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:

Rüdiger, H., Kicherer, A., Greul, U., Spliethoff, H. and Hein, K.R.G. (1996): Investigations in Combined Combustion of Biomass and Coal in Power Plant Technology, which is published within The Journal Energy and Fuels, Vol. 10, pp. 789-796.

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

The possibility of a combined application of coal and biomass using two different co-combustion technologies has been investigated. A blending of pulverized biomass with coal showed a high burnout up to 20% thermal input of biomass for all particle sizes of the biofuels tested. CO emissions were generally lower than 150 mg/m³ (6% O₂) and remain below 100mg/m³ in most cases. Reburn investigations with three pulverized biomasses resulted in NO_x emissions of approximately 300 mg/m³ (6% O₂). With pyrolysis gas as reburn fuel, minimum NO_x emissions of 200 mg/m³ (100 ppm) at 6% O₂ in the flue gas are possible. The main parameters are pyrolysis gas composition, stoichiometry, and residence time in the reduction zone. Best minimising results have been achieved with pyrolysis gas produced at about 800 ^oC using coal as raw material; using biomass as feedstock, the influence of the pyrolysis temperature is only small. The nitrogen concentration, especially in the tar components of the pyrolysis gas, appears to have a positive effect on NO_x reduction in the reburn zone of the combustion reactor.

Further investigation (e.g. air staging, preblended flames) can be found in article in Source.

4. Synopsis