Utilizing stillage in the biorefinery: Economic, technological and energetic analysis

Rex T.L. Ng, Peyman Fasahati, Kefeng Huang and Christos T. Maravelias

Applied Energy, 2019, vol. 241, issue C, 503 pages

Abstract: The goal of this study is to evaluate the economics and energy efficiency of different biorefinery configurations which include stillage valorization strategies for bioproducts synthesis. Specifically, a mixed-integer nonlinear programming (MINLP) model is developed to identify the optimal process network, and the impact of various parameters (e.g., bioproduct selling price, production cost, and energy requirement) on the performance of the biorefinery is investigated. Results show that the optimal strategy leading to a minimum ethanol selling price of $3.44/GGE includes γ-valerolactone deconstruction, glucose and xylose co-fermentation, heat and power generation, and does not include stillage valorization. Economic analyses indicate that the stillage valorization becomes economically viable at bioproduct selling prices above $2.0/kg for a base unit production cost and conversion coefficient of $2.0/kg bioproduct and 0.3 kg bioproduct/kg sugars, respectively. Further studies suggest that under certain scenarios, the biorefinery does not generate sufficient energy if all stillage is utilized for bioproducts production. Therefore, the utilization of stillage has to be optimized in order to achieve an energy self-sufficient biorefinery. Finally, analyses are performed to study how improvements in combinations of parameters can lead to lower cost and higher energy efficiency.

Keywords: Cellulosic biofuels; Optimization; Superstructure; Stillage valorization; Process synthesis; Bioproducts (search for similar items in EconPapers)
Date: 2019
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (4)

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0306261919304118
Full text for ScienceDirect subscribers only

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:eee:appene:v:241:y:2019:i:c:p:491-503

Ordering information: This journal article can be ordered from
http://www.elsevier.com/wps/find/journaldescription.cws_home/405891/bibliographic
http://www.elsevier. ... 405891/bibliographic

DOI: 10.1016/j.apenergy.2019.03.020

Access Statistics for this article

Applied Energy is currently edited by J. Yan

More articles in Applied Energy from Elsevier
Bibliographic data for series maintained by Catherine Liu ().