No abstract

Ensilage is a truncated solid-state fermentation in which anaerobically produced organic acids accumulate to reduce pH and limit microbial activity. Ensilage can be used to both preserve and pretreat biomass feedstock for further downstream conversion into chemicals, fuels, and/or fiber products. This study examined the ensilage of enzyme-treated corn stover as a feedstock for particleboard manufacturing. Corn stover at three different particle size ranges (<100, <10, and <5 mm) was ensiled with and without a commercial enzyme mixture having a cellulase:hemicellulase ratio of 2.54:1, applied at a hemicellulase rate of 1670 IU/kg dry mass. Triplicate 20 L mini-silos were destructively sampled and analyzed on days 0, 1, 7, 21, 63, and 189. Analysis included produced organic acids and water-soluble carbohydrates, fiber fractions, pH, and microorganisms, including Lactobacillus spp. and clostridia were monitored. On days 0, 21, and 189, the triplicate samples were mixed evenly and assembled into particleboard using 10% ISU 2 resin, a soy-based adhesive. Particleboard panels were subjected to industry standard tests for modulus of rupture (MOR), modulus of elasticity (MOE), internal bonding strength (IB), thickness swell (TS), and water absorption at 2 h boiling and 24 h soaking. Enzyme addition did improve the ensilage process, as indicated by sustained lower pH (P < 0.0001), higher water-soluble carbohydrates (P < 0.05), and increased lactic acid production (P < 0.0001). The middle particle size range (<10 mm) demonstrated the most promising results during the ensilage process. Compared with fresh stover, the ensilage process did increase IB of stover particleboard by 33% (P < 0.05) and decrease water adsorption at 2 h boiling and 24 h soaking significantly (P < 0.05). Particleboard panels produced from substrate ensiled with enzymes showed a significant reduction in water adsorption of 12% at 2 h boiling testing. On the basis of these results, ensilage can be used as a long-term feedstock preservation method for particleboard production from corn stover. Enzyme-amended ensilage not only improved stover preservation but also enhanced the properties of particleboard products.

Since launching the PlantBottle™ Packaging program in 2009, The Coca-Cola Company has distributed more than 30 × 109 bottles in nearly 40 countries using its current PlantBottle packaging, which is made from up to 30% plant-based materials. It is estimated the use of PlantBottle packaging since launch has helped save the equivalent annual emissions of more than 315 000 metric tons of carbon dioxide. To expand the application of this innovative packaging material, a sustainable feedstock needs to be identified, and a new technology needs to be developed to allow its integration into PlantBottle technology, for using agriculture waste to produce bio-polyethylene terephthalate (bio-PET), and develop an economically viable supply chain of bio-PET in China. These breakthroughs can also be applied beyond packaging and have the potential to help companies around the world reach their own sustainability goals. Using renewable feedstock to produce bio-PET reduces dependence on petro-based resources, mitigates carbon emissions, and promotes sustainable development. Under the China-US EcoPartnership program, The Coca-Cola Company partners with the Yangtze River Delta Circular Economy Institute of Technologyto identify and advance commercial technologies for converting local agricultural residues or wastes (e.g., corn cob and stover) into the base ingredient, mono-ethylene glycol (MEG), for manufacturing polyester resin/fiber. The Coca-Cola Company is developing bio-MEG conversion technology with a technology and implementation partner, and finalizing the technical conversion process for commercial production. Yangtze River Delta Circular Economy Institute of Technology is exploring the related supply chain and feedstock logistics. Any advancement using agricultural wastes today are likely to have continued relevance to this second part of the journey toward realizing sustainably sourced and fully recyclable PET plastic product solutions.

Ensilage can be used to store lignocellulosic biomass before industrial bioprocessing. This study investigated the impacts of seven commercial enzyme mixtures derived from Aspergillus niger, Trichoderma reesei, and T. longibrachiatum. Treatments included three size grades of corn stover, two enzyme levels (1.67 and 5 IU/g dry matter based on hemicellulase), and various ratios of cellulase to hemicellulase (C:H). The highest C:H ratio tested, 2.38, derived from T. reesei, resulted in the most effective fermentation, with lactic acid as the dominant product. Enzymatic activity during storage may complement industrial pretreatment; creating synergies that could reduce total bioconversion costs.

Ensilage can be used to store lignocellulosic biomass before industrial bioprocessing. This study investigated the impacts of seven commercial enzyme mixtures derived from Aspergillus niger, Trichoderma reesei, and T. longibrachiatum. Treatments included three size grades of corn stover, two enzyme levels (1.67 and 5 IV/ g dry matter based on hemicellulase), and various ratios of cellulase to hemicellulase (C : H). The highest C : H ratio tested, 2.38, derived from T. reesei, resulted in the most effective fermentation, with lactic acid as the dominant product. Enzymatic activity during storage may complement industrial pretreatment; creating synergies that could reduce total bioconversion costs.