@article{hossain_jones_godfrey_saloni_sharara_hartley_2024, title={Characterizing value-added pellets obtained from blends of miscanthus, corn stover, and switchgrass}, volume={227}, ISSN={["1879-0682"]}, url={https://doi.org/10.1016/j.renene.2024.120494}, DOI={10.1016/j.renene.2024.120494}, abstractNote={The current pellet industry primarily relies on woody biomass. Inclusion of a diverse feedstock, such as herbaceous biomass, is necessary to meet the rising demand for pellets in heat and power generation, and for biofuel production. This study was motivated by the need to densify biomass, improving its naturally low energy density, to reach the required pellet standards for biofuel conversion. We developed value-added miscanthus pellets blended with different ratios of corn stover and switchgrass and analyzed their chemical, physical, and mechanical properties. Pure miscanthus pellet durability index (PDI) was less than 85%, well below the ISO 17225-6 standard for herbaceous pellets. While increasing switchgrass and corn stover ratios increases durability beyond 94%, it also increases ash content from 1.6% to 4.6%, a quality unfavorable for biofuel conversion. The moisture content of the blended pellets varied from 7.12% to 12.45%, and positively correlated with the durability of the pellets. Pure miscanthus pellets had the highest bulk density, 633 kg/m3, while pellets containing 75% miscanthus and 25% corn stover had the lowest density, 564 kg/m3. The findings of this study also identified a decrease in the pellet bulk density with the increase in ash content and pellet diameter.}, journal={RENEWABLE ENERGY}, author={Hossain, Tasmin and Jones, Daniela S. and Godfrey, Edward and Saloni, Daniel and Sharara, Mahmoud and Hartley, Damon S.}, year={2024}, month={Jun} }
@article{miller_kulesza_gatiboni_hardy_sharara_2024, title={Implications of current soil phosphorus levels for manureshed analysis in North Carolina}, volume={5}, ISSN={["1435-0661"]}, url={https://doi.org/10.1002/saj2.20694}, DOI={10.1002/saj2.20694}, abstractNote={Abstract Manure relocation strategies are needed to mitigate excessive phosphorus (P) application to agricultural land in areas of intensive animal agricultural production. This requires conceptual frameworks such as the manureshed, which categorizes agricultural areas according to the potential to export or receive manure for P fertilization. To further understand how the manureshed concept could be utilized, assessments of the potential implementation and necessity of the manureshed model are needed. With North Carolina at the center of the largest manureshed in the United States, North Carolina is an ideal test case to identify areas of concern for manure relocation under the manureshed framework. Swine and poultry dominate North Carolina's agricultural production, and because the vast majority of North Carolina producers are not required to limit manure applications to a P‐based rate, P accumulates. Therefore, soil test data from samples submitted to the North Carolina Department of Agriculture and Consumer Services (NCDA&CS) from 2017 to 2019 were used to determine how manureshed classes defined by Spiegal et al. correspond to current soil test P levels. It was determined that 36% of counties experience very high (>100 mg P kg −1 ; N = 36) median P concentrations in soil. Furthermore, fields cultivated with warm‐season forages had the highest mean P concentration (188 mg kg −1 ) and high median P trended toward counties with high animal production. Lastly, while mean soil P for all manureshed classifications fell into the very high category, manure source counties had the highest mean soil P concentrations (188 mg kg −1 ), which was 39%–52% higher than the other classifications. This suggests that, in addition to manuresheds classification, soil test data are needed to design and promote manure redistribution strategies.}, journal={SOIL SCIENCE SOCIETY OF AMERICA JOURNAL}, author={Miller, Steven and Kulesza, Stephanie and Gatiboni, Luciano and Hardy, David and Sharara, Mahmoud}, year={2024}, month={May} }
@article{huezo_jones_edwards_sharara_2024, title={Manure nutrient cycling in US animal agriculture basins-North Carolina case study}, volume={2}, ISSN={["1537-2537"]}, url={https://doi.org/10.1002/jeq2.20545}, DOI={10.1002/jeq2.20545}, abstractNote={Abstract}, journal={JOURNAL OF ENVIRONMENTAL QUALITY}, author={Huezo, Luis and Jones, Daniela and Edwards, Eric and Sharara, Mahmoud}, year={2024}, month={Feb} }
@article{hossain_jones_godfrey iii_saloni_sharara_hartley_2024, title={Nth-plant scenario for blended pellets of Miscanthus, Switchgrass, and Corn Stover using multi-modal transportation: Biorefineries and depots in the contiguous US}, volume={183}, ISSN={["1873-2909"]}, url={https://doi.org/10.1016/j.biombioe.2024.107162}, DOI={10.1016/j.biombioe.2024.107162}, abstractNote={The sustainability of the biofuel industry depends on the development of a mature conversion technology on a national level that can take advantage of the economies of scale: the nth-plant. This study addresses the logistic challenge of mobilizing national cellulosic feedstock supplies for a sustainable bioenergy industry. A Mixed Integer Linear Programming (MILP) model was developed and updated to deliver on-spec biomass that considers both a desired quantity and quality at the biorefinery. Our supply chain analysis includes multi-modal transport (truck and rail), varying depot and biorefinery sizes, and feedstock blends of corn stover (harvested by either a two- or three-pass method), switchgrass, and miscanthus. The following US states: Illinois, Kansas, Missouri, North Carolina, Oklahoma, Georgia, and Texas were identified as key locations for producing accessible miscanthus. Based on our most optimistic scenario, using trucks as the only transportation mode in 2040 with a cost target of $79/dt, corn stover, switchgrass, and miscanthus could help meet 48% of the EPA target, 173 million dry tons that translate into 7.8 billion GGE. The addition of rail transportation for biomass delivery to biorefineries could help meet 79% of the EPA target, 283 million dry tons that translate into 12.7 billion GGE.}, journal={BIOMASS & BIOENERGY}, author={Hossain, Tasmin and Jones, Daniela S. and Godfrey III, Edward and Saloni, Daniel and Sharara, Mahmoud and Hartley, Damon S.}, year={2024}, month={Apr} }
