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The southeastern USA has the potential to be a significant producer of bio‐based products; however, research is still needed to demonstrate the most cost‐effective feedstock delivery system for this region. A logistic system that has shown promise is one utilizing a network of supply depots. This study calculated the cost to produce a stream of size‐reduced herbaceous biomass (i.e., switchgrass) for five theoretical depots in the Piedmont province. Three depots were located in south central Virginia and two in north central North Carolina. A logistics system with a 20‐bale handling unit was used for load‐out operations at 199 theoretical satellite storage locations (SSLs) within a 48 km radius of each depot location. The distribution of potential production fields and the transportation distance from SSLs to the depots were determined with spatial and network analyses. Based on an analysis of potential land cover available for feedstock production, the annual capacity per depot ranged from 80 839 to 170 830 Mg, resulting in a total annual capacity of 555 195 Mg for all five depots. Cost to deliver feedstock for 24/7 operation, 48 weeks per year ranged from 46.03 to 62.86 USD Mg−1 annual capacity. At the low end, these costs were: SSL operation (22%), truck (29%), receiving facility (26%), and debaling‐size‐reduction (23%). The principle economy‐of‐scale factors were the receiving facility and debaling‐size‐reduction costs. To minimize per‐Mg cost, depot capacity should be chosen such that equipment can be operated as close to 80% of design capacity as possible. [ABSTRACT FROM AUTHOR]

The push for renewable energy sources has local government agencies striving to optimize their limited resources. Various energy sources are often explored depending on the region – for example, wind, solar, geothermal, and bioenergy. The Piedmont region of the USA has the potential to be a significant player in the production of biomass to supply a biorefinery. However, before local agencies and private biorefineries can invest in such an endeavor, the potential feedstock supply must be quantified. The goal of this study was to perform a land‐use assessment for the 166 counties spanning five states (Virginia, North Carolina, South Carolina, Georgia, and Alabama) that make up the bulk of the Piedmont region. For each county, the potential for producing and supplying herbaceous feedstock (i.e., switchgrass) was quantified based on 2017 land use. Only 48% of the counties had the potential to supply a biorefinery larger than 0.5 round bales per min (bpm) (97 000 Mg year–1). To supply a more reasonably sized biorefinery, the Piedmont counties were organized into 34 multi‐county zones. For these zones, the potential switchgrass production to supply a biorefinery ranged from 50 000 Mg year–1 to 360 000 Mg year–1. The total feedstock production for the region was 6 470 000 Mg year–1, equal to a potential production of about 3.3% of the current US consumption of ethanol for blending with gasoline. The development of a bioenergy industry in the Piedmont will require local leadership and initiative; however, this study provides the first step in envisioning the potential of such an industry. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

An integrated multi‐feedstock bioenergy (i.e., biofuel, biopower, or bioproduct) supply system has potential to reduce biomass supply system uncertainties and costs. This study identifies optimal configurations of multi‐feedstock biomass‐to‐biorefinery supply chains and pertinent feedstock combinations based on spatial distribution of feedstock and lowest delivered cost to the biorefinery. We used the Supply Characterization Model (SCM) to allocate feedstock supplies to candidate biorefinery facilities. Model runs were performed for herbaceous energy crops, agriculture residue, and woody biomass available in 2017, 2022, 2025, and 2030 as estimated by the Policy Analysis System (POLYSYS) and Forest Sustainable and Economic Analysis Model (ForSEAM) models. Three feedstock supply scenarios were compared: (a) an herbaceous scenario: switchgrass, miscanthus, biosorghum, and corn stover; (b) a woody scenario: coppice wood, noncoppice wood, whole trees, and forestry residues, and (c) a mixed scenario: a combination of all feedstocks in herbaceous and woody scenarios. By 2030 the analyses predicted that 323, 168, and 473 biorefineries were sited in the herbaceous, woody, and mixed scenario, respectively, in the conterminous USA. Feedstock mixes supplied to the biorefineries were mostly dominated by a single feedstock. The most prominent feedstock mixes identified were: (1) switchgrass and miscanthus; (2) coppice and noncoppice wood; and (3) coppice wood, noncoppice wood, switchgrass and miscanthus. Biorefineries using multi‐feedstock would be beneficial for growth of bioeconomy, however flexible and cost‐effective conversion platforms should be developed to efficiently utilize multiple feedstocks. This analysis identifies biorefinery locations and feedstock supply mixes while minimizing delivered feedstock costs based on spatial and temporal feedstock availability. © 2020 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

