scholarly journals Application of a Modeling Tool to Describe Fly Ash Generation, Composition, and Melting Behavior in a Wheat Straw Fired Commercial Power Plant

Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1510
Author(s):  
Ibai Funcia ◽  
Fernando Bimbela ◽  
Javier Gil ◽  
Luis M. Gandía
Keyword(s):  
Fly Ash ◽  
Wheat Straw ◽  
Melting Behavior ◽  
Major Elements ◽  
Solid Particles ◽  
Biomass Combustion ◽  
Chemical Fractionation ◽  
Ash Melting ◽  
Cooling Effects ◽  
Entrainment Effect

Ash behavior is a key operational aspect of industrial-scale power generation by means of biomass combustion. In this work, FactSageTM 6.4 software was used to develop and assess three models of wheat straw combustion in a vibrating grate-fired commercial boiler of 16 MWth, aiming to describe the inorganic elements release as well as fly ash melting behavior and composition. Simulations were carried out solving four consecutive calculation stages corresponding to the main plant sections. Chemical fractionation was adopted in order to distinguish between reactive, inert and partially reactive biomass fractions. The developed models allow take into account different levels of partial reactivity, values of the temperature for each sub-stage on the grate, and ways to apply entrained streams based on data from the elemental analyses of the fly ashes. To this end, two one-week experimental campaigns were conducted in the plant to carry out the sampling. It has been found that considering chemical fractionation is indispensable to describe the entrainment of solid particles in the gas stream. In addition, the best results are obtained by adopting a small reactivity (2%) of the inert fraction. As for fly ash composition, the concentrations of the major elements showed good agreement with the results from the chemical analyses. In the case of S and Cl, calculations revealed a match with gas cooling effects in the superheaters as well as an entrainment effect. The melting behavior together with the presence of KCl and K2SO4 condensates, point out at possible corrosion phenomena in walls at temperatures of 700–750 °C.

scholarly journals Effect of Paper Sludge and Dendromass on Properties of Phytomass Pellets

2020 ◽  
Vol 11 (1) ◽  
pp. 65
Author(s):  
Radovan Nosek ◽  
Alexander Backa ◽  
Peter Ďurčanský ◽  
Michal Holubčík ◽  
Jozef Jandačka
Keyword(s):  
Melting Point ◽  
Wheat Straw ◽  
Plant Biomass ◽  
Combustion Process ◽  
Calorific Value ◽  
Biomass Combustion ◽  
Paper Sludge ◽  
Melting Temperatures ◽  
Wood Sawdust ◽  
Ash Melting

Woody and agricultural wastes are important fuels in many countries, and have the potential of being even more important in the future. The main problems of plant biomass combustion are low ash melting temperatures and increased emissions. The most widely used treatment to solve the problem of low ash melting point is blending a fuel with an additive. In this work, pellets were produced from wheat straw containing wood sawdust and paper sludge in the following proportions 40:40:20 and 45:45:10 (straw/sawdust/paper sludge). The purpose of this work was to study the influence of sludge and dendromass on the straw pellet parameters and combustion process. The highest calorific value of 15.71 MJ kg−1 was registered for a sample with a 10% paper sludge concentration. The effectiveness of paper sludge was proved, and the ash melting temperature was increased from 1025 to 1328 °C for the same sample.

scholarly journals The Influence of Cement Substitution by Biomass Fly Ash on the Polymer–Cement Composites Properties

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3079
Author(s):  
Beata Jaworska ◽  
Dominika Stańczak ◽  
Joanna Tarańska ◽  
Jerzy Jaworski
Keyword(s):  
Fly Ash ◽  
Building Materials ◽  
Raw Materials ◽  
Combustion Process ◽  
Biomass Combustion ◽  
Cement Composites ◽  
Cement Mortars ◽  
Mineral Additive ◽  
Biomass Fly Ash