@article{patil_sharara_shah_kulesza_classen_2023, title={Impacts of utilizing swine lagoon sludge as a composting ingredient}, volume={327}, ISSN={0301-4797}, url={http://dx.doi.org/10.1016/j.jenvman.2022.116840}, DOI={10.1016/j.jenvman.2022.116840}, abstractNote={Lagoon sludge, a byproduct of swine operations in the Southeast United States, poses a management challenge due to its high mineral and metal content. Composting is a low-cost, scalable technology for manure management. However, limited information is available on composting swine lagoon sludge in terms of recipes, greenhouse gas emissions and end-product quality. Moreover, due to its high Zn and Cu content, high inclusion of sludge in composting recipes can potentially inhibit the process. To address these knowledge gaps, in-vessel aerated composting (0.4 m3each) was carried out to evaluate impacts of sludge inclusion, at 10% (Low Sludge, LS-Recipe) and 20% (High sludge, HS-Recipe) wet mass-basis, on composting process and end-product quality. Comparable maximum temperatures (74 ± 2.7 °C, 74.9 ± 2.9 °C), and organic matter loss were observed in both recipes. Similarly, sludge inclusion ratio had no significant impact on cumulative GHG emissions. The global warming potential (20-year GWP) for swine lagoon sludge composting using LS and HS recipes was observed to be 241.9 (±13.3) and 229.9 (±8.7) kg CO2-e/tDM respectively. Both recipes lost 24–28% of initial carbon (C) and 4–15% of nitrogen (N) respectively. Composting and curing did not change water-extractable (WE) phosphorus (P) concentrations while WE Zn and Cu concentrations decreased by 67–74% and 55–59% respectively in both recipes. End compost was stable (respiration rates <2 mgCO2-C/g OM/day) with germination index >93 for both recipes.}, journal={Journal of Environmental Management}, publisher={Elsevier BV}, author={Patil, Piyush and Sharara, Mahmoud and Shah, Sanjay and Kulesza, Stephanie and Classen, John}, year={2023}, month={Feb}, pages={116840} }
@misc{sharara_kolesch_cortus_larson_classen_janni_2022, title={ADDRESSING NUTRIENT IMBALANCES IN ANIMAL AGRICULTURE SYSTEMS}, volume={65}, ISSN={["2769-3287"]}, DOI={10.13031/ja.14661}, abstractNote={Highlights}, number={2}, journal={JOURNAL OF THE ASABE}, author={Sharara, Mahmoud and Kolesch, Richard K. and Cortus, Erin L. and Larson, Rebecca A. and Classen, John J. and Janni, Kevin A.}, year={2022}, pages={235–249} }
@misc{graves_kolar_shah_grimes_sharara_2022, title={Can Biochar Improve the Sustainability of Animal Production?}, volume={12}, ISSN={["2076-3417"]}, url={https://www.mdpi.com/2076-3417/12/10/5042}, DOI={10.3390/app12105042}, abstractNote={Animal production is a significant contributor of organic and inorganic contaminants in air, soil, and water systems. These pollutants are present beginning in animal houses and impacts continue through manure storage, treatment, and land application. As the industry is expected to expand, there is still a lack of affordable, sustainable solutions to many environmental concerns in animal production. Biochar is a low-cost, sustainable biomaterial with many environmental remediation applications. Its physicochemical properties have been proven to provide environmental benefits via the adsorption of organic and inorganic contaminants, promote plant growth, improve soil quality, and provide a form of carbon sequestration. For these reasons, biochar has been researched regarding biochar production, and application methods to biological systems have a significant influence on the moisture content, pH, microbial communities, and carbon and nitrogen retention. There remain unanswered questions about how we can manipulate biochar via physical and chemical activation methods to enhance the performance for specific applications. This review article addresses the positive and negative impacts of biochar addition at various stages in animal production from feed intake to manure land application.}, number={10}, journal={APPLIED SCIENCES-BASEL}, author={Graves, Carly and Kolar, Praveen and Shah, Sanjay and Grimes, Jesse and Sharara, Mahmoud}, year={2022}, month={May} }
@article{patil_sharara_2022, title={Impacts of sonication on biomethane potential (BMP) and degradation kinetics of pig lagoon sludge}, volume={223}, ISSN={["1537-5129"]}, url={https://doi.org/10.1016/j.biosystemseng.2022.08.008}, DOI={10.1016/j.biosystemseng.2022.08.008}, abstractNote={Lagoon sludge is a by-product of pig production in North Carolina. Sludge contains nutrients, minerals, and cellular biomass. Sustainable management of sludge is crucial to avoid accumulation impacts on lagoon performance. This study investigated sonication as a potential pre-treatment for sludge. The impact of sonication on sludge bio-methane potential and degradation kinetics was evaluated. At sonication energy dosage of 20,400 kJ.kgTS−1, the dissolved total carbon (DOC) and soluble chemical oxygen demand (SCOD) increased from 446 to 1055 mg L−1 and from 2297 to 9239 mgO2L−1, respectively. In the bio-methane potential (BMP) study, cumulative biogas and bio-methane yield increased from 21.0 to 28.4 mLbiogas.gVS−1 and from 15.0 to 21.3 mLCH4.gVS−1 due to sonication. Sonicated sludge reached 95% of its experimental biomethane yield more than 10 days earlier compared to raw sludge. The first order kinetics equation showed the highest co-efficient of determination (R2) and least root mean square error (RMSE) when fitted to raw sludge bio-methane production, while transference model was the best fit for sonicated sludge bio-methane production. The transference model substantially overestimated the maximum gas production rate for sonicated sludge. A significantly higher hydrolysis constant (p-value < 0.05) was observed for sonicated sludge (0.6 day−1) in comparison to raw sludge (0.08 day−1). Findings suggest sonication is a promising tool to aid organic matter and nutrient fractionation, and energy recovery pathway but the high energy inputs are still a barrier.}, journal={BIOSYSTEMS ENGINEERING}, author={Patil, Piyush S. and Sharara, Mahmoud A.}, year={2022}, month={Nov}, pages={129–137} }
@article{montefiore_nelson_dean_sharara_2022, title={Reconstructing the historical expansion of industrial swine production from Landsat imagery}, volume={12}, ISSN={["2045-2322"]}, DOI={10.1038/s41598-022-05789-5}, abstractNote={Abstract}, number={1}, journal={SCIENTIFIC REPORTS}, author={Montefiore, Lise R. and Nelson, Natalie G. and Dean, Amanda and Sharara, Mahmoud}, year={2022}, month={Feb} }
