Progress 04/01/04 to 09/30/09

Outputs
OUTPUTS: OUTPUTS include: 1) presentations to public, political, and business/corporate leaders and visitors to project facilities, and at national meetings; 2) publications in scientific and popular media and WEB-based presentations; 3) intra- and extramural academic partnering ; 4) invitations and competitive presentations at national meetings such as the USDA BEAD II conference and an award therefrom for project novelty and impact; 5) presentations to increase awareness that the barriers to adoption of anaerobic digestion for production of renewable energy can be addressed through advanced science and public policy; 6) provision of testimony to the Ohio Senate committee on energy during their development of the Ohio Renewable Energy Policy by the Ohio Legislature which was passed a little over one year ago to provide Renewable Energy Standards to enable and stimulate biomass-based and other renewable energy projects in the state; 7) invited or opportunity-based direct discussion and consultation with industry leaders interested in renewable energy from biomass, or supply-chain providers for such industries in Ohio or nationally; 8) communication that comprehensive production of renewable energy requires integration of multiple technologies ranging from biomass processing to biomass conversion to fuels to conversion of bio-derived fuels to actual thermal, electrical, or motive energy, accomplished through presentations at meetings and also through direct demonstration of integrated systems for such at our biomass to energy research laboratory and facility. In addition support from and interaction with selected corporate partners allowed opportunity for mutual learning and evolution of concepts and systems to enhance and accelerate our ability to develop novel anaerobic digester systems or components, or to foster development and adoption of such by potential corporate adopters or business developers. Another important output is the documentation of the comprehensive financial value of biomass-based renewable energy systems which is determined from the monetary impact combined with the indirect environmental and social benefits of such projects which collectively can provide the overall economic basis for implementation of such projects, and allow political policy makers to justify incentive policies to stimulate such. The activities of this project have included analyzing results from the research experiments of the project and of pilot-scale anaerobic digestion trials conducted with corporate partners who provide anaerobic digestion equipment for prolonged (7-12 months)tests on the site of candidate adopters of the technology, to yield invaluable field-proven information about digester performance and also about the barriers and drivers for commercial adoption of anaerobic digestion for conversion of biomass to energy. Additional activities include a comprehensive survey of the biomass in Ohio for its type, distribution, suitability for conversion to energy via anaerobic digestion, and the potential yield of renewable energy from such (involving surveys and assessments. PARTICIPANTS: Floyd Schanbacher, PI and Diane Borger. Partner organizations providing supporting funding include the US Dept. of Energy who administered the grant for operating funds for most of this project, while the Ohio Third Frontier Program Wright Project award funded through the Ohio Department of Development provided capital funding for facility renovation and acquisition of the major equipment (pilot-scale anaerobic digesters, solid-oxide fuel cell, lab-scale fermentors for anaerobic digestion, and related supporting equipment). The Center for Innovative Food Processing (CIFT) provided additional support and expertise. TARGET AUDIENCES: Target audiences include academic partners, state and federal agencies, state and national public, potential technology adopters, state and federal political leadership and decision makers; commercial technology developers; agricultural and urban biomass producers, brokers, and utilizers. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
This project has contributed to the design, development, and installation of a pilot-scale facility for anaerobic digestion research that includes a novel fuel-versatile solid-oxide fuel cell to be operated on and demonstrate production of electricity with biogas from the pilot-scale anaerobic digesters of novel complete mix down-flow sand bed filter capable of high hydraulic throughput with very short retention times for high strength non-lignin biomass wastes such as from food processing plants, while retaining adapted bacterial biomass regardless of hydraulic flow rates. This is supported by lab-scale and drum- scale digesters that are fully automated for programmed feeding and effluent withdrawal of low-strength particulate or fibrous lignocelllulosic feedstocks or high strength non-lignin feedstocks. We have also developed a biogas processing system for programmed removal or remediation of hydrogen sulfide from biogas at pilot-scale. Collateral work by colleagues (under USDOE funding) has developed metagenomic libraries for anaerobic bacteria of anaerobic digesters operating on livestock or food processing biomass wastes as feedstocks. This genomic capability will soon allow characterization of the microbial population dynamics and metabolic flux in response to feedstock or operating conditions, testable at lab or pilot scale. This project has also contributed to the collaborative study and definition of Ohios biomass resources by defining its geographic distribution, type, potential energy yield, and potential economic impact. These efforts at the research level together with direct involvement of the PI with potential adopters of anaerobic digestion in Ohio have stimulated the installation and operation of commercial-scale anaerobic digesters on a large dairy farm and a large egg farm, the first two anaerobic digesters operating on livestock or poultry wastes in Ohio. Further activity is underway with additional commercial-scale digesters planned for livestock farms and food processing plants. The PI has participated in preparation of consortium grant applications with multiple business and technology partners to develop and implement commercial-scale integrated anaerobic digestion systems for converting waste agricultural, food processing, or municipal solid waste biomass to energy, without competing for food production capacity. The PI provided testimony for production of renewable energy by anaerobic digestion of waste biomass in the Ohio Senate Energy Committees hearing for introduction of the legislative bill for a Renewable Enregy Portfolio Standard (REPS) for Ohio, with the final REPS bill including incentives for renewable energy produced from biomass in Ohio. Research collaboration of this project has focused on enhanced sensors and controls for remote predictive monitoring of anaerobic digestion and integrated systems to convert biomass to renewable energy with a minimum of local operator training and time and minimized risk of failure through prediction and autoremediation of impending failure to prevent failure and assure optimal digester operation and energy yields.

