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ON-Line alkali measurement for fuel quality control in biomass-Operated boilers

Leffler, Tomas LU ; Brackmann, C. LU ; Berg, M.; Li, Z. S. LU and Aldén, M. LU (2016) In IFRF Combustion Journal 2016(1). p.1-19
Abstract

Today's power plants are shifting their combustion toward a more complex fuel mix on the grounds of environmental impact, cost, availability and regulations. Certain new types of fuel can be classified into the following groups: herbaceous material (straw and grass), agricultural by-products (pits, shells and hulls), wood, and waste fuels. These fuels contain various amounts of alkali metals, mainly potassium and sodium, as well as chlorine and sulphur, which are easily vaporised in the combustion process and are involved in processes that cause severe slagging, fouling and high-temperature corrosion problems in the furnace and further downstream in the boiler. In this study, combustion of three different biomass fuel mixes was... (More)

Today's power plants are shifting their combustion toward a more complex fuel mix on the grounds of environmental impact, cost, availability and regulations. Certain new types of fuel can be classified into the following groups: herbaceous material (straw and grass), agricultural by-products (pits, shells and hulls), wood, and waste fuels. These fuels contain various amounts of alkali metals, mainly potassium and sodium, as well as chlorine and sulphur, which are easily vaporised in the combustion process and are involved in processes that cause severe slagging, fouling and high-temperature corrosion problems in the furnace and further downstream in the boiler. In this study, combustion of three different biomass fuel mixes was investigated in a circulating fluidized bed boiler. An on-line alkali-chloride monitoring instrument was used to gather valuable information for evaluating the fuel quality in terms of harmful alkali chlorides, measuring the sum of alkali chlorides (potassium chloride and sodium chloride) based on ultraviolet absorption. In addition, two batches of wood biomass fuel were compared during combustion in a full-scale powder fuel boiler. In all cases the impact of changes in fuel composition on alkali-chloride formation levels were monitored quantitatively with a time resolution in the order of seconds, allowing for analysis and countermeasures. The study concluded that the employment of an on-line alkali monitoring device to prevent alkali-chloride problems is a cost-efficient, sustainable solution that extends the operational time of the boiler and reduces its maintenance costs.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Alkali metals, Fouling and high-temperature corrosion, Prevention of slagging, Reduced maintenance cost
in
IFRF Combustion Journal
volume
2016
issue
1
pages
19 pages
publisher
International Flame Research Foundation
external identifiers
  • scopus:85013414398
ISSN
1562-479X
language
English
LU publication?
yes
id
28ab706b-195e-41b2-b926-0c5e6b8a202f
date added to LUP
2017-03-09 11:03:47
date last changed
2017-10-01 05:31:48
@article{28ab706b-195e-41b2-b926-0c5e6b8a202f,
  abstract     = {<p>Today's power plants are shifting their combustion toward a more complex fuel mix on the grounds of environmental impact, cost, availability and regulations. Certain new types of fuel can be classified into the following groups: herbaceous material (straw and grass), agricultural by-products (pits, shells and hulls), wood, and waste fuels. These fuels contain various amounts of alkali metals, mainly potassium and sodium, as well as chlorine and sulphur, which are easily vaporised in the combustion process and are involved in processes that cause severe slagging, fouling and high-temperature corrosion problems in the furnace and further downstream in the boiler. In this study, combustion of three different biomass fuel mixes was investigated in a circulating fluidized bed boiler. An on-line alkali-chloride monitoring instrument was used to gather valuable information for evaluating the fuel quality in terms of harmful alkali chlorides, measuring the sum of alkali chlorides (potassium chloride and sodium chloride) based on ultraviolet absorption. In addition, two batches of wood biomass fuel were compared during combustion in a full-scale powder fuel boiler. In all cases the impact of changes in fuel composition on alkali-chloride formation levels were monitored quantitatively with a time resolution in the order of seconds, allowing for analysis and countermeasures. The study concluded that the employment of an on-line alkali monitoring device to prevent alkali-chloride problems is a cost-efficient, sustainable solution that extends the operational time of the boiler and reduces its maintenance costs.</p>},
  author       = {Leffler, Tomas and Brackmann, C. and Berg, M. and Li, Z. S. and Aldén, M.},
  issn         = {1562-479X},
  keyword      = {Alkali metals,Fouling and high-temperature corrosion,Prevention of slagging,Reduced maintenance cost},
  language     = {eng},
  number       = {1},
  pages        = {1--19},
  publisher    = {International Flame Research Foundation},
  series       = {IFRF Combustion Journal},
  title        = {ON-Line alkali measurement for fuel quality control in biomass-Operated boilers},
  volume       = {2016},
  year         = {2016},
}