The Northeast Sun Grant is funding eight research and development projects beginning in 2007, through a competitive grants program. The research portfolio contains experiments in the areas of feedstock development, bio-conversion processes, systems analysis, economics, environment and policy.
Feedstock Development
- Developing the Potential of Hazelnuts as a Feedstock for Biodiesel and other Oleochemicals in the Northeast.
- A Biofuel Screening Program for Grass Feedstocks: Diversity, Physiological Traits and Compositional Characteristics for Optimal Yield.
Conversion Processes
- Improving Woody Biomass Separation by Enzymatic Means.
- Development of a Temperature-phased Anaerobic Digestion Process for Enhanced Conversion of Solids in Livestock Manure and Food Wastes to Methane.
- Influence of Alternative Pretreatment Strategies on Cellulosic Ethanol Production using Simultaneous Saccharification and Fermentation at High Solids Concentrations.
- Enhanced Microbial Cellulose Degradation and H2 Production above 80C.
Systems Analysis
Economics, Environment and Policy
Developing the Potential of Hazelnuts as a Feedstock for Biodiesel and other Oleochemicals in the Northeast.
PI: Thomas Molnar, Rutgers University. $58,062
Hazelnuts merit investigation and development as a sustainable and high yielding feedstock for biodiesel and other oleochemicals in the northeastern United States. Calculations suggest 0.89 tonnes of oil/hectare could be realized under current systems in the Pacific Northwest. This is greater than the U.S. average of approximately 0.50 tonnes oil/hectare from soybeans. Production based on the development and commercialization of new high-yielding and much more widely adapted genotypes, such as those recently identified at Rutgers and the University of Nebraska, Lincoln, could lead to oil yields of over one tonne/hectare in the northeastern U.S. (realistic breeding potentials are over 1.30 tonnes/hectare). In addition to yield, hazelnut oil has a unique fatty acid composition, thermal stability, and low temperature properties that should increase its value over soybean oil for a number of applications. The high quality protein meal remaining after oil extraction can add substantial value to oil production. After nearly 10 years of hazelnut germplasm collection and intense evaluation at Rutgers University, in close cooperation with Oregon State University, the USDA Corylus Germplasm Repository, and more recently the University of Nebraska, Lincoln, it has become apparent that the primary limiting factors to production in much of the northeastern U.S., i.e. the disease eastern filbert blight (EFB) and the lack of cold hardiness, can be overcome through traditional breeding using available genetic resources. Currently, nearly 11,000 seedlings and clonal selections are under evaluation in field and greenhouse trials at Rutgers, with approximately 5,000 of these the result of controlled hybridizations. From this collection, a significant number (approximately 200) of genotypes have been identified that express a very high level of resistance to EFB, as well as later flowering - the traits necessary for reliable and significant production in the northeast. While many of these selections produce kernels that do not compete in terms of quality (size, shape, ease of pellicle removal) with those grown commercially, many are highly productive and well adapted to this area. These selections merit further investigation for the sustainable production of oil as a feedstock for biodiesel and/or other oleochemicals, where pellicle removal characteristics or shape of the kernel is not an issue. The objectives of this proposal are to evaluate kernel percentage and kernel oil content of the top 200 hazelnut genotypes existing at Rutgers that express high levels of disease resistance and adaptation to the northeastern United States, in order to identify the genotypes most likely to yield economically significant quantities of oil. The top 25 performers will undergo more specific evaluation of their fatty acid profile to help identify the genotypes most useful for the production of biodiesel or other oleochemicals. The top 10 selections identified from this work will be clonally propagated and established in a replicated yield trial as a basis for further investigation and to build a platform to develop proposals to attract increased interest and funding. In addition, a genetic improvement program will be initiated to examine the inheritance of oil traits and other related characteristics with the ultimate goal to develop superior, well-adapted, reliable, and high yielding oil producing cultivars for the northeast U.S.
A Biofuel Screening Program for Grass Feedstocks: Diversity, Physiological Traits and Compositional Characteristics for Optimal Yield.
