Mobilizing agricultural crop residues for energy and higher value bio-products Niclas Scott Bentsen 1, Patrick Lamers 2, Charles Lalonde 3, Maria Wellisch 4, Virginia H. Dale 5, Ian Bonner 2, Jacob Jacobson 2, Inge Stupak 1, Jian Gan 6, Patrick Girouard 7 1) University of Copenhagen, Denmark 2) Idaho National Laboratory, Idaho, USA 3) Agren Consulting, Guelph, Canada 4) Agriculture and Agri-Food Canada, Ontario, Canada 5) Oak Ridge National Laboratory, Tennessee, USA 6) Texas A&M University, Texas, USA 7) La Coop fédérée, Québec, Canada
Global potential of agricultural crop residues Agricultural crop residues make up a significant partly unused biomass potential. The resource is widely dispersed. The global technical potential in the 2030-2050 period is (probably) around 30 EJ yr -1. Bentsen, N. S., et al. (2014). Agricultural residue production and potentials for energy and materials services. Progress in Energy and Combustion Science 40(0): 59-73. Nakada, S., et al. (2014). Global Bioenergy: Supply and demand projections. Abu Dahbi, UAE, IRENA. Daioglou, V., et al. (2015) Projections of the availability and cost of residues from agriculture and forestry. GCB Bioenergy.
National potential of agricultural crop residues USA: 125 Million tonnes Canada: 55 million tonnes Denmark: 4 million tonnes Schwab, A., et al. (2016). 2013 Bioenergy Market Report. National Renewable Energy Laboratory, Golden, Colorado, USA. Bentsen, N. S., et al (2016). Mobilization of agricultural residues for bioenergy and higher value bio-products: Resources, barriers and sustainability. IEA Bioenergy.
Use of agricultural crop residues Denmark: 1.4 million tonnes (~25 % of total production) used for energy Canada: 0 used for energy 5-7 million tonnes used for livestock USA: < 10 % Bentsen, N. S., et al (2016). Mobilization of agricultural residues for bioenergy and higher value bio-products: Resources, barriers and sustainability. IEA Bioenergy. Schwab, A., et al. (2016). 2013 Bioenergy Market Report. National Renewable Energy Laboratory, Golden, Colorado, USA.
Drivers of the current of use agricultural crop residues for energy Mandates: The 1993 Biomass agreement mandated the use of 1.2 million tonnes of straw for energy. Long term political interest: The 1985 Wind mill agreement drew attention to straw Economic incentives: Feed-in tariffs Organisational framework: Large scale energy producers instrumental in developing the market Danish Straw Suppliers Association has contributed to ensure market stability and transparency Wind mill agreement of 20 December 1985 Acknowledge the need to discuss straw use in the energy supply in the near future. 1985 1986 1990 1993 1997 2000 2008 2012 Electricity agreement of 6 June 1986 80-100 MW decentralised CHP based on domestic resources as natural gas, straw, wood chips, waste or biogas. Biomass agreement of 14 June 1993 By year 2000 1.2 million tonnes straw and 0.2 million tonnes wood chips must be used in the Danish electricity production. Energy agreement of 20 March 1990 Promotes CHP and natural gas and other environmentally benign fuels. chips, waste or biogas. 2 nd revision of the Biomass agreement of 1 march 2000 The targets set in the biomass agreement are sustained and must be met by 2005. 1 st revision of the Biomass agreement of 1 July 1997 Increase the flexibility of biomass sourcing. Energy agreement of 22 March 2012 Target set for solid biomass use of 114 PJ and a 10 % mandatory blend of liquid biofuels by 2020. Energy agreement of 21 February 2008 Guaranteed minimum selling price for biomass electricity increased to improve competitiveness. Bentsen, N. S., et al (2016). Mobilization of agricultural residues for bioenergy and higher value bio-products: Resources, barriers and sustainability. IEA Bioenergy.
Drivers of future use Canada: Climate change and GHG emissions Residue management in high yielding corn areas New supply chain development additional revenue for producers and new industries Eastern Canada: interest in biochemicals from cellulosic sugars Ontario: Potential for 3 million tonnes of crop residue Supply chain under development for corn stover use in Southwestern Ontario Unique producer investment model that includes agriculture producers COMET Biorefining new sugar processor in 2018 USA: Security of energy supply EISA and RFS2 Focus on liquid biofuels Credit trading system (RIN) Schwab, A., et al. (2016). 2013 Bioenergy Market Report. National Renewable Energy Laboratory, Golden, Colorado, USA.
Sustainability Sustainability assessment using the GBEP framework Danish case: Straw used for combined heat and power (CHP) and bioethanol. Opportunities: GHG emission reductions Diversity of energy supply Income generation in rural areas Challenges: Soil carbon Bentsen, N. S., et al (2016). Mobilization of agricultural residues for bioenergy and higher value bio-products: Resources, barriers and sustainability. IEA Bioenergy.
A way ahead Challenges: Feedstock variability (heterogeneity) Opportunities: Network of distributed biomass processing centres generate merchandisable intermediates Intermediates with consistent physical and chemical characteristics that meet conversion quality targets and leverage spatial and temporal variability in supply volumes and costs by improving flowability, transportability (bulk density), and stability/ storability (dry matter loss reduction). Lamers, P., E. C. D. Tan, E. M. Searcy, C. Scarlata, K. G. Cafferty and J. J. Jacobson (2015). Strategic supply system design a holistic evaluation of operational and production cost for a biorefinery supply chain. Biofuels, Bioproducts & Biorefining.
A way ahead Challenges: Business case for new supply chain (higher value products) and soil sustainability Opportunities: Supply and value chain development for biomaterial. Research to confirm soil sustainability parameters with respect to carbon levels. Financing supply aggregation in early years of project development. Long term policy stability including carbon pricing. Better pathways to optimize economic value from cellulosic materials (C5 & C6 sugars and lignin) to bio-chemical. Validation of feedstock quality standards. Bentsen, N. S., et al (2016). Mobilization of agricultural residues for bioenergy and higher value bio-products: Resources, barriers and sustainability. IEA Bioenergy.
In summary agricultural crop residues offer Large biomass resource from existing agricultural land (avoid land use change) Additional source of revenue for an agriculture producer Can be a low cost, sustainable feedstock for production of bioenergy and bioproducts But in general Heterogeneity of the feedstock is challenging. Consistent valorization parameters are yet missing. The resource is dispersed and has a low energy density. Political support and economic incentives are required start off the industry, attract investment in new supply chains. Climate change policies are required, including a price on carbon. For environmental sustainability the main concerns is on maintaining sufficient carbon content of soils to ensure long term soil health and productivity. Long term monitoring is required to ensure soil health. Residue harvest protocols are required to set sustainable harvest rates and crop management practices Efficient supply systems need to be developed for collection and storage of residue to meet processing requirements