Supply Cost and Life-Cycle Greenhouse Gas Footprint of Dry and Ensiled Biomass Sorghum for Biofuel Production

Abstract

Biomass sorghum is a promising feedstock for cellulosic biorefineries because of its high yield and drought tolerance. However, the difficulty of effectively drying sorghum in some regions means it may require different handling than previously studied grassy feedstocks. This study compares the delivered cost and life-cycle greenhouse gas (GHG) footprint of field-drying and baling, module storage (wrapped, densely packed biomass), pelletizing, and ensiling. Ensiling has not been widely considered for use in bioenergy production. For farms within 66 km of the biorefinery, ensiled biomass is the lowest-cost and GHG strategy despite additional cost and energy demands for hauling wet biomass. Field-drying and baling, if feasible, is the most costeffective option for sorghum between 66 km and 104 km, beyond which pellets are preferable. A 2 2000 bone-dry-metric ton (bdt)/day biorefinery can source sorghum with 18 bdt/ha yield cultivated on 5% of surrounding land at costs range from $122 (silage) to $167 (pellets)/bdt and a life-cycle GHG footprint of 111 (silage) to 179 kg CO2e/bdt (pellets). With 28 bdt/ha biomass yield, 10% cultivation of surrounding land, and low fertilizer application, costs can range from $66 (silage) to $85 (pellets)/bdt and GHG footprint of 43 (silage) to 96 kg CO2e (pellets)/bdt.

Quantitative Sustainable Design (QSD) for the Prioritization of Research, Development, and Deployment of Technologies: A Tutorial and Review

“…For example, to mitigate GHG emissions and curb global warming within 1.5°C above the pre-industrial level, different scenarios, each consisting of varying technologies, have been evaluated for decarbonization. 61 Similar applications of scenario analysis can be found in other topics (e.g., water and wastewater treatment, 46,159,298,299 renewable energy, 217,260,279,300 waste management 232 ), or for a certain technique (e.g., using different scenarios of electricity mix in LCA to assess the environmental sustainability of electric vehicles 301 ). In essence, scenario analysis divides the entire problem space into discrete, representative sub-spaces.…”

“…254,255 The analysis of other systems has followed a similar workflow, transferring data among multiple tools used for different steps of QSD. 107,227,[256][257][258][259][260][261][262] Although programming languages can be used to facilitate data formatting and transfer, this nonetheless presents challenges in QSD execution when system simulation and sustainability characterization need to be repeated thousands of times or more to consider uncertainty (Section 5.2). Alternatively, there are ongoing efforts in tool development to integrate system simulation and sustainability characterization on a single, opensource platform (e.g., for sanitation and resource recovery systems, 230 biorefineries 215 ).…”

One-Pot Efficient Biosynthesis of 4-Hydroxyphenylacetic Acid and Its Analogues from Lignin-Related p-Coumaric and Ferulic Acids

“…As a readily available and cheap feedstock, sorghum was selected for the preparation of alkaline-pretreated liquor. , The sorghum stem was collected from Jining (Shandong Province, China). The sorghum pith sample was obtained by peeling roughly.…”

Identifying Forage Sorghum Ideotypes for Advanced Biorefineries

“…Forage Sorghum Feedstock Supply Cost. The forage sorghum supply cost at the biorefinery gate is calculated using our bioenergy sorghum supply logistics model, which is documented in Baral et al 9 Among the different potential supply systems analyzed previously, 9 including chopped ensiled biomass, dry bales, and densely packed modules, this study considers the direct-supply bale system because it is the least GHG-intensive option if the farm-to-biorefinery distance is between 80 and 248 km. 9 Briefly, the direct-supply bale system involves windrowing and in-field drying to 20% moisture content, after which the dried material is baled and directly loaded onto trucks at the field for transport to the biorefinery.…”

“…The forage sorghum supply cost at the biorefinery gate is calculated using our bioenergy sorghum supply logistics model, which is documented in Baral et al 9 Among the different potential supply systems analyzed previously, 9 including chopped ensiled biomass, dry bales, and densely packed modules, this study considers the direct-supply bale system because it is the least GHG-intensive option if the farm-to-biorefinery distance is between 80 and 248 km. 9 Briefly, the direct-supply bale system involves windrowing and in-field drying to 20% moisture content, after which the dried material is baled and directly loaded onto trucks at the field for transport to the biorefinery. To remain consistent with the nutrient regime followed in the field trial, we assume that uniform fertilizer amounts are applied to all hybrids: 131.38 kg/ha of nitrogen, 9 we assume dry matter losses totaling 11.6% over the entire supply chain a land utilization factor (referring to the fraction of land surrounding the biorefinery that is cultivated with sorghum) of 5%.…”