Additives application to wheat straw to increasing the ash fusion temperature

Abstract

Abstract. Biofuels are more and more popular energy source and they are used in more households in the Eastern Europe region. Straw from the agriculture crops is promising and significant biomass source of energy but now it is at least energy utilized. In terms of straw burning is the most important feature of its quick and easy volatilization. Another property, which is negative, is its low ash fusion temperature. The straw ash begin soften at about 830 °C. However, at the temperature 850 °C to 900 °C the ash transform to glass slags and sinters which damage the refractory of the furnace and it is also difficult to remove. The paper deals about the option for reducing the problems of low ash fusion temperature by additives application. The presented results are from the lime application in the laboratory conditions and in the real conditions, in the heat source with the nominal thermal power 2 MW. The results of the experiments showed that the results from the real operation does not correspond with laboratory results.

Investigation of Buckwheat Hulls as Additives in the Production of Solid Biomass Fuel from Straw

“…High moisture content, low raw material density, high volatile matter, non-flammable organic matter content, and low ash melting/sintering temperatures are the main reasons for the low usage of collected straw in thermal conversion processes. The main problemash melting characteristics-can be solved using additives (calcite, kaolin, or dolomite) to increase the melting temperature during the agro-mass combustion process [5][6][7]. Kaolin (Al 2 Si 2 O 5 (OH) 4 ) mainly consists of SiO 2 and Al 2 O 3 compounds, which makes it less effective than dolomite [5][6][7].…”

“…The main problemash melting characteristics-can be solved using additives (calcite, kaolin, or dolomite) to increase the melting temperature during the agro-mass combustion process [5][6][7]. Kaolin (Al 2 Si 2 O 5 (OH) 4 ) mainly consists of SiO 2 and Al 2 O 3 compounds, which makes it less effective than dolomite [5][6][7]. Dolomite (CaMg(CO 3 ) 2 ) is predominantly composed of CaO, MgO, and CaCO 3 compounds, and is one of the most suitable additives for enhancing the melting characteristics of wheat straw ash [5,7].…”

“…Kaolin (Al 2 Si 2 O 5 (OH) 4 ) mainly consists of SiO 2 and Al 2 O 3 compounds, which makes it less effective than dolomite [5][6][7]. Dolomite (CaMg(CO 3 ) 2 ) is predominantly composed of CaO, MgO, and CaCO 3 compounds, and is one of the most suitable additives for enhancing the melting characteristics of wheat straw ash [5,7]. Calcite (CaCO 3 ), like dolomite, also enhances the melting characteristics of ash [6,7].…”

“…Dolomite (CaMg(CO 3 ) 2 ) is predominantly composed of CaO, MgO, and CaCO 3 compounds, and is one of the most suitable additives for enhancing the melting characteristics of wheat straw ash [5,7]. Calcite (CaCO 3 ), like dolomite, also enhances the melting characteristics of ash [6,7]. However, the use of additives can cause additional environmental impacts such as an increase in the amount of fly ash due to the formation of other harmful compounds.…”

Will mixing rule or chemical reactions dominate the ash behavior of biomass mixtures in combustion processes on laboratory and pilot scales?

“…Additives were widely used to decrease agglomeration and sintering levels, but each has its own problem [10][11][12][13]. Their cost is usually high and their application depends on the feedstock [10,14].…”