Publications

• No publications reported this period

Progress 01/01/08 to 12/31/08

Outputs
OUTPUTS: Outputs have included: 1)numerous presentations to visitors (state and federal officials, stakeholders, commercial adopters, and academics peers) to the Biomass to Energy Research Facility established through this program, with handouts describing and illustrating the program and its objectives; 2) invited presentations at national and regional meetings; 3) participation in national program reviews (USDOE & USDA) for biomass utilization and renewable energy; 4) nationally competitive award to our program for its relation to the emerging USDA Biomass to Energy agenda, with an invited poster presentation in Washington DC; 5) display of the program's concept, objectives, and approach at the USDA BEAD II Conference, with attendance by Congressional staff, USDA and USDOE officials, and the public; 6) countless consultations with potential adopters or supply chain manufacturers for biomass to energy sytems and equipment, and for power conversion from biogas to electricity. PARTICIPANTS: Start-up operation of the pilot-scale anaerobic digesters for high-strength wastes was done with dairy whey as feedstock to identify operational problems and limits to either digester. We have found operational faults typical for new equipment designs or scales, and have corrected most. A key limit has been the integrated biogas analyzer that measures flow rate and composition (%CH4, %CO2) of biogas. The fault was identified as due to failure of the biogas chillers necessary to remove moisture prior to compositional analysis by solid-state NIR analyzers; the chillers were replaced. An additional fault was found with the sand management system which depends on an internal rotating bearing that cannot be adjusted correctly without a confined space entry, for which the facility operator will soon undergo training. The pilot-scale digesters have been operating continuously despite fault states to show resilience and robustness of the anaerobic digestion itself. We have begun analysis of the bacterial populations and species in the pilot- and lab-scale anaerobic digesters. We have modified the lab-scale anaerobic digesters to enable continuous feeding, and have arranged with a corporate partner to develop a novel interval feeding system by means of a large-bore low speed pump capable of automaic timed operation for feeding, sampling, or withdrawal of spent digesta. We have upgraded software for both lab- and pilot-scale digester systems to provide more reliable operational control, monitoring, and data acquisition. We have designed a novel sampling port for lab-scale digesters that will allow multiple samples at close intervals for prolonged periods in order to develop the kinetics for digester response after feeding. Collaboration established with process monitoring scientists has developed modeling of digester response to feeding by close interval measurement of volatile fatty acid concentrations, biogas yield and composition, utilization of feedstock (glucose as first model), & pH profile across feeding episodes. This modeling not only predicts the biochemical events surrounding feeding, but also defines the general microbial population in response to feeding. THis model will continue to be refined to allow more definitive analysis of digester response and biogas yield from model or candidate feedstocks. To do so, we will increase our digester test regimen to include feeding of starch and cellulose as the sole nutrient sources, thus separating the kinetics of hydrolysis from metabolism and methanogenesis. Colleagues have begun to define the anaerobic microbial speciation and its dynamics in various digester samples taken from digesters operating on model feedstocks. This will be expanded with more definitive characterization of the microbial speciation through high-throughput microbial genomics analyses. TARGET AUDIENCES: Academic partners, state and national public, potential technology adopters, commercial technology developers, and state and federal agencies. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
THis program's efforts have resulted in installation and operation of the first two anaerobic digesters in Ohio operating on livestock or poultry wastes. The PI has contributed to substantial ongoing advise, estimations, and planning for additional candidate adopters of anaerobic digestion of livestock and food processing wastes. He has also participated in preparation of consortium grant applications with multiple business and technology partners to develop and implement commercial scale integrated systems for converting biomass to energy, with special focus on use of waste biomass (both agricultural and landfill) that does not compete for food production capacity. The PI has testified before State of Ohio Legislative hearings on proposed legislation to establish a Renewable Portfolio Standard for Ohio, and particularly for how biomass-derived renewable energy fits the national and state needs. In addition, this program has established novel alliances and partnerships with industrial and emerging technology developers able to improve the rate, efficiency, reliability, versatility, and resilience of anaerobic digestion of diverse biomass as feedstocks. This offers prospects to develop novel sensors and controls to decrease the operator training, skill, and time required for system operation; to allow remote monitoring and fault remediation of the system; and more versatile and scalable anaerobic digesters and power conversion systems.

