Ultrasonication of Sugary -2 Corn for Enhanced Enzymatic Hydrolysis

This study investigates the potential application of high powered ultrasonics as a liquefaction pretreatment of sugary-2 corn slurry. Ground sugary-2 corn ( Zea Mays L. ) slurry was treated with ultrasonics at 20kHz and amplitudes of 192-320 µ m pp (peak-to-peak) for 5, 10, 15, 20 and 40 seconds. After sonication, enzymes (Stargen TM 001) were added to the samples to hydrolyze the starch into fermentable sugars. It was found that the reducing sugar released in the treated samples were 6-fold higher than in the non-treated samples. Scanning electron microscopy images revealed that the sugary starch was partially gelatinized during sonication. This observation was confirmed by polarized-light microscopic images, where deformed “Maltese crosses” were found. The swelling rate of sonicated samples was nearly 66 times higher than when applying conventional heating. This result confirms better gelatinization capability of ultrasonics compared to conventional heating. The maximum relative net energy gain (additional chemically released energy) of the sonicated samples was at 5s of sonication time with a power setting between 248-330W. The findings in this study indicated ultrasonics as a promising pretreatment step in sugary-2 corn hydrolysis

Sulitest

SULITEST is a program that assesses and promotes sustainability knowledge and awareness in college students. It covers four key areas: sustainable societies, human systems, transitioning to sustainability, and individual and systemic change. SULITEST can be a roadmap for developing knowledge and behaviors that lead to a more sustainable world

Effects of Biodiesel on Plastics

Many chemicals have the ability to attack on plastics as solvents and can lead to failure. In some cases, the source of the solvent is not well defined. In this study, the effect of biodiesel, a fatty acid methyl ester, on various plastics, namely polyamide 6 (PA 6), polycarbonate (PC), acrylonitrile-butadiene- styrene (ABS) and ABS/PC plastic blends was studied. Various feedstocks of biodiesel were also studied, including, soy bean oil (new and used), animal fat (tallow), corn oil as well as choice white grease. The plastics samples were tested under ASTM standard where a predefined strain is applied to the samples prior to exposure to the solvent (biodiesel). It was found that under the majority of combinations, other than PA 6, cracking was seen within 12 hours, and with ABS/PC and PC cracking was seen in minutes. Thus, it has been shown that biodiesel can be a degrading solvent for engineering plastics, such as PC, ABS and ABS/PC blends

Ultrasonic Pretreatment of Corn Slurry in Batch and Continuous Systems

The effects of ultrasonication of corn slurry, on particle size distribution and enzymatic hydrolysis was studied for the dry-grind mill ethanol industry. Two independent ultrasonic experiments were conducted at a frequency of 20 kHz; in batch and continuous systems. The ground corn slurry (33% m/v) was pumped at flow rates 10-28 L/min in continuous flow experiments, and sonicated at constant amplitude (20µmpeak-to-peak(p-p)). Ultrasonic batch experiments were conducted at varying amplitudes of 192-320µmp-p. After ultrasonication, StargenTM001 enzyme was added to the samples and a short 3h hydrolysis followed. The treated samples were found to yield 2-3 times more reducing sugar compared to the control (untreated) samples. In terms of energy density, the batch ultrasonic system was found to deliver 25-times more energy than the continuous flow systems. Although the experiments conducted in continuous system released less reducing sugar than the batch system, the continuous system was more energy efficient. The particle size of the sonicated corn slurry (both batch and continuous) was reduced relative to the controls (without treatment). The reduction of particle size was directly proportional to the energy input during sonication. The study suggests that both batch and continuous flow ultrasonic systems enhances enzymatic hydrolysis yield, reduces particle size of corn slurry and could be a potential effective pretreatment for corn slurry

Ultrasonic pretreatment for enhanced saccharification and fermentation of ethanol production from corn

