Ensiling Corn Stover: Effect of Feedstock Preservation on Particleboard Performance

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.

Influence of Airflow on Laboratory Storage of High Moisture Corn Stover

“…The more extensive hemicellulose degradation compared to cellulose degradation observed in the stored corn stover in this study is consistent with reported values for both aerobic and anaerobic biomass storage conditions. Cellulose enrichment and reduced hemicellulose levels have been documented in the composition of ensiled corn stover [41] and high moisture hay that selfheated during storage [45]. Increased hemicellulose loss compared to cellulose loss has also been documented for fungally degraded corn stover stored aerobically [46].…”

“…The remaining soluble glucose in the low flow reactor is not atypical for ensiled biomass. Water-soluble carbohydrates levels, of which glucose is a component, are reported to account for approximately 1 % of the dry matter remaining in ensiled corn stover [41] and grasses [42,43]; incomplete fermentation, likely due to a declining or aging microbial population, is suggested as the reason for the remaining soluble sugars [41][42][43].…”

Triacylglycerol Production from Corn Stover Using a Xylose-Fermenting Rhodococcus opacus Strain for Lignocellulosic Biofuels

“…It is known that ensiling corn stover is able to preserve large quantities of feedstock from seasonally harvested fields and the corn stover has a high carbohydrate content allowing for easy degradation [37]. We used the ensiling biomass as a feedstock for the TAG production.…”

Wood production, wood technology, and biotechnological impacts

“…Once material filling is finished, the casting trays are transported to the press shown in Fig. 17L for hot-pressing the material (Xu et al , 2006, cotton stalks (Guler & Ozen 2004), banana fibres (Bilba et al 2007), sun-flower stalks (Khristova et al 1998 and peels (Boehme 1993), corn stover (Ren et al 2006) and maize cobs (Sampathrajan et al 1992), rice husks (Panthapulakkal et al 2006), peanut shells (Batalla et al 2005), almond husks (Crespo et al 2007), durian peels (Khedari et al 2004), coconut stem chips (Papadopoulos et al 2002), pith (Sampathrajan et al 1992), and coir (Khedari et al 2004), palm fronds (Suzuki et al 1998, Laemsak & Okuma 2000, sugarcane bagasse , sisal (Agopyan et al , Tonoli et al 2007), rattan (Olorunnisola & Adefisan 2002), and also newsprint (Nada & Hassan 1999) and other types of waste papers , Massijaya & Okuma 1996, Grigoriou 2003, Le Fur et al 2004, Hwang et al 2006. However, these various types of fibres have tremendous variations in chemical and physical properties as compared to wood fibres.…”