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:

Masato Tamura, Roman Weber and Willem van de Kamp (2001): Characterization of Alternative Fuels for Co-firing with Pulverised Coal, which is published within The 13^th IFRF Members Conference, 2001, Noordwijkerhout, The Netherlands

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.

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·         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 combustion of pulverised coal in utility boilers is one of the main methods for electricity generation in Europe. The co-firing of biomass and biomass wastes with pulverised coal in the power generation industry may assist in addressing problems related to waste disposal control of greenhouse gases and noxious gas emissions. Over the last five years or so, substantial efforts have been allocated to the development of the combustion technology for co-firing. Although several demonstration projects at power stations have already been undertaken the effects related to the impact of the alternative fuels on flame stability, NOx, SOx, unburned hydrocarbons, particulates are still not fully understood. Incidences of slagging, fouling and corrosion have been the issues of main concern.

Several research establishments participated into the European APAS programme to carry out preliminary test to establish the technical possibilities of co-firing. As a part of the APAS programme, the IFRF (Morgan and van de Kamp) undertook studies on the co-firing of a range of bituminous coals with straw, waste paper and municipal sewage sludge. The primary objective of the study was to derive a technical guideline for design of industrial burners for co-firing. Several methods of injecting the alternative fuels at the 2.5 MW swirl-stabilised burner were examined. The co-firing ratio was an important burner design parameter. Flames firing 100% straw and sewage sludge were also generated. This important study resulted in determining the relationship between NOx, SO_x and burnout as a function of the co-firing ratio. It was observed that slagging and fouling could increase when the co-firing ratio was excessive. Recently, Hein and Scheurer have published a review of technical activities in the field of co-firing. The review lists the “areas of concern” in co-firing and underlines the co-firing potential. Fuel characteristics have been identified as the factors determining the applicability of the technology.

This paper introduced the IFRF-RS solid fuel characterization facility and some results of biomass characterization programme. The investigation aims to achieve a better understanding of the combustion behaviour of biomass blends with coal, with emphasis on devolatilization, char burnout under pulverised coal combustion conditions.

4. Synopsis