Darrin M. Haagenson

Production and characterization of epoxidized canola oil.

Epoxidized canola oil may be well suited to the partial replacement of petroleum products in composite matrices; however, a process is needed to obtain this material from canola oil at sufficient conversion and scale to assess product properties. Therefore, canola oil was epoxidized in a solvent-free process with a heterogeneous catalyst; a fractional factorial design was used to determine the impact of processing conditions and their two-factor interactions on epoxy group content of epoxidized canola oil. The studied parameters were: molar ratio of acetic acid to unsaturation, molar ratio of hydrogen peroxide to unsaturation, concentration of hydrogen peroxide, concentration of catalyst, and temperature. Epoxidized canola oil with up to 98.5% conversion was produced. The parameters molar ratio of acetic acid to unsaturation, concentration of hydrogen peroxide, temperature, and their interactions were found to be significant in the defined design space. Process conditions that achieved the highest conversion were scaled to 300 g to compare the conversion, production yield, and rheological and melting properties of products of the epoxidation of both canola and soybean oil with and without solvent. Epoxidized canola oil crystallized at room temperature; at 40°C it was shear-thinning with an apparent viscosity of 140 to 150 mPa·s. Elimination of solvent in the epoxidation process decreased the yield 10% but did not reduce the conversion to epoxy groups. Therefore, the scaled-up, solvent-free process is proposed as a green alternative for sufficient epoxidized canola oil to test composite applications.

Study of the Process Parameters of the Canola Oil Epoxidation

Canola oil was epoxidized in situ with peracetic acid in the presence of an ion exchange resin catalyst. A two-level fractional factorial design was used to determine the effect of five parameters on the conversion of double bonds to epoxy groups: (A) molar ratio of acetic acid to double bonds, (B) molar ratio of hydrogen peroxide to double bonds, (C) concentration of hydrogen peroxide, (D) concentration of catalyst, and (E) temperature. The yield of epoxidized oil in the presence of toluene was evaluated in a separate experiment. Iodine value and oxirane oxygen content, which express the presence of double bonds and epoxy groups respectively, were evaluated and characterized by FTIR spectroscopy. The analysis of variance (ANOVA) for oxirane content identified the parameters A, C, E and the interactions AC, AE, and CE statistically significant at p<0.05 with a coefficient of determination of 0.82. The analytical determinations were confirmed by FTIR spectroscopy showing that samples with lower iodine values had higher oxirane oxygen content. The highest conversion of double bonds to epoxy groups (6.5 %) was achieved at acetic acid: hydrogen peroxide (50%): double bonds molar ratio of 0.5:2:1, catalyst concentration of 25% at 60°C. The presence of toluene did not affect the conversion of double bonds to epoxy groups, but increased the yield from 80% to 90% (90g epoxidized canola oil/100 g canola oil).

Oil and Biodiesel from Canola Having a High Content of Green Seed

The price of canola seed is sharply discounted if the content of green seed in the sample is greater than 2%. The main reason for the discount is the higher cost to refine oil from green seed to a food-grade oil. Current practices for swathing and harvesting canola, as recommended by the North Dakota State University Extension Service, are intended to reduce the percentage of green seed in the sample to acceptable levels. Harvest with the swath method is more expensive than the straight cut method. Straight cutting canola would reduce the field operations by farmers and would probably reduce shatter loss by at least 5%. Canola production must be increased greatly to meet the anticipated demand for canola biodiesel. The objective of this study was to determine whether oil from straight-cut canola seed will be acceptable for production of biodiesel.

Canola-based Epoxy Resins Applied to Plastic Composites

Canola-based epoxy resins were obtained by chemical synthesis with peracetic acid derived from the oxidation of acetic acid with hydrogen peroxide in-situ at 50°C. The epoxidation reaction was carried out in different experimental systems (a. Mechanical stirring, 491 rpm at 50 °C; b. Magnetic stirring, 500 rpm at 25 °C, and c. Orbital stirring, 150 rpm at 50 °C.). Under the experimental conditions of the mechanical stirring system, the time of the reaction (1, 3, 5, 7, 9h) and the presence of solvent (at 5h) were evaluated. The highest conversion of double bonds to epoxy ring was 92% with the mechanical stirring system at 5h. The epoxidation at 5h without solvent was difficult to recover, however the conversion was the same as in presence of solvent. The qualitative analysis by Fourier transform infrared spectroscopy confirmed the results of the analytical determinations of the oxirane content of the prepared samples. The content of double bonds decrease with the time at 3007 cm-1, while the formation of the epoxy groups at 823.8 cm-1 increased with the time of reaction until 5h, time after which the oxirane content remained constant. FTIR spectrum of a canola epoxy resin at 5h in absence of solvent showed a lightly lower content of epoxy groups than in presence of solvent, which was not detected by the analytical determination of the oxirane oxygen content.

