Grass to biogas turns arable land to carbon sink LOVISA BJÖRNSSON
Project funding and reporting, Thomas Prade & Mikael Lantz (2016) Grass for biogas - Arable land as carbon sink. Report 2016:280. Energiforsk, Stockholm/Malmö, Sweden. https://energiforskmedia.blob.core.windows.net/media/20192/grass-for-biogas-energiforskrapport-2016-280.pdf, Thomas Prade & Mikael Lantz (2016) Åkermark som kolsänka en utvärdering av miljö- och kostnadseffekter av att inkludera gräsvall för biogas i spannmålsrika växtföljder. Rapport Nr 98, Miljö- och energisystem, Lunds Universitet, Lund, Sweden. http://lup.lub.lu.se/record/c4b9d90c-c7f6-4481-b094-3e2e3fa6ad89
Arable land use and biofuels 30 Share renewable fuels in domestic transport [%] 25 20 EU 28 Sverige 15 10 5 0 2005 2010 2015 EU RED 2009/28/EC iluc-directive (EU) 2015/1513 Eurostat (2017) Share of renewable energy in fuel consumption of transport iluc-directive (EU) 2015/1513
Athmosphere: 750 billion t C Arable land and soil carbon 45% of the soils in the EU have low or very low (0-2%), and declining, soil organic carbon (SOC) content Above ground biomass: 550 billion t C soil resources in many parts of Europe are being overexploited, degraded and irreversibly lost due to inappropriate land management practices A healthy, fertile soil is at the heart of food security Soil: 1 500 billion t C Jones et al. (2012) The state of soil in Europe. Report EUR 25186 EN. JRC, Ispra, Italy. Kätterer & Andrén (1998) Long-term agricultural field experiments in Northern Europe: Analysis of the influence of management on soil carbon stocks using the ICBM model. Agriculture, Ecosystems and Environment. 72, 165-179.
Aim Visualize how existing knowledge on crop and biofuel production can be applied to create a system with dual benefits; Incresing soil carbon content in combination with a locally produced biofuel with low GHG emssions Existing policies tend to address issues in relative isolation
Agricultural specialization S2 D S1, Thomas Prade & Mikael Lantz (2016) Grass for biogas - Arable land as carbon sink. Report 2016:280. Energiforsk, Stockholm/Malmö, Sweden., Thomas Prade & Mikael Lantz (2016) Åkermark som kolsänka en utvärdering av miljö- och kostnadseffekter av att inkludera gräsvall för biogas i spannmålsrika växtföljder. Rapport Nr 98, Miljö- och energisystem, Lunds Universitet, Lund, Sweden.
Grass as biogas feedstock
Soil carbon development 3,0 Markkolsinnehåll [%] 2,5 2,0 1,5 D ökad avkastning och biogödsling D nuvarande S2 med vall och biogödsling S2 med vall S2 nuvarande S1 med vall och biogödsling S1 med vall S1 nuvarande 1,0 0 10 20 30 40 50 Tid [år]
GHG emissions cultivation 2,0 GHG emissions [t CO2-eq per hectare and year] 1,5 1,0 0,5 0,0-0,5 Cultivation input Field emissions Cultivation input Field emissions S2 present S2 modified -1,0 Mineral fertilizer and materials N2O mineral fertilizer N2O indirect SOC Diesel & other energy input N2O crop residues N2O biofertilizer
GHG emissions from a fuel perspective 25 20 GHG emissions [g CO2-eq/MJ biofuel] 15 10 5 0-5 -10-15 S2-20 -25 Replacing crops Biogas production Net climate benefit cultivation
45 40 GHG emission [g CO 2 -eq (MJ) -1 ] 35 30 25 20 15 10 5 0-71% -97% -60% -5 Valin et al. (2015) The land use change impact of biofuels consumed in the EU - Quantification of area and greenhouse gas impacts. ECOFYS, Utrecht, The Netherlands-
To conclude Too narrow perspectives makes us miss systems with dual benefits It is important to consider potential conflicts between sustainable food supply and an increasing demand of biomass in other sectors BUT also consider the fact that current agriculture on our most high yielding soils is not sustainable from a long term perspective and drastic measures will be needed to change this development To introduce integrated cereal and energy grass production is one way to turn the present soil carbon losses BUT grass based biogas production is not sustainable according to the EU RED calculation method for biofuels
Professor Environmental and Energy Systems Studies lovisa.bjornsson@miljo.lth.se 046-222 8324 www.miljo.lth.se