초록
<P><B>Graphical abstract</B></P><P>Long-term air-lime pretreatment/mixed-culture fermentation (ALP/MCF) is a novel bioprocessing strategy by which agriculture residues and herbaceous perennials (e.g., sugarcane trash, sugarcane bagasse, switchgrass, and corn stover) are converted into carboxylate salts. In the MixAlco™ process, the resulting salts are readily transformed into a wide variety of liquid transportation fuels (e.g., ethanol, butanol, mixed alcohols, gasoline, jet fuel) and commodity chemicals (e.g., acetic acid, acetone, ethyl acetate) via well-established petrochemical processes. The ALP/MCF bioprocessing strategy relieves logistics issues of biomass storage, simplifies bioconversion through ultimate consolidated bioprocessing (UCBP), and provides a biomass-biocrude-bioproduct route for both developed and developing countries.</P><ce:figure id='f0020'></ce:figure> <P><B>Abstract</B></P><P>Sugarcane trash (ST) was converted to ammonium carboxylates using a novel bioprocessing strategy known as long-term air-lime pretreatment/mixed-culture fermentation. At mild conditions (50°C, 5weeks, 1-atm air, and excess lime loading of 0.4g Ca(OH)<SUB>2</SUB>/(g dry biomass)), air-lime pretreatment of ST had moderate delignification (64.4%) with little loss in polysaccharides. Without employing detoxification, sterility, expensive nutrients, or costly enzymes, the feedstock (80% treated ST/20% chicken manure) was fermented to primarily ammonium acetate (>75%) and butyrate by a mixed culture of marine microorganisms at 55°C. In the best four-stage countercurrent fermentation, the product yield was 0.36g total acids/(g VS fed) and the substrate conversion was 64%. Model predictions indicate both high acid concentrations (>47.5g/L) and high substrate conversions (>70%) are possible at industrial scale.</P>