@article{harris_fidan_nelson_emanuel_jass_kathariou_niedermeyer_sharara_reyes_riveros-iregui_et al._2021, title={Microbial Contamination in Environmental Waters of Rural and Agriculturally-Dominated Landscapes Following Hurricane Florence}, volume={1}, ISSN={["2690-0637"]}, url={https://doi.org/10.1021/acsestwater.1c00103}, DOI={10.1021/acsestwater.1c00103}, abstractNote={Hurricane Florence brought unprecedented rainfall and flooding to Eastern North Carolina in 2018. Extensive flooding had the potential to mobilize microbial contaminants from a variety of sources. Our study evaluated microbial contaminants in surface waters at 40 sites across Eastern North Carolina 1 week after the hurricane made landfall (Phase 1) and one month later (Phase 2). High concentrations of Escherichia coli were detected in flowing channel and floodwater samples across both phases; however, channel samples during Phase 2 had higher concentrations of E. coli compared to Phase 1. Human- and swine-associated fecal markers were detected in 26% and 9% of samples, respectively, with no trends related to phase of sampling. Arcobacter butzleri was previously shown to be recovered from most (73%) samples, and detection of this pathogen was not associated with any source-associated fecal marker. Detection of Listeria spp. was associated with the swine-associated fecal marker. These results suggest that improved swine and human feces management should be explored to prevent microbial contamination in surface water, especially in regions where extreme rainfall may increase due to climate change. Sampling at higher frequency surrounding rainfall events would provide more detailed characterization of the risks posed by floodwater at different time scales and under different antecedent conditions.}, number={9}, journal={ACS ES&T WATER}, publisher={American Chemical Society (ACS)}, author={Harris, Angela R. and Fidan, Emine N. and Nelson, Natalie G. and Emanuel, Ryan E. and Jass, Theo and Kathariou, Sophia and Niedermeyer, Jeffrey and Sharara, Mahmoud and Reyes, Francis Lajara, III and Riveros-Iregui, Diego A. and et al.}, year={2021}, month={Sep}, pages={2012–2019} }
@article{patil_sharara_2020, title={Evaluating anaerobic digestion kinetics for swine manure using BMP assay tests}, DOI={10.13031/aim.202000358}, abstractNote={Abstract. Anaerobic digestion (AD) is increasingly being adopted to reduce swine manure gaseous emissions and to generate a renewable fuel stream. Assessing the ultimate biomethane potential (BMP) of swine manure is a key step to evaluate its potential as anaerobic digestion feedstock. A reliable and reproducible assay is essential for optimizing process design and to estimate greenhouse gas (GHG) emission or mitigation potential. The objectives of the current study are, a) determine BMP of swine manure solids (RM), b) model reaction kinetics for the RM digestion process, and c) assess the effect of blending pretreatment on BMP of swine manure. Three BMP assays were conducted, two with microcrystalline cellulose (MC) alone as a substrate along with blanks, and one with MC, RM and blended manure (BM) and blanks. The observed biogas yields for MC and RM were in the range 571 â 628 mLBiogas and 601 to 625 mLBiogas per gram of volatile solids (g VS). These values were higher compared to the biogas yields reported in the literature. Comparing the experimental biogas yield for RM and BM indicated no significant difference due to the blending. However, it was observed that logistic and gompertz model provided a better prediction of ultimate biogas yield for BM and RM, MC respectively. The best replicates identified via cross validation of reaction kinetics predicted an ultimate biogas yield of 535-682 mLBiogas/gVS (R2: 0.98-0.99, RMSE:12.94-27.60), 683 mLBiogas/gVS (R2: 0.99, RMSE:9.20), 588 mLBiogas/gVS (R2: 0.99, RMSE:11.79) for MC, RM and BM respectively. The confirmation of assays reliability and repeatability could not be assessed due to facility shutdown as a result of COVID-19 outbreak.}, journal={2020 ASABE Annual International Virtual Meeting, July 13-15, 2020}, publisher={American Society of Agricultural and Biological Engineers}, author={Patil, Piyush S and Sharara, Mahmoud A}, year={2020} }
@article{sharara_owusu-twum_runge_larson_2020, title={Planning methodology for anaerobic digestion systems on animal production facilities under uncertainty}, volume={104}, ISSN={["1879-2456"]}, DOI={10.1016/j.wasman.2020.01.028}, abstractNote={Anaerobic digestion (AD) reduces GHG emission and facilitates renewable energy generation. The slow rate of adoption of this technology is often attributed to economic and technical considerations. Collaboration of two or more dairy farms into a centralized AD system can improve the process economics through economies of scale. However, uncertainties related to the process parameters and the scope/scale of the collaborative implementation impede its adoption. This study presents techno-economic optimization model as a design aid to determine ideal location, capacity, and participation level (cluster size) that maximize economic return on a cooperative digester. This study employs a probabilistic approach to overcome uncertainty regarding project parameters such as manure biomethane potential (BMP), project capital, and electricity sale price. Two case studies based on dairy production regions in Wisconsin were developed to test the model and demonstrate its capabilities. Herd sizes and spatial distribution in a given region were found to be critical factors in determining the viability of digestion projects in general, and collaborative digestion systems in particular. The number of simulation runs needed to capture the probability of profitable AD facility establishment was less than 1000 for both case studies assessed. Electricity sale price and biomethane potential of feedstock utilized were found to be the most restrictive to the feasibility of AD adoption. Changing the optimization objective function, to adopting maximization, favored the formation of collaborative AD facilities for both case studies evaluated.}, journal={WASTE MANAGEMENT}, author={Sharara, Mahmoud A. and Owusu-Twum, Maxwell Y. and Runge, Troy M. and Larson, Rebecca}, year={2020}, month={Mar}, pages={262–269} }
@misc{owusu-twum_sharara_2020, title={Sludge management in anaerobic swine lagoons: A review}, volume={271}, ISSN={["1095-8630"]}, DOI={10.1016/j.jenvman.2020.110949}, abstractNote={Sludge is nutrient and mineral rich residue of anaerobic treatment that is often utilized as a fertilizer. Sludge management is crucial to maintain the function of anaerobic treatment lagoons and ensure efficient nutrient utilization. Intensive livestock production has resulted in accumulation of sludge residue in regions where nutrients are in surplus. This situation adversely impacts the sustainability of livestock production. Alternative uses of sludge needs to be developed and adopted to reduce the negative impacts associated with the nutrients accumulation on farms and nearby crop fields. A thorough understanding of sludge composition is necessary to identify appropriate end use. This review explores swine lagoon sludge (SLS) in relation to its composition, sampling techniques, management approaches, fertilizer value, challenges and opportunities for further development.}, journal={JOURNAL OF ENVIRONMENTAL MANAGEMENT}, author={Owusu-Twum, Maxwell Y. and Sharara, Mahmoud A.}, year={2020}, month={Oct} }
