Supply logistics systems for corn (Zea mays L.) stover and switchgrass (Panicum virgatum L.) with two collection methods, round bales and rectangular bales, are developed. A location in the US Midwest is assumed with corn grown on highly productive crop land and switchgrass grown on less productive land. Bales (15 % moisture wet basis) are stored at local storage sites within 3.2 km (2 mi) of the field at harvest time. Biomass is transported to an end user within a 48 km (30 mi) throughout the year. Round bales are converted to bulk product [bulk density of 240 kg m−3 (15 lb ft−3)] by tub grinding followed by roll-press compacting before truck transport. Rectangular bales are delivered by truck without processing. Total delivered cost is $97.70 Mg−1 ($88.63 ton−1) for corn stover and $137.87 Mg−1 ($125.07 ton−1) for switchgrass when delivered as a bulk compacted product. Total delivered cost is $90.25 Mg−1 ($81.87 ton−1) for corn stover and $128.67 Mg−1 ($116.73 ton−1) for switchgrass when delivered as rectangular bales. Life-cycle fossil energy consumption is higher for delivering switchgrass (9.9 to 13.8 % of energy in dry matter) than for corn stover (5.8 to 9.5 % of energy in dry matter). Excluding any potential change in soil organic carbon (SOC), life-cycle greenhouse gas (GHG) emissions are 59.2 to 99.8 kg CO2e Mg−1 for delivering corn stover and 231.8 to 279.6 kg CO2e Mg−1 for delivering switchgrass. The effect of change in SOC on the life-cycle GHG emissions for corn stover and switchgrass is discussed.
Bibliographical noteFunding Information:
This research was supported by the North Central Regional Sun Grant Center–US Department of Transportation Biobased Transportation Research Program (grant number DOTS59-07-G-00054).
© 2015, Springer Science+Business Media New York.
- Corn stover
- Energy consumption
- GHG emissions