Particulate formation during black liquor char bed burning.

by Saied Haghpanah Kochesfahani

Written in English
Published: Pages: 137 Downloads: 902
Share This
The Physical Object
Pagination137 leaves.
Number of Pages137
ID Numbers
Open LibraryOL19987064M
ISBN 100612411966

12_chapter2- Black Liquor Property - Free download as PDF File .pdf), Text File .txt) or read online for free. Black Liquor Property. In another study, a laboratory scale char bed reactor at IPST was reconstructed to study the formation of particulate during the char burning stage of black liquor combustion. The reactor was connected to a particulate collection system. Three char samples were used with one black liquor source. Need more data on behavior of individual organic components during black liquor processing (heating, hydropyrolysis, combustion, gasification). Also, should study Char bed processes. Understand processes occurring in char beds, and how they determine single-drop black liquor burning model, periodically updated and peer-reviewed. Nitrogen oxide formation during black liquor char combustion and gasification / M. Forssén [et al.]. - In: Journal of pulp and paper science, ISSN , 23 () 3, s. JJ Forssén, Mikael / Förbränningskemiska forskargruppen Nitrogen oxide release during black liquor char combustion and gasification / Mikael Forssén.

; The effects of black liquor sprays on gas phase flows in a recovery boiler / Terry N. Adams and Robert R. Horton ; CFD simulations of recovery boiler char beds with step and smooth surfaces / Wenrui Yang, Robert R. Horton, and Terry N. Adams ; A comparison of CFD simulations of recovery boiler char beds with 2-d and 3-d geometries / Wenrui.   This study details the first application of molecular beam mass spectrometry to investigate the release of sodium, potassium, sulfur, and chlorine during black liquor combustion. Two samples, black liquor with % dry solids and a sample of dry black liquor solids, were combusted in a quartz-tube reactor at °C in 5% O2 in helium. The gaseous black liquor combustion products, including. Black liquor, a byproduct from pulp production, is burned in a recovery boiler to generate electricity and recover inorganic materials. Black-liquor-droplet combustion is fundamental to understanding and potentially improving recovery boiler performance. This investigation reports comprehensive experimental data collected for a suite of five liquors. For example, a drop in the level of char bed of about 15 inches at the sides and 4 feet in the center produces a 50% change in the meter reading. A desirable level for the char bed in the center is about 6 feet. The influx of pump gland seal water into the black liquor can lower the concentration of solids by 3% or 4% if not properly adjusted.

Methyl mercaptan contri- butions did not reach zero until the sodium sulfide levels in the feed liquor were essentially zero.l5 At a third installation where high-degree black liquor oxidation is practiced, the reduced sulfur contribution of the contact evaporator over a hour period ranged from to ppm while residual sodium sulfide. Black Liquor Droplet Swelling Droplet Char Particle Smelt Bead Smelt Bead Formation (4) Char Burning (3) Drying (1) Drying Droplet Devolatilisation (2) Simplified Black Liquor Single Droplet Model Single Droplet Model after Frederick & Hupa, CFD BL • Fixed char bed shape and temperature: K • Droplet landing on wall or char bed. The black liquor is introduced to the furnace through spray guns located in the drying zone. The heat in the furnace is sufficient to evaporate the remaining water from the liquor. The dried solids fall to the hearth to form the char bed. Combustion of the black liquor char begins on the hearth of the furnace. The objective of this project was to develop a new computer model of a recovery boiler furnace using a computational fluid dynamics (CFD) code specifically tailored to the requirements for solving recovery boiler flows, and using improved submodels for black liquor combustion based on continued laboratory fundamental studies. The project originated in October and was scheduled to run for.

Particulate formation during black liquor char bed burning. by Saied Haghpanah Kochesfahani Download PDF EPUB FB2

A negative pictirre of ejecta particles; fi-orn char bed burning experiments of Brown et al. [36]. Figure A picture of particIes king ejected during the char burning stage of a single black liquor droplet combustion (taken by Hupa et al.

[2]). Figure 4- 1- Effect of bed temperature and char composition on fime quantity Figure The formation of particulate during the char-burning stage of black liquor combustion was studied using a laboratory-scale char bed reactor connected to a particulate collection system.