@article{deviney_classen_bruce_sharara_2020, title={Sustainable Swine Manure Management: A Tale of Two Agreements}, volume={13}, ISSN={2071-1050}, url={http://dx.doi.org/10.3390/su13010015}, DOI={10.3390/su13010015}, abstractNote={Intensification and concentration of swine farming has provided economic benefit to rural communities but also negative environmental and human health impacts, particularly from the use of the lagoon-sprayfield system for manure management. Although cost effective, this system is susceptible to poor management, unpleasant odor and other emissions, and inundation during extreme weather events. Competition for manure-spreading acres with other livestock or encroaching development can also pose a problem. This study examines two agreements between industry and government designed to develop and implement improved manure management technologies for swine farms: a voluntary agreement between the attorney general of North Carolina and Smithfield Foods and a consent judgment between the State of Missouri and Premium Standard Farms. Individuals involved in executing these agreements were interviewed to gain insight from their perspective on those processes and lessons they learned from their experience. Common themes among participant responses to support transition processes included the need to involve multiple stakeholder groups, clearly define goals, understand the system, allow time for incremental change, and provide adequate “protected space” for technology development and implementation. Viewing these themes through the lens of multi-level perspective theory identifies leverage points throughout the system to support transitioning farms to a more sustainable path of manure management.}, number={1}, journal={Sustainability}, publisher={MDPI AG}, author={Deviney, Alison and Classen, John and Bruce, Jackie and Sharara, Mahmoud}, year={2020}, month={Dec}, pages={15} }
@article{sharara_sahoo_reddy_kim_zhang_dale_jones_izaurralde_runge_2020, title={Sustainable feedstock for bioethanol production: Impact of spatial resolution on the design of a sustainable biomass supply-chain}, volume={302}, ISSN={["1873-2976"]}, DOI={10.1016/j.biortech.2020.122896}, abstractNote={This study assesses the role of spatial-resolution and spatial-variations in environmental impacts estimation and decision-making for corn-stover harvesting to produce biofuels. Geospatial corn-stover yields and environmental impacts [global warming potential (GWP), eutrophication, and soil-loss] dataset for two study areas in Wisconsin and Michigan were generated through Environmental Policy Integrated Climate (EPIC) model and aggregated at different spatial-resolutions (i.e., 100; 1000; 10,000 ha). For each spatial-resolution, decision-making was accomplished using an optimization routine to minimize different environmental impacts associated with harvesting stover to meet varied biomass demands. The results of the study showed that selective harvesting at higher-resolution (or lower-aggregation level) can result in significantly lower environmental impacts, especially at low stover demand levels. Additionally, the increased spatial resolution had more impact in minimizing the environmental impacts of corn stover harvest under a more variable landscape such as terrains and its influences are more pronounced for soil-loss and eutrophication potential compared to GWP.}, journal={BIORESOURCE TECHNOLOGY}, author={Sharara, Mahmoud A. and Sahoo, Kamalakanta and Reddy, Ashwan Daram and Kim, Seungdo and Zhang, Xuesong and Dale, Bruce and Jones, Curtis Dinneen and Izaurralde, Roberto Cesar and Runge, Troy M.}, year={2020}, month={Apr} }
@article{aguirre-villegas_larson_sharara_2019, title={Anaerobic digestion, solid-liquid separation, and drying of dairy manure: Measuring constituents and modeling emission}, volume={696}, ISSN={["1879-1026"]}, DOI={10.1016/j.scitotenv.2019.134059}, abstractNote={Anaerobic digestion (AD) and solid-liquid separation (SLS) can increase operational flexibility at livestock facilities, but they can also affect environmental impacts during downstream manure handling. In this study, manure was characterized before and after AD, SLS, and drying. The measured data were used as inputs to models to estimate greenhouse gas (GHG) and ammonia (NH3) emissions during manure storage and land application. Nine dairy farms were sampled between each processing component to evaluate total solids (TS), volatile solids (VS), chemical oxygen demand (COD), total nitrogen (TN), total ammoniacal nitrogen (TAN), total phosphorus (TP), and total potassium (TK). AD systems with co-digestion have higher VS reduction than AD systems processing only dairy manure. SLS data indicate that both screw presses and centrifuges achieve higher separation efficiencies (mass in the solids) for TS and VS than for the other manure constituents. The farm with centrifugation achieves the highest separation efficiency for TP. TAN and TK are not well concentrated in the solids fraction for any processing system. TAN remains entirely within the liquid fraction, showing that each constituent has its own separation profile. Drying manure results in moisture, VS, and TAN losses. Since TAN stays with the liquids, these losses are negligible. When analyzing modeling results, most GHGs are emitted during storage as methane. However, land application is the major emitter of nitrous oxide and NH3. Both AD and SLS can reduce GHG emissions, with the combined AD and SLS scenario achieving the highest reduction (41%). AD increases NH3 emissions during storage due to the mineralization process during digestion. SLS alone can achieve significant GHG emission reductions (38%) even greater than AD when using actual performance data from operating systems. Both AD and SLS have the potential to reach higher GHG and NH3 emission reductions with improved technology efficiencies and management.}, journal={SCIENCE OF THE TOTAL ENVIRONMENT}, publisher={Elsevier}, author={Aguirre-Villegas, Horacio A. and Larson, Rebecca A. and Sharara, Mahmoud A.}, year={2019}, month={Dec} }