Publications

• 1. Yu Z, Garcia-Gonzalez R, Schanbacher FL, and Morrison M. 2008. Evaluations of different hypervariable regions of archaeal 16S rRNA genes in profiling of methanogens by Archaea-specific PCR and denaturing gradient gel electrophoresis. Applied and environmental microbiology 74(3):889-93 (2008 Feb)

Progress 01/01/07 to 12/31/07

Outputs
OUTPUTS: Installation of two 1600 gallon sub-pilot complete mix down-flow anaerobic digesters has been completed at the Biomass to Energy Center at OARDC-Wooster. Biogas yield from various biomass waste streams are being quantified within these units. Trials have been initiated to investigate microbial population changes resulting from variable substrate feeds with constant real time analysis of volatile fatty acids, acetagene, and methagene populations. Three 5 liter lab scale digesters were used to compare yield and composition of biogas by different microbial populations in the presence of various substrates including whey permeate, glucose, and corn starch. Microbial sampling of digesta for genomic analysis of populations has been initiated. This project is a joint venture of universities, industry, and government agencies. Discoveries from this project are presented as lectures, scientific meeting presentations, press releases, and peer-reviewed journal articles. Results of trials and knowledge gained are disseminated by direct communication of proprietary information to industry partners. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
Construction of the sub-pilot digesters allows for empirical development of strategies to maximize conversion of bioderived carbon to fuel and energy. This project provides direct evidence that the biomass to energy technology is scalable to allow facilities of various capacities and needs.

Publications

• No publications reported this period

Progress 01/01/06 to 12/31/06

Outputs
Technologies for conversion of biomass to renewable energy range from biological to thermochemical, with Anaerobic Digestion (AnDig) being among the best suited for converting wet or wettable biomass to renewable fuel which can be converted to thermal or electrical energy. This project focuses on anaerobic digestion for converting multiple wet/wettable biomass types to renewable energy as the foundation for a renewable energy strategy that integrates biological and thermochemical technologies able to convert any biomass or residuals to renewable energy. Objectives include optimization of AnDig for high-strength biomass feedstocks for maximum methane content and yield with minimum contaminants (hydrogen sulfide, ammonia) Typical AnDig feedstocks tested include food processing wastes from a potato/corn chip snack food manufacturer with or without inclusion of high-fat wastes, dairy wastes, or livestock (dairy) manures. We have developed small-scale (lab-scale; 5L liq capacity ea) digester systems with feedpumps capable of reliable pumping of highly viscous non-Newtonian hydrated feedstocks (8.5%TS) with non-plugging valving to allow interval or continuous feeding of the digester for prolonged steady-state AnDig studies. We have successfully pumped corn/potato chip wastes and dairy manure wastes in these lab-scale systems to achieve long-term (>40days) steady-state AnDig operation. Analysis of the biogas yield and composition indicates suboptimal methane yield but relatively good biogas methane content(50->60% CH4) We have developed a simple valve system that can be automated to allow near-continuous interval feeding of viscous food processing biomass waste feedstocks, with several days of feeding possible from a single batch of feedstock; feeding of prepared biomass feedstock does not require refrigeration for storage up to 3-4 days before entering the digester, with such storage not appearing detrimental to biogas yield, composition, or quality. A main thrust is to develop lab-scale AnDig systems capable of reliable operation with continuous or near-continuous feeding to simulate steady-state operation of commercial scale anaerobic digesters, and to complement our studies with AnDig in complete mix drum-digesters(55gal ea), complete mix down-flow filter anaerobic digesters at sub-pilot research scale (2 x 1600 gal ea), and a mobile pilot-scale (1 x 8000 gal) digester, all in a dedicated lab and pilot facility. This facility includes a 1 kW solid-oxide fuel cell (SOFC) to be operated on anaerobic digester biogas to test and verify operation of the fuel cell on biogas with varying levels of methane and contaminants determined by feedstock combinations or composition, or digester operating conditions. Fabrication of the drum- and research-scale anaerobic digesters are underway, and fabrication of the SOFC is near complete. These facilities will allow studies of steady-state anaerobic digestion at multiple scales, with novel anaerobic digesters capable of retention of microbial populations at high-throughput and with high strength wastes for the study of anaerobic microbial population dynamics and metabolomics.