Particulate Formation During Black Liquor Char Bed Burning S.H. KOCHESFAHANI, H. TRAN, A.K. JONES, T.M. GRACE, S.J.

LIEN and W. SCHMIDL The formation of particulate during the char-burning. @article{osti_, title = {Kraft recovery boiler physical and chemical processes}, author = {Adams, T N and Frederick, W J and Oregon State Univ., Corvallis, OR}, abstractNote = {The focus of this book is on the recent research into the physical and chemical processes occurring in and around a black liquor recovery boiler.

Almost all of the detailed technical information in this book has. Schmidl's 6 research works with 14 citations and 78 reads, including: Particulate formation during black liquor char bed burning. Esp. interest was aimed at the relative importance of the fume as produced from the burning black liquor droplets vs.

the one volatilized from the char bed. For the first time in this study quant. online data are available on particulate formation during char bed burning, as the liquor spraying was totally interrupted for a few minutes in these. The particulate formation is separately described through a neural network trained with industrial data.

The resulting hybrid model satisfactorily reproduces black liquor burning data obtained from literature and industrial sources. is still formed during the black liquor burning. Part of this material is carried out to other parts of the. Table 1 shows the black liquor elemental composition for a typical open cycle kraft process.

The contents of sodium and sulphur in black liquor vary considerably from one process to another. From the point of view of the recovery boiler chemistry, the molar ratio between total sulphur and sodium in the black liquor, S/Na2, is a useful parameter. The recent mill study by Tamminen et al.

shows that most of the fuming occurs during the in-flight burning of black liquor droplets and only a small part of the fume originates from the char bed. Mathematical models (CFD) of deposition and fume formation [2], [3], [11], [12] have been developed with a view to optimising these processes.

IPST Char Bed Studies ca. 0% 2% 4% 6% 8% 10% 12% 14% Bed Temperature (C) Particulate (% of initial char) Total Fume ISP data from Steve Lien files and Kochesfahani et al, ICRC Proc., p.

The purpose of these studies was to shed new light on the formation mechanism of fume and gaseous emissions (NOx) in recovery boilers, Especially interest was aimed at the relative importance of the fume as produced from the burning black liquor droplets versus the one volatilized from the char bed.

The paper (a) gives a brief description of the kraft process, (b) reviews the experimental and theoretical (modeling) research advances on combustion of kraft-liquor drops during the s and s, (c) reexamines the results of an earlier combustion study in which black-liquor drops were observed in free flight at temperatures near those in.

Particulate material formation mainly occurs during drying, char burning and as a result of chemical reactions between the combustion air and substances coming from the smelt. The mechanism of formation is not completely known (Jokiniemi, Pyykönen, Mikkanen, & Kauppinen, ) and a practical alternative in these cases is to use empirical.

• Char bed burning. Black liquor spraying. Black liquor combustion in the recovery boiler Time of day during ) Heat to steam Time of day. Fouling Black Liquor Burning mm Intermediate Particles.

1 μm Fume particles attached on a carry over particle ° C 2 0 0. Black liquor gasification (BLG) involves pyrolyzing concentrated black liquor into an inorganic phase and a gas phase through reactions with oxygen or air at high temperatures.

BLG technology can be an alternative to using a recovery boiler to produce electricity, chemicals, or fuels such as dimethyl ether, synthetic gas (syngas), methanol. formation mechanism of these Intermediate Sized Particles (ISP) is not well understood, although they are believed to form as a result of fragmentation of black liquor droplets during combustion and/or ejection of material from molten smelt pool during char burning [2,3].

Figure 2 shows a SEM. Different physicochemical processes are involved in the black liquor particle burning phenomenon: drying, pyrolysis, char burning, oxidation and reduction of the inorganic salts (Grace, ; Smook, ).

During the drying process the particles lose their residual humidity (about 30%). Black Liquor 2 Recovery Furnace 2 Objectives 4 2. Liteature Review 5 Flow Field 5 The In-flight Combustion of Balck Liquor Droplets 6 The Char bed 8 Pollutant Formation 9 Gird Generation and Geometry 11 Model Validation 12 Concluding Remarks 13 3.