The generation of energy for the needs of the population is currently a problem. In consideration of that, the biomass combustion process has started to be implemented as a new source of energy. The dynamic increase in the use of biomass for energy generation also resulted in the formation of waste in the form of fly ash. This paper presents an efficient way to manage this troublesome material in the polymer–cement composites (PCC), which have investigated to a lesser extent. The research outlined in this article consists of the characterization of biomass fly ash (BFA) as well as PCC containing this waste. The characteristics of PCC with BFA after 3, 7, 14, and 28 days of curing were analyzed. Our main findings are that biomass fly ash is suitable as a mineral additive in polymer–cement composites. The most interesting result is that the addition of biomass fly ash did not affect the rheological properties of the polymer–cement mortars, but it especially influenced its compressive strength. Most importantly, our findings can help prevent this byproduct from being placed in landfills, prevent the mining of new raw materials, and promote the manufacture of durable building materials.

Fly ash from biomass combustion as replacement raw material and its influence on the mortars durability

2017 ◽  
Vol 20 (2) ◽  
pp. 1006-1015 ◽  
Author(s):  
R. C. E. Modolo ◽  
L. Senff ◽  
V. M. Ferreira ◽  
L. A. C. Tarelho ◽  
C. A. M. Moraes
Keyword(s):  
Fly Ash ◽  
Raw Material ◽  
Biomass Combustion

Modelling Particle Size Distribution of Residual Fly Ash from Pulverized Biomass Combustion

2021 ◽  
Vol 15 (1) ◽  
pp. 75-82
Author(s):  
Mingzi Xu ◽  
Changdong Sheng
Keyword(s):  
Particle Size ◽  
Fly Ash ◽  
Simple Model ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Particle Shape ◽  
Great Influence ◽  
Biomass Combustion ◽  
Ash Formation ◽  
Residual Ash

The present work aims to develop a simple model for describing the particle size distribution (PSD) of residual fly ash from pulverized biomass combustion. The residual ash formation was modelled considering the mechanism of fragmentation and coalescence. The influences of particle shape and stochastic fragmentation on model description of the PSD of the fly ash were investigated. The results showed that biomass particle shape has a great influence on the model prediction, and a larger fragmentation number is required for cylindrical particles than that for spherical particles to get the same PSD of fly ash, and the fragment number of the particles increases with the shape factor increasing. For pulverized biomass with a wide size distribution, the model predicted ash PSD considering the stochastic fragmentation is very similar to that assuming uniform fragmentation. It implies that the simple model assuming uniform fragmentation is applicable for predicting fly ash size distribution in practical processes where biomass particles have a wide range of sizes. For the fuel with a narrower initial PSD, the stochastic fragmentation model generally predicts a coarser PSD of the residual ash than assuming uniform fragmentation. It means the stochastic fragmentation is of great influence to be considered for accurate description of ash formation from the fuel with a narrow PSD.

scholarly journals Adapting the Forchheimer equation for the flow of air through wheat straw beds

2016 ◽  
Vol 20 (suppl. 2) ◽  
pp. 463-470
Author(s):  
Djordjije Doder ◽  
Biljana Miljkovic ◽  
Borivoj Stepanov ◽  
Ivan Pesenjanski
Keyword(s):  
Experimental Investigation ◽  
Pressure Drop ◽  
Wheat Straw ◽  
Measurement Methods ◽  
High Flow ◽  
Biomass Combustion ◽  
Inertial Effects ◽  
Forchheimer Equation ◽  
Flow Rates ◽  
Straw Bale

The paper presents the results of an experimental investigation of air pressure drop while flowing through wheat straw beds. According to Darcy?s law, the smaller the porosity of the bed is, the bigger the pressure drop will be. The investigation was conducted using three different porosities (or three bed densities), and for two different air flow rates. After determining porosity (which is directly measurable), the permeability of straw could be found. For high flow velocities, such as the velocity of air flowing through a straw bale, the Forchheimer equation becomes more relevant as a correction of Darcy?s law with inertial effects included. Otherwise, the permeability tensor depends only on the geometry of the porous medium. With permeability known, the Forchheimer equation coefficients can be easily estimated. These results may be important for the future development of efficient biomass combustion facilities. The measurement methods and facility characteristics are described in more detail.

