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Title: Economic viability and carbon footprint of switchgrass for cellulosic biofuels: Insights from a spatial multi‐feedstock procurement landscape analysis
Abstract

We study a situation in which a multi‐feedstock cellulosic biofuel plant can procure stover from productive cropland and switchgrass from marginal land, where growing corn for stover is typically not profitable. We calibrate our model to growing conditions in a promising area of Indiana, USA. We find that cost‐minimizing biorefineries are likely to include switchgrass in the mix of feedstocks despite their high cost of production relative to corn stover. This is because the biorefinery can reduce cost by buying switchgrass grown on marginal land near the plant instead of paying to cover high transportation costs to procure stover from more distant suppliers. Moreover, the share of switchgrass will rise further if the procurement region is constrained by transaction costs or natural barriers. This is because procuring switchgrass can alleviate the cost of paying to induce land conversion to corn to procure additional stover from the intensive margin. Under the assumption that switchgrass is grown on marginal land, inclusion of switchgrass in the feedstock mix not only reduces the cost of producing biofuels but also their carbon footprint without displacing food crops. A key caveat is that high transaction costs of contracting for switchgrass and/or farmers’ reluctance to grow switchgrass on marginal land can severely undermine its inclusion in the feedstock mix. However, these forces may be countervailed by a differential subsidy for biofuels that include a higher share of switchgrass, which would be warranted because of their lower carbon footprint.

 
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NSF-PAR ID:
10451067
Author(s) / Creator(s):
 ;  ;  
Publisher / Repository:
Wiley-Blackwell
Date Published:
Journal Name:
GCB Bioenergy
Volume:
13
Issue:
7
ISSN:
1757-1693
Page Range / eLocation ID:
p. 1054-1070
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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Variate    Description year    year of the observation method    methods of poplar biomass sampling date    day of the observation (mm/dd/yyyy) replicate    each crop has four replicated plots, R1, R2, R3 and R4 diameter_at_ground    poplar diameter (milliMeter) at the ground diameter_at_15cm    poplar diameter (milliMeter) at 15 cm height biomass_tree    biomass per plot (Grams_Per_Tree) biomass_ha    biomass (megaGrams_Per_Hectare) by multiplying biomass per tree with 0.01 4. Spreadsheet: annual N leaching_vol-wtd conc Description: Annual leaching rate (kiloGrams_N_Per_Hectare) and volume-weighted mean N concentrations (milliGrams_N_Per_Liter) of nitrate (no3) and dissolved organic nitrogen (don) in the leachate samples collected from corn, switchgrass, miscanthus, native grass, restored prairie and poplar plots in Great Lakes Bioenergy Research Center (GLBRC) Biomass Cropping System Experiment (BCSE) during 2009-2016. 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Variate    Description crop    “corn” “switchgrass” “miscanthus” “nativegrass” “restored prairie” “poplar” date    date of the observation (mm/dd/yyyy) replicate    each crop has four replicated plots, R1, R2, R3 and R4 nh4 conc    nh4 concentration (milliGrams_N_Per_Liter) no3 conc    no3 concentration (milliGrams_N_Per_Liter)   9. Spreadsheet: correlations_don VS no3_doc VS don Description: Correlations of don and nitrate concentrations (milliGrams_N_Per_Liter); and doc (milliGrams_Per_Liter) and don concentrations (milliGrams_N_Per_Liter) in the leachate samples of corn, switchgrass, miscanthus, native grass, restored prairie and poplar plots in Great Lakes Bioenergy Research Center (GLBRC) Biomass Cropping System Experiment (BCSE) during 2013-2015. Data of correlation of don and nitrate concentrations shown in Figure S4 a and doc and don concentrations shown in Figure S4 b. 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