Ratna Sharma-Shivappa

This project is meant to continue and build on sweetpotato drying work commenced nearly 20 years ago in the Department of Biological and Agricultural Engineering. This work was given a renewed emphasis as a result of a project conducted in 2011 sponsored by the North Carolina Sweet Potato Commission Foundation and the Rural Advancement Foundation International (RAFI) and various North Carolina sweetpotato grower/packers. In the last year, more focused work has been continued in the Department of Biological Engineering at NCSU by support from Universal Leaf North America - parent company of Carolina Innovative Food Ingredients, Inc., (CIFI).

North Carolina State University, in collaboration with Novozymes and other partners within the State, proposes to construct and operate a pilot-scale biorefinery at one of the University Field Laboratories (UFL), for example the Lake Wheeler Road UFL near Raleigh, to convert waste biomass resources into fuel ethanol and other value-added chemical products. This facility would be used to develop new technology, integrate operations, optimize system performance and demonstrate the feasibility of producing ethanol from different biomass resources found within the State. The pilot plant would process hundreds of pounds per day and be used for teaching and developing the work force that can support this emerging business, as well as by individual researchers at NC State, Novozyme, and other in state business interests to evaluate and optimize process performance and improve economics. It will also support and complement a larger pilot facility (100 tons per day) that would provide more realistic commercial operating economics and optimization.

For a regional biorefinery to be economically viable, production of chemicals and other value-added products from biomass is equally essential (Ragauskas et al., 2006). Considering the unique structure and chemistry of lignin, there is a great potential for catalytically oxidizing lignin into fine chemicals such as vanillin, p-hydroxybenzaldehydes, etc (Zakzeski et al., 2010). In this project, we propose to synthesize and test activated carbon (surface areas > 1000 m2/g) supported metal oxides and noble metal catalysts for partial oxidation of switchgrass lignin. Specifically, we propose to: 1. Synthesize (a) activated carbon supported nickel and cobalt oxides by electrochemical deposition and (b) activated carbon supported platinum and palladium catalysts by wet impregnation. 2. Test the activity of noble and metal oxide catalysts for oxidation of switchgrass lignin into vanillin, syringaldehyde, and p-hydroxybenzaldehydes.

The U.S. faces many challenges in production practices in the livestock industry including pollution of the environment from methane emissions and animal waste that affect our environment and public health. Given our needs in various sectors including energy and global competence, we propose a multi-disciplinary approach through lessons with India to firstly address issues faced by the dairy and poultry industries and to then develop cost-effective technologies that optimize production practices. By engaging representative stakeholders in North Carolina and India, the objectives are to explore and identify new avenues of research in these sectors, educate our students and faculty through comparison, collaboration and assimilation of best practices, and facilitate information transfer through North Carolina State University. To accomplish these objectives, we propose developing a website for information transfer, student and faculty study tours, a workshop in North Carolina involving cooperator Indian experts and NC stakeholders in various sectors ranging from academia to private sector and extension, and dissemination of information to the public and university community through a range of channels. The project will further internationalize the curriculum, research and extension activities of the university, build global competence and understanding, and bridge the activities of academia, the government and non-governmental sectors.

Bioconversion of lignocellulosic feedstocks to fuel ethanol can benefit both the environment and economy of North Carolina by utilizing regional resources and supplementing the energy demand of ethanol plants with non food based resources. Since the cellulosic ethanol industry is in its infancy, ethanol producers and investors are open to several possible alternatives. Pretreatments constitute 1/3rd the total ethanol production cost1 but those like ultrasonication, alkali and ozonolysis offer advantages such as energy-saving, environmental friendliness, simple processes and equipment, or lower operating cost by reducing the intensity of operating conditions. Optimization of treatment parameters for the pretreatment most suited to a feedstock can help in reducing cost of scaled up operations and future economic analyses. Therefore the goal of this project is to add value to energy crops such as miscanthus and switchgrass capable of growth on marginal lands, through conversion to bio-ethanol. Specific objectives are to 1) compare delignification and hemicellulose solublization efficiencies of oxidative pretreatments including alkaline and ozonation on feedstock(s) grown at various location in North Carolina 2) To investigate efficiency of the pretreatment methods by determining the reducing sugar yields through subsequent hydrolysis 3) Determine optimal hydrolysis conditions relative to enzyme loading and enzyme combinations.