Development of Model of Recovery Furnace Used in This Work water entering with the black liquor, the heat of reaction consumed in producing Na2S, and the heat carried out with the molten smelt.

The amount of steam produced is typically about kg per kg black liquor solids, but can range from to about kg steam per kg black liquor solids, depending on the thermal efficiency of the recovery boiler. @article{osti_, title = {Sodium and sulfur release and recapture during black liquor burning}, author = {Frederick, W J and Iisa, K and Wag, K and Reis, V V and Boonsongsup, L and Forssen, M and Hupa, M}, abstractNote = {The objective of this study was to provide data on sulfur and sodium volatilization during black liquor burning, and on SO2 capture by solid sodium carbonate and.

place simultaneously in the char bed (Grace, ). The exothermic oxidation reaction of Na2S with air oxygen forming Na2SO4, takes place in the solid char bed surface. Because Na2S is an active agent of the wood digestion process in the pulp industry, it is desirable to recover it at the end of the black liquor burning process.

Black liquor combustion validated recovery boiler modeling: Final year report. Volume 3 (Appendices II, sections and III) and Experimental data on rates of particulate formation during char bed burning Topics: Nitrogen Oxides.

Volume 3 contains the following appendix sections: Formation and destruction of nitrogen oxides in recovery boilers; Sintering and densification of recovery boiler deposits laboratory data and a rate model; and Experimental data on rates of particulate formation during char bed burning.

@article{osti_, title = {Combustion properties of Kraft Black Liquors}, author = {Frederick, Jr, W J and Hupa, M}, abstractNote = {In a previous study of the phenomena involved in the combustion of black liquor droplets a numerical model was developed.

The model required certain black liquor specific combustion information which was then not currently available, and additional data were. Char burning: reaction at the particle surface.

No clear flame. Slow process, controlled by rate of air, water vapor, and carbon dioxide supply. 0 Figure 1. Black liquor burning stages THE STAGES OF COMBUSTION The combustion of liquor droplets proceeds in four stages, as illustrated in Figure 1.

While most of the heat for this process is provided from burning the black liquor, additional heat from gas or oil-fired auxiliary fuel burners is needed to start up the unit, regulate the char bed, avoid blackouts, and to furnish additional steam.

The complexity of the process and. We paid special attention to the relative importance of the fume produced from the burning black liquor droplets versus the fume volatilized from the char bed.

For the first time through this study, quantitative on-line data are available on the amount of particulate formed during char bed burning, as the liquor spraying was totally interrupted. The work done to date includes CFD model development and validation, acquisition of information on black liquor combustion fundamentals and development of improved burning models, char bed model development, and model application and simplification.}, doi = {/}, journal = {}, number =, volume =, place = {United States}, year.

7th Black Liquor Colloquium, Jyvaskyla, Finland, July 31 – August 2, Scope of this Presentation • Data and observations from 5 recovery boilers to assess the impact of liquor temperature, injection pressure, nozzle type and gun angles on recovery performance.

• Although, Paprican has access on data collected during optimization in 50 recovery boilers (42 in Canada and 8 in the. Book "Kraft Recovery Boilers" By T. Adams, W. Frederic, T. Grace, M. Hupa, K. Iisa, A. Jones, H. Tran Page 6 of 16.

Apparatus and method is disclosed for monitoring black liquor recovery boilers to detect the presence of water leakage into the combustion chamber (furnace) of a black liquor recovery boiler, or extinguishing of flame at the black liquor spray nozzles, to release into the furnace at a relatively high rate of speed an absorption agent to collect the water in the furnace and thereby isolate the.During their descent, the black liquor droplets lose the remaining water by evaporation and the solids pyrolyze to form a char bed at the bottom of the furnace.

The char bed burns under reducing conditions at a temperature of about °° C. and the recovered chemicals, mainly Na 2 CO 3 and Na 2 S, are drained from the furnace as a smelt.The dilute black liquor is usually run through one or more evaporation steps to increase the solids concentration to percent, which is necessary for combustion.

The black liquor is ultimately heated and pressurized, typically to ° F° F. at psig, and is fed through spray nozzles projecting into the black liquor furnace.