The sustainable supply of high‐quality, low‐cost biomass feedstock to cellulosic biorefineries is still a challenge. Utilizing corn stover as the single feedstock to a biorefinery also poses a source of risk to seasonal feedstock availability, affordability, and sustainability. Implementing a year‐round feedstock switching strategy or utilizing an optimal mixture of corn stover, miscanthus, and switchgrass is demonstrated to diminish these concerns while reducing the cost of sugar production by as much as 3.8% and 13.6%, respectively, when compared to a baseline sugar price of 441.9 $ metric ton−1 (t) attributed to a fixed corn stover feedstock basis. This study determines that a mixing ratio of corn stover, miscanthus, and switchgrass of 36%, 50%, and 14%, respectively, minimizes the selling price of sugar. If miscanthus is sufficiently available in the future, its fraction could be further increased to 70% by reducing the fraction of corn stover. We find that the mixed feedstock considered in this study reduces the nutrient replacement and feedstock transportation costs and improves the quality of feedstock (determined by total carbohydrates and ash) relative to corn stover alone. Results suggest that a high‐quality feedstock with a high carbohydrate content is an important metric for consideration, beyond strictly the feedstock cost, to reduce the selling price of sugar and its uncertainties. In the future this may be supported by the increased availability of higher carbohydrate feedstocks such as miscanthus. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

If the US mandates for the use of cellulosic biofuels are ultimately enforced, cellulosic feedstock will be demanded. Native switchgrass is a cellulosic feedstock that has been of substantial interest for this purpose because it is widely grown across the USA, it can be grown on marginal cropland and thus compete minimally with food supplies, it has a low carbon footprint, and in many ways, it is a sustainable source of energy. The purpose of the research reported here is to quantify the potential willingness of producers across 358 counties in a 10-state area in North Central USA to produce this biomass. We conducted a contingent valuation survey of randomly selected farm operators in this area. From the more than 1100 responses, we found that the mean reservation price at which respondents were willing to supply switchgrass from their least productive field is a return of about $228 per acre, which translates to about $82 per dry ton. Respondents were somewhat less willing to lease out their land for this purpose, requiring an additional $3.50 per dry ton to be willing to lease. In sub-regions of counties grouped by opportunity cost, mean reservation prices are equivalent to $75 per ton, $82 per ton, and $99 per ton, very close in the first two subregions to the Department of Energy goal of $84 per dry ton delivered to the biorefinery. Thus, prospects appear favorable that substantial fractions of farmers would be willing to supply switchgrass in this area, particularly in the sub-areas with lower land costs. © 2017 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

Sound crop and land management strategies can maintain land productivity and improve the environmental sustainability of agricultural crop and feedstock production. This study evaluates a strategy of incorporating landscape design and management concepts into bioenergy feedstock production. It examines the effect of land conversion and agricultural best management practices (BMPs) on water quality (nutrients and suspended sediments) and hydrology. The strategy was applied to the watershed of the South Fork Iowa River in Iowa, where the focus was on converting low-productivity land to provide cellulosic biomass and implementing riparian buffers. The Soil and Water Assessment Tool (SWAT) was employed to simulate the impact at watershed and sub-basin scales. The study compared the representation of buffers by using trapping efficiency and area ratio methods in SWAT. Landscape design and management scenarios were developed to quantify water quality under (i) current land use, (ii) partial land conversion to switchgrass, and (iii) riparian buffer implementation. Results show that implementation of vegetative barriers and riparian buffer can trap the loss of total nitrogen, total phosphorus, and sediment significantly. The effect increases with the increase of buffer area coverage. Implementing riparian buffer at 30 m width is able to produce 4 million liters of biofuels. When low-productivity land (15.2% of total watershed land area) is converted to grow switchgrass, suspended sediment, total nitrogen, total phosphorus, and nitrate loadings are reduced by 69.3%, 55.5%, 46.1%, and 13.4%, respectively. Results highlight the significant role of lower-productivity land and buffers in cellulosic biomass and provide insights into the design of an integrated landscape with a conservation buffer for future bioenergy feedstock production. Published 2015. This article is a U.S. Government work and is in the public domain in the USA. Biofuels, Bioproducts and Biorening published by Society of Industrial Chemistry and John Wiley & Sons Ltd. [ABSTRACT FROM AUTHOR]

The benefits of particle size reduction and mechanical densification of biomass feedstock for storage, transportation, and handling must be assessed in relation to the systemic costs and energy consumption incurred due to these operations. The goal of this work was to determine the optimal levels of size reduction and densification through a combination of modeling and experimental studies. Size reduction and densification data for Miscanthus and switchgrass were generated using a two-stage grinding process and the energy requirement and bulk densities for the particle sizes between 1 mm and 25.4 mm were determined. Increase in bulk density through compression by a pressure of 1.2 MPa was also measured. These data were used within BioFeed, a system-level optimization model, to simulate scenarios capturing the possibilities of performing size reduction and densification at various stages of the supply chain. Simulation results assuming size reduction at farms showed that the optimal particle size range for both Miscanthus and switchgrass was 4-6 mm, with the optimal costs of $54.65 Mg-1 and $60.77 Mg-1 for Miscanthus and switchgrass, respectively. Higher hammer mill throughput and lower storage costs strongly impacted the total costs for different particle sizes. Size reduction and densification of biomass at the county-specific centralized storage and pre-processing facilities could reduce the costs by as much as $6.34 Mg-1 for Miscanthus and $20.13 Mg-1 for switchgrass over the base case. These differences provided the upper bound on the investments that could be made to set-up and operate such systems. © 2014 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]