Abstract
The use of straw in pulverised fuel-fired boiler is great technical challenge, especially when it comes to dealing with problems from slagging and fouling. Introduction of straw in the fuel mix of Swedish boilers will most likely be done by co-firing of woody biomass with straw, and this can provide a means to reduce the (well-documented) problems with fouling and slagging from straw. The project will focus on the faith of alkali metals (K and Na) as well as studies on the slagging and fouling propensity in pulverised fuel-fired boilers when straw is co-fired with woody biomass. A total of 5 different fuel mixtures has been fired in a 150 kW pilot-scale pulverised fuel-fired burner: (i) straw 100 %, (ii) straw/bark 50/50 %, (iii) straw/bark 75/25 % (iv) straw/wood 75/25 % (v) straw/wood 50/50 % (wt-%). The adding of woody biomass to straw has in all of the above-mentioned cases had some positive effect. In general, in all of the ash deposits, an increase in the concentration of Calcium (Ca) has been observed as well as a decrease in the concentrations of Potassium (K) and Silicon (Si). These general trends should be considered as a positive when combustion of straw
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Citation Formats
Hedman, Henry, Nordgren, Daniel, Bostroem, Dan, Oehman, Marcus, and Padban, Nader.
Increased electricity production from straw by co-firing with woody biomass; Oekad elproduktion med halm genom sameldning med traedbraenslen.
Sweden: N. p.,
2011.
Web.
Hedman, Henry, Nordgren, Daniel, Bostroem, Dan, Oehman, Marcus, & Padban, Nader.
Increased electricity production from straw by co-firing with woody biomass; Oekad elproduktion med halm genom sameldning med traedbraenslen.
Sweden.
Hedman, Henry, Nordgren, Daniel, Bostroem, Dan, Oehman, Marcus, and Padban, Nader.
2011.
"Increased electricity production from straw by co-firing with woody biomass; Oekad elproduktion med halm genom sameldning med traedbraenslen."
Sweden.
@misc{etde_1004310,
title = {Increased electricity production from straw by co-firing with woody biomass; Oekad elproduktion med halm genom sameldning med traedbraenslen}
author = {Hedman, Henry, Nordgren, Daniel, Bostroem, Dan, Oehman, Marcus, and Padban, Nader}
abstractNote = {The use of straw in pulverised fuel-fired boiler is great technical challenge, especially when it comes to dealing with problems from slagging and fouling. Introduction of straw in the fuel mix of Swedish boilers will most likely be done by co-firing of woody biomass with straw, and this can provide a means to reduce the (well-documented) problems with fouling and slagging from straw. The project will focus on the faith of alkali metals (K and Na) as well as studies on the slagging and fouling propensity in pulverised fuel-fired boilers when straw is co-fired with woody biomass. A total of 5 different fuel mixtures has been fired in a 150 kW pilot-scale pulverised fuel-fired burner: (i) straw 100 %, (ii) straw/bark 50/50 %, (iii) straw/bark 75/25 % (iv) straw/wood 75/25 % (v) straw/wood 50/50 % (wt-%). The adding of woody biomass to straw has in all of the above-mentioned cases had some positive effect. In general, in all of the ash deposits, an increase in the concentration of Calcium (Ca) has been observed as well as a decrease in the concentrations of Potassium (K) and Silicon (Si). These general trends should be considered as a positive when combustion of straw is considered. Out of all ash deposits collected in the furnace, the characteristics of the bottom ash displayed the largest (positive) change and visual inspections and chemical analysis of the bottom ash showed that the ash had become more porous and contained more Calcium as more woody biomass was introduced in the fuel mix. The deposit build-up rate on the air cooled probes was reduced when more woody biomass was co-fired with straw. The reduction was highest in the trial where 50% woody biomass was used and the most apparent changes in composition could be seen in Calcium (increase) and Potassium (decrease). Danish experiences from introducing straw in pulverised fuel-fired boiler indicate that extra soot-blowers should be considered at the furnace walls and in connection to screen-tubes (if any). In addition, the bottom ash hopper and ash conveying from the electrostatic precipitator may need to be modified to cope with when a high slagging propensity fuel such as is co-firing. For Swedish power plants owners interested in introducing straw in the fuel mix, it is recommended to start with lower straw co-firing than those presented in this project. Based on the characteristics of the bottom ash and deposits on air-cooled probes (550 oC) a co-firing ration of 15-25 wt-% straw is initially recommended}
place = {Sweden}
year = {2011}
month = {Jan}
}
title = {Increased electricity production from straw by co-firing with woody biomass; Oekad elproduktion med halm genom sameldning med traedbraenslen}
author = {Hedman, Henry, Nordgren, Daniel, Bostroem, Dan, Oehman, Marcus, and Padban, Nader}
abstractNote = {The use of straw in pulverised fuel-fired boiler is great technical challenge, especially when it comes to dealing with problems from slagging and fouling. Introduction of straw in the fuel mix of Swedish boilers will most likely be done by co-firing of woody biomass with straw, and this can provide a means to reduce the (well-documented) problems with fouling and slagging from straw. The project will focus on the faith of alkali metals (K and Na) as well as studies on the slagging and fouling propensity in pulverised fuel-fired boilers when straw is co-fired with woody biomass. A total of 5 different fuel mixtures has been fired in a 150 kW pilot-scale pulverised fuel-fired burner: (i) straw 100 %, (ii) straw/bark 50/50 %, (iii) straw/bark 75/25 % (iv) straw/wood 75/25 % (v) straw/wood 50/50 % (wt-%). The adding of woody biomass to straw has in all of the above-mentioned cases had some positive effect. In general, in all of the ash deposits, an increase in the concentration of Calcium (Ca) has been observed as well as a decrease in the concentrations of Potassium (K) and Silicon (Si). These general trends should be considered as a positive when combustion of straw is considered. Out of all ash deposits collected in the furnace, the characteristics of the bottom ash displayed the largest (positive) change and visual inspections and chemical analysis of the bottom ash showed that the ash had become more porous and contained more Calcium as more woody biomass was introduced in the fuel mix. The deposit build-up rate on the air cooled probes was reduced when more woody biomass was co-fired with straw. The reduction was highest in the trial where 50% woody biomass was used and the most apparent changes in composition could be seen in Calcium (increase) and Potassium (decrease). Danish experiences from introducing straw in pulverised fuel-fired boiler indicate that extra soot-blowers should be considered at the furnace walls and in connection to screen-tubes (if any). In addition, the bottom ash hopper and ash conveying from the electrostatic precipitator may need to be modified to cope with when a high slagging propensity fuel such as is co-firing. For Swedish power plants owners interested in introducing straw in the fuel mix, it is recommended to start with lower straw co-firing than those presented in this project. Based on the characteristics of the bottom ash and deposits on air-cooled probes (550 oC) a co-firing ration of 15-25 wt-% straw is initially recommended}
place = {Sweden}
year = {2011}
month = {Jan}
}