Impacts
This program and its facilities is aimed to contribute to the capacity to utilize wet or wettable biomass for biological conversion to fuels to meet at least 15% of petroleum energy needs by 2020, but with the novel prospect of demonstrating utility of using a novel solid-oxide fuel cell to utilize both biologically and thermochemically derived liquid or gaseous fuel products from biomass for renewable energy production. Further, this will allow near-complete utilization of bioderived carbon for fuel and energy production, regardless of whether it is from wet or dry biomass. Importantly, this integrated technology approach is scalable to allow installation at both large and small scale facilities in rural or urban areas. Successful implementation of this program strategy will also provide distributed generation of electricity and draw on clean-coal technologies for optimizing energy yield from refractory or complex biomass resources without damaging the environment. In such a scenario, agriculture becomes a realistic producer of renewable energy and energy systems for rural-urban needs. Most of Ohio's residential electricity needs could be produced from biomass from by such systems, and could complement both wind and solar energy strategies and technologies.

Publications

• Schanbacher, FL. Perspectives on Anaerobic Digestion of Livestock and Food Processing Biomass Wastes for Waste Remediation and Renewable Energy. Proceedings XX PanAmerican Congress of Veterinary Sciences and 14th Chilean Congress of Veterinary Medicine, Santiago, Chile/Univ. Chile-Santiago. Nov. 14, 2006.

Progress 01/01/05 to 12/31/05

Outputs
Anaerobic digestion of livestock manures, to produce sufficient methane for limited heating and electrical generation is an established technology. Unfortunately, the cost of the system and the typical biogas composition of approximately 60% methane and 35% carbon dioxide compromise economic returns from power generation in comparison systems using fossil fuels. Biodigestion with manure as the sole feedstock is generally a low-yield stable process, whereas high-strength food waste feedstocks with their higher energy potential often result in unstable biodigestions which fail to produce reliable biogas. A better understanding of bioprocesses associated with the anaerobic digestion of high-energy food wastes would provide a basis for anaerobic digestions of manure-food waste combination feedstocks that can improve biogas yield and composition. We describe here preliminary studies of anaerobic digestion of food processing waste and livestock manure feedstocks in laboratory-scale digesters that were either static or stirred with controlled pH and in a pilot-scale anaerobic digester to identify variables able to enhance biogas yield or quality. Experimental variables included feedstock types, inoculating cultures, buffering agents, and mineral supplementation. Feedstocks used individually or in combinations included dairy cattle manure, corn and potato based snack foods, and corn silage. Inoculating cultures included manure, rumen fluid, and sludge from a food waste anaerobic digester. In static digesters, even when buffered with MgO, NH4HCO3, and NaHCO3, vessel pH was dramatically decreased between 24 and 48 hr in association with volatile fatty acid production. In static digesters, manures declined in pH from near 8 to approximately 6 while the food waste digestions showed a pH decline to 4 or lower. As expected, the initial biogas produced was nearly 100% CO2. After pH adjustment to neutrality with NaOH, production and composition of biogas was dependent on the feedstock and starter culture. Neutralized post-acidification digestions with manure feedstocks produced 60% - 83% CH4 and 12% - 18% CO2. The composition of biogas from neutralized post-acidification food wastes was influenced by the type of inoculating culture; digestions inoculated with digester sludge organisms produced typical biogas composed of 60 to70% CH4 while those inoculated with rumen fluid organisms produced biogas with 40 - 75% H2, little or no CH4, and 10% - 40% CO2. Digestion of food processing wastes in stirred digesters with continuous control to pH 7.4 produced biogas with 20% - 75% CH4 within 48 hr. Digester sludge was the most effective starter culture. Addition of trace minerals and or associated altered start-up conditions in stirred and pH controlled digestions of food waste nearly doubled gas production. A pilot-scale (8,000 gallons) anaerobic digester optimized for high-strength food processing wastes (NewBio LLC) gave sustained biogas production with 76.0 +/-0.7% CH4 and 19.7 +/- 0.4% CO2 when continuously-fed with mixed snack food wastes buffered with MgOH.

