at fuel
pressure of 11 bar. Among all compared fuels, CO emission for B50 is lowest
followed by B25, diesel and B100. At maximum fuel pressure, emission of CO
with diesel, B25, B50, B75 and B100 fuels are 0.0605 %/Vol., 0.0616 %/Vol.,
0.0605 %/Vol., 0.060%/Vol. and 0.05 %/Vol. respectively. CO emission with
B100 fuel is 21% higher compared to diesel fuel. Highest HC emissions for diesel,
B25, B50, B75 and B100 fuel are 18 ppm, 16 ppm, 14 ppm, 13ppm and 12 ppm
respectively at no load. While using B100 fuel emission of HC reduces
approximately half the value of HC emissions using diesel fuel.
