miun.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
GASIFICATION-BASED BIOREFINERY FOR MECHANICAL PULP MILLS
Mid Sweden University, Faculty of Science, Technology and Media, Department of applied science and design. (Bioenergy - gasification)
2012 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

The modern concept of "biorefinery" is dominantly based on chemical pulp mills to create more value than cellulose pulp fibres, and energy from the dissolved lignins and hemicelluloses. This concept is characterized by the conversion of biomass into various biobased products. It includes thermochemical processes such as gasification and fast pyrolysis. In mechanical pulp mills, the feedstock available to the gasification-based biorefinery is significant, including logging residues, bark, fibre material rejects, biosludges and other available fuels such as peat, recycled wood, and paper products. This work is to study co-production of bio-automotive fuels, biopower, and steam via gasification in the context of the mechanical pulp industry.

 

Biomass gasification with steam in a dual-fluidized bed gasifier (DFBG) was simulated with ASPEN Plus. From the model, the yield and composition of the syngas and the contents of tar and char can be calculated. The model has been evaluated against the experimental results measured on a 150 KWth Mid Sweden University (MIUN) DFBG. The model predicts that the content of char transferred from the gasifier to the combustor decreases from 22.5 wt.% of the dry and ash-free biomass at gasification temperature 750 ℃ to 11.5 wt.% at 950 ℃, but is insensitive to the mass ratio of steam to biomass (S/B). The H2 concentration is higher than that of CO under normal DFBG operating conditions, but they will change positions when the gasification temperature is too high above about 950 ℃, or the S/B ratio is too far below about 0.15. The biomass moisture content is a key parameter for a DFBG to be operated and maintained at a high gasification temperature. The model suggests that it is difficult to keep the gasification temperature above 850 ℃ when the biomass moisture content is higher than 15.0 wt.%. Thus, a certain amount of biomass needs to be added in the combustor to provide sufficient heat for biomass devolatilization and steam reforming. Tar content in the syngas can also be predicted from the model, which shows a decreasing trend of the tar with the gasification temperature and the S/B ratio. The tar content in the syngas decreases significantly with gasification residence time which is a key parameter.

 

Mechanical pulping processes, as Thermomechanical pulp (TMP), Groundwood (SGW and PGW), and Chemithermomechanical pulp (CTMP) processes have very high wood-to-pulp yields. Producing pulp products by means of these processes is a prerequisite for the production of printing paper and paperboard products due especially to their important functional properties such as printability and stiffness. However, mechanical pulping processes consume a great amount of electricity, which may account for up to 40% of the total pulp production cost. In mechanical pulping mills, wood (biomass) residues are commonly utilized for electricity production through an associated combined heat and power (CHP) plant. This techno-economic evaluation deals with the possibility of utilizing a biomass integrated gasification combined cycle (BIGCC) plant in place of the CHP plant. Integration of a BIGCC plant into a mechanical pulp production line might greatly improve the overall energy efficiency and cost-effectiveness, especially when the flow of biomass (such as branches and tree tops) from the forest is increased. When the fibre material that negatively affects pulp properties is utilized as a bioenergy resource, the overall efficiency of the system is further improved. A TMP+BIGCC mathematic model is developed based on ASPEN Plus. By means of this model, three cases are studied:

 

1) adding more forest biomass logging residues in the gasifier,

2) adding a reject fraction of low quality pulp fibers to the gasifier, and

3) decreasing the TMP-specific electricity consumption (SEC) by up to 50%.

 

For the TMP+BIGCC mill, the energy supply and consumption are analyzed in comparison with a TMP+CHP mill. The production profit and the internal rate of return (IRR) are calculated. The results quantify the economic benefit from the TMP+BIGCC mill.

 

Bio-ethanol has received considerable attention as a basic chemical and fuel additive. It is currently produced from sugar/starch materials, but can also be produced from lignocellulosic biomass via a hydrolysis--fermentation or thermo-chemical route. In terms of the thermo-chemical route, a few pilot plants ranging from 0.3 to 67 MW have been built and operated for alcohols synthesis. However, commercial success has not been achieved. In order to realize cost-competitive commercial ethanol production from lignocellulosic biomass through a thermo-chemical pathway, a techno-economic analysis needs to be done.

 

In this work, a thermo-chemical process is designed, simulated, and optimized mainly with ASPEN Plus. The techno-economic assessment is made in terms of ethanol yield, synthesis selectivity, carbon and CO conversion efficiencies, and ethanol production cost.

 

Calculated results show that major contributions to the production cost are from biomass feedstock and syngas cleaning. A biomass-to-ethanol plant should be built at around 200 MW. Cost-competitive ethanol production can be realized with efficient equipments, optimized operation, cost-effective syngas cleaning technology, inexpensive raw material with low pretreatment cost, high-performance catalysts, off-gas and methanol recycling, optimal systematic configuration and heat integration, and a high-value byproduct.