The 21st Century human lifestyle has become heavily dependent on hydrocarbon inputs. Energy demand and the global warming effects due to the burning of fossil fuels have continued to increase. Rising awareness of the negative environmental and economic impacts of hydrocarbon dependence has led to a resurgence of interest in renewable energy sources such as ethanol. Fuel ethanol is known to be a cleaner and renewable source of energy relative to gasoline. Many studies have agreed that fuel ethanol has reduced greenhouse gas (GHG) emissions and has larger overall energy benefits compared to gasoline. Currently, the majority of the fuel ethanol in the United States is produced from corn using dry-grind milling process. The typical dry-grind ethanol plant incorporates jet cooking using steam to cook the corn slurry as pretreatment for saccharification; an energy intensive step. In aiming to reduce energy usage, this study evaluated the use of ultrasonics as an alternative to jet cooking. Ultrasonic batch experiments were conducted using a Branson 2000 Series bench-scale ultrasonic unit operating at a frequency of 20 kHz and a maximum output of 2.2 kW. Corn slurry was sonicated at varying amplitudes from 192 to 320 ympeak-to-peak(p-p) for 0-40 seconds. Enzyme stability was investigated by adding enzyme (STARGENTM001) before and after sonication. Scanning electron micrograph (SEM) images and particle size distribution analysis showed a nearly 20-fold size reduction by disintegration of corn particles due to ultrasonication. The results also showed a 30% improvement in sugar release of sonicated samples relative to the control group (untreated). The efficiency exceeded 100% in terms of relative energy gain from the additional sugar released due to ultrasonication compared to the ultrasonic energy applied. Interestingly, enzymatic activity was enhanced when sonicated at low and medium power. This result suggested that ultrasonic energy did not denature the enzymes during pretreatment. Ultrasonication of sugary-2 corn was also investigated in the study. Results similar to those for commodity corn (dent corn) were found, in terms of glucose yield and starch conversion. SEM and polarized-light microscope pictures showed the partial gelatinization of corn slurry due to ultrasound. In the 96-h saccharification time, a model was formulated to fit the sugar release curve. The results have shown 17-21% increase in the extent of sugar production from sonicated samples relative to the control group. Additionally, the reaction rates of the sonicated samples were 2- to 10-fold higher than the reaction rates for the control group. In comparing sugary-2 corn with commodity corn, it was found that sonicated sugary-2 corn saccharified faster than sonicated commodity corn. It is important to note, without ultrasonic treatment, sugary-2 corn released more reducing sugar than commodity corn during saccharification. To further investigate the potential of ultrasonics for scale-up, a continuous flow system was studied. An ultrasonic continuous flow system was tested using Branson's flow-through "donut" horn. The donut horn, which vibrates radially, was placed inside a 5.5 L stainless steel reactor. The amplitude was maintained at 12 ympp and the feed flow rate was varied from 8-27 L/min (2-7 gal/min) with reactor retention times varying from 12-40 seconds. Samples sonicated in continuous flow system showed lower reducing sugar yield than batch ultrasonication. However, considering the ultrasonic energy density of batch and continuous systems, the continuous systems proved to be more energy efficient in terms of glucose production compared with the batch system. It was also seen that particle size disintegration was proportional to energy density regardless of the type of ultrasonic system used. To compare ultrasonics with jet cooking, fermentation experiments were conducted. There were only marginal differences between jet cooked samples and the sonicated samples in terms of ethanol conversion based on theoretical yield. Furthermore, statistical analysis confirmed that there was no significant difference (p Based on these results, ultrasonication is a promising pretreatment method in corn ethanol production, as an alternative to jet cooking.</p

Ultrasonication of Sugary -2 Corn for Enhanced Enzymatic Hydrolysis

This study investigates the potential application of high powered ultrasonics as a liquefaction pretreatment of sugary-2 corn slurry. Ground sugary-2 corn ( Zea Mays L. ) slurry was treated with ultrasonics at 20kHz and amplitudes of 192-320 µ m pp (peak-to-peak) for 5, 10, 15, 20 and 40 seconds. After sonication, enzymes (Stargen TM 001) were added to the samples to hydrolyze the starch into fermentable sugars. It was found that the reducing sugar released in the treated samples were 6-fold higher than in the non-treated samples. Scanning electron microscopy images revealed that the sugary starch was partially gelatinized during sonication. This observation was confirmed by polarized-light microscopic images, where deformed “Maltese crosses” were found. The swelling rate of sonicated samples was nearly 66 times higher than when applying conventional heating. This result confirms better gelatinization capability of ultrasonics compared to conventional heating. The maximum relative net energy gain (additional chemically released energy) of the sonicated samples was at 5s of sonication time with a power setting between 248-330W. The findings in this study indicated ultrasonics as a promising pretreatment step in sugary-2 corn hydrolysis.This is an ASABE Meeting Presentation, Paper No. 084123.</p

Desiccation Cracking Behavior of MICP-Treated Bentonite

This study aims to characterize the effect of microbial-induced calcite precipitation (MICP) on the desiccation cracking behaviors of compacted calcium bentonite soils. We prepare six groups of samples by mixing bentonites with deionized water, pure bacteria solution, pure cementation solution, and mixed bacteria and cementation solutions at three different percentages. We use an image processing tool to characterize the soil desiccation cracking patterns. Experimental results reveal the influences of fluid type and mixture percentage on the crack evolution and volumetric deformation of bentonite soils. MICP reactions effectively delay the crack initiation and remediate desiccation cracking, as reflected by the decreased geometrical descriptors of the crack pattern such as surface crack ratio. The mixture containing 50% bacteria and 50% cementation solutions maximizes the MICP treatment and works most effectively in lowering the soil cracking potential. This study provides new insights into the desiccation cracking of expansive clayey soils and shows the potential of MICP applications in the crack remediation

Effects of Biodiesel on Plastics

Many chemicals have the ability to attack on plastics as solvents and can lead to failure. In some cases, the source of the solvent is not well defined. In this study, the effect of biodiesel, a fatty acid methyl ester, on various plastics, namely polyamide 6 (PA 6), polycarbonate (PC), acrylonitrile-butadiene- styrene (ABS) and ABS/PC plastic blends was studied. Various feedstocks of biodiesel were also studied, including, soy bean oil (new and used), animal fat (tallow), corn oil as well as choice white grease. The plastics samples were tested under ASTM standard where a predefined strain is applied to the samples prior to exposure to the solvent (biodiesel). It was found that under the majority of combinations, other than PA 6, cracking was seen within 12 hours, and with ABS/PC and PC cracking was seen in minutes. Thus, it has been shown that biodiesel can be a degrading solvent for engineering plastics, such as PC, ABS and ABS/PC blends.This is a proceedings from 2013 Society of Plastics Engineers (SPE) ANTEC conference, Cincinnati, Ohio, April 21-24, 2013. Posted with permission.</p