2014 Project List

Synthesis of Novel Interpenetrating Polymer Networks from Natural Sources (Dr. Maria Auad)

Interpenetrating polymer networks (IPNs), a kind of polymer system held together by permanent entanglements between two or more different cross-linked polymers, have created increasing interest due to their excellent thermal stability and outstanding mechanical properties brought about by the synergistic effect induced during the interlocking of the polymer chains. Most of the polymers used to prepare IPNs are derived from petroleum based compounds. Due to the depletion of oil resources and the increasing social emphasis on issues concerning the environmental waste disposal, researchers have pursued different ways to prepare these systems. The use of renewable resources to produce a remarkable variety of chemicals that can be turned into macromolecules represents an extraordinary challenge for researchers.

The objective of this REU project is to synthesize and characterize IPNs prepared from alternatives resources; which can prove to be valuable substitutes for existing materials in various applications. Thus, by employing triglyceride macromonomers as well as isoprene units obtained from natural oils as raw materials; and exploring their potential chemical modifications, the purpose of this project is to cover the major aspects related to the chemical synthesis, physical-chemical characterization and final properties of bio-based IPNs systems.

Production of Carbon Nano-composites using Microwave Decomposition for Battery Application (Dr. Xinyu Zhang)

With development in renewable energy sources and intermittent power generation, a need for high density energy and power storage materials has emerged.  Most advanced batteries rely upon rare inorganic materials for ion exchange.  Renewable materials alone are not good conductors but can be coated with carbon nano-composites (CNCs) to be used as effective electrodes.  Current standards use chemical decomposition to carbonize polymers into CNCs; however, microwave decomposition may serve as a more energy and time effective method to convert conducting polymers to CNCs.  Renewable electrodes have the potential to reduce the production costs of electrodes and produce synergistic energy and power storage effects when successfully composited with conducting polymers. The REU fellow will be responsible for producing CNCs using microwave decomposition and characterizing their potential for energy storage in batteries. 

Conversion of Biomass and Shale Gas into Jet Fuel (Dr. Ram Gupta)

Current jet fuel supply in the United States is based on imported petroleum which is not environmentally or economically sustainable. This project is developing technologies to convert local biomass and methane into jet fuel.  As compared to the petroleum molecules, biomass contains too many oxygen atoms and methane contains too many hydrogen atoms.  The technology used a catalytic conversion process to produce jet fuel and water molecules. The project makes use of supercritical fluids and heterogeneous catalysis with online analyses. The REU participant will examine the effect of pressures, temperatures, residence time, and catalysts on the liquid and gas yields.

Elucidating Xylose Fermentation through Metabolic Network Modeling (Dr. Jin Wang)

Lignocellulosic ethanol has been identified as one of the most promising long-term renewable energy sources, not only because lignocellulosic biomass is the most abundant and inexpensive renewable feedstock for ethanol production, but also because cellulosic ethanol can reduce both energy input and greenhouse gas emissions by more than 85% compared to fossil fuels and corn ethanol. Although ethanol fermentation of glucose derived from cellulosic biomass, using Saccharomyces cerevisiae, is well established on a large scale, the conversion of the xylose, one major sugar component of hemicelluloses, to ethanol is still one of the major barriers of industrializing lignocellulosic ethanol processes. Scheffersomyces stipitis has been shown to be the most promising wild strain for direct high-yield fermentation of xylose without byproduct formation, and it has been a source of genes for engineering xylose metabolism in S. cerevisiae. Dr. Wang’s group has constructed a central carbon metabolic network model as well as a revised genome scale metabolic network model for S. stipitis. In this project, the REU fellow will work with a graduate student to conduct designed experiments to validate the model as well as improve them based on experimental results.

Pretreatment of Corn Stover by Formic Acid (Y.Y. Lee)

There is a growing interest in production of fuels and chemicals from renewable resources such as lignocellulosic biomass. Pretreatment is a necessary unit process in bioconversion of lignocellulosic biomass to value-added products. The objective of this project is to test the technical feasibility of a pretreatment method using formic acid as the pretreatment reagent. Formic acid is a byproduct of levulinic acid production from biomass. Currently it has no established market. As a surplus chemical, its projected cost is much lower than common organic or mineral acids. It is less corrosive than sulfuric acid, one of the widely used pretreatment reagents. The main research task for the REU fellow is to perform laboratory experiments to determine the optimum pretreatment conditions in terms of temperature, acid level, and treatment time using batch reactors, and to determine the pretreatment efficiency by enzymatic hydrolysis of the treated biomass. This project will employ corn stover as a representative biomass feedstock. Prior to the undertaking of the project tasks, the REU fellow will be given a series of training in HPLC analysis pertaining to biomass composition, product analysis, and pretreatment and bioreactor operations.