@article{sharara_kim_sadaka_thoma_2019, title={Consequential Life Cycle Assessment of Swine Manure Management within a Thermal Gasification Scenario}, volume={12}, ISSN={["1996-1073"]}, DOI={10.3390/en12214081}, abstractNote={Sustainable swine manure management is critical to reducing adverse environmental impacts on surrounding ecosystems, particularly in regions of intensive production. Conventional swine manure management practices contribute to agricultural greenhouse gas (GHG) emissions and aquatic eutrophication. There is a lack of full-scale research of the thermochemical conversion of solid-separated swine manure. This study utilizes a consequential life cycle assessment (CLCA) to investigate the environmental impacts of the thermal gasification of swine manure solids as a manure management strategy. CLCA is a modeling tool for a comprehensive estimation of the environmental impacts attributable to a production system. The present study evaluates merely the gasification scenario as it includes manure drying, syngas production, and biochar field application. The assessment revealed that liquid storage of manure had the highest contribution of 57.5% to GHG emissions for the entire proposed manure management scenario. Solid-liquid separation decreased GHG emissions from the manure liquid fraction. Swine manure solids separation, drying, and gasification resulted in a net energy expenditure of 12.3 MJ for each functional unit (treatment of 1 metric ton of manure slurry). Land application of manure slurry mixed with biochar residue could potentially be credited with 5.9 kg CO2-eq in avoided GHG emissions, and 135 MJ of avoided fossil fuel energy. Manure drying had the highest share of fossil fuel energy use. Increasing thermochemical conversion efficiency was shown to decrease overall energy use significantly. Improvements in drying technology efficiency, or the use of solar or waste-heat streams as energy sources, can significantly improve the potential environmental impacts of manure solids gasification.}, number={21}, journal={ENERGIES}, publisher={MDPI AG}, author={Sharara, Mahmoud and Kim, Daesoo and Sadaka, Sammy and Thoma, Greg}, year={2019}, month={Nov} }
@article{sampat_hu_sharara_aguirre-villegas_ruiz-mercado_larson_zavala_2019, title={Coordinated management of organic waste and derived products}, volume={128}, ISSN={["1873-4375"]}, DOI={10.1016/j.compchemeng.2019.06.008}, abstractNote={We propose a coordination framework for managing urban and rural organic waste in a scalable manner by orchestrating waste exchange, transportation, and transformation into value-added products. The framework is inspired by coordinated management systems that are currently used to operate power grids across the world and that have been instrumental in achieving high levels of efficiency and technological innovation. In the proposed framework, suppliers and consumers of waste and derived products as well as transportation and technology providers bid into a coordination system that is operated by an independent system operator. Allocations and prices for waste and derived products are obtained by the operator by solving a dispatch problem that maximizes the social welfare and that balances supply and demand across a given geographical region. Coordination enables handling of complex constraints and interdependencies that arise from transportation and bio-physico-chemical transformations of waste into products. We prove that the coordination system delivers prices and product allocations that satisfy economic and efficiency properties of a competitive market. The framework is scalable in that it can provide open access that fosters transactions between small and large players in urban and rural areas and over wide geographical regions. Moreover, the framework provides a systematic approach to enable coordinated responses to externalities such as droughts and extreme weather events, to monetize environmental impacts and remediation, to achieve complex social goals such as geographical nutrient balancing, and to justify technology investment and development efforts. Furthermore, the framework can facilitate coordination with electrical, natural gas, water, transportation, and food distribution infrastructures.}, journal={COMPUTERS & CHEMICAL ENGINEERING}, publisher={Pergamon}, author={Sampat, Apoorva M. and Hu, Yicheng and Sharara, Mahmoud and Aguirre-Villegas, Horacio and Ruiz-Mercado, Gerardo and Larson, Rebecca A. and Zavala, Victor M.}, year={2019}, month={Sep}, pages={352–363} }
@article{kim_dale_jin_thelen_zhang_meier_reddy_jones_cesar izaurralde_balan_et al._2019, title={Integration in a depot-based decentralized biorefinery system: Corn stover-based cellulosic biofuel}, journal={GCB Bioenergy}, author={Kim, Seungdo and Dale, Bruce E and Jin, Mingjie and Thelen, Kurt D and Zhang, Xuesong and Meier, Paul and Reddy, Ashwan Daram and Jones, Curtis Dinneen and Cesar Izaurralde, Roberto and Balan, Venkatesh and et al.}, year={2019} }
@article{sampat_hu_sharara_zavala_2018, title={A Coordinated Multi-Product Market for Organic Waste Management}, author={Sampat, Apoorva M and Hu, Yicheng and Sharara, Mahmoud A and Zavala, Victor M}, year={2018} }
@article{runge_sharara_primm_2018, title={Comparison of Dairy Manure Pelletization to Granulation for Facilitating Farm Nutrient Export}, DOI={10.13031/aim.201801674}, abstractNote={Abstract. Continued growth in dairy herd sizes and the number of concentrated animal feeding operations (CAFO) has led to an increase in quantity and spatial concentration of manure. This in turn has created management challenges including transportation and storage costs, meeting environmental regulations, and being able to apply the nutrients precisely. Some producers seeking alternative practices have turned to granulation as a means to mitigate some of these management practice challenges. However, not all dairy manures are easily granulated which prompted pilot-scale production tests to compare granulation and pelletization. The results indicate for dairy manure that pelletization was able to densify a wider range of manure types, whereas granulation could only be performed on separated manures with minimal fiber content. Additionally, for whole manure samples the pelletization was able to create a higher density, and more durable composite without the use of binder. Pelletization required higher electricity inputs but could take advantage of lower thermal energy for drying if pad-drying is available.}, journal={2018 Detroit, Michigan July 29 - August 1, 2018}, publisher={American Society of Agricultural and Biological Engineers}, author={Runge, Troy M. and Sharara, Mahmoud A. and Primm, John G.}, year={2018} }
@article{sampat_hu_sharara_aguirre-villegas_ruiz-mercado_larson_zavala_2018, title={Coordinated markets for scalable management of organic waste and derived products}, journal={Under Review}, author={Sampat, Apoorva M and Hu, Yicheng and Sharara, Mahmoud and Aguirre-Villegas, Horacio and Ruiz-Mercado, Gerardo and Larson, Rebecca A and Zavala, Victor M}, year={2018} }
@article{kim_zhang_dale_reddy_jones_cronin_izaurralde_runge_sharara_2018, title={Corn stover cannot simultaneously meet both the volume and GHG reduction requirements of the renewable fuel standard}, volume={12}, number={2}, journal={Biofuels, Bioproducts and Biorefining}, publisher={John Wiley & Sons, Ltd Chichester, UK}, author={Kim, Seungdo and Zhang, Xuesong and Dale, Bruce and Reddy, Ashwan Daram and Jones, Curtis Dinneen and Cronin, Keith and Izaurralde, Roberto Cesar and Runge, Troy and Sharara, Mahmoud}, year={2018}, pages={203–212} }
@article{aguirre-villegas_sharara_larson_2018, title={Nutrient Variability Following Dairy Manure Storage Agitation}, volume={34}, DOI={10.13031/aea.12796}, abstractNote={Abstract. The nutrient profile in stored manure can be highly variable due to the solids building up at the bottom of the storage over time as unagitated manure is removed. This variability can lead to under- or over-application of nutrients potentially reducing crop yields or increasing nutrient losses, respectively. Agitation of stored manure is a common practice to re-suspend solids providing a more uniform nutrient consistency for application. This study explores the solids and nutrient variability in stored dairy manure after agitation and the relationship between the number of samples and the quality of the nutrient content estimate. A total of 16 dairy facilities across Wisconsin were sampled in the study. Samples were taken during agitation and analyzed for total solids (TS), total Kjeldahl nitrogen (TKN), total ammonia nitrogen (TAN), total phosphorus (TP), total potassium (TK), and microminerals. Overall, TKN, TAN, and TP contents were more uniform than TS. The mean concentrations (wet basis) from the 16 farms range from 2.45% to 15.28% for TS, 0.17% to 0.53% for TKN, 0.01% to 0.33 for TAN, 0.02 to 0.06 for TP, and 0.11% to 0.31% for TK. This range is mostly attributed to the between-farms variability in manure nutrient content. In addition, 54% of the total variation in the TS content was attributable to within-farm sample variability. These results show that TS was variable on farms whereas TKN, TAN, and TP were variable between farms. A random resampling analysis showed that three samples generate a mean between 20% to 30% of the true experimental mean for TKN and TAN whereas nine samples are required to be in this range for TP. Results show that the improvement achieved by adding more samples than 11 is less than 10%. Keywords: Dairy manure, Manure agitation, Nutrients, Nutrient variability, Sample size.}, number={6}, journal={Applied Engineering in Agriculture}, publisher={American Society of Agricultural and Biological Engineers (ASABE)}, author={Aguirre-Villegas, Horacio A and Sharara, Mahmoud A and Larson, Rebecca A}, year={2018}, pages={908–917} }
@article{sharara_sadaka_2018, title={Opportunities and Barriers to Bioenergy Conversion Techniques and Their Potential Implementation on Swine Manure}, volume={11}, DOI={10.3390/en11040957}, abstractNote={The objectives of this article are to offer a comprehensive evaluation of the opportunities and barriers for swine manure conversion technologies and to shed light on the gaps that might require further investigation to improve the applicability of these technologies. The challenges of manure management have been propagated alongside the global growth of swine production. Various technologies that target the production of energy, fuels, and bioproducts from swine manure have been reported. These technologies include pretreatments, i.e., drying, and solid separation; biological techniques, i.e., composting, anaerobic digestion, and biodrying; and thermochemical techniques, i.e., combustion, gasification, pyrolysis, liquefaction, and carbonization. The review highlights the yields and qualities of products, i.e., energy, gaseous fuel, liquid fuel, and solid fuel, of each technology. It exhibits that the choice of a conversion technology predominantly depends on the feedstock properties, the specifics of the conversion technique, the market values of the end products as well as the local regulations. The challenges associated with the presented techniques are discussed to ameliorate research and development in these areas. The notable finding of this paper is that there is a need for full-scale research in the area of thermochemical conversion of solid-separated swine manure.}, number={4}, journal={Energies}, publisher={MDPI AG}, author={Sharara, Mahmoud and Sadaka, Sammy}, year={2018}, month={Apr}, pages={957} }
@article{sharara_runge_larson_primm_2018, title={Techno-economic optimization of community-based manure processing}, volume={161}, DOI={10.1016/j.agsy.2018.01.006}, abstractNote={This study investigates community-based processing of manure to produce organic fertilizer using granulation. We developed a mixed-integer optimization model to determine the minimum sale price of granulated manure, i.e., price corresponding to zero net present value (NPV = 0). We used dairy farms inventories for two regions in Wisconsin to develop case studies to evaluate community-based processing. Minimum sale price of granulated manure varied between $360 and $460 per ton based on the region and the imposed aggregation radius. Granulation facilities were located on the farm with the largest herd in each case. Selection of farms for participation in granulation facility relied on both proximity and herd size. Sensitivity analyses were performed to analyze the impacts of market changes and subsidies on the investment. Community-based manure processing was found to offer an opportunity to facilitate processing and export of nutrients due to economies of scale advantage.}, journal={Agricultural Systems}, publisher={Elsevier BV}, author={Sharara, Mahmoud A. and Runge, Troy and Larson, Rebecca and Primm, John G.}, year={2018}, month={Mar}, pages={117–123} }
@article{christensen_dong_ramakrishnan_sharara_ferris_2017, title={A Mixed-Integer Framework for Operational Decision-Making in Sustainable Nutrient Management}, journal={Available at SSRN 2417062}, author={Christensen, Adam and Dong, Hongbo and Ramakrishnan, Jagdish and Sharara, Mahmoud and Ferris, Michael C}, year={2017} }
@article{anthony_sharara_runge_anex_2017, title={Life cycle comparison of petroleum-and bio-based paper binder from distillers grains (DG)}, volume={96}, journal={Industrial crops and products}, publisher={Elsevier}, author={Anthony, Renil and Sharara, Mahmoud A and Runge, Troy M and Anex, Robert P}, year={2017}, pages={1–7} }
@article{sharara_sampat_good_smith_porter_zavala_larson_runge_2017, title={Spatially explicit methodology for coordinated manure management in shared watersheds}, volume={192}, journal={Journal of environmental management}, publisher={Academic Press}, author={Sharara, Mahmoud and Sampat, Apoorva and Good, Laura W and Smith, Amanda S and Porter, Pamela and Zavala, Victor M and Larson, Rebecca and Runge, Troy}, year={2017}, pages={48–56} }
@article{sharara_runge_larson_primm_2017, title={Techno-economic optimization of community-based manure processing}, DOI={10.13031/aim.201700342}, abstractNote={Abstract This study investigates community-based processing of manure to produce organic fertilizer using granulation. We developed a mixed-integer optimization model to determine the minimum sale price of granulated manure, i.e., price corresponding to zero net present value (NPV = 0). We used dairy farms inventories for two regions in Wisconsin to develop case studies to evaluate community-based processing. Minimum sale price of granulated manure varied between $360 and $460 per ton based on the region and the imposed aggregation radius. Granulation facilities were located on the farm with the largest herd in each case. Selection of farms for participation in granulation facility relied on both proximity and herd size. Sensitivity analyses were performed to analyze the impacts of market changes and subsidies on the investment. Community-based manure processing was found to offer an opportunity to facilitate processing and export of nutrients due to economies of scale advantage.}, journal={2017 Spokane, Washington July 16 - July 19, 2017}, publisher={American Society of Agricultural and Biological Engineers}, author={Sharara, Mahmoud A and Runge, Troy and Larson, Rebecca and Primm, John G}, year={2017} }
@article{sadaka_sharara_2016, title={Carbon Footprint - Tips for Arkansas Producers}, author={Sadaka, Sammy and Sharara, Mahmoud}, year={2016} }
@article{sharara_sadaka_costello_vandevender_carrier_popp_thoma_djioleu_2016, title={Combustion kinetics of swine manure and algal solids}, volume={123}, number={1}, journal={Journal of Thermal Analysis and Calorimetry}, publisher={Springer Netherlands}, author={Sharara, Mahmoud A and Sadaka, Sammy S and Costello, Thomas A and VanDevender, Karl and Carrier, Julie and Popp, Michael and Thoma, Greg and Djioleu, Angele}, year={2016}, pages={687–696} }
@article{liu_sharara_gunasekaran_runge_2016, title={Effects of large-scale manure treatment processes on pathogen reduction, protein distributions, and nutrient concentrations}, volume={59}, number={2}, journal={Transactions of the ASABE}, publisher={American Society of Agricultural and Biological Engineers}, author={Liu, Zong and Sharara, Mahmoud and Gunasekaran, Sundaram and Runge, Troy M}, year={2016}, pages={695–702} }
@inproceedings{sharara_larson_runge_2016, title={Spatially-explicit methodology for manure management at the watershed level}, booktitle={2016 ASABE Annual International Meeting}, author={Sharara, Mahmoud and Larson, Rebecca and Runge, Troy}, year={2016}, pages={1} }
@inproceedings{sharara_yang_cox_runge_2016, title={Techno-economic assessment of dairy manure granulation}, booktitle={2016 ASABE Annual International Meeting}, author={Sharara, Mahmoud and Yang, Qiang and Cox, Thomas L and Runge, Troy M}, year={2016}, pages={1} }
@article{sharara_sadaka_2015, title={Gasification of phycoremediation algal biomass}, volume={10}, number={2}, journal={BioResources}, author={Sharara, Mahmoud A and Sadaka, Sammy S}, year={2015}, pages={2609–2625} }
@article{sharara_2015, title={Transformation of Swine Manure and Algal Consortia to Value-added Products}, author={Sharara, Mahmoud A}, year={2015} }
@article{sadaka_sharara_ashworth_keyser_allen_wright_2014, title={Characterization of biochar from switchgrass carbonization}, volume={7}, number={2}, journal={Energies}, publisher={Multidisciplinary Digital Publishing Institute}, author={Sadaka, Samy and Sharara, Mahmoud and Ashworth, Amanda and Keyser, Patrick and Allen, Fred and Wright, Andrew}, year={2014}, pages={548–567} }
@article{ashworth_sadaka_allen_sharara_keyser_2014, title={Influence of pyrolysis temperature and production conditions on switchgrass biochar for use as a soil amendment}, volume={9}, number={4}, journal={BioResources}, author={Ashworth, Amanda Joy and Sadaka, Sammy S and Allen, Fred L and Sharara, Mahmoud A and Keyser, Patrick D}, year={2014}, pages={7622–7635} }
@article{sadaka_sharara_ubhi_2014, title={Performance assessment of an allothermal auger gasification system for on-farm grain drying}, volume={4}, number={1}, journal={Journal of Sustainable Bioenergy Systems}, publisher={Scientific Research Publishing}, author={Sadaka, Samy and Sharara, Mahmoud and Ubhi, Gagandeep}, year={2014}, pages={19} }
@article{sharara_holeman_sadaka_costello_2014, title={Pyrolysis kinetics of algal consortia grown using swine manure wastewater}, volume={169}, DOI={10.1016/j.biortech.2014.06.111}, abstractNote={In this study, pyrolysis kinetics of periphytic microalgae consortia grown using swine manure slurry in two seasonal climatic patterns in northwest Arkansas were investigated. Four heating rates (5, 10, 20 and 40 °C min(-1)) were used to determine the pyrolysis kinetics. Differences in proximate, ultimate, and heating value analyses reflected variability in growing substrate conditions, i.e., flocculant use, manure slurry dilution, and differences in diurnal solar radiation and air temperature regimes. Peak decomposition temperature in algal harvests varied with changing the heating rate. Analyzing pyrolysis kinetics using differential and integral isoconversional methods (Friedman, Flynn-Wall-Ozawa, and Kissinger-Akahira-Sunose) showed strong dependency of apparent activation energy on the degree of conversion suggesting parallel reaction scheme. Consequently, the weight loss data in each thermogravimetric test was modeled using independent parallel reactions (IPR). The quality of fit (QOF) for the model ranged between 2.09% and 3.31% indicating a good agreement with the experimental data.}, journal={Bioresource Technology}, publisher={Elsevier BV}, author={Sharara, Mahmoud A. and Holeman, Nathan and Sadaka, Sammy S. and Costello, Thomas A.}, year={2014}, month={Oct}, pages={658–666} }
@article{sharara_sadaka_2014, title={Thermogravimetric Analysis of Swine Manure Solids Obtained from Farrowing, and Growing-Finishing Farms}, volume={04}, DOI={10.4236/jsbs.2014.41008}, abstractNote={The modern trend of increasing the number of pigs at
production sites led to a noticeable surplus of manure. Separation of manure solids provides an avenue of their utility via
thermochemical conversion techniques. Therefore, the goal of this paper was to assess the physical and thermal
properties of solid separated swine manure obtained from two different farms, i.e., farrowing, and growing-finishing,
and to determine their pyrolysis kinetic parameters. Swine manure solids were
dried and milled prior to assessing their
properties. Differential and integral isoconversional methods (Friedman, and Flynn-Wall-Ozawa) were used to determine the
apparent activation energy as a function of the conversion ratio. Significant
differences were observed in the proximate, ultimate composition between both manure types. The higher heating value
(HHV) for the manure solids from farrowing, and growing-finishing farms reached
16.6 MJ/kg and 19.4 MJ/kg, respectively. The apparent activation energy computed using Friedman and FWO
methods increased with the increase in the degree of conversion. Between 10%
and 40% degrees of conversion, the average activation energies, using Friedman
method, were103 and 116 kJ/mol for the farrowing and growing-finishing manure
solids, respectively. On the other hand, the same activation energies, calculated from FWO method, were 98 and 104 kJ/mol, for solid
manure obtained from farrowing and
growing-finishing farms, respectively. The findings in this study will assist
in the effort to optimize thermochemical conversion processes to accommodate
swine waste. This could, in turn, minimize swine production impacts on the
surrounding ecologies and provide sustainable energy and biochar streams.}, number={01}, journal={Journal of Sustainable Bioenergy Systems}, publisher={Scientific Research Publishing, Inc.}, author={Sharara, Mahmoud and Sadaka, Samy}, year={2014}, pages={75–86} }
@inbook{sharara_clausen_carrier_2012, title={An overview of biorefinery technology}, booktitle={Biorefinery Co-Products: Phytochemicals. Primary Metabolites and Value-Added Biomass Processing}, publisher={Wiley}, author={Sharara, Mahmoud A and Clausen, Edgar C and Carrier, Danielle Julie}, year={2012}, pages={1–18} }
@article{sharara_sadaka_2012, title={Auger Reactor Gasification of Algal Blooms Produced In a Waste Water Treatment Facility}, DOI={10.13031/2013.41851}, abstractNote={Aquatic biomass; i.e., algae have been successfully incorporated in wastewater treatment as nutrients strippers. Low-maintenance algal communities; i.e., wild species, can be a cheap and effective sequestration strategy. Few studies have investigated the quality of wastewater treatment algae as a potential feedstock for thermochemical conversion in atmospheric gasification. This study is a preliminary investigation of the gasification of wastewater treatment algae as means to produce renewable gaseous fuel streams, and also to condense minerals and micro- nutrients into easily managed char using an auger gasifier. Three temperature conditions were investigated in this study; 760, 860 and 960 °C. Temperatures were found to increase the concentration of CO, and H2 in producer gas from 12.8% and 4.7% (vol.) at 760 °C to 16.9% and 11.4% at 960 °C, respectively. On the other hand, concentration of CO2 in producer gas decreased from 14.0% to 11.6% (vol.) with the increase in temperatures from 760 °C to 960 °C, respectively. Tar yields ranged between 15% and 16.6%, whereas char yields fell between 46% and 51% due to the significantly high ash content of raw algae; >40% dry-basis. The high ash content in char, however, might bolster gasification as a minerals concentration step which would facilitate transportation, and re-use of these minerals. Future studies will further investigate the thermodynamic performance of auger gasification on aquatic biomass. Also, fate of various minerals after this process will be investigated in future research.}, journal={2012 Dallas, Texas, July 29 - August 1, 2012}, publisher={American Society of Agricultural and Biological Engineers}, author={Sharara, Mahmoud A and Sadaka, Samy S}, year={2012} }
@inproceedings{sharara_sadaka_2012, title={Auger reactor gasification of algal blooms produced in a waste water treatment facility}, booktitle={2012 Dallas, Texas, July 29-August 1, 2012}, author={Sharara, Mahmoud A and Sadaka, Samy S}, year={2012}, pages={1} }
@article{sharara_sadaka_costello_vandevender_2012, title={Influence of Aeration Rate on the Physio-Chemical Characteristics of Biodried Dairy Manure - Wheat Straw Mixture}, volume={28}, DOI={10.13031/2013.41489}, abstractNote={Animal manure is a prime candidate for thermochemical conversion (co-firing, gasification, and pyrolysis) except for its high moisture content. Biodrying is a promising solution to reduce manure moisture with minimum energy input. This study investigated the effects of different aeration rates; low (0.05 L/min/kg VM), medium (0.80 L/min/kgVM), and high (1.50 L/min/kgVM), on the biodrying of dairy manure mixed with wheat straw. The moisture content dropped in 21 days from 56% to 28%, 34%, and 35% wb under high, medium, and low aeration rates, respectively. The heating value of the mixture decreased from 16.19 MJ/kgdry to 14.31, 13.79, and 13.83 MJ/kgdry under high, medium, and low aeration, respectively. Evaluation of energy consumption to remove a unit mass of moisture showed that high aeration levels required the least energy input, 7.84 MJ/kgH2O, followed by low aeration at 7.93 MJ/ kgH2O, while the medium aeration had a relatively high energy cost for water removal, 9.09 MJ/ kgH2O. The high aeration level was superior in terms of both drying energy and time requirements to the other rates considered. Comparison showed that high aeration level biodrying (1.50 L/min/kgVM) exceeded the range of conventional drying energy demand. However, the ratio of external fossil fuel demand was much lower in biodrying (due to the auto-thermal effect) than in conventional drying.}, number={3}, journal={Applied Engineering in Agriculture}, publisher={American Society of Agricultural and Biological Engineers (ASABE)}, author={Sharara, M. A. and Sadaka, S. and Costello, T. A. and VanDevender, K.}, year={2012}, pages={407–415} }
@article{sadaka_vandevender_costello_sharara_2011, title={Composting for biodrying organic materials}, publisher={University of Arkansas - Division of Agriculture}, author={Sadaka, Sammy and VanDevender, Karl and Costello, Tom and Sharara, Mahmoud}, year={2011} }
@phdthesis{sharara_2010, title={Biodrying-gasification of dairy manure-wheat straw mixture}, school={University of Arkansas}, author={Sharara, Mahmoud A}, year={2010} }
@article{sadaka_vandevender_costello_sharara_2010, title={Partial Composting for Biodrying Organic Materials}, publisher={University of Arkansas Cooperative Extension Service}, author={Sadaka, Samy and VanDevender, Karl and Costello, Thomas and Sharara, Mahmoud}, year={2010} }
@article{ashworth_allen_sadaka_sharara_keyser, title={Conversion System and Heating Value Influence on Switchgrass Biochars for use as a Soil Amendment}, author={Ashworth, Amanda J and Allen, Fred L and Sadaka, Sammy S and Sharara, Mahmoud A and Keyser, Patrick D} }