PI: Jocelyn Rose, Cornell University. $100,000
The generation of energy from plant biomass can be accomplished through a number of different approaches, but one strategy that is emerging as having several major economic and ecological advantages is the conversion of lignocellose from perennial grasses to ethanol (cellulosic ethanol). Such an approach has the potential to reduce current reliance on fossil fuels, enhance energy security, dramatically stimulate regional rural economies and promote the adoption of biofuels in a sustainable framework, thereby promoting public confidence and ultimately consumer acceptance. Research into the development of grass feedstocks as renewable sources of biofuels has focused to date on a small number of grass species that were originally adopted somewhat arbitrarily and the genetic base of existing grass biofuels research programs, both nationally and locally, is therefore remarkably narrow. Another limitation in the development of a robust grass-based biofuel program has been the minimal dialog between traditional breeders of forage grasses and plant biologists with expertise in the basis of quality traits from biofuels; a key element of which is the composition of the plant cell wall, the raw material of lignocellulosic ethanol. This proposal outlines an integrated approach to address these concerns and to lay the foundation for building a robust grass-based biomass feedstock program. To this end, a team has been assembled with complementary expertise in areas such as grass feedstock quality development and assessment, plant breeding and plant cell wall analysis. Specific objectives and deliverables include: (1) collection and performance evaluation of a broad range of monocultures and mixed stands of grass species and cultivars grown at multiple locations, on a range of soil types and under different fertilizer regimes, incorporating a variety of harvesting dates.
Improving Woody Biomass Separation by Enzymatic Means.
PI: Nancy Kravit, Univ. of Maine. $90,581
There is enough biomass in wood in the United States to supply much of the country’s fuel and chemical needs, however, efficient use of that biomass requires fractionation of wood into its macromolecular components: lignin, cellulose, and hemicellulose. The difficulty of fractionating wood into separate lignin, cellulose and hemicellulose feedstreams has prevented forest biomass from fulfilling its potential to provide environmentally sustainable carbon-neutral raw material for energy and chemical synthesis needs. It is believed that chemical bonds (specifically, ether bonds) between lignin and hemicellulose are a major impediment to fractionation. Current fractionation techniques are inefficient and environmentally costly. One alternative to chemical fractionation is to use enzymes. An enzyme-based process has the potential to be both efficient and environmentally friendly; however, enzymes that can break the bonds between lignin, hemicellulose and cellulose without damaging the wood components were not previously known. In our laboratory, we used a novel search strategy to discover three putative enzyme activities that can break hemicellulose-lignin bonds. We used a model compound made from hemicellulose and a lignin-like molecule that fluoresces when the ether bond connecting it to hemicellulose is broken. In order to identify the new activity and to test its specific effect on wood, it must first be isolated from other lignocellulolytic enzymes. The project objectives are 1) to determine the best starting material for the isolation, i. e. whether to use culture supernatant or a subcellular fraction, 2) to devise an isolation scheme, 3) to confirm its activity on natural lignin-hemicellulose complexes as opposed to synthetic model compounds, and 4) to microsequence the activity and determine its identity or reveal similarities to known protein families.
Development of a Temperature-phased Anaerobic Digestion Process for Enhanced Conversion of Solids in Livestock Manure and Food Wastes to Methane.