Influence of Seeds Moisture on in situ Alkaline Transesterification of Canola Seeds for Biodiesel Production

In situ alkaline transesterification is reported to be an efficient method of biodiesel (methyl ester) production from several oilseed crops. Seed moisture content has a significant influence on methyl ester yields from biodiesel made in situ. Biodiesel quality properties are closely associated with the parent feed stock, and methyl esters derived from conventional transesterified canola oil have improved cold flow properties when compared to other oilseed crops. This study evaluated canola in situ alkaline transesterification and examined the impact of seed moisture content on methyl ester yield. Biodiesel quality parameters including oxidative stability, moisture content, kinematic viscosity, free fatty acids and total glycerin were evaluated between biodiesel derived from conventional and in situ methods.

Epoxy Resins from High-Oleic Oils applied to Composites

Vegetable oils are a renewable source for the production of oleochemicals. One chemical modification of vegetable oils is epoxidation, where fatty acid unsaturations are converted to epoxy groups. Oils with high oleic content may be an excellent source for producing epoxy resins, because of the uniform distribution of cross-linking sites. Bio-based epoxy resins can be mixed with structural fibers to produce composite materials. Canola oil and sunflower oil with high oleic content (74% and 86% respectively), canola oil with standard oleic acid content (64%, and soybean oil with low oleic content (22%)were epoxidized in situ with peracetic acid and a heterogeneous catalyst. Bio-based epoxy resins were blended with a synthetic epoxy resin and an anhydride curing agent to be applied as the matrix in the preparation of composites using E-glass as the structural fiber. A control was also prepared with a 100% synthetic epoxy resin. Mechanical properties (flexural, tensile and dynamic mechanical analysis) of the produced composite materials were evaluated. The results showed that the level of unsaturation and the amount contained in the matrix of bio-based epoxy resin directly impacted the mechanical properties of the composites. The application of bio-based epoxy resins in the production of composites materials helps decrease the dependence on petroleum-based resins, and may lead to a high added-value product from vegetable oils.

Plant Resistance to Colorado Potato Beetle (Coleoptera: Chrysomelidae) in Diploid F2 Families Derived From Crosses Between Cultivated and Wild Potato

Abstract Colorado potato beetle, Leptinotarsa decemlineata Say (Coleoptera: Chrysomelidae), is a serious global pest of potato, Solanum tuberosum L. Management of L. decemlineata has relied heavily on insecticides, but repeated evolution of insecticide resistance has motivated the exploration and development of alternative strategies, such as plant resistance.The recent development of two diploid potato families derived from crosses between cultivated and wild potato species (S. chacoense and S. berthaultii) has provided a unique opportunity to reexamine plant traits for resistance breeding. In this 2-yr study, we surveyed select F2 clones for the induction of L. decemlineata mortality and a reduction in defoliation in no-choice feeding assays when challenged with adults and larvae from three sites in Wisconsin. We tested for an association with glandular trichome density and foliar levels of the glycoalkaloids chaconine and solanine. Several potato clones demonstrated resistance in specific feeding assays, but none excelled consistently across experiments. Mortality and defoliation generally differed significantly among L. decemlineata populations, which could be indicative of heritable variation in beetle responses to plant defenses or variation in the physiological status of the beetle populations tested. Contrary to expectations, higher trichome density increased mortality or decreased defoliation in only a few cases, and levels of mortality and defoliation were unrelated to foliar glycoalkaloid content, warranting further investigation of the defense mechanisms of resistant clones. In addition to identifying several potential L. decemlineata resistance sources, this study underscores the need to include multiple insect populations in surveys of plant resistance to this diverse pest.

