Tables 2 and 3 present the ash collection and unburned carbon analyses during combustion tests. Generally, the mass balance on the ashes particles accounted for over 90% of the ash input from the fuel. The analyses of the ash collected in all tests for unburned carbon dem­onstrates that with biomass only, there was the least […]

In order to enable comparison of CO from all tests were converted to CO emitted 6% flue gas oxygen. Figure 4, it is evident that there are significant fluctuations in CO emissions, which between 200 and 900 ppm under the same conditions. The orders of fluctuation were similar to those observed by Abelha et al. […]

Figure 3 illustrates the axial temperature distributions along the FBC height for fuel studied at 50% excess air. As can be seen from the figure, coal combustion gives higher bed tempera­ture (y = 0-40cm) but lower freeboard temperature (y = 450-120cm) in comparison to bio­mass. Then, all the temperatures shows start to fall from 120 […]

The combustion tests were performed using different coal mass fraction; 0, 50 and 100%, corresponding to heat input of 10kW under optimum excess air conditions. Figure 2 shows the effect of different mixtures of rice husk and palm kernel shell with coal on carbon com­bustion efficiency with the same heat input. Generally, Carbon combustion efficiency […]

This section describes the combustion of agricultural residue in a fluidized bed combustor. The influences of fuel properties such as particle size, particle density and volatility as well as influences of operating parameters such as excess air, fluidizing velocity on axial temper­ature profile, the combustion efficiencies and CO emissions are discussed.

The carbon combustion efficiency of a system has been expressed as: hce=C-x100% (1) whereB and C are the mass fractions of burnt and total carbon in the fuel, respectively. Knowing the flue gas composition, the flue gas composition, fractional excess air and the fuel ultimate analyses of the fuel, B can be determined [20]. This […]

In this experiment, baseline data was first obtained for single combustion of 100% British bi­tuminous coal. Also, single combustion of other biomass fuels was carried out to investigate their combustion characteristics in comparison to coal during the co-combustion study. Co­combustion tests at biomass fractions of 30%, 50%, and 70% were performed. For each bio­mass fraction, […]

1.1. Raw materials and characterizations In this study British coal, rice husk and palm kernel shell originated from Perlis were em­ployed as fuel. These fuels were open air dried for 2 to 3 days to remove moisture. The proxi­mate and ultimate analyses were performed on coal and rice husk are summarized in Table 1. British […]