Integrating enzyme fermentation in lignocellulosic ethanol production: life-cycle assessment and techno-economic analysis
Olofsson, Johanna LU ; Barta, Zsolt ; Börjesson, Pål LU and Wallberg, Ola LU
(2017)
In Biotechnology for Biofuels
10.
- Abstract
Background
Cellulase enzymes have been reported to contribute with a significant share of the total costs and greenhouse gas emissions of lignocellulosic ethanol production today. A potential future alternative to purchasing enzymes from an off-site manufacturer is to integrate enzyme and ethanol production, using microorganisms and part of the lignocellulosic material as feedstock for enzymes. This study modelled two such integrated process designs for ethanol from logging residues from spruce production, and compared it to an off-site case based on existing data regarding purchased enzymes. Greenhouse gas emissions and primary energy balances were studied in a life-cycle assessment, and cost performance in a techno-economic... (More)
Background
Cellulase enzymes have been reported to contribute with a significant share of the total costs and greenhouse gas emissions of lignocellulosic ethanol production today. A potential future alternative to purchasing enzymes from an off-site manufacturer is to integrate enzyme and ethanol production, using microorganisms and part of the lignocellulosic material as feedstock for enzymes. This study modelled two such integrated process designs for ethanol from logging residues from spruce production, and compared it to an off-site case based on existing data regarding purchased enzymes. Greenhouse gas emissions and primary energy balances were studied in a life-cycle assessment, and cost performance in a techno-economic analysis.
Results
The base case scenario suggests that greenhouse gas emissions per MJ of ethanol could be significantly lower in the integrated cases than in the off-site case. However, the difference between the integrated and off-site cases is reduced with alternative assumptions regarding enzyme dosage and the environmental impact of the purchased enzymes. The comparison of primary energy balances did not show any significant difference between the cases. The minimum ethanol selling price, to reach break-even costs, was from 0.568 to 0.622 EUR L−1 for the integrated cases, as compared to 0.581 EUR L−1 for the off-site case.
Conclusions
An integrated process design could reduce greenhouse gas emissions from lignocellulose-based ethanol production, and the cost of an integrated process could be comparable to purchasing enzymes produced off-site. This study focused on the environmental and economic assessment of an integrated process, and in order to strengthen the comparison to the off-site case, more detailed and updated data regarding industrial off-site enzyme production are especially important.
(Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/4678a9a3-ad8a-4fbf-8ab2-194b45bc8080
- author
- Olofsson, Johanna
LU
; Barta, Zsolt
; Börjesson, Pål
LU
and Wallberg, Ola
LU
- organization
- publishing date
- 2017-02-23
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Biotechnology for Biofuels
- volume
- 10
- article number
- 51
- publisher
- BioMed Central (BMC)
- external identifiers
-
- scopus:85014958854
- pmid:28250818
- wos:000395703700001
- ISSN
- 1754-6834
- DOI
- 10.1186/s13068-017-0733-0
- language
- English
- LU publication?
- yes
- id
- 4678a9a3-ad8a-4fbf-8ab2-194b45bc8080
- date added to LUP
- 2017-02-24 09:11:53
- date last changed
- 2023-12-01 05:16:54
@article{4678a9a3-ad8a-4fbf-8ab2-194b45bc8080,
abstract = {{<br/>Background<br/><br/>Cellulase enzymes have been reported to contribute with a significant share of the total costs and greenhouse gas emissions of lignocellulosic ethanol production today. A potential future alternative to purchasing enzymes from an off-site manufacturer is to integrate enzyme and ethanol production, using microorganisms and part of the lignocellulosic material as feedstock for enzymes. This study modelled two such integrated process designs for ethanol from logging residues from spruce production, and compared it to an off-site case based on existing data regarding purchased enzymes. Greenhouse gas emissions and primary energy balances were studied in a life-cycle assessment, and cost performance in a techno-economic analysis.<br/>Results<br/><br/>The base case scenario suggests that greenhouse gas emissions per MJ of ethanol could be significantly lower in the integrated cases than in the off-site case. However, the difference between the integrated and off-site cases is reduced with alternative assumptions regarding enzyme dosage and the environmental impact of the purchased enzymes. The comparison of primary energy balances did not show any significant difference between the cases. The minimum ethanol selling price, to reach break-even costs, was from 0.568 to 0.622 EUR L−1 for the integrated cases, as compared to 0.581 EUR L−1 for the off-site case.<br/>Conclusions<br/><br/>An integrated process design could reduce greenhouse gas emissions from lignocellulose-based ethanol production, and the cost of an integrated process could be comparable to purchasing enzymes produced off-site. This study focused on the environmental and economic assessment of an integrated process, and in order to strengthen the comparison to the off-site case, more detailed and updated data regarding industrial off-site enzyme production are especially important.<br/>}},
author = {{Olofsson, Johanna and Barta, Zsolt and Börjesson, Pål and Wallberg, Ola}},
issn = {{1754-6834}},
language = {{eng}},
month = {{02}},
publisher = {{BioMed Central (BMC)}},
series = {{Biotechnology for Biofuels}},
title = {{Integrating enzyme fermentation in lignocellulosic ethanol production: life-cycle assessment and techno-economic analysis}},
url = {{http://dx.doi.org/10.1186/s13068-017-0733-0}},
doi = {{10.1186/s13068-017-0733-0}},
volume = {{10}},
year = {{2017}},
}