Energy canes represent grasses in the ?sugarcane complex? and include sugarcanes, miscanthus, and their hybrids. The perennial, cold-hardy species in this complex have considerable potential as biomass crops in North Carolina. These crops can be used as fuel for heat and power generation, production of fiber composite products, forage for livestock, and ultimately as a fuelstock for cellulosic ethanol production. These energy canes are characterized as having broad adaptability, high water and nitrogen use efficiencies, excellent pest resistance, and tremendous biomass production. Research at NC State University is underway to evaluate performance of these crops across North Carolina, develop production practices and recommendations, breed and develop improved varieties, and improve efficiency of bioprocessing and cellulosic ethanol conversion. These activities will support new economic development and a new sustainable bioenergy industry in North Carolina.

Bioconversion of lignocellulosic feedstocks to fuel ethanol can benefit both the environment and economy of corn deficient states in the United States by utilizing regional resources. Feedstocks like agricultural residues and energy crops can supplement the energy demand of ethanol plants with non food based resources at reduced transportation costs. However, unlike corn, conversion of lignocellulosic materials offers several challenges during their pretreatment to reduce lignin and increase carbohydrate (cellulose and hemicelluloses) accessibility for hydrolysis to convert carbohydrates to sugars and fermentation of sugars to ethanol. Pretreatment constitutes 1/3rd of the total ethanol production cost and novel effective methods beyond conventional dilute acid pretreatment need to be investigated based on feedstock composition. Oxidative techniques like catalytic ozonolysis and ultrasonication offer advantages such as limited need for corrosion resistant equipment, low environmental impact, and simple processes. Optimization of the treatment parameters for pretreatments most suited to a feedstock can help in reducing cost of scaled up operations and provide new avenues for ethanol producers/investors who are open to the several possible alternatives since the cellulosic ethanol industry is in its infancy.

North Carolina biodiesel manufacturers face uncertain economic circumstances as the price of their primary raw material, virgin vegetable oil, has risen steadily in recent months. This situation is made worse by the equally dramatic decline in the value of the primary byproduct of biodiesel manufacture, glycerol, driven by increasing worldwide biodiesel production. Researchers at North Carolina State University (NCSU) have recently achieved commercially attractive performance from an enzyme system that converts glycerol into glycerol carbonate. Glycerol carbonate is a versatile platform chemical used in the production of polymers and fine chemicals, and has a value twenty to thirty times that of crude glycerol. Commercial implementation of this technology requires a dramatic reduction in enzyme costs. Collaborators from NCSU and Appalachian State University (ASU) propose to demonstrate the glycerol conversion technology at the small pilot scale using an inexpensive whole cell immobilization technique that eliminates enzyme purification costs by displaying the enzymes on the immobilized cell's surface, much like a porcupine's quills, using the whole porcupine rather than extracting the individual quills. Field-testing at NC biodiesel production facilities will follow the pilot demonstration. Given the NC biodiesel production levels forecast by industry observers for 2008 and beyond, successful demonstration and commercial implementation of this technology could represent an increase in biodiesel profitability in excess of 60 cents per gallon, which translates into more than $30 million per year.

Bio-fuels production is a growing part of the larger bioprocessing sector of the economy and there exists the potential in North Carolina to contribute to the national supply of these fuels and / or to the production of appropriate feedstocks. Two main feedstocks for bioethanol production are corn and lignocellulosic biomass, both of which can be produced in large quantities in North Carolina. The Neuse River Wastewater Treatment Plant in Raleigh, North Carolina operates a large agricultural production enterprise for the disposal of biosolids and use of nutrients. The overall goal of this work is to provide information including pros and cons and recommendations to the Reuse Division Superintendent regarding how best to integrate the City of Raleigh?s Neuse River Wastewater Treatment facility into bio-fuel production systems.

The economics of producing methane by the selected digester system and optimized methanol system will be evaluated to direct final system design rather than relying on just technical considerations. The long term goal is the integration of an on-farm, low-cost, low-tech digester with a methanol production system that can be economically justified, protects environmental quality and utilizes valuable waste constituents.