PI: Dr. Zhongtang Yu, Ohio State University. $100,000
Methane production by anaerobic digestion (AD) recently received considerable renewed attention because it produces renewable bioenergy to reduce the dependency on foreign oil while remediating the environmental/socioeconomic impact of waste biomass. Biomethanation is considered one of the most appropriate technologies to generate methane bioenergy, especially from waste biomass such as livestock manures and food- processing wastes, however, up to 50% of the lignocellulosic solids passes through AD undigested. This low conversion efficiency results in (1) a considerable loss of bioenergy, (2) a larger volume of digesta that needs to be disposed of, and (3) a failure to fully utilize biomass carbon already collected and transported as feedstock. To this end, our first objective is to develop a temperature-phased AD (TPAD) that enhances digestion of the solids present in livestock manure and food wastes by increasing the hydrolysis of lignocellulose in these wastes. Given the significant improvement (≥20%) in solid digestion achieved in TPAD receiving sewage sludge as feedstuff, we anticipate a ≥10% increase in conversion to methane of lignocellulosic wastes present in livestock manure and food wastes. If achieved, such an improvement would potentially produce additional 3.5-7.0 billion m3/year of CH4 from the 87 million dry tons of livestock manure available for bioenergy production alone. Our second objective is to implement an integrated research platform consisting of rrs gene sequencing and metagenomics to identify the key microbes and their metabolisms potentially underpinning biomethanation, both supporting the first objective and advancing the general knowledge of AD microbiology. This study will build upon the capabilities developed in our Biomass-to-Energy program which focuses on production, from livestock manure and food wastes, of methane biogas to be used directly for electricity generation by solid-oxide fuel cells. To complete this project, we will use a collaborative effort combining expertise on livestock manure AD, molecular microbial ecology and metagenomics. High-value products such as elite enzymes to degrade lignocellulose may also be found from the cDNA and metagenomic libraries. A substantial sequence (rrs and mRNA) database will be created that can aid in development of habitat-specific phylogenetic and functional microarrays, which can be used in comparative studies of microbial communities underpinning AD. The knowledge learned may help design more efficient AD or improve existing AD. The sequence data obtained will also be useful for future community genome sequencing of AD. The TPAD technology will be introduced to interested parties through workshops and training sessions, while the sequence data will be disseminated broadly to the scientific community through public databases. This project will benefit the bioenergy sector, livestock producers, and the scientific community through research, education, and partnership activities that combine technology development and basic research of national and regional interest.
Influence of Alternative Pretreatment Strategies on Cellulosic Ethanol Production using Simultaneous Saccharification and Fermentation at High Solids Concentrations.
PI: James Gossett, Cornell University. $99,999
Ethanol produced from renewable, lignocellulosic biomass (such as switchgrass) has the potential to replace some or all of the petroleum consumed in the transportation sector. The preferred process for ethanol production from lignocellulose is a thermochemical pretreatment followed by enzymatic hydrolysis to fermentable sugars that microorganisms transform into ethanol. Few studies on ethanol production from lignocellulose have been conducted at high biomass concentrations, important to the economic feasibility of cellulosic ethanol production. High solids loading during saccharification and fermentation reduces water consumption, size of reactors, and results in higher ethanol concentration, lowering subsequent distillation costs. Biomass hydrolysis can be conducted separately from fermentation or the processes can be combined into SSF (simultaneous saccharification-fermentation). The advantage of SSF is that, when high solids concentrations are employed, the consumption of sugars by fermenting yeasts prevents their accumulation to levels that would inhibit further saccharification. The drawbacks of conducting SSF at high solids concentration include challenges in pumping and mixing, and high concentrations of inhibitory byproducts of pretreatment. Investigations on the nature and mechanisms of saccharification and fermentation inhibitors (many of which are lignin degradation products) are required to achieve higher and commercially viable ethanol yields. This research will investigate the effects of two classes of pretreatment – (1) mildly acidic (represented by steam explosion); and (2) alkaline (represented by ammonia fiber explosion) – on SSF of lignocellulosic biomass to ethanol conducted at high solids concentrations (20-40% w/v). We will investigate fundamental aspects apart from issues of mixing, because mixing at high-solids concentrations is best studied a pilot- or full-scale. We propose fundamental, laboratory-scale studies addressing pretreatment effects on biomass that the published literature suggests will result in the following issues at high-solids loading: (i) Product inhibition of saccharification (e.g., through direct