The fundamentals of ignition, NO x (NO and N 2 O) emissions, and ash formation characteristics for biomass and mixtures of coal with biomass are precisely elucidated in this study. In this study, biomass, coal, and a biomass-coal mixture are burned, using an electrically heated drop tube furnace. In the combustion test, the focus is on the ignition behavior, combustion efficiency, NO x emission behavior, and formation characteristics of particulate matter, based on the results of gas compositions along the furnace axis and a collection of particulate matter by a low-pressure impactor. As a result, the addition of biomass into low-rank coal affects combustion behavior, especially for ignition enhancement. The NO and N 2 O concentrations in co-combustion are almost the same as those in coal combustion, even if the quantity of input fuel nitrogen under the cocombustion condition is half of that under the coal combustion conditions. A kinetic simulation of the NO and N 2 O behavior results is conducted, using the homogeneous reaction schemes at constant temperature. The simulation result of NO concentration agrees with the experimental result obtained. However, the N 2 O concentration calculated is less than the experimental result, because the heterogeneous schemes that are related to N 2 O are not considered in this simulation. Fine particulates with a size of <2 µm during biomass combustion are produced. Burning the biomass with coal shifts the particle size distribution from fine particles to coarse particles, which can be captured by dust collection systems.

fempaku-che, :Ibyohashi Fundamentals ef pyrolysis and combustion characteristics of several types of biomass were studied, using a thermogravimetric analyzer. In order to elucidate effect of the biomass addition on coal combustien behavior, combustion perfbrmance, NOx emission characteristics and ash formation were discussed, using an electrically heated drop tube fumace. The results obtained showed that pyrolysis and combustion characteristics of biomass depended on lignin and cellulose compositien in the biornass. The biomass could enhance the ignition of the lowrank coal. However, NO and N20 emission behaviors under the ce-combustion condition resembled those under the coal eombustion.When the biornass was burned alone, fine paniculates ef less than 2.rn are produced. Under the co-combustion condition, coal ash could capture the fine particulates from thc biomass during combustion.

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