Aligned Cellulose Nanocrystal Coatings (Dr. Virginia Davis)

Dr. Virginia Davis’ group is focused on the assembly of nanoscale building blocks into bulk materials.  Cellulose nanocrystals (CNC) produced by the acid hydrolysis of natural cellulosic materials are increasingly being recognized for their potential in advanced materials applications. They have similar surface chemistry to silicon and high mechanical strength.  The research group is looking at how the optical and mechanical properties of CNC films can be controlled by changing the concentration, shear rate thickness and drying method. The REU student will contribute to this research by making dispersions and films and characterizing them for their optical and mechanical properties. The ultimate goal is to develop CNC films for both more energy efficient displays and MEMS applications. 

Bio-oil-epoxy (“Green”) Adhesive for Laminated Wood (Dr. Brian Via)

The development of new epoxy adhesives faces several hurdles including a poor bond-line performance between the epoxy and wood substrate during and after moisture exposure. Additionally, the adhesive is too expensive when compared to other common adhesives.  Ways to improve the dimensional stability of the substrate surface is necessary to more uniformly distribute and reduce localized forces on the oil-epoxy bond-line.  Pyrolysis or liquefaction oil may assist in the improvement of dimensional stability by bulking up the cell wall and can simultaneously act as a crosslinking agent for the epoxy adhesive resulting in a greener and cheaper substitute for phenols.  The objective of this research will be the development of a moisture resistant bio-oil-epoxy “green” adhesive for wood.  The student will participate in the development of pyrolysis or liquefaction of biomass into bio-oil and then will test the moisture resistance and wet mechanical properties of the adhesive when bonded to wood.   The student will use florescence and hyperspectral microscopy and NIR/FT-IR spectroscopy to investigate any changes in the bond-line and to elucidate possible interactions between the adhesive and substrate functional groups to better understand and improve the adhesion mechanics of the bond-line. 

Biochemical Conversion of Lignocellulosic Biomass to Butanol by Clostridium Acetobutylicum (Dr. Maobing Tu)

Butanol is one of the promising advanced biofuels for the next generation of alternative fuels. However, there is a critical need to understand the effects of enzymatic hydrolysis rates on acid production in the simultaneous saccharification and fermentation (SSF) process, which could further affect butanol production rate and final butanol yield significantly. Hence, the REU fellow will use organosolv and dilute acid (except for pine) processes to pretreat biomass (switchgrass, sweetgum and loblolly pine) and generate substrates with different enzymatic hydrolyzability. Subsequently, the initial hydrolysis rate and 72-h hydrolysis yield of pretreated biomass will be determined in a separate enzymatic hydrolysis with similar conditions in the SSF process. Furthermore, the fellow will determine undissociated butyric acid concentration during the exponential phase, and butanol and butyrate production rate during exponential and stationary phases. Finally, the REU students will establish correlations between the initial enzymatic hydrolysis rate and butanol production rate, and between 72-h hydrolysis yield and final butanol yield.

Production of Gasoline from Methanol using ZSM-5 Catalyst   (Dr. Sushil Adhikari)

Synthesis gas derived from biomass gasification can be used to produce alcohols or hydrocarbons. However, there is a limitation on how much alcohols can be blended with conventional transportation fuels without adversely impacting engines. Process like Fisher-Tropsch synthesis (FTS) can be used to produce syngas to hydrocarbons but the FTS produces wide range of products and selectivity towards a particular type of fuel is low.  Synthesis gas to methanol is highly selective and Mobil oil was the first to discover and develop zeolite based methanol to gasoline technology using zeolite ZSM-5 catalyst. In this project, the REU fellow will study the effect of temperature, pressure, and catalyst type on gasoline production from methanol.  In addition, the fellow will compare the performance of methanol to gasoline process between fixed-bed and microchannel reactors.

Effect of Shaking and Tapping Frequency and Amplitude on Bulk Density of Lobolly Pine (Dr. Oladiran Fasina)
Biomass feedstock logistics encompasses all the unit operations necessary to harvest biomass and move it from the field or forest to the throat of the biorefinery conversion plant. Biomass logistics thus impacts all the pathways used to convert biomass into biofuels, bioenergy and bioproducts. Bulk density is one of the significant engineering properties that influence logistics and processing costs. The property directly determines the space required to store and transport biomass. Since lignocellulosic biomass have low bulk densities (typically less than 200 kg/m3), it is expensive and also a challenge to transport biomass to biorefinery plants at a reasonable cost. The overall goal of the project is to develop cost-effective systems to increase the bulk density of lignocellulosic biomass feedstocks. The specific tasks for the REU fellow are to investigate the influence of tapping and shaking on bulk density of different sizes of ground loblolly pine. The effects of moisture content and tapping/shaking frequency and amplitude will also be quantified.

Last Updated: Nov 12, 2013