1. Sources

The present Combustion File is part of the cluster of CFs produced within the literature survey phase of the industrial sponsored research and development project PowerFlam1 and is confidential to the participants registered for that project.

This CF is specifically concerned with the research project:

Morgan, D.J. and van de Kamp W.L. (1996): The co-firing of pulverised bituminous coals with straw, waste paper and municipal sewage sludge, which is published within The Journal of Combustion Science and Technology, Vol. 121, pp.317-332.

2. Background

·         This combustion file is concerned with the provision of combustion related data to the sponsors.

·         In this html file the source of the data is summarised in section 4 below, in order to give the reader a general overview of the way the data was collected.

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3. Abstract

The co-firing of different coals with straw, waste paper, and municipal sewage sludge were subjected to semi-industrial scale studies. The single burner experiments were performed with a swirl stabilized aerodynamically air staged burner (AASB) in a boiler chamber simulator with internal dimensions of 2 × 2 × 6.3 m. Pulverized bituminous coals of high and medium volatile content, and low and high sulfur content were used, while straw and waste paper were employed as the biomass fuels. The co-firing ratios varied from 0-100% straw. Similar trends in NOx and SO2 emissions were shown by different coals. The main parameters affecting the NOx, SO2 emissions, and burnout were the co-firing ratio, coal type and flame type. Preferential burning was observed in the 20-40% straw/coal co-firing range and trends were different for high and medium volatile coal. The co-firing of pulverized coal with dried sewage sludge has demonstrated that the sewage may be milled and fired successfully as a pulverized fuel in the range 0-30, 50, 70, and 100%. NOx was reduced by 60% with fuel placement and by 70-80% with the introduction of air staging. Co-firing of pulverized coal with and straw and municipal sewage is possible. Due to the higher concentrations of fuel-bound nitrogen, increased concentrations of NOx, relative to a 100% coal flame, were observed.

Earlier version of the same report can be found in Source: Clean Coal Technology Programme 1992-1994 Vol. II, Combined Combustion of Biomass/Sewage Sludge and Coals: Final Reports, EC-Research Project: APAS-Contract COAL-CT92-0002. Editor – Hein, K.R.G.

4. Synopsis