umu.sePublications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Phase chemistry in process models for cement clinker and lime production
Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics. (Thermal Energy Conversion Laboratory)
2014 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The goal of the thesis is to evaluate if developed phase chemical process models for cement clinker and lime production processes are reliable to use as predictive tools in understanding the changes when introducing sustainability measures.

The thesis describes the development of process simulation models in the application of sustainability measures as well as the evaluation of these models. The motivation for developing these types of models arises from the need to predict the chemical and the process changes in the production process, the impact on the product quality and the emissions from the flue gas.

The main chemical reactions involving the major elements (calcium, silicon, aluminium and iron) are relatively well known. As for the minor elements, such as sodium and potassium metals, sulphur, chlorine, phosphorus and other trace elements, their influence on the main reactions and the formation of clinker minerals is not entirely known. When the concentrations of minor and trace elements increase due to the use of alternative materials and fuels, a model that can accurately predict their chemistry is invaluable. For example, the shift towards using less carbon intensive fuels and more biomass fuels often leads to an increased phosphorus concentration in the products.

One way to commit to sustainable development methods in cement clinker and lime production is to use new combustion technologies, which increase the ability to capture carbon dioxide. Introducing oxy-fuel combustion achieves this, but at the same time, the overall process changes in many other ways. Some of these changes are evaluated by the models in this work.

In this thesis, a combination of the software programs Aspen Plus™ and ChemApp™ constitutes the simulation model. Thermodynamic data from FACT are evaluated and adjusted to suit the chemistry of cement clinker and lime.

The resulting model has been verified for one lime and two cement industrial processes.

Simulated scenarios of co-combustion involving different fuels and different oxy-fuel combustion cases in both cement clinker and lime rotary kiln production are described as well as the influence of greater amounts of phosphorus on the cement clinker quality.

Place, publisher, year, edition, pages
Umeå: Umeå Universitet , 2014. , 67 p.
Keyword [en]
Process modelling, phase chemistry, cement clinker, lime, sustainability, CO2, energy
National Category
Chemical Process Engineering
Identifiers
URN: urn:nbn:se:umu:diva-86004ISBN: 978-91-7459-801-8 (print)OAI: oai:DiVA.org:umu-86004DiVA: diva2:696534
Public defence
2014-03-14, N420, Naturvetarhuset, Umeå, 13:00 (Swedish)
Opponent
Supervisors
Funder
Swedish Energy Agency, 30527-1Bio4Energy
Available from: 2014-02-21 Created: 2014-02-14 Last updated: 2014-02-24Bibliographically approved
List of papers
1. A predictive chemistry model for the cement process
Open this publication in new window or tab >>A predictive chemistry model for the cement process
2008 (English)In: Zement, Kalk, Gips International: ZKG international, ISSN 0949-0205, Vol. 61, no 7, 60-70 p.Article in journal (Other academic) Published
Abstract [en]

A tool has been developed that enables prediction of the chemistry in cement production with thermodynamic phase equilibrium calculations. Reactions in gas, solid and liquid phases are calculated in the process from preheating tower, including exhaust gas cleaning, through rotary kiln, clinker cooler and ends at the output of clinker. The simulated values are compared to measured or calculated data from a full scale plant. This is a cement plant producing 2000 t clinker per day using both traditional and alternative fuels. The chemistry model shows good agreement especially on material chemistry at various places in the process and on composition of the clinker. A new way to define fuels is used and is straightforward and reliable. In the future work the model has to be improved and more elements are to be added to the thermodynamic database.

Place, publisher, year, edition, pages
Gutersloh, Germany: Bauverlag BV, 2008
Keyword
Kiln, process model, cement clinker
National Category
Chemical Process Engineering
Identifiers
urn:nbn:se:umu:diva-85998 (URN)
Funder
Swedish Energy Agency
Available from: 2014-02-14 Created: 2014-02-14 Last updated: 2017-12-06Bibliographically approved
2. Improved Process Modeling for a Lime Rotary Kiln Using Equilibrium Chemistry
Open this publication in new window or tab >>Improved Process Modeling for a Lime Rotary Kiln Using Equilibrium Chemistry
2012 (English)In: Journal of engineering technology, ISSN 0747-9964, Vol. 29, no 1, 8-18 p.Article in journal (Refereed) Published
Abstract [en]

This article describes an improved process model for simulation of the manufacturing process of lime in a rotary kiln. The model simulates ideal behavior of complex chemical systems with an assumed homogenous mixing without time-dependent factors. It is a totally predictive model that excludes the empirical parameters. The model is a chemical phase equilibrium model that calculates the final product in a non-equilibrium mode, according to established methods. The phase chemistry is among the most complex found in the literature for lime manufacturing. The thermodynamic data used in the model is based on 11 components (Ca, Si, Al, Fe, K, S, Cl, C, H, O and N). The fuel has an important role in the lime manufacturing process. Special attention is required since it is fed directly into the process via the burner and can influence the process and final product. In the model, the fuel is defined in order to have it behave in a realistic way, and operational data from a full scale lime plant verify the simulation results. The simulated amounts of gas and solids correlate well with operational data. The predicting chemical composition of the product needs improvement by adding more system components and their related compounds to the thermodynamic database. Simulation results from co-combustion of coal and processed waste based fuel oil that it is a versatile tool for predicting product quality and amount, temperature profiles of the rotary kiln, and exhaust gas composition and amount.

