Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • 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
Upgrading of a traditional sugar cane mill to a modern milland assessing the potential of energy saving during steady stateand transient conditions: part II: models for a modifiedcogeneration unit
KTH, School of Industrial Engineering and Management (ITM), Energy Technology.ORCID iD: www.0000-0001-8091-8767
KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
Addis Ababa University, Ethiopia.
KTH, School of Industrial Engineering and Management (ITM), Energy Technology.ORCID iD: 0000-0002-3661-7016
2016 (English)In: Biomass Conversion and Biorefinery, ISSN 2190-6823, Vol. 6, no 2, p. 233-245Article in journal (Refereed) Published
Abstract [en]

It is known that there is a significant amount ofthermal energy used for the sugar cane industry for the purposeof power production and for use in the sugar or ethanolprocessing in cane sugar industries. Likewise, it is understoodthat there are substantial amounts of waste heat that is notbeing recovered, in particular for traditional sugar mills. Regardlessof this, energy conservation is given less considerationas compared to operational convenience due to the factthat sugar mills are self-sufficient in energy (heat and power).The identification of such potential heat loss areas (especiallyduring transient conditions) suggests the sugar mills play avital role in energy saving. In this study, a modified setup ofthe base case plant considered in part I of this paper is assessedfor its energy potential and possible major heat losses duringsteady state and transient conditions where 2-h stoppage of themill presses are considered to occur. For the modified setup,there are two major scenarios considered having two subscenarioseach. The result of the assessment showed that thesteady state assumption scenario of the modified plant (wherebagasse drying is not considered) indicated a 20 % reductionin the losses considered which resulted in a 57 % power generationincrease as compared to the steady state model of thebase case plant. It is also possible to save excess bagasse bydrying the bagasse for later use during unexpected stoppage.The carbon dioxide emission (amounting 29 t/day in case 2aof this study) that occurs during the use of fuel oil during suchstoppages will thus be avoided. The simple economic analysisshowed that it is only in case 2a where fuel oil cost is includedin the operation cost that resulted in a negative NPV. Since therest of the scenarios use bagasse as a fuel which is free, theNPV for all was positive. For the electricity price of 0.04 US$/kWh and discount rate of 15 %, the minimum paybackperiod attained is about 3 years (case 1b) where the bagassemoisture content is 30 % whereas the maximum payback periodis 6 years (case 1a) where there is no bagasse dryingconsidered.

Place, publisher, year, edition, pages
Springer, 2016. Vol. 6, no 2, p. 233-245
Keywords [en]
Sugar cane, Bagasse drying, Steady state, Transient state, Heat loss
National Category
Energy Engineering
Research subject
Energy Technology
Identifiers
URN: urn:nbn:se:kth:diva-185730DOI: 10.1007/s13399-015-0180-8ISI: 000377398800011Scopus ID: 2-s2.0-84978024580OAI: oai:DiVA.org:kth-185730DiVA, id: diva2:923182
Funder
Sida - Swedish International Development Cooperation Agency
Note

QC 20160512

Available from: 2016-04-25 Created: 2016-04-25 Last updated: 2019-05-20Bibliographically approved
In thesis
1.
The record could not be found. The reason may be that the record is no longer available or you may have typed in a wrong id in the address field.
2. Process Utility Performance Evaluation and Enhancements in the Traditional Sugar Cane Industry
Open this publication in new window or tab >>Process Utility Performance Evaluation and Enhancements in the Traditional Sugar Cane Industry
2019 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The need to achieve sustainable development has led to devising various approaches for the efficient utilization of natural resources. Renewable energy technology and energy efficiency measures feature prominently in this regard, and in particular for industries such as sugar production:  the sugar cane industry’s eponymous feedstock is a renewable resource, and mills have potential for increased energy savings via improvements to cogeneration units, electric drive retrofitting, and other measures.  The overall objective of this research work is to investigate different approaches of efficiency improvements for enhancing sugar cane conversion, thereby increasing the services obtained including surplus electric power delivery. Traditional sugar cane mills, i.e. those that lack modern components such as high-performance boilers and electric drives, are the focus of this investigation. 

System simulations show that modern mills generate more electrical power as compared to traditional mills, with power-to-heat ratios nearly one order of magnitude higher (i.e. 0.3-0.5).  Comparison of the thermodynamic performance of three retrofits showed that such modifications could raise the performance of traditional mills to approach those for their modern counterparts. Results for a base case traditional plant show that losses related to mechanical prime movers are high, since the mills and shredder are driven by steam and generate excess mechanical power. When considering press mill stoppages, steam is wasted during the ensuing fuel oil-fired start-up period. CO2emission for such transient conditions can be decreased owing via bagasse drying and storage. 

 

In studying both energy and water impacts, a comparison of four technological improvements demonstrates benefits outside the crushing season for three scenarios: recovery of excess wastewater for enhanced imbibition; recovery of waste heat for thermally-driven cooling; and pelletization of excess bagasse. The fourth option, involving upgrading of the mill’s cogeneration unit, is advantageous for continuous surplus power supply.

Place, publisher, year, edition, pages
KTH Royal Institute of Technology, 2019. p. 120
Series
TRITA-ITM-AVL ; 2019:21
Keywords
Sugar cane, energy saving, heat loss, steady state, transient state, CO2 emission; absorption chiller, pellet, bagasse drying, energy perfor-mance, traditional mills, modern mills, waste water, surplus power
National Category
Energy Engineering
Research subject
Energy Technology
Identifiers
urn:nbn:se:kth:diva-251736 (URN)978-91-7873-231-9 (ISBN)
Public defence
2019-08-20, F3, Lindstedtsvägen 26, KTH, Stockholm, 10:00 (English)
Opponent
Supervisors
Funder
Sida - Swedish International Development Cooperation Agency
Available from: 2019-05-24 Created: 2019-05-20 Last updated: 2019-05-24Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full textScopus

Authority records BETA

Martin, Andrew

Search in DiVA

By author/editor
Birru, EyerusalemErlich, CatharinaMartin, Andrew
By organisation
Energy Technology
Energy Engineering

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 155 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • 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