Scale-up and Technology Transfer of Protein-based Plastic Products

Over the last number of years researchers at ISU have been developing protein based plastics from soybeans, funded by Soy Works Corporation. These materials have been characterized and the processing of these materials into prototype products has been demonstrated. A wide range of net-shape forming processes, including but not limited to extrusion, injection molding and compression molding have been studied. Issues, including technology transfer, re-formulation and product consistency, have been addressed partially during this contract. Also, commercial-scale processing parameters for protein based plastic products were designed, but not yet applicable in the industry. Support in the trouble shooting processing and the manufacturing of protein based plastic products was provided by Iowa State University during the one year contract

Enhancing Biodiesel Production from Soybean Oil Using Ultrasonics

Our objective was to determine the effect of ultrasonics on biodiesel production from soybean oil. In this study, ultrasonic energy was applied in two different modes: pulse and continuous sonication. Soybean oil was mixed with methanol and a catalytic amount of sodium hydroxide, and the mixture was sonicated at three levels of amplitude (60, 120, and 180 μmpp) in pulse mode (5 s on/25 s off). In the continuous mode, the same reaction mixture was sonicated at 120 μmpp for 15 s. The reaction was monitored for biodiesel yield by stopping the reaction at selected time intervals and analyzing the biodiesel content by thermogravimetric analysis (TGA). The results were compared to a control group, in which the same reactant composition was allowed to react at 60 °C for intervals ranging from 5 min to 1 h without ultrasonic treatment. It was observed that ultrasonic treatment resulted in a 96% by weight isolated yield of biodiesel in less than 90 s using the pulse mode, compared to 30−45 min for the unsonicated control sample with comparable yields (83−86%). In the pulse mode, the highest yield (96%) was obtained by sonicating the mixture at 120 μmpp amplitude. In the continuous sonication mode, the highest biodiesel yield was 86% by weight, which was obtained in 15 s

Evaluation of Effects of Ultrasonic Pretreatment on Biogas Production Potential from Corn Ethanol By-products

This paper reviews the biochemical methane potential (BMP) production from anaerobic digestion of corn-ethanol by-products including dried distiller grain with solubles (DDGS), centrifuge solids, thin stillage, and corn-syrup as well as evaluating the effects of ultrasonic pretreatment on biogas production from these feedstocks. Ultrasonic pretreatment was applied with three amplitude settings of 33% (52.8 µm pp ), 66% (105.6 µm pp ), and 100% (160 µm pp ) as well as five time settings of 10, 20, 30, 40, and 50 seconds, respectively, to each of the four by-products before setting up a bench top BMP trial. Biogas production was measured and analyzed for methane content and accumulated methane production. Without ultrasound pretreatment, corn-syrup had the highest methane production potential (408 ml/g VS added) compare to the other by-products. Methane production was increased by 25 and 12% for the ultrasound pretreated DDGs samples and solids samples, respectively, compared with untreated samples. The ultrasonic pretreatment of ethanol co-products was shown to increase methane production from the anaerobic digestion of these products. The ultrasonic pre-treatment of solids co-products (DDGS and centrifuge solids) was far more effective than on liquid co-products (syrup and thin stillage). An energy balance showed that ultrasonic pretreatment of DDGS provided 70% more energy than was required to operate the ultrasonic unit. An energy balance for other co-products however, indicated that the ultrasonic pre-treatment required more energy than was generated by the process in terms of additional biogas production

Effect of Ultrasonic Pretreatment on Methane Production Potential from Corn Ethanol Coproducts

This article addresses the biochemical methane potential (BMP) production from anaerobic digestion of corn-ethanol coproducts including dried distiller grain with solubles (DDGS), distiller\u27s wet grains (DWG), thin stillage, and condensed distiller\u27s solubles (CDS) as well as evaluating the effects of ultrasonic pretreatment on methane production from these feedstocks. Ultrasonic pretreatment was applied with three amplitude settings of 33% (52.8 µmpp), 66% (105.6 µmpp), and 100% (160 µmpp) as well as five time settings (10, 20, 30, 40, and 50 s) to each of the four coproducts prior to conducting benchtop BMP trials. Ultrasonic pretreatment reduced mean particle size of DDGS and DWG by 45% and 43%, respectively. Without ultrasound pretreatment, CDS had the highest methane production potential (407 mL g-1 VS added) compared to the other coproducts. Ultrasonic pretreatment of DWG co-products (DDGS and DWG) resulted in greater increases in methane production than on liquid coproducts (CDS and thin stillage). Methane yields were increased by 25% and 12% for the ultrasound pretreated DDGS and DWG, respectively, compared with untreated samples. An energy balance for the DWG, thin stillage, and CDS coproducts indicated that ultrasonic pretreatment required more energy than was generated by the process in terms of additional biogas production. However, an energy balance for ultrasonic pretreatment of DDGS provided 70% more energy than was required to operate the ultrasonic unit