Impacts
Estimates have been made that by the year 2020 up to 15% of petroleum energy could be replaced by biogas generated from biomass. It has been suggested that production of energy rich crops for biogas production may be feasible. An added advantage of producing energy in closed anaerobic digestion systems is the reduction of atmospheric emissions of ammonia, methane, and fossil fuel based carbon dioxide. To be competitive with petroleum based fuels, the efficiencies of biodigesters must be improved and it is advantageous for digesters to be able to utilize a wide variety of feedstocks.

Publications

• Willett, L. B., D. C. Borger, and D.L. Elwell. 2005. Concentrations of malodorous chemicals from manures as influenced by aging and composting. Proc. 2005 Animal Waste Management Symposium pp 294-304. Research Triangle Park, NC. Oct. 5-7. Abstract p 48
• Schanbacher, F.L., L.B. Willett, D. C. Borger, R. L. Neiswander, and M. Gratz. 2005. Bioprocesses associated with anaerobic digestion of manures and food wastes for the production of biogas. Proc. 2005 Animal Waste Management Symposium pp 317-328. Research Triangle Park, NC. Oct. 5-7. Abstract p 50

Progress 01/01/04 to 12/31/04

Outputs
Anaerobic digestion of livestock manures, to produce sufficient methane for limited heating and electrical generation, is an established technology. Unfortunately, typical biogas compositions of approximately 60% methane and 35% carbon dioxide yield marginal returns when compared to fossil fuels. Whereas, biodigestion with manure as the sole feedstock is generally a low-yield stable process, high-energy potential food wastes often result in unstable processes which fail to produce reliable biogas. A better understanding of bioprocesses associated with the anaerobic digestion of high-energy food wastes should have the potential for manure-food waste combinations that can improve biogas quantities and composition. A series of preliminary studies has been conducted with laboratory static and stirred-controlled digesters as well as pilot-scale anaerobic digesters, to identify variables that can enhance biogas production. Experimental variables have included feedstocks, inoculating cultures, buffering agents, and mineral supplementation. Feedstocks used included dairy cattle manure, corn and potato based snack foods, and corn silage. Inoculating cultures have included manure, rumen fluid, and sludge from a food waste biodigester. In static digesters, even when buffered with MgO, NH4HCO3, and NaHCO3, vessel pH dropped rapidly between 24 and 48 hr associated with the production of volatile fatty acids. In static models, pH of manures declined from values near 8 to approximately 6 while the food wastes declined to pH 4 or lower. As expected, initial biogas composition was nearly 100% CO2. Following pH adjustment with NaOH, production and composition of biogas was dependent on the feedstock and starter culture. Manures readily produced 60 to 83% CH4 and 12 to 18% CO2. Biogas composition of food wastes was influenced by the source of inoculating culture. Digester sludge organisms produced typical biogas containing 60 to70% CH4 while rumen fluid organisms produced biogas that was 40 to 75% H2, little or no CH4, and 10 to 40% CO2. Digestion of food waste, in stirred digesters where the pH was controlled at 7.4, produced biogas with 20 to 75% CH4 within 48 hr. Digester sludge was the most effective starter culture. Addition of trace minerals Ca, Mg, Fe, Ni, Co, Zn, Mn, and Mo in stirred and controlled digestions of food waste increased gas production up to five-fold. Mixed snack food waste, buffered with MgOH, was able to maintain sustainable biogas production with 76.0+/-0.7% CH4 and 19.7+/-0.4% CO2 with pilot-scale conditions.

Impacts
Estimates have been made that by the year 2020 up to 15% of petroleum energy could be replaced by biogas generated from biomass. It has been suggested that production of energy rich crops for biogas production may be feasible. An added advantage of producing energy in closed anaerobic digestion systems is the reduction of atmospheric emissions of ammonia, methane, and fossil fuel based carbon dioxide. To be competitive with petroleum based fuels, the efficiencies of biodigesters must be improved and it is advantageous for digesters to be able to utilize a wide variety of feedstocks.

Publications

• None 2004