Place, publisher, year, edition, pages
American Society for Engineering Education, 2012
Keyword
Burning process, thermodynamic aspects
National Category
Chemical Process Engineering
Identifiers
urn:nbn:se:umu:diva-85999 (URN)000315244400002 ()
Funder
Swedish Energy Agency, 2006-06679Bio4Energy
Available from: 2014-02-14 Created: 2014-02-14 Last updated: 2017-12-06Bibliographically approved
3. Modelling the cement process and cement clinker quality
Open this publication in new window or tab >>Modelling the cement process and cement clinker quality
2014 (English)In: Advances in Cement Research, ISSN 0951-7197, E-ISSN 1751-7605, Vol. 26, no 6, 311-318 p.Article in journal (Refereed) Published
Abstract [en]

This paper presents a recently developed simulation model that can be used as a tool for evaluating sustainable development measures for cement and lime production processes. Examples of such measures are introducing new combustion technologies such as oxy-fuel combustion, using biomass fuel and using alternative materials in the raw material feed. One major issue when introducing process changes is the need to maintain product quality. In some ways, oxygen-enriched air combustion resembles oxy-fuel combustion. The model results were validated and found to be consistent with full-scale operational data for normal running conditions and for a full-scale test with oxygenenriched air. The model shows, for example, that with an additional 1500 m3/h of oxygen, fuel addition at the calciners can increase up to 108% and the raw material feed rate can increase up to 116% for a process with a raw meal feed of 335.5 t/h.

Place, publisher, year, edition, pages
ICE Publishing, 2014
National Category
Chemical Process Engineering
Identifiers
urn:nbn:se:umu:diva-86000 (URN)10.1680/adcr.13.00050 (DOI)000344814500002 ()
Funder
Bio4EnergySwedish Energy Agency, 30527-1
Available from: 2014-02-14 Created: 2014-02-14 Last updated: 2017-12-06Bibliographically approved
4. Simulation of oxy-fuel combustion in cement clinker manufacturing
Open this publication in new window or tab >>Simulation of oxy-fuel combustion in cement clinker manufacturing
2015 (English)In: Advances in Cement Research, ISSN 0951-7197, E-ISSN 1751-7605, Vol. 27, no 1, 42-49 p.Article in journal (Refereed) Published
Abstract [en]

A thermodynamic process model is used as an evaluation tool. Full oxy-fuel combustion is evaluated for circulation of 20–80% of flue gases to the burn zone of a rotary kiln. The full oxy-fuel combustion simulations exhibit altered temperature profiles for the process. With 60% recirculation of flue gases, the temperature in the burn zone is comparable to the reference temperature, and carbon dioxide concentration in the flue gases increases from 33 to 76%. If water is excluded, carbon dioxide concentration is 90%. The partial oxy-fuel combustion method is evaluated for 20 and 40% recirculation of flue gases from one cyclone string to both calciners. Fuel and oxygen feed to the burning zone and calciners are optimised for the partial oxy-fuel scenario. The lowest specific energy consumption is desired while maximising the amount of carbon dioxide theoretically possible to capture. By introducing partial oxy-fuel combustion with 20% recirculation of flue gases in the carbon dioxide string, total carbon dioxide emissions increases by 4%, with 84% possible to capture. Within the limits of the model, the introduction of full oxy-fuel and partial oxyfuel combustion is possible while maintaining product quality. When simulating partial oxy-fuel combustion, the energy consumption will increase even when no power consumption for the production of oxygen is included.

Place, publisher, year, edition, pages
Thomas Telford: ICE Publishing, 2015
Keyword
cement clinker production, process modell, oxy-fuel combustion
National Category
Chemical Process Engineering
Identifiers
urn:nbn:se:umu:diva-86361 (URN)10.1680/adcr.13.00068 (DOI)000351286400006 ()
Available from: 2014-02-24 Created: 2014-02-24 Last updated: 2017-12-05Bibliographically approved

Open Access in DiVA

Phase chemistry in process models for cement clinker and lime production(4868 kB)16134 downloads
File information
File name FULLTEXT01.pdfFile size 4868 kBChecksum SHA-512
4c2b0bc881466230d7c30bb974b82c9b1fbe189b897de50d5c52aa361bd7a3eefc940b4a1adbf70b98a5bc92f42aaae005c0a1f979897cfbb87f4d7671b03d6f
Type fulltextMimetype application/pdf
Spikblad(64 kB)111 downloads
File information
File name FULLTEXT02.pdfFile size 64 kBChecksum SHA-512
945246baadf43a9122bc80668d86096b2e2dfe3d1f53cfde0ecd5962e2989ec6c7e93e8a93180ce0119d246f42f783f5c5bef3a2522b51b0c3bf823b52867e41
Type spikbladMimetype application/pdf

Search in DiVA

By author/editor
Hökfors, Bodil
By organisation
Department of Applied Physics and Electronics
Chemical Process Engineering

Search outside of DiVA

GoogleGoogle Scholar
Total: 16245 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 1087 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf