Technoeconomic evaluation of recent process improvements in production of sugar and high-value lignin co-products via two-stage Cu-catalyzed alkaline-oxidative pretreatment

Zhaoyang Yuan; Bryan D Bals; Eric L Hegg; David B Hodge

doi:10.1186/s13068-022-02139-5

Technoeconomic evaluation of recent process improvements in production of sugar and high-value lignin co-products via two-stage Cu-catalyzed alkaline-oxidative pretreatment

Biotechnol Biofuels Bioprod. 2022 May 4;15(1):45. doi: 10.1186/s13068-022-02139-5.

Authors

Zhaoyang Yuan^#¹, Bryan D Bals^#², Eric L Hegg³, David B Hodge^{4

5}

Affiliations

¹ Department of Biochemistry & Molecular Biology, Michigan State University, 603 Wilson Road, East Lansing, MI, 48824, USA.
² Michigan Biotechnology Institute, 3815 Technology Boulevard, Lansing, MI, 48910, USA. bryanbals@gmail.com.
³ Department of Biochemistry & Molecular Biology, Michigan State University, 603 Wilson Road, East Lansing, MI, 48824, USA. erichegg@msu.edu.
⁴ Department of Chemical & Biological Engineering, Montana State University, Bozeman, MT, 59717, USA. david.hodge3@montana.edu.
⁵ Division of Sustainable Process Engineering, Luleå University of Technology, Luleå, Sweden. david.hodge3@montana.edu.

^# Contributed equally.

Abstract

Background: A lignocellulose-to-biofuel biorefinery process that enables multiple product streams is recognized as a promising strategy to improve the economics of this biorefinery and to accelerate technology commercialization. We recently identified an innovative pretreatment technology that enables of the production of sugars at high yields while simultaneously generating a high-quality lignin stream that has been demonstrated as both a promising renewable polyol replacement for polyurethane applications and is highly susceptible to depolymerization into monomers. This technology comprises a two-stage pretreatment approach that includes an alkaline pre-extraction followed by a metal-catalyzed alkaline-oxidative pretreatment. Our recent work demonstrated that H₂O₂ and O₂ act synergistically as co-oxidants during the alkaline-oxidative pretreatment and could significantly reduce the pretreatment chemical input while maintaining high sugar yields (~ 95% glucose and ~ 100% xylose of initial sugar composition), high lignin yields (~ 75% of initial lignin), and improvements in lignin usage.

Results: This study considers the economic impact of these advances and provides strategies that could lead to additional economic improvements for future commercialization. The results of the technoeconomic analysis (TEA) demonstrated that adding O₂ as a co-oxidant at 50 psig for the alkaline-oxidative pretreatment and reducing the raw material input reduced the minimum fuel selling price from $1.08/L to $0.85/L, assuming recoverable lignin is used as a polyol replacement. If additional lignin can be recovered and sold as more valuable monomers, the minimum fuel selling price (MFSP) can be further reduced to $0.73/L.

Conclusions: The present work demonstrated that high sugar and lignin yields combined with low raw material inputs and increasing the value of lignin could greatly increase the economic viability of a poplar-based biorefinery. Continued research on integrating sugar production with lignin valorization is thus warranted to confirm this economic potential as the technology matures.

Keywords: Alkaline hydrogen peroxide pretreatment; Biomass; Biorefinery; Cellulosic biofuels; Enzymatic hydrolysis; Hybrid poplar; Lignin; Technoeconomic evaluation.

Abstract

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