November 2023
·
54 Reads
Biomass Conversion and Biorefinery
Roots and stems comprise a large proportion of traditional Chinese medicines and often serve as the energy storage units of plants. However, their decoction residues still contain a significant amount of starch, and direct landfilling, incineration, or carbon disposal results in a wastage of resources. In this study, five types of starch-rich traditional Chinese medicine decoction residues (TCMDRs)c, namely, Radix Isatidis Rhizoma Dioscoreae, Rhizoma Corydalis and Fritillaria Thunbergii. Radix Paeoniae Alba were screened and hydrolyzed using amylase-glucoamylase to produce fermentable sugar. The resulting glucose yields were 87.54%, 84.51%, 85.14%, 82.55%, and 87.75%, respectively. The enzymatic hydrolysate, after flocculation-decolorization treatment, was used to produce D-lactic acid and ethanol, resulting in a concentration and yield of 121.11 g/L (0.97 g/g) and 54.17 g/L (0.49 g/g), respectively. When single or mixed starch-rich TCMDRs were directly used as feedstocks for ethanol production via simultaneous saccharification and fermentation (SSF), they exhibited similar ethanol fermentability, with yields ranging from 0.33 to 0.43 g/g. The SSF residues were thermochemically transformed into biochar with a specific surface area of 89–459 m²/g to reduce secondary waste generation. The utilization value of starch-rich TCMDRs was significantly improved through the implementation of enzymatic hydrolysis to produce fermentable sugars, anaerobic fermentation to produce D-lactic acid and ethanol, and the utilization of fermentation residues for biochar production. Graphical abstract
![The influence of different catalysts and concentrations on LG, LGO, total carbon yield. (1) Experimental conditions: 1 g of IIR residues, 190 °C, 2 h, 40 μL of 15 mM catalyst (TsOH, MSA, H2SO4), and 100 mL Diox. (2) Experimental conditions: 1 g of IIR residues, 190 °C, 2 h, 40 μL of H2SO4 concentrations (10 mM, 15 mM, 25 mM, 30 mM), and 100 mL Diox. Note: YieldTotalcarbon%\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\left[\mathrm{Yield}\right]}_{\mathrm{Total carbon}} \left(\mathrm{\%}\right)$$\end{document}=YieldHMF%+YieldFF%+YieldLG%+YieldLGO%\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\left[\mathrm{Yield}\right]}_{\mathrm{HMF}} \left(\mathrm{\%}\right)+{\left[\mathrm{ Yield}\right]}_{\mathrm{FF}} \left(\mathrm{\%}\right)+{\left[\mathrm{ Yield}\right]}_{\mathrm{LG}} \left(\mathrm{\%}\right)+{\left[\mathrm{ Yield}\right]}_{\mathrm{LGO}} \left(\mathrm{\%}\right)$$\end{document}, and these yields were the highest yield](https://www.researchgate.net/publication/368362854/figure/fig4/AS:11431281119725123@1676175472739/The-influence-of-different-catalysts-and-concentrations-on-LG-LGO-total-carbon-yield_Q320.jpg)
