Biogas production from crop residues on a farm-scale level in Sweden: scale, choice of substrate and utilisation rate most important parameters for financial feasibility

Anaerobic digestion would enable the energy potential of agricultural crop residues such as ley crops and sugar beet tops to be harnessed in Sweden. In the present study, the financial prospects of single-stage fed-batch high-solids digestion on three different scales, 51, 67, and 201 kW, were calculated on the basis of experimental results and observations. In addition to scale, the effects of methane yield and fertiliser recovery (compared to green manuring) was investigated by testing different substrate mixtures. The biogas was disposed as heat, combined heat and power, or as vehicle fuel. Besides the positive effect of scale, the results indicate the importance of choosing substrates with a high methane yield and high nitrogen content, and the necessity of fully utilising both the capacity of the equipment installed and the energy carriers produced. Net unit costs of 5.3 and 8.1 €ct/kWh were achieved (201 kW), heat and vehicle fuel, respectively.

[1]  Mattias Svensson,et al.  The Technology and Economy of Farm-Scale, High-Solids Anaerobic Digestion of Plant Biomass , 2005 .

[2]  A. Lehtomäki,et al.  Two-Stage Anaerobic Digestion of Energy Crops: Methane Production, Nitrogen Mineralisation and Heavy Metal Mobilisation , 2006, Environmental technology.

[3]  Leo Schrattenholzer,et al.  Learning curves and technology assessment , 2002, Int. J. Technol. Manag..

[4]  I. W. Koster,et al.  Dry anaerobic batch digestion of the organic fraction of municipal solid waste , 2007 .

[5]  H. M. Junginger,et al.  Learning in renewable energy technology development , 2001 .

[6]  Ruud Smits,et al.  Notions on learning applied to wind turbine development in the Netherlands and Denmark , 2004 .

[7]  Paolo Benincasa,et al.  Anaerobically digested crop material for improved nitrogen efficiency in a crop rotation with beetroot (Beta vulgaris var. conditiva Alef.). , 2006 .

[8]  W. F. Cormack,et al.  Legume Species and Management for Stockless Organic Farming , 2003 .

[9]  Henrik Lund,et al.  Biogas plants in Denmark : technological and economic developments , 1999 .

[10]  L M Svensson,et al.  Biogas production from crop residues on a farm-scale level: is it economically feasible under conditions in Sweden? , 2005, Bioprocess and biosystems engineering.

[11]  Robert Legrand,et al.  Methane from biomass systems analysis and C02 abatement potential , 1993 .

[12]  Erik Strøjer Madsen,et al.  The establishment of the danish windmill industry—Was it worthwhile? , 2003 .

[13]  T Evans,et al.  Sustainable biosolids--welcomed practice through community partnership and the consequential economic benefits. , 2004, Water science and technology : a journal of the International Association on Water Pollution Research.

[14]  B. Mattiasson,et al.  Straw bed priming enhances the methane yield and speeds up the start-up of single-stage, high-solids anaerobic reactors treating plant biomass , 2006 .

[15]  C. Stopes,et al.  Dry matter and nitrogen accumulation by three leguminous green manure species and the yield of a following wheat crop in an organic production system , 1996 .

[16]  Bo Mattiasson,et al.  Enhancing performance in anaerobic high-solids stratified bed digesters by straw bed implementation. , 2007, Bioresource technology.

[17]  S. Ghosh,et al.  Solid-phase digestion of low-moisture feeds , 1984 .

[18]  K. Hjort-Gregersen,et al.  Socio-economic analysis of centralised biogas plants - with technical and corporate economic analysis. , 2002 .

[19]  Maija-Liisa Salo.  Ensiling, preservation losses and effluent binding of sugar beet tops , 1978 .