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
Impacts of retrofitting analysis on first generation ethanol production: process design and techno-economics
University of Borås, School of Engineering. (Biotechnology)
University of Borås, Faculty of Textiles, Engineering and Business. (Resource Recovery)ORCID iD: 0000-0003-4887-2433
2014 (English)In: Bioprocess and biosystems engineering (Print), ISSN 1615-7591, E-ISSN 1615-7605, Vol. 38, no 2Article in journal (Refereed) Published
Sustainable development
The content falls within the scope of Sustainable Development
Abstract [en]

More than half of the bioethanol plants in operation today use corn or grains as raw materials. The downstream processing of mash after fermentation to produce ethanol and distiller grains is an energy-demanding process, which needs retrofitting for optimization. In addition, the fluctuation in the ethanol and grain prices affects the overall profitability of the plant. For this purpose, a process simulation was performed in Aspen Plus® based on an existing industrial plant located in Sweden. The simulations were compared using different scenarios including different concentrations of ethanol, using the stillage for biogas production to produce steam instead of distiller grains as a by-product, and altering the purity of the ethanol produced. Using stillage for biogas production, as well as utilizing the steam, reduced the overall energy consumption by 40 % compared to the plant in operation. The fluctuations in grain prices had a high impact on the net present value (NPV), where grain prices greater than 349 USD/ton reached a zero NPV. After 20 years, the plant in operation producing 41,600 tons ethanol/year can generate a profit of 78 million USD. Compared to the base case, the less purified ethanol resulted in a lower NPV of 30 million USD.

Place, publisher, year, edition, pages
Springer , 2014. Vol. 38, no 2
Keyword [en]
Resource Recovery
National Category
Industrial Biotechnology
Research subject
Resource Recovery
Identifiers
URN: urn:nbn:se:hb:diva-1929DOI: 10.1007/s00449-014-1278-2Local ID: 2320/14367OAI: oai:DiVA.org:hb-1929DiVA: diva2:870007
Available from: 2015-11-13 Created: 2015-11-13 Last updated: 2016-10-07Bibliographically approved
In thesis
1. Industrial Bioprocess Developments for Biogas and Ethanol Production
Open this publication in new window or tab >>Industrial Bioprocess Developments for Biogas and Ethanol Production
2015 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Current biofuels face a noteworthy misfortune on commercialization because of its economiccomparison with low-cost fuel from the oil reserves. To compete with gasoline as a fuel, thebiofuels need to be economically feasible and demonstrated on a large-scale. Biogas and ethanolhave a great potential as commercial biofuels, even though it has difficulties, for example, highcapitalinvestment, absence of demonstrated innovations, and availability of raw materials and soforth. This thesis focuses on different application-driven bioprocess developments for improvingthe techno-economic feasibility of the biogas and ethanol industries.

The biogas industry was studied from three different perspectives:

1) Modeling approach in which a Process Simulation Model (PSM) model was developed forpredicting the biogas productions, as exploiting new substrates is vital for a biogas industrygrowth. The PSM model was created using Aspen Plus® which includes 46 reactions of differentphases in the Anaerobic Digestion (AD) processes. It also contains certain important processparameters, thermodynamics, rate-kinetics, and inhibitions involved in the AD processes. PSMwas a library model for the AD processes, which was validated against the laboratory andindustrial data. The validation showed that the PSM predicted the biogas production about 5% inexcess, which could ease the biogas industry to predict biogas from new substrates.

2) Simulation approach to study the imperative components affecting the profitability of theplant. For this purpose, a local municipality plant was studied under distinct situations. The choiceof upgrading method, capacity, cost of waste and its processing, number of digesters used, etc.were exploited. The results showed that the collection and transportation fee, landfilling fee, andthe reduced operation of a plant were the main considerations in influencing its profitability.Moreover, it was identified that for bigger cities the decentralization strategy could beat theexpense of collection and transportation of waste, and the plant could obtain a 17.8% return oninvestment.

3) Rethinking digester technology in which the cost of the digester was significantly lessenedusing a cutting-edge textile, which was principally intended for developing countries. The digestercost played an important role in consuming biogas for different applications. The textile digesterwas tested on a laboratory scale, followed by field tests in different countries including India,Indonesia, and Brazil. Textile digesters cost one-tenth of the conventional digesters, and thepayback was more or less between 1–3 years, when replacing the Liquefied Petroleum Gas (LPG)and kerosene as a cooking fuel for households.

When it comes to ethanol, the first generation ethanol production using grains was financiallypossible with a payback of about 13 years. Nonetheless, with the fluctuation of the oil prices, theethanol industries need to look for alternative sources of revenues. Different retrofits wereconsidered, including the effect of thin-stillage/whole-stillage to ethanol and biomass, in additionto the integration of the first and second generation ethanol production. The results revealed that4% additional ethanol could be obtained when the thin-stillage was converted into ethanol andfungal biomass, while the payback was reduced to 11.5 years. The integration of the first andsecond generation ethanol production revealed that it has a positive influence on the overalleconomics of the process with a payback of 10.5 years. This could help the ethanol industries toconsider a revamp for a better environmental, economic, and energy efficient process.

Place, publisher, year, edition, pages
Borås: Högskolan i Borås, 2015. 64 p.
Series
Skrifter från Högskolan i Borås, ISSN 0280-381X ; 71
Keyword
biogas, ethanol, process design, techno-economic analysis, simulation, modeling
National Category
Environmental Biotechnology
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-668 (URN)978-91-87525-71-1 (ISBN)978-91-87525-72-8 (ISBN)
Public defence
2015-11-06, E310, Allegatan 1, Borås, 10:00 (English)
Available from: 2015-10-02 Created: 2015-08-25 Last updated: 2017-05-04Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Rajendran, K.Taherzadeh, Mohammad J
By organisation
School of EngineeringFaculty of Textiles, Engineering and Business
In the same journal
Bioprocess and biosystems engineering (Print)
Industrial Biotechnology

Search outside of DiVA

GoogleGoogle Scholar

Altmetric score

Total: 564 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