effects on cellulases or through lignin-product deposition on substrate cellulose affecting substrate accessibility and/or presenting unproductive binding sites to cellulases); (ii) Product inhibition of fermentation. We will characterize the effects of both pretreatment classes in terms of physical and chemical changes of the biomass, and the influence each treatment has on subsequent high-solids SSF. Physical/chemical changes to be investigated include dry-matter losses; pore-size distribution; FTIR spectra; characterization of solubilized carbohydrates; and lignin analyses that will include alterations in solid-phase lignin, as well as lignin degradation products released during pretreatment. Since successful SSF depends on sufficient disruption of the lignocellulosic matrix during pretreatment, a fundamental understanding of how biomass structure is altered should help improve the overall cellulosic-ethanol production process. The physical and chemical modifications of lignoellulose that occur during pretreatment affect binding of cellulases to their solid substrate (a prerequisite of cellulose hydrolysis), and therefore we will conduct cellulase-binding studies on both pretreated substrates at high-solids concentrations. Another aspect of pretreatment that is of great interest is how pretreatment-degradation products (e.g. phenolics formed from lignin hydrolysis and furfurals formed from monomeric sugar degradation) may interfere with SSF processes conducted at high solids loadings. If one or both pretreatments adversely affect high-solids SSF, we will conduct studies to differentiate between inhibition of hydrolysis versus inhibition of fermentation, and we will identify specific interference mechanisms to suggest remedy to such problems. This study may show that mildly acidic or alkaline pretreatment results in more successful ethanol production; but ultimately we hope to identify fundamental mechanisms of pretreatment that influence high-solids SSF to elucidate differences between the pretreatment classes and suggest solutions to problems raised.
Enhanced Microbial Cellulose Degradation and H2 Production above 80C.
PI: James Holden, Univ. of Massachusetts. $22,346
The development of cellulose conversion processes and consolidated bioprocessing is a priority for broad-scale biofuel production and the displacement of imported petroleum. The primary impediment to the use of cellulose as a biofuel feedstock has been the cost necessary to overcome the recalcitrance of the material when converting it from a polymer into oligosaccharides that are then fermented by microorganisms for biofuel production. This study addresses some fundamental questions related to this problem. It was reported that microbial growth rates on cellulose increase with temperature but the analysis did not extend beyond 74ºC. Since cellulose hydrolysis is generally the rate limiting step for the growth of cellulolytic microorganisms, the anticipation is that the rates of cellulolytic enzyme activity (i.e., β(1→4)-endoglucanases) and cellulose degradation also increase with temperature. Certain microorganisms that grow optimally above 80ºC, so-called ‘hyperthermophiles’, and belong to the genus Pyrococcus encode active cellulases in their genomes and grow on cellobiose, but their growth on cellulose has not been shown. They and closely-related Thermococcus species grow on cellobiose and produce H2, acetate, and CO2 as primary waste products when grown on maltose, which suggests that they might degrade cellulose and yield industrially-useful amounts of H2 in a single processing step. The central objectives of this seed project are to: • Screen the Pyrococcus and Thermococcus strains within the PI’s culture collection (>25) for their ability to grow on a commercially available form of microcrystalline cellulose (Avicel). Avicel was chosen to compare our results with those for other organisms grown previously on microcrystalline cellulose. • Determine the specific microbial growth rates for these organisms when grown on cellulose and whether these rates are higher than those measured for other known cellulose degraders below 80ºC. • Determine whether these organisms can degrade cellulose with H2 as the primary waste product and the amount of H2 produced per cell doubling. Scientific merit. It is anticipated that several hyperthermophile strains within the Holden lab culture collection are capable of growth on crystalline cellulose. The specific growth rates of these organisms will be higher than those reported previously for organisms that grow at lower temperature. The cellulases that they produce would be useful for in vitro industrial hydrolysis of cellulose into oligosaccharides. It is also anticipated that these cellulolytic hyperthermophiles will produce significant amounts of H2 when grown on cellulose thus providing efficient consolidated bioprocessing step for biofuel H2 production. Education and public outreach. The proposed research will be conducted in part by an undergraduate honor’s student working with the PI to enhance his undergraduate training and experience. Holden teaches undergraduate and graduate level courses on microbial physiology each year and the information obtained from this study and the techniques employed will be used in these courses as examples of analytical approaches to cellular modeling and chemical-biological interactions. Holden has also been involved in public education and outreach and will continue his involvement with these programs.
