StrawFeed model: An integrated model of straw feedstock supply chain for bioenergy in China

With the growing concerns of fossil fuel scarcity and its negative impacts on global environment, bioenergy as an alternative energy source has attracted more attention as climate change mitigation. As one of the largest carbon emission and agricultural production countries in the world, China has abundant straw resources and great potential for energy utilization, and the number of straw-to-energy business projects is increasing dramatically. Correspondingly, there is a strong demand to design a stable and sustainable straw feedstock supply chain. However, due to the uncertainty of system boundary and neglect of potential risks, the procurement cost for bioenergy conversion plants (BCP) is varied significantly. Model is a critical approach in strengthening the understanding that leads to promoting supply efficiency. Therefore, an open-source & GIS-enabled linear programming model, named StrawFeed, is proposed to simulate the operation of straw feedstock supply. The costs of raking, baling, loading and transporting have been investigated as components in the StrawFeed model. The model is applied to case analysis of corn straw supply in Nongan county, a major corn production region in Northeast China. The results illustrate that the straw supply cost could be 172 CNY/ton, and the reasonable profit allocation mechanism could achieve the triple-win solution among farmers, brokers, and BCP. Furthermore, the challenges and opportunities for optimization are investigated with scenario analysis, based on unique circumstances and supporting policies in China. Unfavorable weather could delay the available working day, and thereby cost would increase up to 13%. The optimized scheme of straw utilization could achieve better environmental and ecological benefits, but the transportation distance for straw supply has to be expanded and the increased cost would be up to 53%. Cross-regional operation of agricultural machinery and machine procurement subsidies could reduce the cost by 18% and 5% respectively. This model is helpful to estimate accurate supply cost and deploy sustainable straw feedstock supply, which could contribute to assisting investors and policymakers for bioenergy industry in China.