Characterization of Ultrasonic Treatment of Ethanol Co-Products for Enhanced Biogas Production

This study evaluates the change in particle size of dry-milling corn ethanol co-products by using ultrasonic energy to increase the production of the biogas from the anaerobic digestion of ethanol dry-milling co-products, namely: dried distiller grain with solubles (DDGS), solids, thin stillage, and corn-syrup. The co-product samples were treated with various ultrasonic conditions and compared to non-treated samples (control sample). The ultrasonic amplitude was varied from 52.8 µm pp to 160 µm pp and the sonication time was varied from 10 to 50s. The samples were characterized with scanning electron and optical microscopy (SEM, OM) and particle distribution analysis (PDA). It was found that with solid/liquid suspensions (DDGS, solids), there was a significant decrease in particle size, increasing the surface area to volume ratio, to possibly enhance biogas yield during anaerobic digestion of these materials. In the case of thin stillage and corn syrup, the results were surprising in that an increase in particle size was seen

Novel bio-based composites of polyhydroxyalkanoate (PHA)/distillers dried grains with solubles (DDGS)

The PHA/DDGS composite is a promising low-cost, bio-based material for use in crop containers for the horticulture industry. This research effort has quantified the effects on mechanical and thermal properties of adding different amounts of DDGS to a PHA matrix. PHA and DDGS were mixed using a twin-screw microcompounder. Fracture surface morphology and thermal and rheological properties were evaluated using scanning electron microscopy (SEM), thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), and rheometer measurements. The adhesion between PHA and DDGS decreased with an increase in DDGS content from 10% to 30%. Melting temperature and crystalline temperature decreased with the increasing content of DDGS filler, indicating that PHA and DDGS interacted favorably. The complex viscosity and elastic shear modulus of the blends were increased by the increasing DDGS content. The storage modulus and glass transition temperature showed little change across the different ratios of DDGS, indicating that DDGS should be a useful filler that can decrease the cost of PHA-based materials significantly while preserving the dynamic mechanical properties and glass transition temperature

Biodegradation behavior of bacterial-based polyhydroxyalkanoate (PHA) and DDGS composites

The extensive use of plastics in agriculture has increased the need for development and implementation of polymer materials that can degrade in soils under natural conditions. The biodegradation behavior in soil of polyhydroxyalkanoate (PHA) composites with 10 wt% distiller\u27s dried grains with solubles (DDGS) was characterized and compared to pure PHA over 24 weeks. Injection-molded samples were measured for degradation weight loss every 4 weeks, and the effects of degradation times on morphological, thermomechanical, and viscoelastic properties were evaluated by scanning electron microscopy (SEM), dynamic mechanical analysis (DMA), and small-amplitude oscillatory shear flow experiments. Incorporation of DDGS had a strong effect on biodegradation rate, mechanical properties, and production cost. Material weight loss increased linearly with increasing biodegradation time for both neat PHA and the PHA/DDGS 90/10 composites. Weight loss after 24 weeks was approximately six times greater for the PHA/DDGS 90/10 composites than for unaltered PHA under identical conditions. Rough surface morphology was observed in early biodegradation stages (≥8 weeks). With increasing biodegradation time, the composite surface eroded and was covered with well-defined pits that were evenly distributed, giving an areolate structure. Zero shear viscosity, Tg, gelation temperature, and cold crystallization temperature of the composites decreased linearly with increasing biodegradation time. Addition of DDGS to PHA establishes mechanical and biodegradation properties that can be utilized in sustainable plastics designed to end their lifecycle as organic matter in soil. Our results provide information that will guide development of PHA composites that fulfill application requirements then degrade harmlessly in soil