Small Farm Integrated Energy System.
PI: Norm Scott, Cornell University. $75,010
This project proposes the analysis and demonstration of a unique small farm, integrated energy production system. The farm, Snowyfields Farm, near Groton, NY will serve as the test case for this project. Its owner and operator, Pegi Merrick Ficken, is enrolled as an M.P.S. candidate in Biological and Environmental Engineering at Cornell University and as farm owner and operator combines her academic and on-farm interests in this proposal. The primary objective will be a demonstration of small-scale ethanol production, electric generation, and anaerobic digestion in an integrated system. On the farm, ethanol will be extracted from corn grain and wet distillers’ grain (WDG) will be fed directly to the cows. Manure from the cows will be collected and supplied to a small anaerobic digester. The methane that is produced will be used to fuel the ethanol still. Ethanol would be used to fuel an engine-generator set or used as motor fuel. Under present regulations, a farm can produce up to 10,000 gallons of ethanol annually with only minimal paperwork. Because there is no additional transportation or drying costs, the economics of the on-farm system are much more favorable than those of a centralized plant. The system must be inexpensive and simple to operate. Because it is a closed-loop system, efficiencies of either the still or the generator are not of great concern. An inefficient conversion in one area will allow recapture of materials in another stage of the process. According to the 1997 USDA census of agriculture, the 14 states in the Northeast region have approximately 300,000 farms. If only 1% of these farms were to install the proposed still system, they would have the potential to create 30,000,000 gallons of ethanol annually, which could potentially generate 100,000 megawatt hours of electricity. While this is not an enormous amount of energy on a national scale, it can be very significant at a local small farm scale. The digester portion of the system makes a positive contribution in several areas. Biogas can fuel the still. It reduces odors and is a key component to reduce air and water pollution. It also offers opportunities to reduce the greenhouse gas emissions and, thus, the potential to trade methane and carbon credits (14). In addition to the energy production and reduction in greenhouse gases, this proposed system’s greatest potential benefit is increased profitability for a small farm. The subvention of grid purchased electricity and engine fuels will improve a small farm’s economic position. However, it cannot be emphasized too strongly that the intention is not to optimize production or efficiency in each specific area. For example, if the ethanol conversion efficiency is not optimal, the cows will have more energy in their feed. In the final analysis the system must be simple, inexpensive and easy to operate and maintain, or it will not get implemented. Therefore, the value of this proposed project is demonstration and assessment of a unique system for a small farm. Past research has largely ignored the needs of small farms and we believe the proposed integrated energy system can provide some interesting possibilities for the small farmer.
Biomass Feedstock Production in the Northeast: Economic and Environmental Implications.
PI: Tom Richard, Penn State University Collaborating Institutions: Michigan State, Cornell, USDA-ARS, Univ. Maryland - Eastern Shore $450,000.
The goal of this project is to assist landowners and land managers, their technical advisors, and policy developers in evaluating options for dramatically increasing the biomass productivity of landscapes in the Northeast Sun Grant region. The project will examine the economic and environmental impacts and opportunities from a range of feedstock production systems relevant to the Northeastern US, including utilization of crop residues, cover crops, and perennials from agricultural cropping systems; more intensive management of public and private forestlands; and dedicated perennial grass and silvicultural systems on underutilized, marginal, and reclaimed lands. It will conduct this integrated analysis at multiple scales, from farm to watershed (and biorefinery) to the Northeast region as a whole. At the farm-scale, the project will enhance, validate and pilot I-FARM, a free, web-based whole farm decision tool, and engage farmers, Natural Resource Conservation Service (NRCS) and Farm Services Administration (FSA) staff in integrating that tool with existing environmental and economic incentive programs. At all scales, the integrated analysis will be used to generate a scenarios that explore strengths, weaknesses, opportunities and threats relevant to the Northeastern US. Information developed through this project will be shared through stakeholder workshops, on-line internet resources, and policy briefs.