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:

Spliethoff, H. and Hein, K.R.G. (1998): Effect of Co-Combustion of Biomass on Emissions In Pulverized Fuel Furnaces, which is published within The Journal of Fuel Processing Technology, 54, pp. 189-205.

Articles with similar content can be found in the Source. Spliethoff, H., Hein, K.R.G. (1999): Effect of Co-combustion of Sewage Sludge and Biomass on Combustion Behaviour and Emissions in Pulverized Fuel Systems, publishing within the  6^th Annual Int. Pittsburgh Coal Conference. October 11-15, USA.

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.

·         Fuel and related data, prepared for calculation, are presented in individual Microsoft Excel Worksheets, all contained within a Workbook.

·         Please note that in some cases, the worksheet tabs within a workbook are not all visible without scrolling horizontally.

·         This workbook can be down-loaded by the reader and saved to her/his hard disk.

·         To achieve this click on the “xls” icon on the left hand side of the banner above. The file will be retrieved from the server, and with up-to-date versions of the browser, will appear in a separate window, from which it may be saved to the user’s hard disk.

·         The data in these worksheets are protected – thus the reader cannot change the worksheet without knowledge of the protection password.

·         However the reader can copy and paste the data into his/her own project work book as required – at this point the accuracy and integrity of the data becomes the responsibility of the reader. Included in this workbook are copies of the abstract and synopsis for reference purposes.

·         All credits and sources, and where necessary, instructions/advice for data use, are presented in this html file. These are not necessarily reproduced in the Excel Work Sheets.

3. Abstract

Biomass not only has a considerable potential as an additional fuel source but it also shows a reasonable cost level in comparison to other renewable energies. The practicable fuel types are both residual material from forestry and agriculture, such as wood or straw, and especially cultivated reproducible feedstock such as Miscanthus Sinensis, whole cereal plants, poplars, or willows. Besides, as single fuel, it is also considered to be sensible to utilize biomass in co-combustion in existing firing systems, such as pc-fired power stations. In order to promote the employment of biogenetic fuels, the European Union, within the framework of the APAS Clean Coal Technology Programme, initiated a research project concerning the co-combustion of biomass in existing firing systems. The focus of the investigations in experimental and industrial scale plants was to establish the impact of co-combusting biomass and sewage sludge in coal-fired systems with regard to combustion behaviour and pollutant formation. The investigations were carried out on laboratory scale and pilot scale, as well as in large-scale plants. The task of the Institut für Verfahrenstechnik und Dampfkesselwesen (IVD), University of Stuttgart, within the EU clean coal technology programme, was to investigate the effects of co-combustion of solid biomass Miscanthus, straw and municipal sewage sludge together with the primary fuel hard coal. The experimental plant used was a semi-industrial pulverised fuel test rig 0.5 MW. Within the scope of this publication, a synopsis shall be given of the outcome of the project, with special regard to the effect of co-combustion on emissions. The investigations reveal that biomass addition has a positive effect on emissions. Since biomass in most cases contains considerably less sulphur than coal, an increasing biomass share in the thermal output makes the SO emissions decrease proportionally. In addition, SO can partly be captured in the ash by the alkaline–earth fractions of the biomass ash. As for sewage sludge, the emissions of SO correlate with the sulphur content of the fuel and, hence, rise with an increasing share of this biomass. Due to the high volatile content of the biomass, low NO emissions can be achieved both by air staging and by reburning.

4. Synopsis