Place, publisher, year, edition, pages
Sundsvall: Mid Sweden University , 2012. , 40 p.
Series
Mid Sweden University licentiate thesis, ISSN 1652-8948 ; 93
Keyword [en]
Gasification, Mechanical Pulping, Bio-fuels, Power Generation, Biomass Residues, ASPEN Plus
National Category
Chemical Process Engineering
Identifiers
URN: urn:nbn:se:miun:diva-17472ISBN: 978-91-87103-43-8 (print)OAI: oai:DiVA.org:miun-17472DiVA: diva2:572722
Presentation
2012-12-03, Lecture hall O111, Campus Sundsvall, Campus Sundsvall, 13:15 (English)
Opponent
Supervisors
Available from: 2012-11-30 Created: 2012-11-28 Last updated: 2012-12-13Bibliographically approved
List of papers
1. Techno-economic evaluation of a mechanical pulp mill with gasification
Open this publication in new window or tab >>Techno-economic evaluation of a mechanical pulp mill with gasification
2013 (English)In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, Vol. 28, no 3, 349-357 p.Article in journal (Refereed) Published
Abstract [en]

Mechanical pulping processes, including thermomechanical pulp (TMP), groundwood (SGW andPGW), and chemithermomechanical pulp (CTMP) processes, each have a very high wood-to-pulp yield. Producing pulp by means of these processes is a prerequisite for paper (such as printing paper and paperboard) grades requiring high printability and stiffness. However, mechanical pulping processes consume a great amount of electricity, which may account for up to 40% of the total pulp production cost.

In mechanical pulping mills, wood (biomass) residues are commonly utilized for electricity production through an associated combined heat and power (CHP) plant. This techno-economic evaluation deals with the possibility of utilizing a biomass integrated gasification combined cycle (BIGCC) plant in place of the CHP plant.

Implementing BIGCC in a mechanical pulp production line might greatly improve the overall energy efficiency and cost-effectiveness, especially when more biomass from forest (such as branches and tree tops) is available. When the fibre material that negatively affects pulp properties is utilized as a bioenergy resource, the overall efficiency will be further improved. A TMP+BIGCC mathematical model is developed with ASPEN Plus. By means of modeling, three cases are studied:

1) adding more forest biomass logging residues in the gasifier,2) adding the reject fibres in the gasifier, and3) decreasing the TMP-specific electricity consumption (SEC) by up to 50%.

For a TMP+BIGCC mill, the energy supply and consumption are analyzed in comparison with a TMP+CHP mill. The production profits are evaluated.

Keyword
Gasification, Mechanical Pulping, Power Generation, Biomass Residues, ASPEN Plus
National Category
Chemical Process Engineering Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-17702 (URN)000325145900004 ()
Note

In Jie He's Licentiate thesis the submitted version of this article is appended

Available from: 2012-12-13 Created: 2012-12-13 Last updated: 2014-09-16Bibliographically approved
2. Simulation of biomass gasification in a dual fluidized bed gasifier
Open this publication in new window or tab >>Simulation of biomass gasification in a dual fluidized bed gasifier
2012 (English)In: Biomass Conversion and Biorefinery, ISSN 2190-6815, E-ISSN 2190-6823, Vol. 2, no 1, 1-10 p.Article in journal (Refereed) Published
National Category
Bioenergy
Identifiers
urn:nbn:se:miun:diva-16182 (URN)10.1007/s13399-011-0030-2 (DOI)2-s2.0-84978021765 (Scopus ID)
Available from: 2012-05-07 Created: 2012-05-04 Last updated: 2017-07-04Bibliographically approved
3. Techno-economic evaluation of thermo-chemical biomass-to-ethanol
Open this publication in new window or tab >>Techno-economic evaluation of thermo-chemical biomass-to-ethanol
2011 (English)In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 88, no 4, 1224-1232 p.Article in journal (Refereed) Published
Abstract [en]

Bio-ethanol has received considerable attention as a basic chemical and fuel additive. Bio-ethanol is presently produced from sugar/starch materials, but can also be produced from lignocellulosic biomass via hydrolysis-fermentation route or thermo-chemical route. In terms of thermo-chemical route, a few pilot plants ranging from 0.3 to 67 MW have been built and operated for alcohols synthesis. However, commercial success has not been found. In order to realize cost-competitive commercial ethanol production from lignocellulosic biomass through thermo-chemical pathway, a techno-economic analysis needs to be done. In this paper, a thermo-chemical process is designed, simulated and optimized mainly with ASPEN Plus. The techno-economic assessment is made in terms of ethanol yield, synthesis selectivity, carbon and CO conversion efficiencies, and ethanol production cost. Calculated results show that major contributions to the production cost are from biomass feedstock and syngas cleaning. A biomass-to-ethanol plant should be built around 200 MW. Cost-competitive ethanol production can be realized with efficient equipments, optimized operation, cost-effective syngas cleaning technology, inexpensive raw material with low pretreatment cost, high performance catalysts, off-gas and methanol recycling, optimal systematic configuration and heat integration, and high value byproduct.

Keyword
Ethanol; Syngas; Biomass; BTL; Efficiency; Economy
National Category
Environmental Biotechnology
Identifiers
urn:nbn:se:miun:diva-12645 (URN)10.1016/j.apenergy.2010.10.022 (DOI)000286707300024 ()2-s2.0-78650543159 (Scopus ID)
Available from: 2010-12-13 Created: 2010-12-13 Last updated: 2014-09-16Bibliographically approved

Open Access in DiVA

fulltext(2349 kB)957 downloads
File information
File name FULLTEXT03.pdfFile size 2349 kBChecksum SHA-512
d607bbd887c4ca7c19b06074544a3d6cde94b1395951d9f05de1c04b2668b293e11910cb54af44b0e6b96d92d70d578785fd71a3f79f1e5a5efce9e18a7155d8
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
He, Jie
By organisation
Department of applied science and design
Chemical Process Engineering

Search outside of DiVA

GoogleGoogle Scholar
Total: 980 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

Total: 1886 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