Evaluation of the effect of combined storage techniques on the preservation of industrial sugars from sugar beets for bioproducts

Abstract. Sugar beets are a major source of sucrose which may be converted into bioproducts. Sugar beets are conventionally stored frozen in open piles for up to 6 mo. in the North Central Red River Valley which is characterized by extreme winter conditions. Nevertheless, freezing enhances the rupture of cell walls thus making cell contents susceptible to leaching during beet thawing, a step that requires large quantities of water and energy. Therefore, alternative storage techniques are desired to preserve industrial sugars from sugar beets and allow yearlong operation of bioprocessing facilities. The focus of this research was to evaluate the combined effectiveness of beet surface treatment and storage techniques such as modified atmosphere storage at two storage temperatures on the retention of industrial sugars in sugar beets. The surface treatments evaluated consisted of one senescence inhibitor and two antimicrobial agents applied independently to the beet surface. The senescence inhibitor used was N 6 -benzylaminopurine and the antimicrobial agents were acetic acid and a commercial product with 40% to 50% acidic calcium sulfate as its active ingredient (pHresh 10.0®). The senescence inhibitor was applied at concentrations of 0.05% and 0.1% (w w -1 ) whereas the antimicrobial agents were applied at concentrations of 0.1% and 1% (w w -1 ). An ambient atmosphere and an initially modified atmosphere were assessed for storage. The modified atmosphere consisted of 5.11±0.02% CO2 and 5.47±0.04% O2 (v v -1 ) balanced with N 2 . The experimental units were stored at either 4°C or 25°C for 24 wk. After storage, beet-tissue samples were collected from each unit and analyzed for moisture and sugar content. Multiple comparisons of means indicated that surface treatments and temperature did not constitute a significant benefit on sugar preservation (at I±=0.05) in beets stored under aerobic conditions. Sugar beets stored under an initially modified atmosphere and at 4°C and 25°C lost up to 28% and 35% of initial sugars, respectively, without a statistically significant difference at I±=0.05. Atmosphere composition did not constitute an additional benefit on industrial sugar preservation (at I±=0.05).

Change in Fermentable Sugars in Sugar Beets Stored Anaerobically

High-yielding sugar beets are becoming an attractive feedstock for the production of ethanol in the Red River Valley region of the United States. Long-term storage methods are necessary to preserve fermentable sugars in beets and allow successful yearlong operation of beet ethanol plants. Anaerobic storage of sugar beets was evaluated as an alternative to conventional pile storage currently used in sugar processing factories. Preliminary results indicated a loss of <15% in total fermentable sugars in sugar beets stored anaerobically for 14 wk at 4°C. After 14 wk of storage, 99±3.6% of the initial total fermentable sugars was preserved in beets stored aerobically at 4°C. Sugar beets stored aerobically and anaerobically at 25°C preserved 82±8.5% and 48±10.8% of their initial total fermentable sugars, respectively. After 7 wk of anaerobic storage at 25°C, a CO2 concentration of 61.1±1.7% was detected within the storage units. The CO2 reached a maximum concentration of 97.1±2.7% after 10 wk of storage before dropping to approximately 78.7±0.7% by week 12 and remained stable at week 14. The results suggested an improvement in storage by temperature reduction; however, the elimination of oxygen in the storage atmosphere resulted in a decrease of total fermentable sugars. Future ethanol quantification in both, the beet tissue and exudate within the anaerobic storage units, will provide valuable information to determine if the overall ethanol yield from stored sugar beets is preserved.

Near infrared analysis of sugar beet raw thick juice for ethanol production

Minimal fermentable sugar loss is essential for successful sugar beet processing, and storage of concentrated (thick) juice may improve economics by extending the processing campaign. However, an accurate, real time evaluation of juice quality is necessary, and reference chemical methods are time consuming and expensive. The objective of this study was to develop and validate near infrared spectroscopic (NIRS) calibration models for predicting quality of sugar beet thick juice used in bioethanol applications. Thick juice possessing varied refractometeric dry solids (60 to 70°Brix) were stored across contrasting pH (2 to 11) for 24 wk at 21°C. NIR spectra and reference chemistry values for brix, water activity (aw), pH, were collected at 2 wk intervals and carbohydrate concentrations were quantified at the beginning and conclusion of the 24 wk storage experiment. NIR spectra (535 samples) were collected with a diode array spectrometer, equipped with a syrup module. A partial-least squares calibration model with mean centered preprocessing and multiplicative signal correction provided the best models for thick juice evaluation. An RPD value > 4.8 suggests useful calibrations were obtained for brix across all pH ranges and for aw from samples stored under acidic storage conditions. The juice pH calibration were poor (RPD 2.1, 1.5) and additional sample data must be included to accurately assess the model performance of carbohydrate predictions.