scholarly journals The mineral sequestration of CO2 with the use of fly ash from the co-combustion of coal and biomass

2017 ◽  
Vol 33 (4) ◽  
pp. 143-155 ◽  
Author(s):  
Alicja Uliasz-Bocheńczyk ◽  
Aleksandra Pawluk ◽  
Michał Pyzalski
Keyword(s):  
Phase Composition ◽  
Fly Ash ◽  
Co2 Emissions ◽  
Energy Production ◽  
Binding Capacity ◽  
Renewable Energy Sources ◽  
Biomass Combustion ◽  
Composition Analysis ◽  
Fly Ashes ◽  
Carbonation Process

Summary As a result of energy production processes, the power industry is the largest source of CO2 emissions in Poland. Emissions from the energy sector accounted for 52.37% (162 689.57 kt) of the total emissions in 2015, which was estimated at 310.64 million tons of CO2. In recent years, the tightening of regulations on the use of renewable energy sources has resulted in an increased amount of biomass used in the professional energy industry. This is due to the fact that the CO2 emissions from biomass combustion are not included in the total emissions from the combustion of fuels, resulting in the zero- emission factor for biomass. At the same time, according to the hierarchy of waste management methods, recycling is the preferred option for the management of by-products generated during energy production. The fly ashes resulting from the biomass combustion in pulverized boilers (which, due to their chemical composition, can be classified as silicate ash) were subjected to analysis. These ashes can be classified as waste 10 01 17 - fly ash from co-firing other than mentioned in 10 01 16 according to the Regulation of the Minister of the Environment of December 9, 2014 on waste catalogues. The maximum theoretical carbon dioxide binding capacity for the analyzed fly ashes resulting from the co-combustion of biomass is 8.03%. The phase composition analysis of the fly ashes subjected to carbonation process has shown, in addition to the components identified in pure fly ash samples (SiO2, mullite), the presence of calcium carbonate − calcite − the primary product of the carbonation process, as indicated by the results of both X-ray and thermogravimetric analysis.The degree of carbonation has been determined based on the analysis of the results of the phase composition of fly ash resulting from the co-firing of biomass and bituminous coal. The calculated degree of carbonation amounted to 1.51%. The carbonation process is also confirmed by the lowered pH of the water extracts, decreasing from 11.96 for pure ashes to 8.7 for CO2 treated fly ashes. In addition, the carbonation process has reduced the leaching of pollutants, most notably chlorides, sulphates, and potassium.

Biological denitrification of drinking water using various natural organic solid substrates

2004 ◽  
Vol 48 (11-12) ◽  
pp. 489-495 ◽  
Author(s):  
S. Aslan ◽  
A. Türkman
Keyword(s):  
Drinking Water ◽  
Carbon Source ◽  
Wheat Straw ◽  
Nitrate Removal ◽  
Solid Particles ◽  
Effluent Water ◽  
Activated Carbon Adsorption ◽  
Organic Solid ◽  
Solid Substrates ◽  
Laboratory Reactor

Denitrification of drinking water was studied using various natural organic solid substrates (NOSS) such as poplar, hornbeam, pine shavings and wheat straw as a carbon source in a batch unit. The highest nitrate removal efficiency was observed with the wheat straw, so it was chosen as the carbon source for biodenitrification in an upflow laboratory reactor. In order to remove solid particles from the effluent water, a sand filter unit was placed after the denitrification reactor. The soluble DOC contents in the reactor affected the efficiency of nitrate elimination and nitrate concentration of the effluent water remained below acceptable values (50 mg/l NO3-). In order to remove colour, DOC and nitrate from the water, powdered activated carbon adsorption studies were performed in the batch unit.

Sign in / Sign up

Export Citation Format

Share Document